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Ann V Schwartz - One of the best experts on this subject based on the ideXlab platform.

  • chronic kidney disease and peripheral Nerve Function in the health aging and body composition study
    Nephrology Dialysis Transplantation, 2019
    Co-Authors: Ranjani N Moorthi, Suzanne Satterfield, Brittney S Langemaia, Ann V Schwartz, Simit Doshi, Linda F Fried, Sharon M Moe, Mark J Sarnak, Michael G Shlipak, Tamara B Harris
    Abstract:

    BACKGROUND Chronic kidney disease (CKD) is associated with poor mobility. Peripheral Nerve Function alterations play a significant role in low mobility. We tested the hypothesis that early CKD is associated with altered sensory, motor and autonomic Nerve Function. METHODS Participants in the Health, Aging and Body Composition cohort who had kidney Function measures in Year 3 (1999-2000) and Nerve Function measurements at Year 4 (2000-01) were analyzed (n = 2290). Sensory (vibration threshold, monofilament insensitivity to light and standard touch), motor [compound motor action potentials (CMAPs), Nerve conduction velocities (NCVs)] and autonomic (heart rate response and recovery after a 400-m walk test) Nerve Function as well as participant characteristics were compared across cystatin C- and creatinine-based estimated glomerular filtration rate categorized as ≤60 (CKD) or >60 mL/min/1.73 m2 (non-CKD). The association between CKD and Nerve Function was examined with logistic regression adjusted for covariates. RESULTS Participants with CKD (n = 476) were older (77 ± 3 versus 75 ± 3 years; P < 0.05) and had a higher prevalence of diabetes (20.6% versus 13.1%; P < 0.001). CKD was associated with higher odds for vibration detection threshold {odds ratio [OR] 1.7 [95% confidence interval (CI) 1.1-2.7]} and light touch insensitivity [OR 1.4 (95% CI 1.1-1.7)]. CMAPs and NCVs were not significantly different between CKD and non-CKD patients. In adjusted analyses, participants with CKD had higher odds of an abnormal heart rate response [OR 1.6 (95% CI 1.1-2.2)] and poor heart rate recovery [OR 1.5 (95% CI 1.1-2.0)]. CONCLUSIONS CKD is associated with changes in sensory and autonomic Nerve Function, even after adjustment for demographics and comorbidities, including diabetes. Longitudinal studies in CKD are needed to determine the contribution of Nerve impairments to clinically important outcomes.

  • relationship between sensorimotor peripheral Nerve Function and indicators of cardiovascular autonomic Function in older adults from the health aging and body composition study
    Experimental Gerontology, 2017
    Co-Authors: Brittney S Langemaia, Suzanne Satterfield, Anne B Newman, John M Jakicic, Jane A Cauley, Robert M Boudreau, Ann V Schwartz, Eleanor M Simonsick, Aaron I Vinik, Sasa A Zivkovic
    Abstract:

    Abstract Background Age-related peripheral nervous system (PNS) impairments are highly prevalent in older adults. Although sensorimotor and cardiovascular autonomic Function have been shown to be related in persons with diabetes, the nature of the relationship in general community-dwelling older adult populations is unknown. Methods Health, Aging and Body Composition participants (n = 2399, age = 76.5 ± 2.9 years, 52% women, 38% black) underwent peripheral Nerve testing at the 2000/01 clinic visit. Nerve conduction amplitude and velocity were measured at the peroneal motor Nerve. Sensory Nerve Function was assessed with vibration detection threshold and monofilament (1.4-g/10-g) testing at the big toe. Symptoms of lower-extremity peripheral neuropathy were collected by self-report. Cardiovascular autonomic Function indicators included postural hypotension, resting heart rate (HR), as well as HR response to and recovery from submaximal exercise testing (400 m walk). Multivariable modeling adjusted for demographic/lifestyle factors, medication use and comorbid conditions. Results In fully adjusted models, poor motor Nerve conduction velocity ( Conclusions Motor Nerve Function and indicators of cardiovascular autonomic Function remained significantly related even after considering many potentially shared risk factors. Future studies should investigate common underlying processes for developing multiple PNS impairments in older adults.

  • sensorimotor peripheral Nerve Function and the longitudinal relationship with endurance walking in the health aging and body composition study
    Archives of Physical Medicine and Rehabilitation, 2016
    Co-Authors: Brittney S Langemaia, Paolo Caserotti, Anne B Newman, John M Jakicic, Jane A Cauley, Robert M Boudreau, Tamara B Harris, Stephen B Kritchevsky, Nancy W Glynn, Ann V Schwartz
    Abstract:

    Abstract Objectives To determine whether lower extremity sensorimotor peripheral Nerve deficits are associated with reduced walking endurance in older adults. Design Prospective cohort study with 6 years of follow-up. Setting Two university research clinics. Participants Community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from the 2000–2001 annual clinical examination (N=2393; mean age ± SD, 76.5±2.9y; 48.2% men; 38.2% black) and a subset with longitudinal data (n=1178). Interventions Not applicable. Main Outcome Measures Participants underwent peripheral Nerve Function examination in 2000–2001, including peroneal motor Nerve conduction amplitude and velocity, vibration perception threshold, and monofilament testing. Symptoms of lower extremity peripheral neuropathy included numbness or tingling and sudden stabbing, burning, pain, or aches in the feet or legs. The Long Distance Corridor Walk (LDCW) (400m) was administered in 2000–2001 and every 2 years afterward for 6 years to assess endurance walking performance over time. Results In separate, fully adjusted linear mixed models, poor vibration threshold (>130μm), 10-g and 1.4-g monofilament insensitivity were each associated with a slower 400-m walk completion time (16.0s, 14.4s, and 6.9s slower, respectively; P P Conclusions Poorer sensorimotor peripheral Nerve Function is related to slower endurance walking and greater slowing longitudinally. Interventions to reduce the burden of sensorimotor peripheral Nerve Function impairments should be considered to help older adults maintain walking endurance—a critical component for remaining independent in the community.

  • sensory and motor peripheral Nerve Function and longitudinal changes in quadriceps strength
    Journals of Gerontology Series A-biological Sciences and Medical Sciences, 2015
    Co-Authors: Rachel E Ward, Paolo Caserotti, Sasa A Zivkovic, Suzanne Satterfield, Robert M Boudreau, Ann V Schwartz, Tamara B Harris, Bret H Goodpaster, Stephen B Kritchevsky, Aaron I Vinik
    Abstract:

    Poor strength in late-life contributes to poor physical Function (1), mobility disability (2), hospitalization (3), and mortality (4). Given its major role in late-life outcomes, investigating risk factors for strength decline in older adults is essential. Although age-related muscle atrophy plays a major role in declining strength, maintaining or gaining muscle mass does not guarantee prevention of strength loss with age (5), suggesting that other factors must contribute. One proposed contributing factor to strength decline is poor peripheral Nerve Function (6). Estimated motor unit loss using surface electromyography (sEMG) is cross-sectionally associated with lower strength in older adults (age ≥60 years) (7). Moreover, strength gains occurring during early phases of training prior to increases in muscle size are associated with increased amplitude measured using sEMG (8). This technique assesses the sum of motor unit potentials, providing a global measure of neuromuscular activity. Nerve Conduction Studies (NCS) allow direct stimulation of the Nerve and measurement of the signal magnitude and the speed of response across the Nerve. This method is considered the clinical gold standard to measure the degree of Nerve damage and to distinguish between demyelination and axonal degeneration (9). Small clinical studies have found cross-sectional associations between motor axon loss or axonal degeneration, estimated using NCS, and muscle weakness in patients with Charcot-Marie-Tooth disease (10) and chronic inflammatory demyelinating polyradiculoneuropathy (11). In a large cohort of older adults, the Health, Aging, and Body Composition Study found that both motor peripheral Nerve Function measured using NCS and sensory peripheral Nerve Function were related to lower quadriceps and ankle dorsiflexion strength cross-sectionally, independent of lean mass (6). Clinically, early identification of changes in Nerve Function that may be able to predict strength decline may lead to timely intervention and help prevent resulting disability. Therefore, we utilized standard clinical assessments to evaluate the relationship between Nerve Function and strength loss. Our primary aim was to investigate the longitudinal relationship between clinical measures of sensorimotor Nerve Function and subsequent change in quadriceps strength over 6 years. We hypothesized that poor sensory and motor Nerve Function would be associated with both lower quadriceps strength and faster declining strength. As an exploratory aim, we also examined the relationship between concurrent change in sensorimotor Nerve Function and quadriceps strength.

  • relationship between vitamin b12 and sensory and motor peripheral Nerve Function in older adults
    Journal of the American Geriatrics Society, 2012
    Co-Authors: Kira Leishear, Robert M Boudreau, Ann V Schwartz, Stephen B Kritchevsky, Luigi Ferrucci, Stephanie A Studenski, Caterina Rosano, Nathalie De Rekeneire, Denise K Houston, Aaron I Vinik
    Abstract:

    Objectives: To examine whether deficient B12 status or low serum B12 levels are associated with worse sensory and motor peripheral Nerve Function in older adults. Design: Cross-sectional. Setting: Health, Aging and Body Composition Study. Participants: Two thousand two hundred and eighty-seven adults aged 72 to 83 (mean 76.5 ± 2.9; 51.4% female; 38.3% black). Measurements: Low serum B12 was defined as serum B12 less than 260 pmol/L, and deficient B12 status was defined as B12 less than 260 pmol/L, methylmalonic acid (MMA) greater than 271 nmol/L, and MMA greater than 2-methylcitrate. Peripheral Nerve Function was assessed according to peroneal Nerve conduction amplitude and velocity (NCV) (motor), 1.4 g/10 g monofilament detection, average vibration threshold detection, and peripheral neuropathy symptoms (numbness, aching or burning pain, or both) (sensory). Results: B12-deficient status was found in 7.0% of participants, and an additional 10.1% had low serum B12 levels. B12 deficient status was associated with greater insensitivity to light (1.4 g) touch (odds ratio = 1.50, 95% confidence interval = 1.06�2.13) and worse NCV (42.3 vs 43.5 m/s) (? = -1.16, P = .01) after multivariable adjustment for demographics, lifestyle factors, and health conditions. Associations were consistent for the alternative definition using low serum B12 only. No significant associations were found for deficient B12 status or the alternative low serum B12 definition and vibration detection, Nerve conduction amplitude, or peripheral neuropathy symptoms. Conclusion: Poor B12 (deficient B12 status and low serum B12) is associated with worse sensory and motor peripheral Nerve Function. Nerve Function impairments may lead to physical Function declines and disability in older adults, suggesting that prevention and treatment of low B12 levels may be important to evaluate.

Aaron I Vinik - One of the best experts on this subject based on the ideXlab platform.

  • relationship between sensorimotor peripheral Nerve Function and indicators of cardiovascular autonomic Function in older adults from the health aging and body composition study
    Experimental Gerontology, 2017
    Co-Authors: Brittney S Langemaia, Suzanne Satterfield, Anne B Newman, John M Jakicic, Jane A Cauley, Robert M Boudreau, Ann V Schwartz, Eleanor M Simonsick, Aaron I Vinik, Sasa A Zivkovic
    Abstract:

    Abstract Background Age-related peripheral nervous system (PNS) impairments are highly prevalent in older adults. Although sensorimotor and cardiovascular autonomic Function have been shown to be related in persons with diabetes, the nature of the relationship in general community-dwelling older adult populations is unknown. Methods Health, Aging and Body Composition participants (n = 2399, age = 76.5 ± 2.9 years, 52% women, 38% black) underwent peripheral Nerve testing at the 2000/01 clinic visit. Nerve conduction amplitude and velocity were measured at the peroneal motor Nerve. Sensory Nerve Function was assessed with vibration detection threshold and monofilament (1.4-g/10-g) testing at the big toe. Symptoms of lower-extremity peripheral neuropathy were collected by self-report. Cardiovascular autonomic Function indicators included postural hypotension, resting heart rate (HR), as well as HR response to and recovery from submaximal exercise testing (400 m walk). Multivariable modeling adjusted for demographic/lifestyle factors, medication use and comorbid conditions. Results In fully adjusted models, poor motor Nerve conduction velocity ( Conclusions Motor Nerve Function and indicators of cardiovascular autonomic Function remained significantly related even after considering many potentially shared risk factors. Future studies should investigate common underlying processes for developing multiple PNS impairments in older adults.

  • sensory and motor peripheral Nerve Function and longitudinal changes in quadriceps strength
    Journals of Gerontology Series A-biological Sciences and Medical Sciences, 2015
    Co-Authors: Rachel E Ward, Paolo Caserotti, Sasa A Zivkovic, Suzanne Satterfield, Robert M Boudreau, Ann V Schwartz, Tamara B Harris, Bret H Goodpaster, Stephen B Kritchevsky, Aaron I Vinik
    Abstract:

    Poor strength in late-life contributes to poor physical Function (1), mobility disability (2), hospitalization (3), and mortality (4). Given its major role in late-life outcomes, investigating risk factors for strength decline in older adults is essential. Although age-related muscle atrophy plays a major role in declining strength, maintaining or gaining muscle mass does not guarantee prevention of strength loss with age (5), suggesting that other factors must contribute. One proposed contributing factor to strength decline is poor peripheral Nerve Function (6). Estimated motor unit loss using surface electromyography (sEMG) is cross-sectionally associated with lower strength in older adults (age ≥60 years) (7). Moreover, strength gains occurring during early phases of training prior to increases in muscle size are associated with increased amplitude measured using sEMG (8). This technique assesses the sum of motor unit potentials, providing a global measure of neuromuscular activity. Nerve Conduction Studies (NCS) allow direct stimulation of the Nerve and measurement of the signal magnitude and the speed of response across the Nerve. This method is considered the clinical gold standard to measure the degree of Nerve damage and to distinguish between demyelination and axonal degeneration (9). Small clinical studies have found cross-sectional associations between motor axon loss or axonal degeneration, estimated using NCS, and muscle weakness in patients with Charcot-Marie-Tooth disease (10) and chronic inflammatory demyelinating polyradiculoneuropathy (11). In a large cohort of older adults, the Health, Aging, and Body Composition Study found that both motor peripheral Nerve Function measured using NCS and sensory peripheral Nerve Function were related to lower quadriceps and ankle dorsiflexion strength cross-sectionally, independent of lean mass (6). Clinically, early identification of changes in Nerve Function that may be able to predict strength decline may lead to timely intervention and help prevent resulting disability. Therefore, we utilized standard clinical assessments to evaluate the relationship between Nerve Function and strength loss. Our primary aim was to investigate the longitudinal relationship between clinical measures of sensorimotor Nerve Function and subsequent change in quadriceps strength over 6 years. We hypothesized that poor sensory and motor Nerve Function would be associated with both lower quadriceps strength and faster declining strength. As an exploratory aim, we also examined the relationship between concurrent change in sensorimotor Nerve Function and quadriceps strength.

  • relationship between vitamin b12 and sensory and motor peripheral Nerve Function in older adults
    Journal of the American Geriatrics Society, 2012
    Co-Authors: Kira Leishear, Robert M Boudreau, Ann V Schwartz, Stephen B Kritchevsky, Luigi Ferrucci, Stephanie A Studenski, Caterina Rosano, Nathalie De Rekeneire, Denise K Houston, Aaron I Vinik
    Abstract:

    Objectives: To examine whether deficient B12 status or low serum B12 levels are associated with worse sensory and motor peripheral Nerve Function in older adults. Design: Cross-sectional. Setting: Health, Aging and Body Composition Study. Participants: Two thousand two hundred and eighty-seven adults aged 72 to 83 (mean 76.5 ± 2.9; 51.4% female; 38.3% black). Measurements: Low serum B12 was defined as serum B12 less than 260 pmol/L, and deficient B12 status was defined as B12 less than 260 pmol/L, methylmalonic acid (MMA) greater than 271 nmol/L, and MMA greater than 2-methylcitrate. Peripheral Nerve Function was assessed according to peroneal Nerve conduction amplitude and velocity (NCV) (motor), 1.4 g/10 g monofilament detection, average vibration threshold detection, and peripheral neuropathy symptoms (numbness, aching or burning pain, or both) (sensory). Results: B12-deficient status was found in 7.0% of participants, and an additional 10.1% had low serum B12 levels. B12 deficient status was associated with greater insensitivity to light (1.4 g) touch (odds ratio = 1.50, 95% confidence interval = 1.06�2.13) and worse NCV (42.3 vs 43.5 m/s) (? = -1.16, P = .01) after multivariable adjustment for demographics, lifestyle factors, and health conditions. Associations were consistent for the alternative definition using low serum B12 only. No significant associations were found for deficient B12 status or the alternative low serum B12 definition and vibration detection, Nerve conduction amplitude, or peripheral neuropathy symptoms. Conclusion: Poor B12 (deficient B12 status and low serum B12) is associated with worse sensory and motor peripheral Nerve Function. Nerve Function impairments may lead to physical Function declines and disability in older adults, suggesting that prevention and treatment of low B12 levels may be important to evaluate.

  • the relationship of reduced peripheral Nerve Function and diabetes with physical performance in older white and black adults the health aging and body composition health abc study
    Diabetes Care, 2008
    Co-Authors: Elsa S Strotmeye, E H Goodpaste, A V Schwartz, Tamara Harris, Aaron I Vinik, Nathalie De Rekeneire, Helaine E Resnick, Ronald I Sho, Kimberly A Faulkne, Anne Newma
    Abstract:

    OBJECTIVE—Poor peripheral Nerve Function is prevalent in diabetes and older populations, and it has great potential to contribute to poor physical performance. RESEARCH DESIGN AND METHODS—Cross-sectional analyses were done for the Health, Aging, and Body Composition (Health ABC) Study participants (n = 2,364; 48% men; 38% black; aged 73–82 years). Sensory and motor peripheral Nerve Function in legs/feet was assessed by 10- and 1.4-g monofilament perception, vibration detection, and peroneal motor Nerve conduction amplitude and velocity. The Health ABC lower-extremity performance battery was a supplemented version of the Established Populations for the Epidemiologic Studies of the Elderly battery (chair stands, standing balance, and 6-m walk), adding increased stand duration, single foot stand, and narrow walk. RESULTS—Diabetic participants had fewer chair stands (0.34 vs. 0.36 stands/s), shorter standing balance time (0.69 vs. 0.75 ratio), slower usual walking speed (1.11 vs. 1.14 m/s), slower narrow walking speed (0.80 vs. 0.90 m/s), and lower performance battery score (6.43 vs. 6.93) (all P < 0.05). Peripheral Nerve Function was associated with each physical performance measure independently. After addition of peripheral Nerve Function in fully adjusted models, diabetes remained significantly related to a lower performance battery score and slower narrow walking speed but not to chair stands, standing balance, or usual walking speed. CONCLUSIONS—Poor peripheral Nerve Function accounts for a portion of worse physical performance in diabetes and may be directly associated with physical performance in older diabetic and nondiabetic adults. The impact of peripheral Nerve Function on incident disability should be evaluated in older adults.

  • reduced peripheral Nerve Function is related to lower hip bmd and calcaneal qus in older white and black adults the health aging and body composition study
    Journal of Bone and Mineral Research, 2006
    Co-Authors: Elsa S Strotmeye, A V Schwartz, Jane A Cauley, Aaron I Vinik, Nathalie De Rekeneire, Helaine E Resnick, Joseph M Zmuda, Ronald I Sho, Frances A Tylavsky, Tamara Harris
    Abstract:

    Bone tissue is innervated, and peripheral Nerve Function may impact BMD. Older black and white men and women (N = 2200) in the Health, Aging, and Body Composition Study with worse sensory and motor peripheral Nerve Function had lower hip BMD and calcaneal BUA independent of lean mass, strength, physical ability, and diabetes. Poor peripheral Nerve Function may directly affect bone. Introduction: Bone tissue is innervated, yet little is known about the impact of Nerve Function on BMD. Poor peripheral Nerve Function may contribute to lower BMD and higher fracture risk, particularly in those with diabetic neuropathy. Materials and Methods: The Health, Aging, and Body Composition (Health ABC) Study included annual exams in white and black men and women 70–79 years of age recruited from Pittsburgh and Memphis. Nerve Function in legs/feet was assessed by 1.4- and 10-g monofilament detection, vibration threshold, and peroneal motor Nerve conduction velocity (NCV) and amplitude (CMAP). Total hip BMD, heel broadband ultrasound attenuation (BUA), and total fat and lean mass were measured 1 year later (QDR 4500A, Sahara QUS; Hologic). Results: Participants (N = 2200) were 48% men and 37% black. Poor Nerve Function (lower monofilament detection, higher vibration threshold, lower CMAP, lower NCV) was associated with 1.4–5.7% lower BUA and significant for all but NCV, adjusted for demographics, diabetes, body composition, and physical ability. Results were similar for adjusted hip BMD, with 1.0–2.9% lower BMD, significant for monofilament and CMAP testing. When considering the components of BMD, total hip area was 1.8–4.9% higher in those with the worst Nerve Function, although BMC showed little difference. Lower monofilament detection and CMAP were independently associated with lower heel BUA (p < 0.01), and monofilament detection was associated with lower hip BMD (p < 0.05) in regression additionally adjusted for lifestyle factors, bone-active medications, and diabetes-related complications. Conclusions: Poor peripheral Nerve Function may directly related to lower BMD, likely through an increase in bone area in older adults, independent of lean mass, strength, physical ability, and diabetes. Whether those with impaired Nerve Function are at higher risk for fracture independent of falls needs to be studied.

Tamara B Harris - One of the best experts on this subject based on the ideXlab platform.

  • chronic kidney disease and peripheral Nerve Function in the health aging and body composition study
    Nephrology Dialysis Transplantation, 2019
    Co-Authors: Ranjani N Moorthi, Suzanne Satterfield, Brittney S Langemaia, Ann V Schwartz, Simit Doshi, Linda F Fried, Sharon M Moe, Mark J Sarnak, Michael G Shlipak, Tamara B Harris
    Abstract:

    BACKGROUND Chronic kidney disease (CKD) is associated with poor mobility. Peripheral Nerve Function alterations play a significant role in low mobility. We tested the hypothesis that early CKD is associated with altered sensory, motor and autonomic Nerve Function. METHODS Participants in the Health, Aging and Body Composition cohort who had kidney Function measures in Year 3 (1999-2000) and Nerve Function measurements at Year 4 (2000-01) were analyzed (n = 2290). Sensory (vibration threshold, monofilament insensitivity to light and standard touch), motor [compound motor action potentials (CMAPs), Nerve conduction velocities (NCVs)] and autonomic (heart rate response and recovery after a 400-m walk test) Nerve Function as well as participant characteristics were compared across cystatin C- and creatinine-based estimated glomerular filtration rate categorized as ≤60 (CKD) or >60 mL/min/1.73 m2 (non-CKD). The association between CKD and Nerve Function was examined with logistic regression adjusted for covariates. RESULTS Participants with CKD (n = 476) were older (77 ± 3 versus 75 ± 3 years; P < 0.05) and had a higher prevalence of diabetes (20.6% versus 13.1%; P < 0.001). CKD was associated with higher odds for vibration detection threshold {odds ratio [OR] 1.7 [95% confidence interval (CI) 1.1-2.7]} and light touch insensitivity [OR 1.4 (95% CI 1.1-1.7)]. CMAPs and NCVs were not significantly different between CKD and non-CKD patients. In adjusted analyses, participants with CKD had higher odds of an abnormal heart rate response [OR 1.6 (95% CI 1.1-2.2)] and poor heart rate recovery [OR 1.5 (95% CI 1.1-2.0)]. CONCLUSIONS CKD is associated with changes in sensory and autonomic Nerve Function, even after adjustment for demographics and comorbidities, including diabetes. Longitudinal studies in CKD are needed to determine the contribution of Nerve impairments to clinically important outcomes.

  • sensorimotor peripheral Nerve Function and the longitudinal relationship with endurance walking in the health aging and body composition study
    Archives of Physical Medicine and Rehabilitation, 2016
    Co-Authors: Brittney S Langemaia, Paolo Caserotti, Anne B Newman, John M Jakicic, Jane A Cauley, Robert M Boudreau, Tamara B Harris, Stephen B Kritchevsky, Nancy W Glynn, Ann V Schwartz
    Abstract:

    Abstract Objectives To determine whether lower extremity sensorimotor peripheral Nerve deficits are associated with reduced walking endurance in older adults. Design Prospective cohort study with 6 years of follow-up. Setting Two university research clinics. Participants Community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from the 2000–2001 annual clinical examination (N=2393; mean age ± SD, 76.5±2.9y; 48.2% men; 38.2% black) and a subset with longitudinal data (n=1178). Interventions Not applicable. Main Outcome Measures Participants underwent peripheral Nerve Function examination in 2000–2001, including peroneal motor Nerve conduction amplitude and velocity, vibration perception threshold, and monofilament testing. Symptoms of lower extremity peripheral neuropathy included numbness or tingling and sudden stabbing, burning, pain, or aches in the feet or legs. The Long Distance Corridor Walk (LDCW) (400m) was administered in 2000–2001 and every 2 years afterward for 6 years to assess endurance walking performance over time. Results In separate, fully adjusted linear mixed models, poor vibration threshold (>130μm), 10-g and 1.4-g monofilament insensitivity were each associated with a slower 400-m walk completion time (16.0s, 14.4s, and 6.9s slower, respectively; P P Conclusions Poorer sensorimotor peripheral Nerve Function is related to slower endurance walking and greater slowing longitudinally. Interventions to reduce the burden of sensorimotor peripheral Nerve Function impairments should be considered to help older adults maintain walking endurance—a critical component for remaining independent in the community.

  • sensory and motor peripheral Nerve Function and longitudinal changes in quadriceps strength
    Journals of Gerontology Series A-biological Sciences and Medical Sciences, 2015
    Co-Authors: Rachel E Ward, Paolo Caserotti, Sasa A Zivkovic, Suzanne Satterfield, Robert M Boudreau, Ann V Schwartz, Tamara B Harris, Bret H Goodpaster, Stephen B Kritchevsky, Aaron I Vinik
    Abstract:

    Poor strength in late-life contributes to poor physical Function (1), mobility disability (2), hospitalization (3), and mortality (4). Given its major role in late-life outcomes, investigating risk factors for strength decline in older adults is essential. Although age-related muscle atrophy plays a major role in declining strength, maintaining or gaining muscle mass does not guarantee prevention of strength loss with age (5), suggesting that other factors must contribute. One proposed contributing factor to strength decline is poor peripheral Nerve Function (6). Estimated motor unit loss using surface electromyography (sEMG) is cross-sectionally associated with lower strength in older adults (age ≥60 years) (7). Moreover, strength gains occurring during early phases of training prior to increases in muscle size are associated with increased amplitude measured using sEMG (8). This technique assesses the sum of motor unit potentials, providing a global measure of neuromuscular activity. Nerve Conduction Studies (NCS) allow direct stimulation of the Nerve and measurement of the signal magnitude and the speed of response across the Nerve. This method is considered the clinical gold standard to measure the degree of Nerve damage and to distinguish between demyelination and axonal degeneration (9). Small clinical studies have found cross-sectional associations between motor axon loss or axonal degeneration, estimated using NCS, and muscle weakness in patients with Charcot-Marie-Tooth disease (10) and chronic inflammatory demyelinating polyradiculoneuropathy (11). In a large cohort of older adults, the Health, Aging, and Body Composition Study found that both motor peripheral Nerve Function measured using NCS and sensory peripheral Nerve Function were related to lower quadriceps and ankle dorsiflexion strength cross-sectionally, independent of lean mass (6). Clinically, early identification of changes in Nerve Function that may be able to predict strength decline may lead to timely intervention and help prevent resulting disability. Therefore, we utilized standard clinical assessments to evaluate the relationship between Nerve Function and strength loss. Our primary aim was to investigate the longitudinal relationship between clinical measures of sensorimotor Nerve Function and subsequent change in quadriceps strength over 6 years. We hypothesized that poor sensory and motor Nerve Function would be associated with both lower quadriceps strength and faster declining strength. As an exploratory aim, we also examined the relationship between concurrent change in sensorimotor Nerve Function and quadriceps strength.

Robert M Boudreau - One of the best experts on this subject based on the ideXlab platform.

  • relationship between sensorimotor peripheral Nerve Function and indicators of cardiovascular autonomic Function in older adults from the health aging and body composition study
    Experimental Gerontology, 2017
    Co-Authors: Brittney S Langemaia, Suzanne Satterfield, Anne B Newman, John M Jakicic, Jane A Cauley, Robert M Boudreau, Ann V Schwartz, Eleanor M Simonsick, Aaron I Vinik, Sasa A Zivkovic
    Abstract:

    Abstract Background Age-related peripheral nervous system (PNS) impairments are highly prevalent in older adults. Although sensorimotor and cardiovascular autonomic Function have been shown to be related in persons with diabetes, the nature of the relationship in general community-dwelling older adult populations is unknown. Methods Health, Aging and Body Composition participants (n = 2399, age = 76.5 ± 2.9 years, 52% women, 38% black) underwent peripheral Nerve testing at the 2000/01 clinic visit. Nerve conduction amplitude and velocity were measured at the peroneal motor Nerve. Sensory Nerve Function was assessed with vibration detection threshold and monofilament (1.4-g/10-g) testing at the big toe. Symptoms of lower-extremity peripheral neuropathy were collected by self-report. Cardiovascular autonomic Function indicators included postural hypotension, resting heart rate (HR), as well as HR response to and recovery from submaximal exercise testing (400 m walk). Multivariable modeling adjusted for demographic/lifestyle factors, medication use and comorbid conditions. Results In fully adjusted models, poor motor Nerve conduction velocity ( Conclusions Motor Nerve Function and indicators of cardiovascular autonomic Function remained significantly related even after considering many potentially shared risk factors. Future studies should investigate common underlying processes for developing multiple PNS impairments in older adults.

  • sensorimotor peripheral Nerve Function and the longitudinal relationship with endurance walking in the health aging and body composition study
    Archives of Physical Medicine and Rehabilitation, 2016
    Co-Authors: Brittney S Langemaia, Paolo Caserotti, Anne B Newman, John M Jakicic, Jane A Cauley, Robert M Boudreau, Tamara B Harris, Stephen B Kritchevsky, Nancy W Glynn, Ann V Schwartz
    Abstract:

    Abstract Objectives To determine whether lower extremity sensorimotor peripheral Nerve deficits are associated with reduced walking endurance in older adults. Design Prospective cohort study with 6 years of follow-up. Setting Two university research clinics. Participants Community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from the 2000–2001 annual clinical examination (N=2393; mean age ± SD, 76.5±2.9y; 48.2% men; 38.2% black) and a subset with longitudinal data (n=1178). Interventions Not applicable. Main Outcome Measures Participants underwent peripheral Nerve Function examination in 2000–2001, including peroneal motor Nerve conduction amplitude and velocity, vibration perception threshold, and monofilament testing. Symptoms of lower extremity peripheral neuropathy included numbness or tingling and sudden stabbing, burning, pain, or aches in the feet or legs. The Long Distance Corridor Walk (LDCW) (400m) was administered in 2000–2001 and every 2 years afterward for 6 years to assess endurance walking performance over time. Results In separate, fully adjusted linear mixed models, poor vibration threshold (>130μm), 10-g and 1.4-g monofilament insensitivity were each associated with a slower 400-m walk completion time (16.0s, 14.4s, and 6.9s slower, respectively; P P Conclusions Poorer sensorimotor peripheral Nerve Function is related to slower endurance walking and greater slowing longitudinally. Interventions to reduce the burden of sensorimotor peripheral Nerve Function impairments should be considered to help older adults maintain walking endurance—a critical component for remaining independent in the community.

  • sensory and motor peripheral Nerve Function and longitudinal changes in quadriceps strength
    Journals of Gerontology Series A-biological Sciences and Medical Sciences, 2015
    Co-Authors: Rachel E Ward, Paolo Caserotti, Sasa A Zivkovic, Suzanne Satterfield, Robert M Boudreau, Ann V Schwartz, Tamara B Harris, Bret H Goodpaster, Stephen B Kritchevsky, Aaron I Vinik
    Abstract:

    Poor strength in late-life contributes to poor physical Function (1), mobility disability (2), hospitalization (3), and mortality (4). Given its major role in late-life outcomes, investigating risk factors for strength decline in older adults is essential. Although age-related muscle atrophy plays a major role in declining strength, maintaining or gaining muscle mass does not guarantee prevention of strength loss with age (5), suggesting that other factors must contribute. One proposed contributing factor to strength decline is poor peripheral Nerve Function (6). Estimated motor unit loss using surface electromyography (sEMG) is cross-sectionally associated with lower strength in older adults (age ≥60 years) (7). Moreover, strength gains occurring during early phases of training prior to increases in muscle size are associated with increased amplitude measured using sEMG (8). This technique assesses the sum of motor unit potentials, providing a global measure of neuromuscular activity. Nerve Conduction Studies (NCS) allow direct stimulation of the Nerve and measurement of the signal magnitude and the speed of response across the Nerve. This method is considered the clinical gold standard to measure the degree of Nerve damage and to distinguish between demyelination and axonal degeneration (9). Small clinical studies have found cross-sectional associations between motor axon loss or axonal degeneration, estimated using NCS, and muscle weakness in patients with Charcot-Marie-Tooth disease (10) and chronic inflammatory demyelinating polyradiculoneuropathy (11). In a large cohort of older adults, the Health, Aging, and Body Composition Study found that both motor peripheral Nerve Function measured using NCS and sensory peripheral Nerve Function were related to lower quadriceps and ankle dorsiflexion strength cross-sectionally, independent of lean mass (6). Clinically, early identification of changes in Nerve Function that may be able to predict strength decline may lead to timely intervention and help prevent resulting disability. Therefore, we utilized standard clinical assessments to evaluate the relationship between Nerve Function and strength loss. Our primary aim was to investigate the longitudinal relationship between clinical measures of sensorimotor Nerve Function and subsequent change in quadriceps strength over 6 years. We hypothesized that poor sensory and motor Nerve Function would be associated with both lower quadriceps strength and faster declining strength. As an exploratory aim, we also examined the relationship between concurrent change in sensorimotor Nerve Function and quadriceps strength.

  • relationship between vitamin b12 and sensory and motor peripheral Nerve Function in older adults
    Journal of the American Geriatrics Society, 2012
    Co-Authors: Kira Leishear, Robert M Boudreau, Ann V Schwartz, Stephen B Kritchevsky, Luigi Ferrucci, Stephanie A Studenski, Caterina Rosano, Nathalie De Rekeneire, Denise K Houston, Aaron I Vinik
    Abstract:

    Objectives: To examine whether deficient B12 status or low serum B12 levels are associated with worse sensory and motor peripheral Nerve Function in older adults. Design: Cross-sectional. Setting: Health, Aging and Body Composition Study. Participants: Two thousand two hundred and eighty-seven adults aged 72 to 83 (mean 76.5 ± 2.9; 51.4% female; 38.3% black). Measurements: Low serum B12 was defined as serum B12 less than 260 pmol/L, and deficient B12 status was defined as B12 less than 260 pmol/L, methylmalonic acid (MMA) greater than 271 nmol/L, and MMA greater than 2-methylcitrate. Peripheral Nerve Function was assessed according to peroneal Nerve conduction amplitude and velocity (NCV) (motor), 1.4 g/10 g monofilament detection, average vibration threshold detection, and peripheral neuropathy symptoms (numbness, aching or burning pain, or both) (sensory). Results: B12-deficient status was found in 7.0% of participants, and an additional 10.1% had low serum B12 levels. B12 deficient status was associated with greater insensitivity to light (1.4 g) touch (odds ratio = 1.50, 95% confidence interval = 1.06�2.13) and worse NCV (42.3 vs 43.5 m/s) (? = -1.16, P = .01) after multivariable adjustment for demographics, lifestyle factors, and health conditions. Associations were consistent for the alternative definition using low serum B12 only. No significant associations were found for deficient B12 status or the alternative low serum B12 definition and vibration detection, Nerve conduction amplitude, or peripheral neuropathy symptoms. Conclusion: Poor B12 (deficient B12 status and low serum B12) is associated with worse sensory and motor peripheral Nerve Function. Nerve Function impairments may lead to physical Function declines and disability in older adults, suggesting that prevention and treatment of low B12 levels may be important to evaluate.

  • vitamin b12 and homocysteine levels and 6 year change in peripheral Nerve Function and neurological signs
    Journals of Gerontology Series A-biological Sciences and Medical Sciences, 2012
    Co-Authors: Kira Leishear, Robert M Boudreau, Luigi Ferrucci, Fulvio Lauretani, Stephanie A Studenski, Caterina Rosano, Rosanna Abbate, Anna Maria Gori, Anna Maria Corsi, Angelo Di Iorio
    Abstract:

    Vitamin B12 deficiency affects 5%–20% of older adults, while up to 40% have low B12 levels (1,2). The prevalence of poor B12 increases with age (3). B12 deficiency can cause myelin damage as a result of deficient methylation of myelin basic protein (4). Along with hematological, neuropsychological, and cardiovascular diseases, B12 deficiency has been associated with myeloneuropathy, optic neuropathy, peripheral neuropathy (PN), loss of sensation in peripheral Nerves, and weakness in lower extremities (2,5–6). Because vitamin B6, B12, and folate work synergistically to convert homocysteine (Hcy) to methionine, low B12 or folate levels may result in high Hcy levels. Hyperhomocysteinemia has a prevalence of about 30% in older adults when defined as more than 14 μmol/L (7). Hyperhomocysteinemia has been associated with older age, male sex, white race, smoking, high coffee consumption, lack of physical activity (PA), cognitive impairment, depression, cardiovascular disease, poor renal Function, slower gait speed, lower quadriceps strength, Functional decline, and an increased risk of mortality (8–12). The prevalence of poor peripheral Nerve Function and neuropathy is high in older adults and increases with age (13,14); more than 25% of older adults have PN or clinically positive tests for neuropathy (15). Diabetes mellitus (DM) is the major risk factor for clinical PN in older adults but accounts for only half of the cases (13). Subclinically, poor peripheral Nerve Function is associated with lower physical performance and strength in older adults, independent of DM (16,17). Therefore, implications for disability associated with subclinical peripheral Nerve Function exist and identifying key risk factors for poor peripheral Nerve Function is critical. To our knowledge, there have been no cohort studies examining the association between vitamin B12 or Hcy and peripheral Nerve Function, despite their clear association with aging. We hypothesized that low B12 and high Hcy and sustained low B12 and high Hcy are associated with greater decline in neurological Function, compared with sustained normal B12 and Hcy levels. The purpose of this study is to examine whether low B12 or high Hcy levels are associated cross-sectionally or longitudinally with: (i) peripheral Nerve Function, (ii) clinical neurological signs, and (iii) PN symptoms.

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  • swallowing impairment in older adults association with sensorimotor peripheral Nerve Function from the health aging and body composition study
    Aging Clinical and Experimental Research, 2021
    Co-Authors: Rafaela Soares Rech, Brittney S Langemaia, Elsa S Strotmeyer, Fernando Neves Hugo, Barbara Niegia Garcia De Goulart, Juliana Balbinot Hilgert, Eleanor M Simonsick
    Abstract:

    The purpose of this study was to examine whether impairments in sensorimotor peripheral Nerve Function are associated with a higher likelihood of swallowing impairment in older adults. Health, Aging and Body Composition participants (n = 607, age = 75.8 ± 2.7 years, 55.8% women, 32.3% black) underwent peripheral Nerve testing at Year 4 and 11 with swallowing difficulty assessed at Year 4 and 15. Nerve conduction amplitude and velocity were measured at the peroneal motor Nerve. Sensory Nerve Function was assessed with the vibration detection threshold and monofilament (1.4-g/10-g) testing at the big toe. Symptoms of lower extremity peripheral neuropathy and difficulty swallowing were collected by self-report. Data analysis was performed using a hierarchical approach. Odds ratios (ORs) were estimated using non-conditional logistic regression. At Year 15 108 (17.8%) participants had swallowing impairments. In fully adjusted models, the peripheral Nerve impairments associated with swallowing impairment were numbness (OR 4.67; 95%CI 2.24–9.75) and poor motor Nerve conduction velocity (OR 2.26; 95%CI 1.08–4.70). Other peripheral Nerve impairments were not related to swallowing. The association between slow motor Nerve conduction velocity and numbness and a higher likelihood of swallowing difficulties a decade later in our prospective study identifies an important area for further investigation in older adults.

  • chronic kidney disease and peripheral Nerve Function in the health aging and body composition study
    Nephrology Dialysis Transplantation, 2019
    Co-Authors: Ranjani N Moorthi, Suzanne Satterfield, Brittney S Langemaia, Ann V Schwartz, Simit Doshi, Linda F Fried, Sharon M Moe, Mark J Sarnak, Michael G Shlipak, Tamara B Harris
    Abstract:

    BACKGROUND Chronic kidney disease (CKD) is associated with poor mobility. Peripheral Nerve Function alterations play a significant role in low mobility. We tested the hypothesis that early CKD is associated with altered sensory, motor and autonomic Nerve Function. METHODS Participants in the Health, Aging and Body Composition cohort who had kidney Function measures in Year 3 (1999-2000) and Nerve Function measurements at Year 4 (2000-01) were analyzed (n = 2290). Sensory (vibration threshold, monofilament insensitivity to light and standard touch), motor [compound motor action potentials (CMAPs), Nerve conduction velocities (NCVs)] and autonomic (heart rate response and recovery after a 400-m walk test) Nerve Function as well as participant characteristics were compared across cystatin C- and creatinine-based estimated glomerular filtration rate categorized as ≤60 (CKD) or >60 mL/min/1.73 m2 (non-CKD). The association between CKD and Nerve Function was examined with logistic regression adjusted for covariates. RESULTS Participants with CKD (n = 476) were older (77 ± 3 versus 75 ± 3 years; P < 0.05) and had a higher prevalence of diabetes (20.6% versus 13.1%; P < 0.001). CKD was associated with higher odds for vibration detection threshold {odds ratio [OR] 1.7 [95% confidence interval (CI) 1.1-2.7]} and light touch insensitivity [OR 1.4 (95% CI 1.1-1.7)]. CMAPs and NCVs were not significantly different between CKD and non-CKD patients. In adjusted analyses, participants with CKD had higher odds of an abnormal heart rate response [OR 1.6 (95% CI 1.1-2.2)] and poor heart rate recovery [OR 1.5 (95% CI 1.1-2.0)]. CONCLUSIONS CKD is associated with changes in sensory and autonomic Nerve Function, even after adjustment for demographics and comorbidities, including diabetes. Longitudinal studies in CKD are needed to determine the contribution of Nerve impairments to clinically important outcomes.

  • relationship between sensorimotor peripheral Nerve Function and indicators of cardiovascular autonomic Function in older adults from the health aging and body composition study
    Experimental Gerontology, 2017
    Co-Authors: Brittney S Langemaia, Suzanne Satterfield, Anne B Newman, John M Jakicic, Jane A Cauley, Robert M Boudreau, Ann V Schwartz, Eleanor M Simonsick, Aaron I Vinik, Sasa A Zivkovic
    Abstract:

    Abstract Background Age-related peripheral nervous system (PNS) impairments are highly prevalent in older adults. Although sensorimotor and cardiovascular autonomic Function have been shown to be related in persons with diabetes, the nature of the relationship in general community-dwelling older adult populations is unknown. Methods Health, Aging and Body Composition participants (n = 2399, age = 76.5 ± 2.9 years, 52% women, 38% black) underwent peripheral Nerve testing at the 2000/01 clinic visit. Nerve conduction amplitude and velocity were measured at the peroneal motor Nerve. Sensory Nerve Function was assessed with vibration detection threshold and monofilament (1.4-g/10-g) testing at the big toe. Symptoms of lower-extremity peripheral neuropathy were collected by self-report. Cardiovascular autonomic Function indicators included postural hypotension, resting heart rate (HR), as well as HR response to and recovery from submaximal exercise testing (400 m walk). Multivariable modeling adjusted for demographic/lifestyle factors, medication use and comorbid conditions. Results In fully adjusted models, poor motor Nerve conduction velocity ( Conclusions Motor Nerve Function and indicators of cardiovascular autonomic Function remained significantly related even after considering many potentially shared risk factors. Future studies should investigate common underlying processes for developing multiple PNS impairments in older adults.

  • sensorimotor peripheral Nerve Function and the longitudinal relationship with endurance walking in the health aging and body composition study
    Archives of Physical Medicine and Rehabilitation, 2016
    Co-Authors: Brittney S Langemaia, Paolo Caserotti, Anne B Newman, John M Jakicic, Jane A Cauley, Robert M Boudreau, Tamara B Harris, Stephen B Kritchevsky, Nancy W Glynn, Ann V Schwartz
    Abstract:

    Abstract Objectives To determine whether lower extremity sensorimotor peripheral Nerve deficits are associated with reduced walking endurance in older adults. Design Prospective cohort study with 6 years of follow-up. Setting Two university research clinics. Participants Community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from the 2000–2001 annual clinical examination (N=2393; mean age ± SD, 76.5±2.9y; 48.2% men; 38.2% black) and a subset with longitudinal data (n=1178). Interventions Not applicable. Main Outcome Measures Participants underwent peripheral Nerve Function examination in 2000–2001, including peroneal motor Nerve conduction amplitude and velocity, vibration perception threshold, and monofilament testing. Symptoms of lower extremity peripheral neuropathy included numbness or tingling and sudden stabbing, burning, pain, or aches in the feet or legs. The Long Distance Corridor Walk (LDCW) (400m) was administered in 2000–2001 and every 2 years afterward for 6 years to assess endurance walking performance over time. Results In separate, fully adjusted linear mixed models, poor vibration threshold (>130μm), 10-g and 1.4-g monofilament insensitivity were each associated with a slower 400-m walk completion time (16.0s, 14.4s, and 6.9s slower, respectively; P P Conclusions Poorer sensorimotor peripheral Nerve Function is related to slower endurance walking and greater slowing longitudinally. Interventions to reduce the burden of sensorimotor peripheral Nerve Function impairments should be considered to help older adults maintain walking endurance—a critical component for remaining independent in the community.