Growing old with HIV: The AIDS epidemic and an aging population

Two emerging groups of patients with HIV/AIDS are persons who are infected with HIV and living longer and persons newly infected with HIV at an older age. At the end of 2005, approximately 115,871 persons older than 50 years were living with AIDS in the United States, an estimated 24.3% of the total population of persons living with AIDS, up from 19.9% in 2001.1 In comparison to persons aged 35 to 49 years, older people generally contract the virus through sexual transmission, are mostly male, and are less likely to have contracted the virus through IV drug use.2,3 Overall, the number of older persons living with HIV/AIDS is trend ing upward (see Figure 1). In 2005, the United States Senate Special Committee on Aging predicted that by the year 2015, nearly 50% of persons living with HIV/AIDS will be older than 50 years.4 By and large, this is a reflection on the effectiveness of HAART and its increasing availability.

The percentage of new diagnoses of HIV infection in persons older than 50 years increased from 13.3% to 15.4% of all cases between 2001 and 2005.1 An assumption that older adults are not sexually active is often made. However, Lindau and colleagues found that the prevalence of sexual activity among those aged 57 to 64 years was 73% and declined to 53% among respondents aged 65 to 74 years.5 The increasing availability of oralerectile dysfunction medications that help men enjoy sex at older ages and more often is also a factor in the prevalence of sexual activity among older adults.6

Although most HIV/AIDS cases among older adults occur in men, women are also increasingly becoming infected with HIV/AIDS at an older age.7,8 Between 1990 and 2000, the number of women 50 years and older with a new diagnosis of HIV has more than doubled.9 Few AIDS studies address women in later adulthood; however, numerous risk factors become an issue for these older adults. Zablotsky and Kennedy note HIV risk factors for older women are affected by various biophysical changes such as atrophic vaginitis, changes in sexual behavior after menopause with regard to contraception, and changes in sexual relationships related to marital status (divorced, widowed, etc.).8

When addressing issues related to HIV/AIDS, researchers, policy makers, and even some health care providers often overlook older adults. Hidden infection and delay in diagnosis may be more prevalent because many clinicians do not ask older patients about their sexual activity; therefore, highrisk behaviors are not identified.6 In a recent study of older Americans, only 38% of men and 22% of women reported that they discussed their sex life with their health care provider after reaching age 50 years.5 This highlights the importance of identifying sexual risk factors and the potential for transmission of HIV among older persons.

By not identifying those at risk, health care providers are less likely to test for HIV and thus may delay diagnosis. A delay in making a diagnosis in older adults is shown to have a negative impact on survival.10,11 Those patients who did receive a diagnosis are often receiving HAART. But few studies have focused on the safety of antiretrovirals in older populations, and many risk factors of other medications are certainly of importance in older HIV-infected persons. Decreased renal function and clearance and reduced hepatic function can result in difficulties with drug-related toxicity and tolerability.10

Data on the therapeutic response to HAART in older persons have been mixed. Some studies indicate that survival is shorter in older persons because of compromised immune function,12,13 whereas other studies suggest the response is the same as in younger persons.14,15 Other researchers have suggested that older patients may mount sufficient immunologic and virologic responses with HAART but simply have lower CD4 counts at the time of diagnosis than do younger patients.3 More importantly, however, HAART can significantly improve the survival rate of older adults, and those persons who do not receive antiretroviral therapy have twice the hazard ratio for death than does a younger cohort.16 These findings certainly suggest that delaying or missing a diagnosis places an unnecessary risk on persons who are infected with HIV later in life. Furthermore, Perez and Moore found that older persons who receive HAART have a 72% decrease in hazard ratio for death compared to older untreated persons.16 Again, this illustrates the importance of making an early diagnosis and initiating appropriate therapy in older persons.

COMORBIDITIES: IS IT HIV OR AGING?

An emerging challenge in diagnosing HIV/AIDS in older persons is the difficulty in deciphering the signs and symptoms of infection, which may mimic those of aging. Older patients with HIV infection may present with lymphadenopathy, fatigue, chest infection, confusion, weight loss, and rashes.6 Many of these same symptoms are associated with aging. The Veterans Aging Cohort 3 Site Study and HIV Cost and Service Utilization Study demonstrated that older persons with HIV infection reported fewer symptoms to health care providers than did their younger counterparts.17 These symptoms included diarrhea, white oral patches, sinus trouble, headache, fever, chills, nausea, vomiting, and complaints of “feeling down.” Older persons are more likely to report neuropathic and weight loss symptoms. Chiao and colleagues reviewed the literature and found that older patients with HIV infection presented with atypical dermatologic findings, malignancies, and new-onset dementia.11 In addition, ongoing research is showing that HIV and the associated effects of HAART can manifest in a variety of ways.15,18 Unique changes in neurocognition and metabolic and hormonal disturbances that mimic aging are being seen in HIV-infected persons at a younger age than would be seen in the general population.

Neurocognitive effects Recently, a number of studies have begun to examine the cognitive effects of HIV and HAART in older persons. As HIV-infected persons live longer, the lines between cognitive changes, such as dementia, induced by therapy and viral effects and those changes caused by the natural effects of aging begin to blur. HIV-associated dementia (HAD) is a subcortical disorder that affects mostly the white matter and glia, with patients typically exhibiting slower response times and psychomotor speed, poor cognitive flexibility, and emotional lability.18,19 Cortical disorders, such as Alzheimer's disease, usually show a global deterioration in intellect and cerebral atrophy in later stages, both of which are uncommon in persons with HAD. In contrast to other types of dementia, studies have demonstrated that temporal fluctuations in cognitive deficits are often seen in patients with HAD, most likely because of the varying levels of viral suppression.20

As a group, persons with HIV/AIDS who live longer are beginning to overlap into an age-group where Alzheimer's disease is common, thus complicating the clinical picture. Research has shown that the neuropsychologic changes seen in aging are similar to those seen in younger patients with AIDS.21 Older patients with HIV infection are proven to have an increased risk of HAD.22 Studies indicate that HAART may also be creating a phenomenon that may be an additional risk factor for Alzheimer's disease. Immune reconstitution syndrome is an autoimmune condition in which new T-cell populations attack opportunistic pathogens that flourished under a previously suppressed T-cell HIV state and causes connective tissue disorders and vasculitis.19 The lipodystrophic and metabolic effects of HAART medications can also lead to known Alzheimer's disease risk factors such as hyperlipidemia, coronary artery disease, and insulin resistance.19 Another potential risk factor for Alzheimer's disease is the build-up of amyloid levels in the brain.23,24 However, Larussa and colleagues found that HAART appeared to have a neuroprotective effect on HAD progression in patients with HIV/AIDS.25 These researchers demonstrated that HAD prevalence was 27.3% in the patients who were not treated compared to 11.9% in the patients who did receive HAART therapy.25 If further research verifies these potential effects of HAART medications, the difference between age-related dementia and HAD will continue to diminish as the HIV-infected population grows older.

Metabolic and hormonal disorders In addition to cognitive changes caused by HIV and antiretroviral therapy, many metabolic and hormonal changes that can occur mimic those caused by normal aging. A number of studies have shown that both the disease and antiretroviral therapy increase the risk for osteopenia, hypogonadism, diabetes mellitus, and dyslipidemia.26-30 Determining whether these changes are caused by aging or HIV infection can be a challenge.

Two common metabolic and hormonal changes that affect middle-age and older women are bone loss and menopause. Osteopenia and osteoporosis have been reported in both men and women as a result of HIV alone, making these conditions an important consideration in older HIV-infected persons.27 Common therapies among the general population for these disorders, such as alendronate (Fosamax) and combination vitamin D and calcium, have demonstrated effectiveness in HIV-infected men and women.31 In addition to a postmenopausal increase in risk of osteopenia, studies indicate that nearly 50% of HIV-infected women reach menopause by age 46 years—4 to 6 years earlier than the general population.30,32 This may be attributed only in part to HIV; other factors such as socioeconomic status, tobacco use, and disadvantaged minority status are all common elements of the HIV epidemic in women and are associated with earlier onset of menopause.30,32

The potential for immune reconstitution syndrome certainly poses a risk for increased lipid abnormalities and decreased glucose tolerance, but risk for cardiovascular disease is also increased. Studies have shown that persons receiving combination antiretroviral therapy had a 26% relative increase in the rate of MI per year of use in comparison to the MI rate in persons not on antiretroviral therapy.28 Other risk factors that can contribute to vascular changes and dementia have also been demonstrated.33,34

IMPLICATIONS FOR QUALITY OF LIFE

Shippy and Karpiak poignantly state that the goal in the first 2 decades of the HIV/AIDS epidemic was to “keep people alive and healthy” with cutting-edge therapies; but goals for the third decade should focus on the quality of the extended life that older persons infected with HIV now have.35 PAs can play an important role in differentiating the signs and symptoms of HIV infection, the effects of HAART, and the effects of aging. Obtaining a good sexual history in older patients is a simple but effective step in HIV screening that can potentially lead to an early diagnosis. It is important to distinguish between subcortical and cortical signs of dementia in order to identify the etiology of the dementia and avoid a delay in making a diagnosis; this distinction is also important for disease management. Many simple screening tools used in the general population may also be effective in HIV patients. For example, data shows that screening with the Framingham risk factors is effective for identifying cardiovascular disease risks and initiating appropriate therapy in HIV-infected persons.36

Health care providers who routinely care for older patients understand that much of disease management in this population focuses on improving quality of life through decreasing disability, as opposed to resolving disease states. This is true in HIV-infected persons as well. Research shows that antiretroviral therapy does improve patients' quality of life when managed well.37,38 The patient-provider relationship plays a significant role, specifically in regard to providing patientcentered disease management and patient adherence to therapy.39 Given the dynamics of our society, ageism, and the stigma of an HIV diagnosis, the social networks commonplace among younger HIV-infected patients may not be as effective for older patients.35,40 An excellent provider and patient resource for information on HIV/AIDS in older persons is the National Institute on Aging Web site's Age Page: HIV, AIDS, and Older People (www.nia.nih.gov/HealthInformation/Publications/hiv-aids.htm).

CONCLUSION

The long-term effects of disease management on the aging population are something that both health care providers and policy makers often overlook. A review of the literature demonstrates that this is especially true with older persons with HIV/AIDS. Important epidemiologic and clinical differences exist between younger and older HIV-infected persons. Health care providers need to address the issues of sexuality in our older patients and the similarity between the conditions associated with HIV and those of aging, such as dementia. Current research is demonstrating just how blurred the lines between HIV and aging etiologies can become in older patients.19

To address this and other emerging issues, further research is needed on the long-term effects of antiretroviral therapy, HAD, and the many metabolic and hormonal changes that occur in HIV-infected persons. These studies need to identify cohorts of older persons because clinicians must delineate the lines between HIV and aging. Lifelong trends in sexual and social behaviors should also be examined so that at-risk behaviors, social trends, and public policy can be appropriately addressed. For some clinicians, a discussion of HIV with an older patient can feel foreign. An emerging challenge for health care providers is to find ways to better meet the needs of an aging HIV-infected population. JAAPA

Jeffrey Myers works at the Siskiyou Community Health Center, Cave Junction, Oregon. He has indicated no relationships to disclose relating to the content of this article.

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