Objective: To identify risk factors for decreased libido among women in the late reproductive years.
Design: Prospective cohort. Women aged 35 to 47 years identified through random digit dialing were prospectively followed for 4 years with serial hormone assays and standardized questionnaires. Mean hormone values, hormone trends over 4 years, and fluctuation in hormone levels were compared among women with and without a decrease in libido at the last assessment period. Total testosterone, dihydroepiandrosterone sulfate, estradiol, follicle-stimulating hormone, luteinizing hormone, body mass index, psychosocial, and socioeconomic variables were evaluated using multivariable logistic regression.
Results: Of 326 women, 87 (27%) reported a decreased libido, whereas 239 (73%) did not. Participant-specific means for all hormone levels over the study period were similar among both groups. However, total testosterone fluctuation over the study was significantly different between groups. Women whose testosterone levels fluctuated from 3.8 to 21.5 ng/dL around a mean value of 9 ng/dL were four times more likely to report decreased libido compared with women with little fluctuation in testosterone [odds ratio (OR) 4.0; 95% CI, 1.6-10.0]. Depression (OR 3.4; 95%CI, 1.9-6.1), vaginal dryness (OR 3.5; 95%CI, 1.8-6.6), and children living at home (OR 1.4; 95%CI, 1.1-1.7) were also independently associated with decreased libido.
Conclusions: Decreased libido in the late reproductive years is associated with a pronounced fluctuation in total testosterone over time. Other independent risk factors for decreased libido include vaginal dryness, depression, and living with children. Sexual dysfunction is a complex disorder, related to physiological and psychosocial factors, requiring further investigation.