Aging & Women's Sexuality
AGING AND SEXUAL DESIRE AND ACTIVITY
The age-related decline in sexual interest and desire is frequently reported to be more severe among aging women than men. Such assertions are often based on studies which compare the incidence of sexual activity between aging males and females. For example, recent research indicates that approximately 56% of married women over age 60 (vs. 75% married men) are sexually active, as are approximately 30% of women 80 to 102 years (vs. 63% of males). Often in studies of this nature, sexual interest and activity are measured solely by intercourse frequency. Given that by age 80 and above there are 39 men for every 100 women, opportunity alone may well count for a large portion of such gender differences. More importantly, gender differences in the incidence of intercourse and masturbation are apparent in adolescence and throughout adulthood, not simply among the aging. Hence, examination of age-related changes in sexual activity may best be understood by examining change across one's life span rather than comparing incidence between genders. To this end, the Janus report noted surprisingly little change in sexual activity across the female life span. Sixty-eight percent of women aged 39 to 50 engaged in sexual activity at least once a week, as did 65% of women aged 51 to 64, and 74% of women over the age of 65. Masturbation frequency has been noted to decline with age among women but continues to be practiced by approximately half of healthy women over age 60. In contrast to reports of declining sexual desire with age, according to one study conducted in Denmark , 9% of women report an increase in sexual desire during or after menopause.
One primary cause of decreased sexual desire in postmenopausal women is decreased vaginal lubrication and/or a thinning of the vaginal lining which leads to pain during vaginal intercourse. In such cases, sexual desire generally returns once some form of treatment (e.g., estrogen, lubricants) has relieved the symptoms. A lack of bioavailable testosterone may also reduce sexual desire in women. Although there is no absolute level of testosterone necessary for sexual desire, it has been suggested that there is a threshold of circulating androgen, below which desire levels are affected. Reports of increased sexual desire among aging women may also be explained by hormonal changes which occur following menopause. When estrogen levels decline, FSH (follicle-stimulating hormone) and LH (Luteinizing hormone) are increased in an effort to stimulate estrogen production. The increase in LH and FSH stimulate certain cells in the ovarian stromal tissue to produce testosterone. There is wide variability among women with regard to efficiency in producing testosterone in this manner. Possibly, women who experience an increase in testosterone production during or after menopause also experience an increase in sexual desire. Of course psychological factors such as elimination of the fear of conception may also play a role in increasing sexual desire postmenopause.
PHYSIOLOGICAL ASPECTS OF AGING AND SEXUALITY
Impact of Menopause
Menopause, which occurs for most women around age 50, is associated with significant reductions in levels of estrogen, progesterone, and androgen. Following menopause, estrogen is almost exclusively derived from peripheral conversion of adrenal androgens. Around age 65, there is a further fall in adrenal androgen production. The decline in estrogen which accompanies menopause leads to a number of normal, age-related changes in genital appearance. Such changes include: a reduction in pubic hair, a loss of fat and subcutaneous tissue from the mons pubis, atrophy of the labia majora, and shortening and loss of elasticity of the vaginal barrel. Vaginal secretions decrease in quantity as a result of both atrophy of the Bartholin glands and a decrease in the number and maturity of vaginal cells. The vaginal epithelium, which is highly estrogen dependent, becomes flattened and loses glycogen which leads to a decrease in lactobacillus, lactic acid, and a rise in vaginal pH. These alterations affect the vaginal microbial population and put aging women at a greater risk for developing bacterial infections. Together with decreased vaginal lubrication, the reduction in thickness of the epithelium from approximately 8 to 10 cell layers to 3 to 4 cell layers may lead to postcoital bleeding, mild burning sensations during intercourse, and pain. For such reasons, dyspareunia is the most common sexual complaint among older women seeking gynecological consultation (Bachmann, Leiblum & Grill, 1989). With decreased estrogenic stimulation, the uterus is reduced in size and the total collagen and elastic content decreased by 30-50%. The uterine cervix also becomes atrophic and loses fibromuscular stroma, and the ovary, with no remaining follicles, become reduced in size and weight and the ovarian stromal tissue becomes fibrotic and sclerotic.
The Sexual Response Cycle
In addition to structural changes which occur among normal aging women, there are age-related changes which influence the sexual response cycle. During the excitement phase, vaginal blood flow and genital engorgement is less than in younger women and takes longer to occur. This may be less marked in women who continue to be sexually active than in those who are celibate, although the precise mechanism for this is not well understood. Vaginal lubrication is also delayed and reduced in quantity. Whereas in younger women the excitement stage with lubrication may take only 10 to 15 seconds, in the postmenopausal woman it may take up to 5 minutes or longer. The decrease in vaginal vasocongestion and lubrication may contribute to dryness of the vagina and may make intercourse painful. A variety of topical lubricants such as K-Y Jelly or Astroglide have been successfully used to help compensate for insufficient vaginal lubrication. For women who prefer not to use a lubricant during intercourse, nonhormonal preparations such as Replens or oil from a vitamin E capsule applied vaginally every other day may significantly improve vaginal dryness, as may taking oral zinc or eating foods rich in zinc (e.g., nuts, seafood, wheat germ). Despite these physiological changes which occur with aging, several studies have reported that postmenopausal women report little or not changes in the subjective or psychological experience of sexual arousal.
The plateau phase of sexual responding is prolonged in the older woman, uterine elevation is less, the labia majora do not elevate to the same degree as in younger years, and the breasts become less vasocongested and nipple erection is less likely to occur. The orgasmic response, however, is not significantly impacted with age. Women retain multiorgasmic capacity, although the number and intensity of orgasmic and rectal contractions are reduced. While younger women average 5 to 10 vaginal contractions with orgasm, the older woman averages 2 to 3 . As is the case in men, resolution in the older woman is characterized by a rapid loss of vasocongestion.
ILLNESS, MEDICATION USE AND SEXUALITY AMONG THE ELDERLY
Physical illness can impact sexual function directly by interfering with endocrine, neural, and/or vascular processes that mediate the sexual response, nonspecifically by causing weakness or pain, and psychologically by provoking changes in body image and self esteem. Surgery for gynecologic and breast cancer often negatively impacts sexual function in women by assaulting body image. Although breast or vulvo-vaginal surgery undoubtedly impact the self-esteem of women of all ages, the deleterious effects may be further compounded in older women whose self-esteem may already be negatively altered by the effects of aging on body image. Urinary incontinence is a common symptom in older women, present in up to 25% of older women during intercourse. Urinary incontinence may lead to a withdrawal from sexual contact due to the embarrassment of urine leakage during sexual activity. Sexual functioning has been reported to be negatively impacted in 46% of women with this disorder. Renal failure has been reported to cause anorgasmia, decreased libido, and impaired vaginal lubrication in women on dialysis. Hysterectomy, the most commonly performed surgery in women, with over a third of women in the US having had a hysterectomy by age 60, has not been shown to directly impact sexual function. Some women, however, report a decline in orgasmic pleasure following hysterectomy due to the absence of uterine contractions. For women who view hysterectomy as a further negation of femininity, self-esteem and body image may be negatively impacted. For women who experience a relief from pain, abnormal bleeding, or cramping, hysterectomy may result in improved sexual function. In contrast to the effects of diabetes on the sexual function of men, little is known about its impact on the sexual function of diabetic women. Decreased sexual desire and anorgasmia have been identified among some women with Type II diabetes mellitus, as has difficulty obtaining sufficient vaginal lubrication during sexual arousal. The duration of diabetes, age, or insulin dose does not appear to be correlated with sexual function among diabetic women, and there is no evidence that peripheral or autonomic neuropathies directly affect the female sexual response.
Research on the side effects of medication use on female sexual function has lagged considerably behind that of men. Antidepressant drugs are most commonly reported to impact sexual functioning in women. Side effects associated with antidepressant medications include: decreased sexual desire, impaired arousal and lubrication, vaginal anesthesia, delayed orgasm, and impaired orgasm. Serotonergic systems are frequently implicated in antidepressant-induced sexual side effects, although data are conflicting as to whether the role of serotonin on sexual behavior is largely inhibitory, excitatory, or both. Antipsychotic and neuroleptic medications have been linked to impaired sexual function in women. Most recently, the antihypertensive drug clonidine has been shown to impair physiological sexual responses in women by decreasing both vaginal blood volume and vaginal pressure pulse responses.