Number of children and risk of metabolic syndrome in women.

BACKGROUND: In the United States, there is a high prevalence of metabolic syndrome, as defined by The Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III). The relationship between reproductive factors and metabolic syndrome in women is unknown.
METHODS: We examined the association of number of children and breastfeeding history with metabolic syndrome risk among women. We used nationally representative data from the Third National Health and Nutrition Examination Survey (NHANES III). A total of 4699 (age > or = 20) nonpregnant women were included in this report. Metabolic syndrome was defined according to ATP III.
RESULTS: Overall, 22.6% of women were determined to have metabolic syndrome. The rate of metabolic syndrome was significantly higher with increasing numbers of children, demonstrating a dose-response relationship (p < 0.0001). After controlling for age, race/ethnicity, income, education, and other sociodemographic, reproductive, and behavioral risk factors, the odds of metabolic syndrome increased 13% (95% CI, 6%-20%) with each additional child. In a similarly controlled analysis in parous women, the odds of metabolic syndrome decreased 22% (95% CI, 1%-39%) in women with a history of breastfeeding for >1 month. However, both effects were no longer significant after inclusion of body mass index (BMI) categories.
CONCLUSIONS: In a national sample of women, increasing number of children was associated with higher rates of metabolic syndrome, and history of breastfeeding was associated with decreased rates of metabolic syndrome. The strength of these relationships was decreased after additional adjustment for BMI, suggesting that weight or weight changes may be an important mediator of the effects of parity and breastfeeding on the risk of metabolic syndrome.