Associations between body mass index and sexual functioning in midlife women: the Study of Women's Health Across the Nation.

OBJECTIVE This study aims to examine baseline and longitudinal associations between body mass index (BMI) and sexual functioning in midlife women. METHODS Midlife women (N = 2,528) from the Study of Women's Health Across the Nation reported on sexual functioning and underwent measurements of BMI annually beginning in 1995-1997, with follow-up spanning 13.8 years. Associations between baseline levels and longitudinal changes in BMI and sexual desire, arousal, intercourse frequency, and ability to climax were assessed with generalized linear mixed-effects models. Models were adjusted for demographic variables, depressive symptoms, hormone therapy use, alcohol intake, menopause status, smoking status, and health status. RESULTS Mean BMI increased from 27.7 to 29.1 kg/m2, whereas all sexual functioning variables declined across time (P values ≤ 0.001). Higher baseline BMI was associated with less frequent intercourse (P = 0.003; 95% CI, -0.059 to -0.012). Although overall change in BMI was not associated with changes in sexual functioning, years of greater-than-expected BMI increases relative to women's overall BMI change trajectory were characterized by less frequent intercourse (P < 0.001; 95% CI, -0.106 to -0.029) and reduced sexual desire (P = 0.020; 95% CI, -0.078 to -0.007). CONCLUSIONS Although women's overall BMI change across 13.8 years of follow-up was not associated with overall changes in sexual functioning, sexual desire and intercourse frequency diminished with years of greater-than-expected weight gain. Results suggest that adiposity and sexual functioning change concurrently from year to year. Further research should explore the impact of weight management interventions as a strategy for preserving sexual functioning in midlife women.