Journal Article

25-Hydroxyvitamin D, IGF-1, and Metabolic Syndrome at 45 Years of Age

Barbara J. Boucher, Diane J. Berry, Chris Power, Elina Hyppönen

2008

Overview

25-Hydroxyvitamin D, IGF-1, and Metabolic Syndrome at 45 Years of Age A Cross-Sectional Study in the 1958 British Birth Cohort Elina Hyppönen 1 , Barbara J. Boucher 2 , Diane J. Berry 1 and Chris Power 1 1 Centre for Paediatric Epidemiology and Biostatistics, University College London Institute of Child Health, London, U.K 2 Centre for Diabetes and Metabolic Medicine, Institute of Cell and Molecular Science, Barts and the London, Queen Mary School of Medicine and Dentistry, London, U.K Address correspondence and reprint requests to Dr. Elina Hyppönen, Center for Paediatric Epidemiology and Biostatistics, Institute of Child Health, 30 Guilford St., London, WC1N 1EH, U.K. E-mail: e.hypponen{at}ich.ucl.ac.uk Abstract OBJECTIVE —Hypovitaminosis D and reduced IGF-1 are associated, individually, with metabolic syndrome. Physiological interactions between vitamin D and IGF-1 are reported; this is the first study to investigate their combined associations with metabolic syndrome prevalence. RESEARCH DESIGN AND METHODS —Data on 25-hydroxyvitamin D (25(OH)D), IGF-1, and metabolic syndrome abnormalities (abdominal obesity; raised A1C, blood pressure, and triglycerides; and low HDL cholesterol) were collected from 6,810 British white subjects in the 1958 cohort, surveyed during 2002–2004 (age 45 years). RESULTS —IGF-1 concentrations increased with 25(OH)D up to ∼75–85 nmol/l but not thereafter. Both 25(OH)D and IGF-1 were inversely associated with metabolic syndrome. There was an interaction between 25(OH)D and IGF-1 ( P = 0.025) on metabolic syndrome prevalence: IGF-1 was not significantly associated with metabolic syndrome among those with the lowest levels of 25(OH)D ( P > 0.09), whereas higher 25(OH)D was associated with metabolic syndrome at all IGF-1 concentrations ( P ≤ 0.006). Metabolic syndrome prevalence was lowest for participants with the highest concentrations of both 25(OH)D and IGF-1 (odds ratio for highest vs. lowest third of both 0.26 [95% CI 0.17–0.40], P < 0.0001; adjusted for sex, month, hour, inactivity, alcohol consumption, smoking, and social class). 25(OH)D was associated with the prevalence of high A1C, blood pressure, and triglycerides after adjustment for IGF-1, obesity, and social and lifestyle variations ( P ≤ 0.004 for all comparisons). CONCLUSIONS —Serum 25(OH)D is inversely associated with metabolic syndrome, whereas the inverse association with IGF-1 was found only among those without hypovitaminosis D. These results suggest that metabolic syndrome prevalence is the lowest when both 25(OH)D and IGF-1 are high. Footnotes Published ahead of print at http://diabetes.diabetesjournals.org on November 2007. DOI: 10.2337/db07-1122. 1,25-(OH) 2 D, 1,25-dihydroxyvitamin D; 25(OH)D, 25-hydroxyvitamin D; IGFBP-1, IGF-1 binding protein; LRT, likelihood ratio test. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Accepted October 29, 2007. Received August 9, 2007. DIABETES

• Publisher: American Diabetes Association