Relation of body fat distribution to reproductive factors in pre- and postmenopausal women.

The cross-sectional relations of several reproductive characteristics with self-reported waist-to-hip circumference ratio were evaluated in 44,487 pre- and postmenopausal women 40 to 65 years of age who were free of cancer, cardiovascular disease, and diabetes. All results were adjusted for age, body mass index, cigarette smoking, physical activity, and alcohol intake. Current use of postmenopausal hormones was associated with a significantly lower waist-to-hip ratio than either past or never use independent of type of menopause (0.778 versus 0.784, p = 0.0001 and 0.787, p = 0.0001, respectively), although associations with type (unopposed estrogens versus combined estrogen and progesterone) and duration of hormone therapy were not noted. Waist-to-hip ratio did not differ between pre- and postmenopausal women, but demonstrated weak positive associations with age at menarche, parity, and age at first birth, and a weak inverse association with past duration of breast-feeding. These data confirm relations of several reproductive factors and use of hormone replacement therapy with body fat distribution. Epidemiologic studies relating body fat distribution to disease outcomes in women should consider these factors as potential confounders.