Association between serum osteocalcin level and visceral obesity in Chinese postmenopausal women.

Abstract

A low serum osteocalcin level, visceral obesity and postmenopausal status are recognized risk factors for cardiovascular disease. We investigated the relationship between the serum osteocalcin level and visceral fat content in a population of Chinese postmenopausal women. In total, 1481 postmenopausal women (mean age ± standard deviation, 57·1 ± 4·8 years) were selected from the Shanghai Obesity Study. Abdominal fat accumulation was quantified using magnetic resonance imaging. Subjects with a visceral fat area (VFA) of ≥80 cm(2) were classified as abdominally obese. The total serum osteocalcin level was measured by electrochemiluminescence immunoassay. The median serum osteocalcin level was 20·66 μg/l (interquartile range, 16·88-25·42 μg/l). The overall prevalence of abdominal obesity was 49·1% (n = 727). Abdominally obese subjects had lower serum osteocalcin levels than did nonabdominally obese subjects [19·14 (16·02-23·82) vs 21·97 (18·14-26·77) μg/l, respectively; P < 0·001]. Partial correlation analysis showed that the serum osteocalcin level was still negatively correlated with VFA after adjusting for age, years since menopause and body mass index (P < 0·01). Moreover, VFA was independently associated with the serum osteocalcin level after adjustment for confounding factors (P < 0·05). A low serum osteocalcin level was an independent risk factor for abdominal obesity (odds ratio, 0·972; 95% confidence interval, 0·953-0·991; P = 0·004). The serum osteocalcin level was inversely correlated with the visceral fat content in these Chinese postmenopausal women.