Serum adiponectin levels and lifestyle factors in Japanese men

Adiponectin plays an important role in the development of various lifestyle-related diseases such as obesity, hypertension, type II diabetes mellitus, hyperlipidemia, and metabolic syndrome, leading to the development of heart and vascular diseases. However, the determinants that affect circulating adiponectin levels, including lifestyle factors, have still not been thoroughly investigated, in a general male population in particular. A total of 109 healthy Japanese male subjects (mean age, 55 +/- 14 years) with constant lifestyles were enrolled. All were on no medication. Fasting serum adiponectin levels were measured with an enzyme-linked immunosorbent assay. Each subject's lifestyle was assessed by the self-administered Breslow Questionnaire (a well-established method to estimate various lifestyles) with minor modifications. Partial correlation analysis for serum adiponectin levels, after controlling age and all lifestyle factors, revealed a significant and independent negative correlation between serum adiponectin levels and body mass index (BMI) (r = -0.222, P = 0.025), and a significant and independent positive correlation between serum adiponectin levels and sleep duration (r = 0.252, P = 0.011). No significant correlations were observed between adiponectin and other lifestyle factors. These data suggest that increased BMI and shorter sleep duration may be significant independent risks for low serum adiponectin levels in healthy males. Therefore, these factors may be intervention targets to modulate adiponectin to its proper levels for the prevention of cardiovascular disorders.