Sexual Function in the Geriatric Patient
Individuals age 65 years or older numbered nearly 36 million in 2003. By 2030, this age cohort is expected to double to nearly 72 million persons in the United States.1 While sexual activity may decline with age and sexual dysfunction tends to increase, a survey conducted in 1969 reported that 68% of men and 30% of women over the age of 60 were still sexually active.2 A recent study in Australia found that more than 55% of women over the age of 70 are still interested in sexual activity.3 This highlights the importance of sexuality in older patients and clinicians being aware of issues influencing both normal and impaired sexual functioning in their older patients.
NEUROBIOLOGY OF SEXUAL FUNCTION
The clinician must understand the role of sexual interest and capacity for each individual. Careful questioning when appropriate should allow the patient to review the role of sexual activity during his or her life. For some patients, it will be an essential element in their quality of life. For others, it will be less important. Only the patient can determine this. The presence or absence of a sexual partner is also an important variable to understand. The absence of a sexual partner can be a painful issue that is often ignored by clinicians. Nevertheless, it is helpful for the patient to discuss the pain of such an absence, especially if it is coupled with bereavement issues. The presence of a partner can also be complicated by a significant other having a different level of sexual interest or functional ability than the patient; this can cause problems if such differences foster interpersonal problems. Finally, for some older individuals who have met new partners following the loss of their significant others, sexuality may foster guilt about being “unfaithful” to the deceased. All such issues need to be discussed. To assess sexual function in patients of all age ranges, the clinician must understand the sexual response cycle, a psychophysiologic cascade of events leading to orgasm. The biological basis of each phase—desire, arousal, and orgasm—should be understood to correlate organic issues with functional problems in each phase. This will enable accurate diagnosis and etiologic assessment of sexual complaints.
Divided into three phases (desire, arousal, and orgasm), there is a complex interplay of the endocrine, nervous, and vascular systems4 (Figure). Sexual desire (libido) is the final result of interacting input from the central and peripheral nervous systems, hormonal action, and psychological factors, both current and remote.5 Initial sexual motivation may occur from sources such as fantasy, visual images, or direct tactile input.6 Testosterone contributes to sexual desire in both men and women, with decreased levels in hypogonadal men and menopausal women that contribute to reduced desire.7 Neither estrogen nor progesterone appears to contribute to sexual desire in either men or women. Nevertheless, estrogen, often utilized in postmenopausal women, may potentiate a sense of “well-being,” as well as modify the effects of estrogen deprivation such as vaginal dryness. Central dopaminergic neurotransmission may also stimulate sexual desire.8 Prolactin acts as a dopamine-inhibiting factor and can suppress libido, which may explain why some psychotropic medications lower sexual desire.
Arousal consists of both the subjective feeling of sexual excitement along with the physiological alterations that occur to foster penile tumescence in men and vaginal lubrication and expansion in women. Sensory afferent impulses from the pudendal nerve reach higher centers of the cerebral cortex (eg, limbic system, interhemispheric region), while vasogenic efferent parasympathetic impulses extend to the corpus cavernosum. Smooth muscle relaxation and vascular engorgement follow input from the parasympathetic nervous system and release of nitric oxide from the vascular endothelium of the penis. The second messenger, cyclic guanosine monophosphate, mediates the effects of the nitric oxide. Some evidence indicates the presence of nitric oxide in clitoral tissue.9 The arousal phase evolves into the plateau prior to orgasm. There is further labial engorgement and uterine elevation in women, while the heart rate and blood pressure accelerate in men. Nipple erection occurs in women and often in men.
Orgasm is the final phase of release and resolution of sexual tension that includes both the psychological and physiological components.4 During orgasm, rhythmic contractions of the genital and reproductive organs, changes in cardiovascular and respiratory function, and release of sexual tension occur. For men, orgasm consists of two phases: emission and ejaculation. Emission involves propulsion of seminal fluid into the bulbar urethra, which is controlled by the thoracolumbar spinal reflex. This is achieved by the release of norepinephrine, causing smooth muscle contractions of the vas deferens, prostate, and seminal vessels. Following sympathetic discharge to the somatic efferent pudendal nerve, contraction of the bulbocavernosus and pelvic floor muscle leads to ejaculation. In women, contractions of the vaginal wall occur. Women are capable of multiple orgasms, whereas men have a significant refractory period that expands with aging before another orgasm is possible.
EFFECTS OF AGING ON SEXUAL FUNCTION
Research into the effects of age have generally shown a decline in sexual activity over time that appears attributable to many factors, including gender, physiological changes, physical health, mobility, mental health, and partner availability.10 Pre-existing attitudes toward sexuality also play an important role. For women, estrogen levels decline during menopause, causing atrophy of vaginal epithelium, labia majora, and Bartholin’s glands. Shortening and loss of elasticity of the vaginal canal also occurs. Reductions in vaginal blood flow, genital engorgement, and vaginal lubrication lead to delays in achieving sexual arousal. Loss of lubrication also contributes to dyspareunia. While orgasmic capacity is retained with age, there are reductions in the number and intensity of vaginal contractions. Furthermore, some women experience painful uterine contractions during orgasm. Androgen levels also decline with age, especially between the third and fifth decades of life.
Testosterone does influence female sexual behavior in the central nervous system, with low levels leading to impaired sexual desire, arousal, responsiveness, genital sensation, and orgasm. Despite this, consistent evidence showing a direct relationship between reduced testosterone levels and change in sexual functioning has been lacking.11 As men age, there is a gradual decline in sexual responsiveness, marked by longer periods necessary to achieve full erections and reduced effectiveness of psychic and tactile stimuli.12 Maintenance of erection also requires a greater degree of direct genital stimulation. Orgasms frequently become less intense, and ejaculatory volume decreases. Following orgasm, penile detumescence occurs more rapidly and the refractory period lengthens considerably. Testosterone is felt to be necessary for normal libido and also contributes to erectile function. Levels progressively decline with age, while levels of sex hormone–binding globulin increase.13 As a result, more testosterone is bound and physiologically unavailable. Furthermore, free testosterone levels will exhibit a greater reduction with age as compared with total serum testosterone levels. Despite the need for testosterone, the relationship between declining testosterone and changes in male sexual behavior with advancing age remains unclear.
Sexual dysfunctions are more common in the elderly population and cause significant distress.14 There are limited data regarding sexual dysfunction in the older woman without a comorbid medical disorder due to the common issue of lack of sexual partners and the ability of women to have sexual activity without an active tumescence found in men. There are significant data, however, regarding sexual disorders in the aging male. Erectile dysfunction (ED), the inability to achieve or maintain an erection for satisfactory sexual function, is especially problematic for older males. Studies have found the prevalence of ED to be significantly higher among older men as compared with those in younger age groups.15 The Massachusetts Male Aging Study16 found a tripling of the prevalence of complete ED among men age 70 years as compared with those age 40 years. Similarly, the risk of developing ED increased fourfold for men in their 60s as compared with those in their 40s.16 In this study, age was found to be the strongest predictor for ED. Due to the strength of its relationship to age, other risk factors were age-adjusted. Treated medical conditions such as hypertension, diabetes, and heart disease were also significantly associated with this dysfunction. Obesity, smoking, hypercholesterolemia, and lack of physical activity were also linked to ED. Compared with men in their 20s, those in the oldest age group (70-75 years) had a 14-fold higher relative risk for ED. Poor health, depressed mood, and prostate disease were also contributing factors.17,18
The evaluation of the sexual functioning of older individuals is similar to their younger counterparts. This demands attention to biological, psychological, and social issues in the patient and sexual partner, if present. In the older patient, however, it is particularly important to pay attention to both systemic diseases and medications that he or she is taking. The clinician must take an initial history and ascertain if there is a psychiatric disorder present, as depression or dementing illnesses would modify sexual functioning. Is there an available sexual partner with sexual interests and the capacity for sexual intimacy? Has the loss of a partner led to ongoing depression and inability to fully accept both the loss and the reality of being alone? It is also essential to understand the individual’s attitudes and past experiences regarding sexuality. If there have been long-standing sexual problems both in function or attitudinal inhibitions, the current situation must consider this. The time course for developing the dysfunction may aid in understanding etiologic factors in the dysfunction.
If the difficulty concurred with onset of an illness or initiation of a medication, the role of such variables must be included. Gradual onset also points toward organic factors in etiology. For men, questions about masturbatory ability may help in organizing causal factors. If the patient can develop full and sustained tumescence during masturbation with orgasm, psychogenic factors should be considered if ED is the presenting complaint. For women, the presence of vaginal lubrication and ability to have an orgasm should be ascertained. The next step is to document the current ability to function sexually. The clinician may wish to specifically question the individual about his or her last sexual experience. For men, it is useful to have them estimate the turgidity of their erection on a scale of 1 (total flaccidity) to 10 (full tumescence) and have their partner estimate the erectile ability as well. Graphic representation of the sexual response cycle developed by Masters and Johnson is a useful aid in documenting areas of difficulty in both men and women.4 The clinician should plot the actual sexual dysfunction or dysfunctions in each partner by specifically ascertaining whether there are disorders of desire, arousal, or orgasm. Illnesses due to malaise, pain, or actual organic limitations may modify any one of the phases of sexual functioning.
Can the male develop a sufficiently adequate erection (the arousal phase) to perform intercourse, or can the female become sufficiently aroused via lubrication to prevent painful intercourse? Is orgasm possible? If the individual has an ongoing sexual partner, it is generally useful to evaluate his or her impressions as well. Men tend to overestimate their erectile ability, and their sexual partner provides a concurrent validator. It is also essential to understand the older individual’s actual sexual experiences and attitudes throughout his or her life cycle. Have there been periods of similar dysfunction in younger years or attitudes that might modify sexual enjoyment and function? Finally, medications may often modify sexuality, so it is important to find out what medicines are being taken.
COMMON ORGANIC ETIOLOGIES OF SEXUAL DYSFUNCTION
Medications often impair sexual functioning (Table).19-21 Psychotropic medication can diminish libidinal desire in both men and women, as well as orgasmic potential in both genders. Men may also complain of ED due to serotonin reuptake inhibitors. Antihypertensives also impair sexual function. H2 blocking agents for hyperacidity frequently limit erectile ability. (Note: Not all medications in a class have equal sexual side effects [eg, cimetidine is more likely than ranitidine to cause ED].) Finally, alcohol, not usually considered a medication, may seriously impair sexual function. It is important to ascertain the temporal relationship between beginning a medication and the onset of a sexual dysfunction so that there is evidence that a medication is a contributing factor in the problem.
SPECIFIC MEDICAL DISORDER
Several medical disorders may impair sexual functioning.
Chronic renal disease
In the patient with chronic renal failure, sexual enjoyment may be inhibited by fatigue and malaise.22 Biological factors are also very important. Vascular disease and neuropathies are elements in such dysfunction, but endocrine abnormalities are consistent features in chronic renal failure.23 Both free and total testosterone are lowered in chronic renal failure and are reversed following transplantation.24 Diminished sexual function also seems to be related to dysfunction between the pituitary and the Leydig axis. Exogenous testosterone may restore sexual function, but it cannot be used because it augments atherosclerosis.25 Both erythropoietin and vitamin E have been reported to improve sexual function in men with renal failure.26 Sildenafil has been demonstrated to successfully treat erectile difficulties in such populations.27 Sexual difficulties in women are primarily related to the malaise of the disease, as well as psychological and social problems associated with renal failure and dialysis, but such concerns clearly need to be addressed in all patients.28 Fortunately, renal transplantation improves sexual functioning that was impaired due to the renal failure.29,30
Cardiovascular disease may physically and psychologically interfere with sexual functioning. Studies of patients after myocardial infarction have revealed a significant incidence of sexual problems in both men and women.31 Sexual intercourse and a vigorous walk around a city block place equivalent demands on the heart. There is great intersubject variability in blood pressure and heart rate increases during sexual intercourse. Generally, an individual who can walk vigorously or pedal 600 kpm per minute on a bicycle ergometer without symptoms, blood pressure increase, or electrocardiogram changes can tolerate sexual intercourse. A number of antihypertensives may cause erectile and ejaculatory problems. Digoxin can decrease sexual desire (Table). Following a myocardial infarction, many patients have concerns about intercourse that include anxiety about inability to perform or fear that one may die during coitus.32 Angina may foster such fears of coital coronaries that complicate libidinal desire. Anxiety and depression, common after an infarct, can interfere with sexual functioning. Increasing use of serotonin reuptake inhibitors in the cardiac patient may increase sexual problems due to such drugs’ sexual side effects.
There are increasing data about sexual difficulties in women with cardiac disease. Problems in desire, arousal, and orgasm are significant in older women with cardiac problems.33 Management includes open discussion with the patient and spouse about fears and limitations. Sexual abstinence is recommended for 8-12 weeks after infarction, although there is minimal evidence to justify such prohibition in uncomplicated patients. Because superior positions may heighten cardiac demand, side-by-side or patient-inferior positions may be recommended. After infarction, gradual resumption of sexual activity is recommended, often beginning with non-coital contact.34 Prior to intercourse, use of beta blockers and sublingual nitrates in selected patients reduces angina. Patients, however, must be counseled not to consider phosphodiesterase inhibitors if taking such medications. Ongoing counseling and support following myocardial infarction has been demonstrated to minimize sexual problems in those who have incurred such a cardiac event.35
Insulin-dependent (type 1) diabetes mellitus may diminish sexual functioning in both men and women. In men with type 1 diabetes, ED has been reported in up to 50% of cohorts, while in men with noninsulin–dependent (type 2) diabetes, up to one-third experience erectile difficulties.36,37 As men with diabetes age, the rates of erectile failure can reach 70%.38 Comorbid smoking and alcohol abuse predict earlier onset of ED.39 Men with diabetes often develop ED secondary to either neurologic or microvascular lesions.40 Thus, clinically, the presence of neuropathy or retinopathy will be associated with sexual dysfunction. This should alert the clinican to inquire about this domain of life quality. Hypogonadism in men with diabetes has been reported and may be secondary to vascular disease.41 Sexual dysfunction in women with diabetes is often overlooked but can occur in up to 50% of those surveyed. Loss of lubrication fostering dyspareunia and orgasmic problems are among the problems cited.42
Chronic pulmonary disease
Sexual dysfunction has been identified in patients with chronic pulmonary disease. Testosterone depression associated with chronic arterial hypoxia is a possible mechanism for diminished desire. In addition, respiratory difficulties may limit one’s physical ability to engage in sexual activity.43
There has been increasing emphasis on enhancing the quality of life of patients with cancer. Sexual functioning may be affected by psychological factors, physical aspects of the neoplasm, and side effects from treatment.44
Breast cancer. Psychological and medical factors may interfere with sexual functioning in patients with breast cancer.45 Dysphoria from the disease and fears of death and disfigurement may diminish sexual desire before treatment has begun. Women who have a prior history of marital difficulties and who did not have discussions with their spouse about the possibility of mastectomy are at increased risk for post-mastectomy sexual difficulties. Shame about a scar may lead to decreased orgasmic ability. In a recent study, patients who had a lumpectomy were compared with patients who had a mastectomy, and the former were found to have a greater sense of sexual desirability but no difference in frequency of sexual relations or frequency of orgasm. Medical issues that may contribute to sexual dysfunction include pain; fatigue; chemotherapy-induced ovarian dysfunction leading to decreased libido, dyspareunia, and vaginal mucosal dryness; and nausea and vomiting from chemotherapy. Tamoxifen, which induces premature menopause, accelerates such difficulties.46 Treatment includes minimizing medical problems that are inhibiting sexuality. If possible, open communication between patient and partner is desirable at all stages of treatment. It is helpful for the partner to observe the mastectomy wound soon after surgery.47,48 Rapid resumption of sexual activities has also been recommended, and alternative sexual positions and vaginal lubrication may be beneficial when needed. Breast reconstruction may also enhance self-image, and therapy may improve sexual functioning.
Colon cancer. Surgery for colon cancer may result in the need for an ostomy, a major cause of sexual difficulties. Anxiety, depression, and marital difficulties are frequent sequelae. Fear of fecal spillage and odor may inhibit sexual pleasure. Women with ostomies can develop dyspareunia due to fistula formation.49 Men who require posterior abdominal perineal resection may become impotent due to ablation of autonomic nerves to the penis.50 Use of nerve-sparing techniques around the rectal sphincter may preserve some sexual function in such procedures. Treatment may include the use of alternative positions, wearing clothes during intercourse, and open discussions between patient and partner about psychological effects of the presence and care of the ostomy.51 A penile prosthesis may help men rendered impotent from surgery.
Male genitourinary neoplasia. The effects of prostate cancer vary with treatment. Although surgery for prostate cancer may frequently cause ED, the introduction of nerve-sparing techniques greatly improves post-surgical preservation of sexual function.52 Patients may need to wait 2-3 years following surgery for maximum function to return. Retrograde ejaculation can impede enjoyment and lead to fantasies about where the ejaculate goes; thus, it is imperative that a complete discussion of the effects of surgery on sexuality be conducted with both patient and partner, if available.53 Radiation therapy produced impotence in over 50% of one sample.54 Phosphodiesterase inhibitors and prosthetic devices can be useful to modify such post-treatment dysfunctions. Testicular cancer, common in young men, may be associated with decreased self-esteem. Use of a sperm bank prior to radiation therapy or chemotherapy should be considered. Staging surgery may result in ejaculatory dysfunction and ED.
Female genitourinary neoplasms. As is true with male genital malignancies and breast cancer, there are often profound psychological sequelae of female genitourinary cancer. It is essential to include the sexual partner in discussions about sexual problems following treatment for such difficulties. Sexual difficulties with cervical carcinoma vary with treatment approach.55,56 In general, surgery has fewer sexual side effects than radiation therapy. Radical hysterectomy compromises sexual functioning because of vaginal shortening, but difficulties are reduced when there is ongoing sexual activity. The most important variable predicting sexual dysfunction following hysterectomy is whether the ovaries are removed. Ovarian absence will lower desire and foster dyspareunia. Radiation therapy promotes vaginal atrophy and stenosis due to impaired ovarian functioning. Treatment may include education and support of patient and partner, and use of lubricants and alternative sexual positions.56 The extent of surgical treatment for vulvar carcinoma often determines sexual side effects. From a medical perspective, local excision often does not interfere with sexuality. More extensive surgery may promote numbness.57 Psychological issues such as guilt over delay in seeking treatment must often be addressed. Sexual disorders from ovarian cancer often result from knowledge of the severity of the illness, surgically induced menopause, and loss of the capacity to bear children. In addition, loss of estrogen promotes vaginal dryness and dyspareunia.58 Treatment includes open communication between patient and sexual partner, use of alternative positions, and vaginal lubrication.
TREATMENT ISSUES OF SEXUAL DYSFUNCTIONS
When a sexual problem involves both the person with the dysfunction and his or her partner, it is best to discuss the problem with both members of the dyad. Often, each member will have a different version of the problem. It is not unusual for men to overestimate their potency or to exaggerate their partner’s distress. To initiate such an interview, the clinician should allow the identified patient to describe the dysfunction and then ask the partner, “What do you think about this report?” Such open-ended questions can be followed up by more specific queries that best pinpoint the exact dysfunction (ie, a desire, arousal, and/or orgastic problem).
It is essential to understand the role of sexuality in each person’s life. What is the desired level of frequency? Have there been problems before? What has changed in the relationship? Is there any evidence of substance abuse? Following reports from the couple together, it is important to interview each person individually. For widowed patients in second marriages (or significant relationships), the role of guilt regarding deceased partners may foster sexual problems. This is often difficult to report in front of new partners. Another important data element is whether intimacy is viewed as a derivative of interpersonal closeness or libidinal release. This issue is often seen when one partner reports that being close to one another is as important as complete intercourse, but the other member is focused upon limits in function.
Finally, it is essential for the clinician to understand the role of illness or aging in each member. Does the presence of a painful state such as osteoarthritis limit movement? Does cardiovascular disease limit the physical demands of intercourse? Have the physical changes in aging created embarrassment in the person or modified sexual interest in the partner? All of these issues must be considered in the context of the individual’s present physical and emotional state. Is there a psychiatric disorder present that could modify sexuality? Depressive disorders can lower libido, while dementing illness may disinhibit patients and increase the wish for sexual activity. The clinician must integrate all such data into a reasonable treatment plan. If there is a prominent psychological component, psychotherapy—either individual or couples—should be utilized. If the dysfunction is thought to have a significant organic component, the adjunctive use of medications to improve desire or arousal should be considered. Such medications, however, must be used in the broader context of the psychological and relationship issues in the patient and partner. If the clinician does not feel comfortable in managing such issues, referral to a mental health professional is appropriate.
SPECIFIC MEDICATIONS THAT MAY FOSTER SEXUAL FUNCTION
There are presently available medications that may offset sexual dysfunction. Phosphodiesterase V inhibitors act peripherally on the penile vascular system to allow improved tumescence. These medications increase cyclic GMP in the penile corpus cavernosum to relax the smooth muscle in the penile vasculature and foster blood flow.59 Three preparations are now available: sildenafil, vardenafil, and tadalafil, whose essential difference is its half-life. A major contraindication is combining such agents with nitrates for angina. Other agents for erectile problems include transurethral and injectable prostaglandin E1, which is less convenient for patients to administer. The role of phosphodiesterase inhibitors in women is essentially limited to offsetting selective serotonin reuptake inhibitor sexual side effects.60,61 One study, however, found that sildenafil was well tolerated in postmenopausal women with sexual dysfunctions but did not significantly improve sexual functioning.62 For postmenopausal women with lowered sexual desire, there is some evidence that testosterone therapy benefits such patients.63 Although a recent report suggests that many women following oophorectomy have no decline in sexual health, a subset of women with lowered androgen may complain of lowered sexual desire.64 The data are short term, and there is limited safety information regarding its use. Finally there are data that bupropion may have limited “pro-sexual effect.” In both normative subjects and patient cohorts, improvements in desire, arousal, and orgasm were reported after bupropion administration.65 The effects seem independent of antidepressant efficacy.
Sexuality remains an important domain in quality of life in many older patients. The clinician must ascertain whether there is a problem in this sphere of life, and evaluate the nature of the dysfunction and possible etiologic issues. It is essential to include the sexual partner, if available. Treatments include newer biologic agents and psychosocial interventions. Only by comprehensively utilizing a biopsychosocial perspective can an accurate and useful treatment plan be established.
Dr. Wise serves on the speakers bureaus of Pfizer Inc., Eli Lilly and Company, and GlaxoSmithKline, and has received grant support for antidepressant research from Pfizer Inc. and Eli Lilly and Company. He reports no relevant financial interests in any products discussed in this article.
Dr. Crone reports no relevant financial interests.