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.