With the advent of Viagra, the midlife sexual problems of men burst onto the front page and into the consciousness of the American public. Now it's time for women to receive some long-overdue attention to the sexual problems they may face in the years surrounding menopause.

Hormonal levels dip, desire declines
Research presented at the annual meeting of the International Academy of Sex Research in Paris in July 2000 cited aging, menopause, and lack of estrogen as the three major factors that affect a woman's sexual responsiveness.

As a woman heads toward menopause, estrogen production by the ovaries starts to decline, affecting tissues in the genital area. The vaginal lining, or epithelium, consists of layers of squamous cells and connective tissue, interlaced with blood vessels and nerves. All these tissues have receptors for estrogen, which fits into those receptors like a key fits into a lock. Estrogen keeps vaginal tissue constantly regenerating and promotes blood circulation in the area. When estrogen levels decline, vaginal tissue doesn't renew itself and begins to thin and dry out, losing elasticity. Circulation to the area also decreases. The end result: a woman may be slower to lubricate during arousal, and thinned genital tissues can become painful, making penetration uncomfortable and increasing the risk of vaginal infection. Genital tissue atrophy can also cause vaginal or clitoral irritation after orgasm. Not surprisingly, this can affect a woman's desire for sex.

A recent analysis of data from the 1992 National Health and Social Life Survey found that roughly a third of women aged 40 to 59 reported a lack of interest in sex. Other findings of that survey, published in the Journal of the American Medical Association, are summarized in the table below:

Sexual problem	Women age 40–49	Women age 50–59
Lack of interest in sex	30%	27%
Unable to reach orgasm	22%	23%
Pain during intercourse	13%	8%
Sex not a pleasurable experience	17%	17%
Anxious about sexual performance	11%	6%
Trouble lubricating	21%	27%

Adapted from Laumann E, Paik A, Rosen RC. Sexual dysfunction in the United States: prevalence and predictors. JAMA. 1999;281:537-544.

"It is extremely difficult to tease apart what is the effect of low estrogen, what is the effect of lack of arousal, and what is the effect of low libido," observes Mary Lake Polan, MD, professor and chair of Obstetrics and Gynecology at Stanford University School of Medicine in California. "If you are not aroused, you are not going to lubricate. If your tissues are dry to begin with, and you're uncomfortable during sex, that's going to compound the problem."

Also playing a role: a decline in testosterone production, which dampens libido for many women. The ovaries produce about half of a woman's circulating testosterone before menopause (the adrenal glands produce the rest). Though levels in women are only a fraction of what they are in men, testosterone plays a major role in sexual desire, and as levels decline, some women report a lessening of sexual interest and pleasure.

Low libido is a common complaint from patients who are perimenopausal or menopausal, says Alan M. Altman, MD, assistant clinical professor of Obstetrics, Gynecology and Reproductive Biology at Harvard Medical School and co-author of Making Love the Way We Used to... or Better (Contemporary Books, 2000). Often, he says, these women are experiencing a drop in hormones, but there may be other factors at play. "Libido is a multifaceted concept--it's not just hormonal," Altman states. "There are lots of things going on in midlife, what I call the 'taffy pull of life.' You've got your kids pulling at you, if you're married and have children. You have your parents pulling at you because they're living longer and needing more care. You've got your job, your spouse—everyone is putting pressure on this person. They say: 'Sex? Are you're kidding?' That's libido, too."

When medical problems interfere
Common health problems at midlife unrelated to hormones can also interfere with sex. For men, reduced circulation to the penis due to hypertension, diabetes, or atherosclerosis can interfere with erections. "Some reduction in blood flow to the penis is normal as men age, which is why 50% of men over age 50 have some degree of erectile dysfunction," says Dr. Altman. "You have a very similar problem in diminished blood flow to the vagina and the clitoris, which is similar in many ways to the penis, hampering physical sexual responsiveness."

The greater the blood flow to the genital area, the greater the engorgement, the more pleasure and sensation a woman experiences, and the more likely she is to have an orgasm. But a recent study has found that high blood pressure can hamper blood flow to the genital area and cause reduced sexual responsiveness and lubrication in women (as can some of the medications used to treat hypertension). Women are at slightly higher risk of developing hypertension after age 55. Diabetes and other medical conditions can also affect blood flow and sexual responsiveness in women.

Depression, which seems to spike during the years before menopause, can also decrease a woman's libido and sexual responsiveness (as can certain antidepressant medications).

Finding Solutions
"A woman needs a complete medical evaluation and a careful history by a physician to determine what's causing her sexual dysfunction," says Barbara Bartlik, MD, a clinical assistant professor of psychiatry at the Weill Medical College of Cornell University and a member of the staff of the Human Sexuality Program at New York-Presbyterian Hospital. "Sexual dysfunction can clearly be a symptom of other problems, such as depression." There are many options for helping women with sexual problems during midlife. Among them:

• Systemic estrogen (pills or patch) can reverse vaginal atrophy and prevent painful sex for many women.
• Applied locally, estrogen cream, the new Estring vaginal ring, or the new vaginal tablet VagiFem can also reverse vaginal atrophy.
• Pelvic floor muscle exercises (known as Kegel exercises) can help maintain muscle tone.
• Lubricants (such as Vagisil Intimate Moisturizer, Replens, KY Long Lasting and Astroglide) can help maintain moisture.
• Testosterone patches may help boost libido. (A recent study in the New England Journal of Medicine found that an experimental testosterone patch improved sexual functioning and psychological well-being among women who had undergone surgical menopause.)