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Nobuo Murakami - One of the best experts on this subject based on the ideXlab platform.
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postoperative Tetany in graves disease important role of vitamin d metabolites
Annals of Surgery, 1999Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Tsukasa Murakami, Masafumi Shiiba, Hitoshi Kawamoto, Masakatsu Toda, Nobuo MurakamiAbstract:OBJECTIVE: To test the authors' hypothesis of the causal mechanism(s) of postoperative Tetany in patients with Graves disease. SUMMARY BACKGROUND DATA: Previous studies by the authors suggested that postoperative Tetany in patients with Graves disease occurs during the period of bone restoration and resulted from continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. PATIENTS AND METHODS: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)2D), and bone metabolic markers in 109 consecutive patients with Graves disease who underwent subtotal thyroidectomy. RESULTS: Preoperative serum iPTH levels negatively correlated with ionized calcium levels and positively correlated with 1,25(OH)2D or 1,25(OH)2D/25OHD. After the operation, there was a significant decline in levels of ionized calcium, magnesium, and iPTH. Serum iPTH was not detected in 15 patients after surgery. Four of these 15 patients, and 1 patient whose iPTH level was below normal, developed Tetany. Preoperative serum ionized calcium levels were significantly lower, and iPTH levels were higher, in the 5 patients with Tetany than in the 11 patients who did not develop Tetany despite undetectable iPTH levels. The Tetany group had significantly lower serum 25OHD levels and higher 1,25(OH)2D levels, and had increased 1,25(OH)2D/25OHD as an index of the renal 25OHD-1-hydroxylase activity than those in the nonTetany group. These results suggest that patients with a high serum level of iPTH as a result of low serum calcium levels (secondary hyperparathyroidism) are susceptible to Tetany under conditions of hypoparathyroid function after surgery. CONCLUSIONS: Postoperative Tetany occurs in patients with secondary hyperparathyroidism caused by a relative deficiency in calcium and vitamin D because of their increased demand for bone restoration after preoperative medical therapy concomitant with transient hypoparathyroidism after surgery. Calcium and vitamin D supplements may be recommended before and/or after surgery for patients in whom postoperative Tetany is expected to develop.
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postoperative Tetany in patients with graves disease a risk factor analysis
Clinical Endocrinology, 1997Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Hitoshi Kawamoto, Masakatsu Toda, Kazuki Tahara, Nobuo MurakamiAbstract:OBJECTIVE There is little information regarding the clinical risk factors for postoperative Tetany in patients with Graves' disease. We analysed the risk factors responsible for postoperative Tetany by univariate and multivariate analysis in thyroidectomized patients with Graves' disease, and we discuss the mechanisms of hypocalcaemia and Tetany after surgery. PATIENTS The subjects were 1742 consecutive patients with Graves' disease who underwent subtotal thyroidectomy between 1992 and 1994. RESULTS Univariate analysis of 15 possible risk factors demonstrated that 10 were significant: sex, required operation time, blood loss, preoperative serum calcium level, estimated weight of thyroid remnant, size of goitre, amount of excised thyroid tissue, serum alkaline phosphatase concentration, age at operation and TSH-binding inhibitory immunoglobulin (TBII). In multivariate analysis in female patients, the risk factors were: preoperative lower serum calcium level, younger age, higher serum alkaline phosphatase concentration, larger size of goitre and higher value of TBII, in order of decreasing probability of significance. CONCLUSION These results, combined with previous observations in which a significant decline in serum parathyroid hormone level was found in patients with Graves' disease who suffered postoperative Tetany, suggest that postoperative Tetany may occur during the period of bone restoration due to antithyroid drug therapy and be due to continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. Calcium supplements during the preoperative period and/or after surgery may be appropriate for patients who are anticipated to develop postoperative Tetany based on these risk factors.
Hiroyuki Yamashita - One of the best experts on this subject based on the ideXlab platform.
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Intraoperative Parathyroid Hormone Assay in Patients with Graves’ Disease for Prediction of Postoperative Tetany
World Journal of Surgery, 2005Co-Authors: Taiki Moriyama, Hiroyuki Yamashita, Shiro Noguchi, Yuji Takamatsu, Takahiro Ogawa, Shin Watanabe, Shinya Uchino, Akira Ohshima, Syoji Kuroki, Masao TanakaAbstract:We measured intraoperative parathyroid hormone (IOPTH) levels before and after thyroidectomy in a large group of patients to test whether changes in IOPTH can predict postoperative Tetany. Subjects were 111 consecutive patients (94 females and 17 males) with Graves' disease undergoing subtotal thyroidectomy. Blood samples for IOPTH assay were obtained after anesthesia (basal) and following skin closure (postoperative). Data were compared between patients who developed Tetany (n = 9) and those who did not (n = 102). There was no significant difference in sex, age, period of antithyroid drug administration, or the weight of the thyroid between the two groups. The preoperative serum calcium level was significantly lower (p < 0.05) and the basal IOPTH significantly higher (p < 0.05) in the Tetany group than in the non-Tetany group. The IOPTH level was significantly lower (p < 0.005) and the average percent decrease in IOPTH levels was higher (p < 0.001) in the Tetany group than in the non-Tetany group. A decrease in IOPTH of more than 70% was shown to be 78% sensitive, 94% specific, and 93% accurate, and it has 78% positive predictive value and 94% negative predictive value for the development of Tetany. Our study shows that a postoperative decrease of IOPTH level is the most predictive of postoperative Tetany of the clinical risk factors investigated. We recommend IOPTH measurement as an adjunct to postoperative management of patients with Graves' disease to assist in preventing hypocalcemia and determining the earliest time for safe discharge.
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seasonal changes in calcium homeostasis affect the incidence of postoperative Tetany in patients with graves disease
Surgery, 2000Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Akira Ohshima, Tsukasa Murakami, Hitoshi Kawamoto, Masakatsu Toda, Hiroto YamashitaAbstract:Background: We have found that postoperative Tetany occurs in patients with Graves' disease who have secondary hyperparathyroidism caused by a deficiency in calcium and vitamin D concomitant with transient hypoparathyroidism after surgery. There are seasonal variations in serum 25-hydroxyvitamin D (25[OH]D) concentrations. The purpose of this study was to investigate the effects of seasonal changes in calcium homeostasis on the incidence of postoperative Tetany in patients with Graves' disease who undergo subtotal thyroidectomy. Patients and Methods: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25(OH)D, and 1,25-dihydroxyvitamin D (1,25[OH]2D) in female patients with Graves' disease who underwent subtotal thyroidectomy during the summer (n = 89) and during the winter (n = 89). Results: The serum levels of calcium, magnesium, and 25(OH)D were significantly higher, but iPTH levels and 1,25(OH)2D levels were lower in summer than in winter. The percentage of vitamin D deficiency (25(OH)D < 25nmol/L) was 23% in summer and 62% in winter (P < .001). iPTH was below the detection limit on the first postoperative day in 15 patients (13.8%) in summer and in 13 patients (11.4%) in winter. In summer, Tetany developed in only 4 of 15 patients and in one patient whose iPTH level was below normal (incidence of Tetany, 5.6%). In winter, however, Tetany developed in 6 of 13 patients and in 4 patients whose iPTH level was below normal (incidence of Tetany, 11.2%). Conclusions: Patients with Graves' disease are more susceptible to calcium and vitamin D deficiency during the winter than during the summer, resulting in the tendency toward a higher incidence of postoperative Tetany in winter. (Surgery 2000;127:377-82.)
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postoperative Tetany in graves disease important role of vitamin d metabolites
Annals of Surgery, 1999Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Tsukasa Murakami, Masafumi Shiiba, Hitoshi Kawamoto, Masakatsu Toda, Nobuo MurakamiAbstract:OBJECTIVE: To test the authors' hypothesis of the causal mechanism(s) of postoperative Tetany in patients with Graves disease. SUMMARY BACKGROUND DATA: Previous studies by the authors suggested that postoperative Tetany in patients with Graves disease occurs during the period of bone restoration and resulted from continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. PATIENTS AND METHODS: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)2D), and bone metabolic markers in 109 consecutive patients with Graves disease who underwent subtotal thyroidectomy. RESULTS: Preoperative serum iPTH levels negatively correlated with ionized calcium levels and positively correlated with 1,25(OH)2D or 1,25(OH)2D/25OHD. After the operation, there was a significant decline in levels of ionized calcium, magnesium, and iPTH. Serum iPTH was not detected in 15 patients after surgery. Four of these 15 patients, and 1 patient whose iPTH level was below normal, developed Tetany. Preoperative serum ionized calcium levels were significantly lower, and iPTH levels were higher, in the 5 patients with Tetany than in the 11 patients who did not develop Tetany despite undetectable iPTH levels. The Tetany group had significantly lower serum 25OHD levels and higher 1,25(OH)2D levels, and had increased 1,25(OH)2D/25OHD as an index of the renal 25OHD-1-hydroxylase activity than those in the nonTetany group. These results suggest that patients with a high serum level of iPTH as a result of low serum calcium levels (secondary hyperparathyroidism) are susceptible to Tetany under conditions of hypoparathyroid function after surgery. CONCLUSIONS: Postoperative Tetany occurs in patients with secondary hyperparathyroidism caused by a relative deficiency in calcium and vitamin D because of their increased demand for bone restoration after preoperative medical therapy concomitant with transient hypoparathyroidism after surgery. Calcium and vitamin D supplements may be recommended before and/or after surgery for patients in whom postoperative Tetany is expected to develop.
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postoperative Tetany in patients with graves disease a risk factor analysis
Clinical Endocrinology, 1997Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Hitoshi Kawamoto, Masakatsu Toda, Kazuki Tahara, Nobuo MurakamiAbstract:OBJECTIVE There is little information regarding the clinical risk factors for postoperative Tetany in patients with Graves' disease. We analysed the risk factors responsible for postoperative Tetany by univariate and multivariate analysis in thyroidectomized patients with Graves' disease, and we discuss the mechanisms of hypocalcaemia and Tetany after surgery. PATIENTS The subjects were 1742 consecutive patients with Graves' disease who underwent subtotal thyroidectomy between 1992 and 1994. RESULTS Univariate analysis of 15 possible risk factors demonstrated that 10 were significant: sex, required operation time, blood loss, preoperative serum calcium level, estimated weight of thyroid remnant, size of goitre, amount of excised thyroid tissue, serum alkaline phosphatase concentration, age at operation and TSH-binding inhibitory immunoglobulin (TBII). In multivariate analysis in female patients, the risk factors were: preoperative lower serum calcium level, younger age, higher serum alkaline phosphatase concentration, larger size of goitre and higher value of TBII, in order of decreasing probability of significance. CONCLUSION These results, combined with previous observations in which a significant decline in serum parathyroid hormone level was found in patients with Graves' disease who suffered postoperative Tetany, suggest that postoperative Tetany may occur during the period of bone restoration due to antithyroid drug therapy and be due to continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. Calcium supplements during the preoperative period and/or after surgery may be appropriate for patients who are anticipated to develop postoperative Tetany based on these risk factors.
Shin Watanabe - One of the best experts on this subject based on the ideXlab platform.
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Intraoperative Parathyroid Hormone Assay in Patients with Graves’ Disease for Prediction of Postoperative Tetany
World Journal of Surgery, 2005Co-Authors: Taiki Moriyama, Hiroyuki Yamashita, Shiro Noguchi, Yuji Takamatsu, Takahiro Ogawa, Shin Watanabe, Shinya Uchino, Akira Ohshima, Syoji Kuroki, Masao TanakaAbstract:We measured intraoperative parathyroid hormone (IOPTH) levels before and after thyroidectomy in a large group of patients to test whether changes in IOPTH can predict postoperative Tetany. Subjects were 111 consecutive patients (94 females and 17 males) with Graves' disease undergoing subtotal thyroidectomy. Blood samples for IOPTH assay were obtained after anesthesia (basal) and following skin closure (postoperative). Data were compared between patients who developed Tetany (n = 9) and those who did not (n = 102). There was no significant difference in sex, age, period of antithyroid drug administration, or the weight of the thyroid between the two groups. The preoperative serum calcium level was significantly lower (p < 0.05) and the basal IOPTH significantly higher (p < 0.05) in the Tetany group than in the non-Tetany group. The IOPTH level was significantly lower (p < 0.005) and the average percent decrease in IOPTH levels was higher (p < 0.001) in the Tetany group than in the non-Tetany group. A decrease in IOPTH of more than 70% was shown to be 78% sensitive, 94% specific, and 93% accurate, and it has 78% positive predictive value and 94% negative predictive value for the development of Tetany. Our study shows that a postoperative decrease of IOPTH level is the most predictive of postoperative Tetany of the clinical risk factors investigated. We recommend IOPTH measurement as an adjunct to postoperative management of patients with Graves' disease to assist in preventing hypocalcemia and determining the earliest time for safe discharge.
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seasonal changes in calcium homeostasis affect the incidence of postoperative Tetany in patients with graves disease
Surgery, 2000Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Akira Ohshima, Tsukasa Murakami, Hitoshi Kawamoto, Masakatsu Toda, Hiroto YamashitaAbstract:Background: We have found that postoperative Tetany occurs in patients with Graves' disease who have secondary hyperparathyroidism caused by a deficiency in calcium and vitamin D concomitant with transient hypoparathyroidism after surgery. There are seasonal variations in serum 25-hydroxyvitamin D (25[OH]D) concentrations. The purpose of this study was to investigate the effects of seasonal changes in calcium homeostasis on the incidence of postoperative Tetany in patients with Graves' disease who undergo subtotal thyroidectomy. Patients and Methods: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25(OH)D, and 1,25-dihydroxyvitamin D (1,25[OH]2D) in female patients with Graves' disease who underwent subtotal thyroidectomy during the summer (n = 89) and during the winter (n = 89). Results: The serum levels of calcium, magnesium, and 25(OH)D were significantly higher, but iPTH levels and 1,25(OH)2D levels were lower in summer than in winter. The percentage of vitamin D deficiency (25(OH)D < 25nmol/L) was 23% in summer and 62% in winter (P < .001). iPTH was below the detection limit on the first postoperative day in 15 patients (13.8%) in summer and in 13 patients (11.4%) in winter. In summer, Tetany developed in only 4 of 15 patients and in one patient whose iPTH level was below normal (incidence of Tetany, 5.6%). In winter, however, Tetany developed in 6 of 13 patients and in 4 patients whose iPTH level was below normal (incidence of Tetany, 11.2%). Conclusions: Patients with Graves' disease are more susceptible to calcium and vitamin D deficiency during the winter than during the summer, resulting in the tendency toward a higher incidence of postoperative Tetany in winter. (Surgery 2000;127:377-82.)
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postoperative Tetany in graves disease important role of vitamin d metabolites
Annals of Surgery, 1999Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Tsukasa Murakami, Masafumi Shiiba, Hitoshi Kawamoto, Masakatsu Toda, Nobuo MurakamiAbstract:OBJECTIVE: To test the authors' hypothesis of the causal mechanism(s) of postoperative Tetany in patients with Graves disease. SUMMARY BACKGROUND DATA: Previous studies by the authors suggested that postoperative Tetany in patients with Graves disease occurs during the period of bone restoration and resulted from continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. PATIENTS AND METHODS: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)2D), and bone metabolic markers in 109 consecutive patients with Graves disease who underwent subtotal thyroidectomy. RESULTS: Preoperative serum iPTH levels negatively correlated with ionized calcium levels and positively correlated with 1,25(OH)2D or 1,25(OH)2D/25OHD. After the operation, there was a significant decline in levels of ionized calcium, magnesium, and iPTH. Serum iPTH was not detected in 15 patients after surgery. Four of these 15 patients, and 1 patient whose iPTH level was below normal, developed Tetany. Preoperative serum ionized calcium levels were significantly lower, and iPTH levels were higher, in the 5 patients with Tetany than in the 11 patients who did not develop Tetany despite undetectable iPTH levels. The Tetany group had significantly lower serum 25OHD levels and higher 1,25(OH)2D levels, and had increased 1,25(OH)2D/25OHD as an index of the renal 25OHD-1-hydroxylase activity than those in the nonTetany group. These results suggest that patients with a high serum level of iPTH as a result of low serum calcium levels (secondary hyperparathyroidism) are susceptible to Tetany under conditions of hypoparathyroid function after surgery. CONCLUSIONS: Postoperative Tetany occurs in patients with secondary hyperparathyroidism caused by a relative deficiency in calcium and vitamin D because of their increased demand for bone restoration after preoperative medical therapy concomitant with transient hypoparathyroidism after surgery. Calcium and vitamin D supplements may be recommended before and/or after surgery for patients in whom postoperative Tetany is expected to develop.
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postoperative Tetany in patients with graves disease a risk factor analysis
Clinical Endocrinology, 1997Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Hitoshi Kawamoto, Masakatsu Toda, Kazuki Tahara, Nobuo MurakamiAbstract:OBJECTIVE There is little information regarding the clinical risk factors for postoperative Tetany in patients with Graves' disease. We analysed the risk factors responsible for postoperative Tetany by univariate and multivariate analysis in thyroidectomized patients with Graves' disease, and we discuss the mechanisms of hypocalcaemia and Tetany after surgery. PATIENTS The subjects were 1742 consecutive patients with Graves' disease who underwent subtotal thyroidectomy between 1992 and 1994. RESULTS Univariate analysis of 15 possible risk factors demonstrated that 10 were significant: sex, required operation time, blood loss, preoperative serum calcium level, estimated weight of thyroid remnant, size of goitre, amount of excised thyroid tissue, serum alkaline phosphatase concentration, age at operation and TSH-binding inhibitory immunoglobulin (TBII). In multivariate analysis in female patients, the risk factors were: preoperative lower serum calcium level, younger age, higher serum alkaline phosphatase concentration, larger size of goitre and higher value of TBII, in order of decreasing probability of significance. CONCLUSION These results, combined with previous observations in which a significant decline in serum parathyroid hormone level was found in patients with Graves' disease who suffered postoperative Tetany, suggest that postoperative Tetany may occur during the period of bone restoration due to antithyroid drug therapy and be due to continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. Calcium supplements during the preoperative period and/or after surgery may be appropriate for patients who are anticipated to develop postoperative Tetany based on these risk factors.
Shinya Uchino - One of the best experts on this subject based on the ideXlab platform.
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Intraoperative Parathyroid Hormone Assay in Patients with Graves’ Disease for Prediction of Postoperative Tetany
World Journal of Surgery, 2005Co-Authors: Taiki Moriyama, Hiroyuki Yamashita, Shiro Noguchi, Yuji Takamatsu, Takahiro Ogawa, Shin Watanabe, Shinya Uchino, Akira Ohshima, Syoji Kuroki, Masao TanakaAbstract:We measured intraoperative parathyroid hormone (IOPTH) levels before and after thyroidectomy in a large group of patients to test whether changes in IOPTH can predict postoperative Tetany. Subjects were 111 consecutive patients (94 females and 17 males) with Graves' disease undergoing subtotal thyroidectomy. Blood samples for IOPTH assay were obtained after anesthesia (basal) and following skin closure (postoperative). Data were compared between patients who developed Tetany (n = 9) and those who did not (n = 102). There was no significant difference in sex, age, period of antithyroid drug administration, or the weight of the thyroid between the two groups. The preoperative serum calcium level was significantly lower (p < 0.05) and the basal IOPTH significantly higher (p < 0.05) in the Tetany group than in the non-Tetany group. The IOPTH level was significantly lower (p < 0.005) and the average percent decrease in IOPTH levels was higher (p < 0.001) in the Tetany group than in the non-Tetany group. A decrease in IOPTH of more than 70% was shown to be 78% sensitive, 94% specific, and 93% accurate, and it has 78% positive predictive value and 94% negative predictive value for the development of Tetany. Our study shows that a postoperative decrease of IOPTH level is the most predictive of postoperative Tetany of the clinical risk factors investigated. We recommend IOPTH measurement as an adjunct to postoperative management of patients with Graves' disease to assist in preventing hypocalcemia and determining the earliest time for safe discharge.
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seasonal changes in calcium homeostasis affect the incidence of postoperative Tetany in patients with graves disease
Surgery, 2000Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Akira Ohshima, Tsukasa Murakami, Hitoshi Kawamoto, Masakatsu Toda, Hiroto YamashitaAbstract:Background: We have found that postoperative Tetany occurs in patients with Graves' disease who have secondary hyperparathyroidism caused by a deficiency in calcium and vitamin D concomitant with transient hypoparathyroidism after surgery. There are seasonal variations in serum 25-hydroxyvitamin D (25[OH]D) concentrations. The purpose of this study was to investigate the effects of seasonal changes in calcium homeostasis on the incidence of postoperative Tetany in patients with Graves' disease who undergo subtotal thyroidectomy. Patients and Methods: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25(OH)D, and 1,25-dihydroxyvitamin D (1,25[OH]2D) in female patients with Graves' disease who underwent subtotal thyroidectomy during the summer (n = 89) and during the winter (n = 89). Results: The serum levels of calcium, magnesium, and 25(OH)D were significantly higher, but iPTH levels and 1,25(OH)2D levels were lower in summer than in winter. The percentage of vitamin D deficiency (25(OH)D < 25nmol/L) was 23% in summer and 62% in winter (P < .001). iPTH was below the detection limit on the first postoperative day in 15 patients (13.8%) in summer and in 13 patients (11.4%) in winter. In summer, Tetany developed in only 4 of 15 patients and in one patient whose iPTH level was below normal (incidence of Tetany, 5.6%). In winter, however, Tetany developed in 6 of 13 patients and in 4 patients whose iPTH level was below normal (incidence of Tetany, 11.2%). Conclusions: Patients with Graves' disease are more susceptible to calcium and vitamin D deficiency during the winter than during the summer, resulting in the tendency toward a higher incidence of postoperative Tetany in winter. (Surgery 2000;127:377-82.)
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postoperative Tetany in graves disease important role of vitamin d metabolites
Annals of Surgery, 1999Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Tsukasa Murakami, Masafumi Shiiba, Hitoshi Kawamoto, Masakatsu Toda, Nobuo MurakamiAbstract:OBJECTIVE: To test the authors' hypothesis of the causal mechanism(s) of postoperative Tetany in patients with Graves disease. SUMMARY BACKGROUND DATA: Previous studies by the authors suggested that postoperative Tetany in patients with Graves disease occurs during the period of bone restoration and resulted from continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. PATIENTS AND METHODS: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)2D), and bone metabolic markers in 109 consecutive patients with Graves disease who underwent subtotal thyroidectomy. RESULTS: Preoperative serum iPTH levels negatively correlated with ionized calcium levels and positively correlated with 1,25(OH)2D or 1,25(OH)2D/25OHD. After the operation, there was a significant decline in levels of ionized calcium, magnesium, and iPTH. Serum iPTH was not detected in 15 patients after surgery. Four of these 15 patients, and 1 patient whose iPTH level was below normal, developed Tetany. Preoperative serum ionized calcium levels were significantly lower, and iPTH levels were higher, in the 5 patients with Tetany than in the 11 patients who did not develop Tetany despite undetectable iPTH levels. The Tetany group had significantly lower serum 25OHD levels and higher 1,25(OH)2D levels, and had increased 1,25(OH)2D/25OHD as an index of the renal 25OHD-1-hydroxylase activity than those in the nonTetany group. These results suggest that patients with a high serum level of iPTH as a result of low serum calcium levels (secondary hyperparathyroidism) are susceptible to Tetany under conditions of hypoparathyroid function after surgery. CONCLUSIONS: Postoperative Tetany occurs in patients with secondary hyperparathyroidism caused by a relative deficiency in calcium and vitamin D because of their increased demand for bone restoration after preoperative medical therapy concomitant with transient hypoparathyroidism after surgery. Calcium and vitamin D supplements may be recommended before and/or after surgery for patients in whom postoperative Tetany is expected to develop.
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postoperative Tetany in patients with graves disease a risk factor analysis
Clinical Endocrinology, 1997Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Hitoshi Kawamoto, Masakatsu Toda, Kazuki Tahara, Nobuo MurakamiAbstract:OBJECTIVE There is little information regarding the clinical risk factors for postoperative Tetany in patients with Graves' disease. We analysed the risk factors responsible for postoperative Tetany by univariate and multivariate analysis in thyroidectomized patients with Graves' disease, and we discuss the mechanisms of hypocalcaemia and Tetany after surgery. PATIENTS The subjects were 1742 consecutive patients with Graves' disease who underwent subtotal thyroidectomy between 1992 and 1994. RESULTS Univariate analysis of 15 possible risk factors demonstrated that 10 were significant: sex, required operation time, blood loss, preoperative serum calcium level, estimated weight of thyroid remnant, size of goitre, amount of excised thyroid tissue, serum alkaline phosphatase concentration, age at operation and TSH-binding inhibitory immunoglobulin (TBII). In multivariate analysis in female patients, the risk factors were: preoperative lower serum calcium level, younger age, higher serum alkaline phosphatase concentration, larger size of goitre and higher value of TBII, in order of decreasing probability of significance. CONCLUSION These results, combined with previous observations in which a significant decline in serum parathyroid hormone level was found in patients with Graves' disease who suffered postoperative Tetany, suggest that postoperative Tetany may occur during the period of bone restoration due to antithyroid drug therapy and be due to continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. Calcium supplements during the preoperative period and/or after surgery may be appropriate for patients who are anticipated to develop postoperative Tetany based on these risk factors.
Shiro Noguchi - One of the best experts on this subject based on the ideXlab platform.
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Intraoperative Parathyroid Hormone Assay in Patients with Graves’ Disease for Prediction of Postoperative Tetany
World Journal of Surgery, 2005Co-Authors: Taiki Moriyama, Hiroyuki Yamashita, Shiro Noguchi, Yuji Takamatsu, Takahiro Ogawa, Shin Watanabe, Shinya Uchino, Akira Ohshima, Syoji Kuroki, Masao TanakaAbstract:We measured intraoperative parathyroid hormone (IOPTH) levels before and after thyroidectomy in a large group of patients to test whether changes in IOPTH can predict postoperative Tetany. Subjects were 111 consecutive patients (94 females and 17 males) with Graves' disease undergoing subtotal thyroidectomy. Blood samples for IOPTH assay were obtained after anesthesia (basal) and following skin closure (postoperative). Data were compared between patients who developed Tetany (n = 9) and those who did not (n = 102). There was no significant difference in sex, age, period of antithyroid drug administration, or the weight of the thyroid between the two groups. The preoperative serum calcium level was significantly lower (p < 0.05) and the basal IOPTH significantly higher (p < 0.05) in the Tetany group than in the non-Tetany group. The IOPTH level was significantly lower (p < 0.005) and the average percent decrease in IOPTH levels was higher (p < 0.001) in the Tetany group than in the non-Tetany group. A decrease in IOPTH of more than 70% was shown to be 78% sensitive, 94% specific, and 93% accurate, and it has 78% positive predictive value and 94% negative predictive value for the development of Tetany. Our study shows that a postoperative decrease of IOPTH level is the most predictive of postoperative Tetany of the clinical risk factors investigated. We recommend IOPTH measurement as an adjunct to postoperative management of patients with Graves' disease to assist in preventing hypocalcemia and determining the earliest time for safe discharge.
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seasonal changes in calcium homeostasis affect the incidence of postoperative Tetany in patients with graves disease
Surgery, 2000Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Akira Ohshima, Tsukasa Murakami, Hitoshi Kawamoto, Masakatsu Toda, Hiroto YamashitaAbstract:Background: We have found that postoperative Tetany occurs in patients with Graves' disease who have secondary hyperparathyroidism caused by a deficiency in calcium and vitamin D concomitant with transient hypoparathyroidism after surgery. There are seasonal variations in serum 25-hydroxyvitamin D (25[OH]D) concentrations. The purpose of this study was to investigate the effects of seasonal changes in calcium homeostasis on the incidence of postoperative Tetany in patients with Graves' disease who undergo subtotal thyroidectomy. Patients and Methods: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25(OH)D, and 1,25-dihydroxyvitamin D (1,25[OH]2D) in female patients with Graves' disease who underwent subtotal thyroidectomy during the summer (n = 89) and during the winter (n = 89). Results: The serum levels of calcium, magnesium, and 25(OH)D were significantly higher, but iPTH levels and 1,25(OH)2D levels were lower in summer than in winter. The percentage of vitamin D deficiency (25(OH)D < 25nmol/L) was 23% in summer and 62% in winter (P < .001). iPTH was below the detection limit on the first postoperative day in 15 patients (13.8%) in summer and in 13 patients (11.4%) in winter. In summer, Tetany developed in only 4 of 15 patients and in one patient whose iPTH level was below normal (incidence of Tetany, 5.6%). In winter, however, Tetany developed in 6 of 13 patients and in 4 patients whose iPTH level was below normal (incidence of Tetany, 11.2%). Conclusions: Patients with Graves' disease are more susceptible to calcium and vitamin D deficiency during the winter than during the summer, resulting in the tendency toward a higher incidence of postoperative Tetany in winter. (Surgery 2000;127:377-82.)
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postoperative Tetany in graves disease important role of vitamin d metabolites
Annals of Surgery, 1999Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Tsukasa Murakami, Masafumi Shiiba, Hitoshi Kawamoto, Masakatsu Toda, Nobuo MurakamiAbstract:OBJECTIVE: To test the authors' hypothesis of the causal mechanism(s) of postoperative Tetany in patients with Graves disease. SUMMARY BACKGROUND DATA: Previous studies by the authors suggested that postoperative Tetany in patients with Graves disease occurs during the period of bone restoration and resulted from continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. PATIENTS AND METHODS: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)2D), and bone metabolic markers in 109 consecutive patients with Graves disease who underwent subtotal thyroidectomy. RESULTS: Preoperative serum iPTH levels negatively correlated with ionized calcium levels and positively correlated with 1,25(OH)2D or 1,25(OH)2D/25OHD. After the operation, there was a significant decline in levels of ionized calcium, magnesium, and iPTH. Serum iPTH was not detected in 15 patients after surgery. Four of these 15 patients, and 1 patient whose iPTH level was below normal, developed Tetany. Preoperative serum ionized calcium levels were significantly lower, and iPTH levels were higher, in the 5 patients with Tetany than in the 11 patients who did not develop Tetany despite undetectable iPTH levels. The Tetany group had significantly lower serum 25OHD levels and higher 1,25(OH)2D levels, and had increased 1,25(OH)2D/25OHD as an index of the renal 25OHD-1-hydroxylase activity than those in the nonTetany group. These results suggest that patients with a high serum level of iPTH as a result of low serum calcium levels (secondary hyperparathyroidism) are susceptible to Tetany under conditions of hypoparathyroid function after surgery. CONCLUSIONS: Postoperative Tetany occurs in patients with secondary hyperparathyroidism caused by a relative deficiency in calcium and vitamin D because of their increased demand for bone restoration after preoperative medical therapy concomitant with transient hypoparathyroidism after surgery. Calcium and vitamin D supplements may be recommended before and/or after surgery for patients in whom postoperative Tetany is expected to develop.
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postoperative Tetany in patients with graves disease a risk factor analysis
Clinical Endocrinology, 1997Co-Authors: Hiroyuki Yamashita, Shiro Noguchi, Shin Watanabe, Shinya Uchino, Hitoshi Kawamoto, Masakatsu Toda, Kazuki Tahara, Nobuo MurakamiAbstract:OBJECTIVE There is little information regarding the clinical risk factors for postoperative Tetany in patients with Graves' disease. We analysed the risk factors responsible for postoperative Tetany by univariate and multivariate analysis in thyroidectomized patients with Graves' disease, and we discuss the mechanisms of hypocalcaemia and Tetany after surgery. PATIENTS The subjects were 1742 consecutive patients with Graves' disease who underwent subtotal thyroidectomy between 1992 and 1994. RESULTS Univariate analysis of 15 possible risk factors demonstrated that 10 were significant: sex, required operation time, blood loss, preoperative serum calcium level, estimated weight of thyroid remnant, size of goitre, amount of excised thyroid tissue, serum alkaline phosphatase concentration, age at operation and TSH-binding inhibitory immunoglobulin (TBII). In multivariate analysis in female patients, the risk factors were: preoperative lower serum calcium level, younger age, higher serum alkaline phosphatase concentration, larger size of goitre and higher value of TBII, in order of decreasing probability of significance. CONCLUSION These results, combined with previous observations in which a significant decline in serum parathyroid hormone level was found in patients with Graves' disease who suffered postoperative Tetany, suggest that postoperative Tetany may occur during the period of bone restoration due to antithyroid drug therapy and be due to continuation of a calcium flux into bone concomitant with transient hypoparathyroidism induced by surgery. Calcium supplements during the preoperative period and/or after surgery may be appropriate for patients who are anticipated to develop postoperative Tetany based on these risk factors.
