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 antiinflammatory 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.