The relationships of adiponectin with insulin and lipids are strengthened with increasing adiposity

Context: Adipose tissue inflammation has been implicated in the pathogenesis of obesity-related comorbidities. Adiponectin, an anti-inflammatory protein, improves insulin sensitivity and lipid levels systemically. Because adiponectin is secreted by adipocytes, it may also act locally to counteract insulin resistance and dyslipidemia worsened by inflammation. Objective: The aim of this study was to determine whether associations between adiponectin and insulin sensitivity and lipids are stronger with increasing adiposity. Design: This cross-sectional study involved participants in The Princeton School District Study. Setting: The study was conducted in the Princeton City schools ( Cincinnati, OH) during the 2001 - 2002 school year. Participants: A total of 1196 non-Hispanic White and Black students in grades 5 - 12 participated. Main Outcome Measure: The relationships between adiponectin and high-density lipoprotein, triglycerides, and insulin were measured. To test our hypothesis, we: 1) compared correlation and regression coefficients of lean and nonlean individuals, and 2) incorporated an adiponectin by adiposity interaction in regression models. Results: For high-density lipoprotein and triglycerides, the relationship with adiponectin, although present among lean adolescents, strengthened with increasing adiposity. However, with insulin, a relationship with adiponectin was only present among nonlean adolescents. Conclusions: These analyses suggest that adiponectin's relationship with insulin and lipids strengthens with increasing adiposity, such that heavier adolescents have a greater benefit from high levels of adiponectin than their lean counterparts.