Relationships between adiponectin and bone: Sex difference.
OBJECTIVES
Despite being secreted exclusively by adipocytes, circulating adiponectin (ApN) is negatively associated with obesity. Moreover, obesity is traditionally viewed as leading to increased bone mass and density. Therefore, ApN may play a biological role in regulating fat and bone metabolism. The objective of this study is to evaluate the relationship between ApN, measures of obesity, and bone mineral density (BMD) in healthy adults living in Singapore.


METHODS
We conducted a cross-sectional study of 300 participants (112 men), and measured body composition (i.e., fat mass, fat-free mass, BMD, and bone mineral content) by dual-energy x-ray absorptiometry. Serum leptin and ApN levels were determined by radioimmunoassay.


RESULTS
Our results showed that serum ApN levels were significantly associated with obesity measures in both men and women, and the greater effect was observed in men. In contrast, the relationship between ApN and BMD was sex-dependent. Levels of ApN were negatively associated with BMD in women, but not in men. This relationship persisted even after adjustment for potential confounding factors, such as leptin and body mass index. Moreover, serum ApN was found to be a major determinant of BMD in women on the multivariate regression analysis.


CONCLUSIONS
Our results suggest that ApN, an adipocyte-derived hormone, may affect bone metabolism, which may be mediated by sex hormones.
['Bi|Xinyan|X|', 'Loo|Yi Ting|YT|', 'Henry|Christiani Jeyakumar|CJ|']
D015502:Absorptiometry, Photon D052242:Adiponectin D000273:Adipose Tissue D000328:Adult D000368:Aged D001823:Body Composition D015992:Body Mass Index D015519:Bone Density D001842:Bone and Bones D003430:Cross-Sectional Studies D005260:Female D006801:Humans D020738:Leptin D008297:Male D008875:Middle Aged D009765:Obesity D012044:Regression Analysis D012727:Sex Characteristics D055815:Young Adult
Adiponectin Sex difference Body adiposity Bone health