Contribution of adipocytokines to low-grade inflammatory state as expressed by circulating C-reactive protein in Japanese men: comparison of leptin and adiponectin.

Background: Circulating C-reactive protein (CRP) is a marker of inflammation and is associated with the incidence of cardiovascular events. Although it has been known that adiponectin protects, whereas leptin accelerates, the development of atherosclerotic diseases, the comparative strength of their reciprocal effects on circulating CRP remains unclear.

Methods: We studied a population of 2049 Japanese men aged 35 to 66. For all subjects, multiple regression analysis performed with log-transformed CRP concentration as the dependent variable, and with log-transformed leptin, log-transformed adiponectin, age, BMI, smoking status, and components of metabolic syndrome as independent variables.

Results: Both leptin (positively) and adiponectin (negatively) were significantly and independently associated with CRP concentration. The absolute value of the standardized regression coefficient (st-beta) of leptin (st-beta=0.201) was higher than that of adiponectin (st-beta=-0.082). After subjects were stratified by current BMI level, both of the adipocytokines were significantly associated with CRP concentration among subjects with BMI <25 kg/m(2), whereas only leptin was significantly associated with CRP concentration among subjects with BMI >=25 kg/m(2).

Conclusions: Both leptin and adiponectin were independently associated with CRP concentration. Leptin was more strongly related to CRP levels than adiponectin was, especially among obese subjects.