The circulating concentration and ratio of total and high molecular weight adiponectin in post-menopausal women with and without osteoporosis and its association with body mass index and biochemical markers of bone metabolism

Objectives: There is increasing evidence suggesting that adiponectin plays a role in the regulation of bone metabolism. Design and methods: This was a cross-sectional study of 34 post-menopausal women with and 37 without osteoporosis. All subjects had body mass index (BMI), bone mineral density (BMD), total-, high molecular weight (HMW)-adiponectin and their ratio, osteoprotegerin (OPG), a marker of bone resorption (beta CTX) and formation (P1NP) measured. Results: We observed a positive correlation between BMI and BMD (r = 0.44, p<0.001). When normalised for BMI, total-, HMW-adiponectin concentrations and HMW/total-adiponectin ratio were significantly lower in obese compared to lean subjects but there was no difference between those with or without osteoporosis. There were significant negative correlations between HMW/total-adiponectin ratio and BMI (r = -0.27, p = 0.030) and with OPG (r = -0.44, p<0.001). Conclusions: Our data suggests that there is no significant difference in the circulating concentration of fasting early morning total-or HMW-adiponectin in post-menopausal women with or without osteoporosis. The correlation between HMW/total-adiponectin ratio and OPG may indicate that adiponectin could influence bone metabolism by altering osteoblast production of OPG thereby affecting osteoclasts mediated bone resorption. (C) 2009 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.