SEATTLE, June 5 -- Women whose sexual desire diminishes during menopause are more likely to report disturbed sleep, night sweats, and depression, researchers here reported.
Of 341 peri- and postmenopausal participants in a randomized trial of alternative menopause therapies, 64% reported diminished libido, 18% had moderate to severe depression, and 43% had poor quality sleep, according to a study published in the June issue of the American Journal of Obstetrics and Gynecology.
Factors associated with diminished libido in women during midlife are complex, but include depression, disturbed sleep, and night sweats, all common symptoms of the menopausal transition period and early menopause, said Susan D. Reed, M.D., M.P.H., of the University of Washington, and colleagues.
It seems reasonable that night sweats can disturb sleep and that poor sleep can reduce energy for everything else, including sex, Dr. Reed said.
However, she added, the relationships are so complex that the interactions can be difficult to tease apart, and the researchers' cross-sectional study was not designed to determine causative relationships.
The data came from a 2001 to 2002 baseline survey of 341 women, ages 45 to 55, in the Group Health's Herbal Alternative for Treatment of Menopause Symptoms (HALT) study, a randomized placebo-controlled trial investigating alternative therapies for menopause.
The women were required to have had a least two hot flashes or night sweats per day, and no hormone therapy, including herbal treatments, for at least three months before the start of the study.
Sexual desire or libido was quantified using a modification of the Index of Female Sexual Function, a tool validated previously.
The study participants averaged 4.6 hot flashes and 1.9 night sweats per day. Depressive symptoms (P=0.003), poor sleep (P=0.02), and night sweats (P=0.04), but not hot flashes were significantly associated with diminished libido, the researchers reported.
Although the investigators did not have information about children living at home, they did find that women who were nulliparous, and therefore unlikely to have children living in the home, were less likely to have normal libido.
This finding is opposite to that anticipated from other studies that found that children living at home can account for diminished libido in their parent.
The researchers also found that women with diminished libido were less apt to be "satisfied with their partner" (P<0.0001).
Use of tricyclic antidepressants, selective serotonin reuptake inhibitors, or St. John's wort were not associated with diminished libido (P=0.98), and neither was the use of sleeping medications.
Consistent with certain other studies, women with dyspareunia or vaginal dryness were more apt to have diminished libido. Given that the women were required to be off any hormone therapies, the finding is not unexpected, the researchers said.
In contrast to previous studies, the researchers said they did not find an association of diminished libido with use of antidepressant medication, but only 41 women (11.7%) were using antidepressants; another 13 (3.8%) reported using an over-the-counter medication (St. John's wort, for example) for depression.
Poor sleep quality was highly correlated with depression and night sweats, the researchers reported. However, because of this high correlation, the researchers were unable to assess their independent associations with libido.
However, when women with depression were excluded from the analysis, the association of diminished libido and night sweats remained significant, while the association of diminished libido and sleep disturbances was no longer significant, the investigators found.
Furthermore, because the data were lacking, the researchers were unable to study the importance of other previously described risk factors for diminished libido, including deterioration in social status, duration of relationship with partner, history of sexual assault, and diminishing hormone levels.
Among the study's limitations, the researchers noted, was its cross-sectional design, and therefore the inability to assess changes through the menopausal transition and postmenopausal period. Because the women were not taking hormones, the study could not address the effect of hormone therapy on the associations uncovered in the study. Also, the researchers noted that the majority of the women in the study were white.
Addressing depression with nonpharmacologic therapies and treating difficulties with sleep and night-time vasomotor symptoms may be important steps toward improving libido in midlife, the researchers said.
"However, it is important to bear in mind that the significance of these factors for women is most likely overshadowed by the importance of intimate relationships with their partners," Dr. Reed and her colleagues concluded.
In a discussion in the same article, Lorna Marshall, M.D., of Virginia Mason Medical Center in Seattle, said that because this was a cross-sectional study, libido was not defined as a decrease from the premenopausal years, but as a decrease from an expectation of "normal libido." Previous studies suggest a much lower prevalence of decreased sexual desire in these individuals.
Unfortunately, she added, the study's cross-sectional design did not allow speculation on any causative relationship or trends over time.
Dr. Marshall acknowledged that this is an exceedingly difficult topic to study because of the complexity of quantifying libido, confounding factors, such as health or sexual function issues, lack of a partner, or presence of a female partner. The authors should be congratulated on tackling such a difficult topic, she said.