Up to 16 million U.S. women 50 years or older experience low sexual desire, while as many as 4 million of them suffer significant distress as a result, a new study suggests.

Dr. Suzanne L. West, who is now with RTI International in Research Triangle Park, North Carolina, and her colleagues analyzed the results of a survey of 2,207 women between 30 and 70 years old who were in a stable relationship for three months or longer. West’s group examined the prevalence of low sexual desire and a clinical condition called hypoactive sexual desire disorder (HSDD) in women before and after menopause, including women who had undergone surgical menopause, meaning their ovaries had been removed.

HSDD is defined by the Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition as “a deficiency or absence of sexual fantasies and desire for sexual activity” that causes “marked distress or interpersonal difficulty,” and isn’t due to a medical condition, another mental disorder, or the effects of a substance.

Among the 755 premenopausal women in the study, the prevalence of low sexual desire was 26.7 percent, while 7.7 percent had HSDD. For women who went through menopause naturally, 52.4 percent had low sexual desire and 6.6 percent had HSDD, while 39.7 percent of women who underwent surgical menopause had low sexual desire and 12.5 percent had HSDD.

Surgical menopause may be more likely to cause sexual desire problems than natural menopause because of its suddenness and also because the ovaries have been removed, West noted in an interview with Reuters Health; even after menopause, women’s ovaries will continue to release hormones that may affect sex drive, she explained.

The research was funded by Procter & Gamble, which makes a testosterone skin patch called Intrinsa that is approved in six European countries for treating low sexual desire in women after surgical menopause. West said P&G is in negotiations with the US Food and Drug Administration about the possibility of marketing the drug in the U.S.

In 2004, an FDA advisory committee voted against approving the drug, citing concerns that it could increase the risk of heart attack and stroke.

SOURCE: Archives of Internal Medicine, July 14, 2008.