Context: Determinants of adiponectin and its association with insulin resistance (IR) are less well studied in youth than in adults.

Objectives: To describe, in youth, the age- and sex-specific distribution of adiponectin concentrations, and the association with demographic, anthropometric, and lifestyle factors, parental diabetes, and markers of IR.

Design, Setting, Participants: We studied 1632 French Canadian youth aged 9, 13 and 16 yr who participated in the Quebec Child and Adolescent Health and Social Survey, a province-wide school-based survey conducted in 1999.

Results: Boys had lower adiponectin concentrations than girls by 17% (P < 0.0001). At age 16, mean adiponectin concentrations were 27.7% (boys, P < 0.0001) and 13.3% (girls, P < 0.0001) lower than at age 9 (p_interaction = 0.009). Mean adiponectin decreased for every unit increase in BMI Z-score by 8.1% in boys and 11.2% in girls (P < 0.0001). Growth-related change in BMI explained half the age effect in boys and all the age effect in girls. Self-reported pubertal status, physical activity, smoking and parental diabetes were not independently associated with adiponectin. Fasting insulin and HOMA-IR were not associated with adiponectin concentration. However, the interaction of adiponectin and BMI Z-score was significant in a multiple regression model of fasting insulin.

Conclusions: Male sex and changes in body fat may be major determinants of the decreasing adiponectin concentrations of growing youth, which are accompanied by a dissociation of adiponectin and markers of IR. The relationship between adiposity and markers of IR is attenuated in those with higher adiponectin concentrations, making adiponectin a potential intervention target or risk marker.