Gender-related behavior during childhood and associations with adult abdominal obesity: a nested case-control study in women.

Abdominal obesity affects many aspects of women's health, and recent studies indicate that hyperandrogenicity (HA) may contribute to the excess of body fat in women. As hormone behavior research attributes male-like play patterns in childhood to the effects of androgens, the aim of the present study was to assess the potential association of such behavior with obesity in adult women. In a randomly selected sample of 40-year-old women (n = 1464), 78% volunteered to respond to a questionnaire collecting information on the effect of other variables on childhood behavior. Self-reported body weight, height, and waist and hip circumferences were used to calculate body mass index (BMI) and waist/hip ratio (WHR). Age at menarche showed an inverse association with overweight (BMI > or = 25) (odds ratio [OR] = 0.82). Reports of gender-related behavior as a child showed that playing with girls and girl toys was negatively related to both overweight and abdominal obesity (WHR > or = 0.85). Among respondents who were overweight, relationships were found for playing with boys (OR = 0.90) and fighting (OR = 1.70). The OR of playing with boy toys and fighting among respondents with abdominal obesity were increased 1.12 and 1.65, respectively. Interests in athletics as a child seemed to decrease the risk for overweight (OR = 0.89) and abdominal obesity (OR = 0.91). Furthermore, dose-response analysis between the individual exposure levels and the OR for overweight showed a negative trend for playing with girls (p = 0.002) and girl toys (p = 0.017) and a positive trend for playing with boys (p = 0.011) and fighting (p = 0.031). Among respondents with abdominal obesity, positive dose-response effects were found for playing with boys (p = 0.026) and boy toys (p = 0.036) and fighting (p = 0.008). Thus, women with an elevated WHR showed a preference to play with boys and boy toys and also fought frequently as children. This might be a sign of a relative HA in childhood ("tomboyism"). These preliminary observations suggest that HA may originate in childhood.