CONTEXT: Several studies define optimal serum 25-hydroxyvitamin D (25-OHD) levels based on serum PTH level reaching an asymptote. However, results differ widely, ranging from 25-OHD levels of 12-44 ng/ml: many studies are constrained by small sample size. OBJECTIVE: The objective of the study was to determine the relationship between serum PTH and 25-OHD levels and age in a very large reference laboratory database. DESIGN: This was a detailed cross-sectional analysis of 312,962 paired serum PTH and 25-OHD levels measured from July 2010 to June 2011. RESULTS: Median PTH levels and the proportion of patients (PTH > 65 pg/ml), from 63 successive 25-OHD frequency classes of 5000 patients, provide smooth, exceptionally well-fitted curves (R(2) = 0.994 and R(2) = 0.995, respectively) without discernible inflection points or asymptotes but with striking age dependencies. Serum 25-OHD was below the recent Institute of Medicine sufficiency guidance of 20 ng/ml in 27% (85,000) of the subjects. More importantly, 40 and 51% of subjects (serum 25-OHD <20 and 10 ng/ml, respectively) had biochemical hyperparathyroidism (PTH > 65 pg/ml). CONCLUSIONS: This analysis, despite inevitable inherent limitations, introduces several clinical implications. First, median 25-OHD-dependent PTH levels revealed no threshold above which increasing 25-OHD fails to further suppress PTH. Second, the large number of subjects with 25-OHD deficiency and hyperparathyroidism reinforces the Third International Workshop on Asymptomatic Primary Hyper parathyroidism's recommendations to test for, and replete, vitamin D depletion before considering parathyroidectomy. Third, strong age dependency of the PTH-25-OHD relationship likely reflects the composite effects of age-related decline in calcium absorption and renal function. Finally, this unselected large population database study could guide clinical management of patients based on an age-dependent, PTH-25-OHD continuum.
CONTEXT: Several studies define optimal serum 25-hydroxyvitamin D (25-OHD) levels based on serum PTH level reaching an asymptote. However, results differ widely, ranging from 25-OHD levels of 12-44 ng/ml: many studies are constrained by small sample size. OBJECTIVE: The objective of the study was to determine the relationship between serum PTH and 25-OHD levels and age in a very large reference laboratory database. DESIGN: This was a detailed cross-sectional analysis of 312,962 paired serum PTH and 25-OHD levels measured from July 2010 to June 2011. RESULTS: Median PTH levels and the proportion of patients (PTH > 65 pg/ml), from 63 successive 25-OHD frequency classes of 5000 patients, provide smooth, exceptionally well-fitted curves (R(2) = 0.994 and R(2) = 0.995, respectively) without discernible inflection points or asymptotes but with striking age dependencies. Serum 25-OHD was below the recent Institute of Medicine sufficiency guidance of 20 ng/ml in 27% (85,000) of the subjects. More importantly, 40 and 51% of subjects (serum 25-OHD <20 and 10 ng/ml, respectively) had biochemical hyperparathyroidism (PTH > 65 pg/ml). CONCLUSIONS: This analysis, despite inevitable inherent limitations, introduces several clinical implications. First, median 25-OHD-dependent PTH levels revealed no threshold above which increasing 25-OHD fails to further suppress PTH. Second, the large number of subjects with 25-OHD deficiency and hyperparathyroidism reinforces the Third International Workshop on Asymptomatic Primary Hyper parathyroidism's recommendations to test for, and replete, vitamin D depletion before considering parathyroidectomy. Third, strong age dependency of the PTH-25-OHD relationship likely reflects the composite effects of age-related decline in calcium absorption and renal function. Finally, this unselected large population database study could guide clinical management of patients based on an age-dependent, PTH-25-OHD continuum.
Authors: A Kuwabara; N Tsugawa; K Tanaka; Y Uejima; J Ogawa; N Otao; N Yamada; T Masaki; C Nishigori; S Moriwaki; T Okano Journal: Eur J Clin Nutr Date: 2015-02-11 Impact factor: 4.016
Authors: Daniela Alves Salazar; Maria João Silva Ferreira; João Sérgio Neves; Jorge Manuel Pires Pedro; Vanessa Alexandra Guerreiro; Sara E Silva Viana; Fernando Mendonça; Maria Manuel Silva; Sandra Patrícia Belo; Ana Varela Sande; Paula Freitas; David Maurício Carvalho Journal: Obes Surg Date: 2020-04 Impact factor: 4.129