Osteocalcin as a predictor of the metabolic syndrome in older persons: a population-based study.

BACKGROUND Recent evidence indicates that the osteoblast-derived protein osteocalcin is able to influence adiposity and glucose homeostasis in mice. Little is known about this relationship in humans. OBJECTIVE To investigate the association of plasma osteocalcin levels with the metabolic syndrome in a community-dwelling cohort of older persons in the Netherlands. DESIGN AND PARTICIPANTS Data were used from the Longitudinal Aging Study Amsterdam (LASA), an ongoing multidisciplinary cohort study in a representative sample of the older Dutch population (≥65 years old). A total of 1284 subjects (629 men and 655 women) between the age of 65 and 88 years participated in this study. MEASUREMENTS Metabolic syndrome (U.S. National Cholesterol Education Program definition) and its individual components were assessed as well as plasma osteocalcin levels. RESULTS Among the participants, the prevalence of the metabolic syndrome was 37·1%. The median osteocalcin level was 2·0 nmol/l. Plasma osteocalcin was inversely associated with the metabolic syndrome. The odds ratio (OR) was 3·68 with 95% confidence interval (CI) 2·53-5·34 for the lowest osteocalcin quartile compared to the highest quartile. The association between osteocalcin and the metabolic syndrome was mainly determined by high triglycerides, low HDL, waist circumference and hypertension. CONCLUSION Low plasma osteocalcin levels are strongly associated with the metabolic syndrome in an older community-dwelling population.