The Aging Face Of AIDS

Jeffrey T. Lauer, M.D.
Jeffrey Lauer, M.D. is a Senior Infectious Disease Fellow with
the University of Florida Health Science Center / Jacksonville.

Since its first appearance in the 1980s, the acquired immune deficiency syndrome (AIDS) has affected persons of all ages. Initially considered a gay lifestyle disease, it has spread to all segments of society. Initial epidemiological studies estimated approximately 10% of the AIDS population at 50 years of age or older.^1-4 This has not significantly changed with the CDC 1996 data indicating 11%.⁵ AIDS in the older population had been attributed to blood transfusions rather than to homosexual exposure or drug abuse.^1,2,4,6,7 Through 1989, receipt of contaminated blood or blood products accounted for only 1% of cases among persons 13-49 years; in comparison, this risk accounted for 6%, 28%, and 64% of cases among persons aged 50-59 years, 60-69 years, and greater than or equal to 70 years, respectively.⁵ The advent of blood screening for HIV has been a major determinant in the shift of risk for acquiring HIV in the older population and represented only approximately 2% of the HIV exposure category in 1996.⁵ As the risk and proportion of exposure to transfusion related disease has declined, the other risk categories have subsequently increased maintaining the same incidence of disease. In fact, this shift has now identified sexual contact, either homosexual or heterosexual, as the major risk for this population. Older Americans often lead active, vigorous lives, in which unsafe sexual activity may occur.^6,8 The introduction of silbenafil (ViagraŽ) may now allow older adults to increase their sexual activity. Thought to be at low risk and no need for pregnancy prevention, the elderly are the least likely to practice HIV preventive measures.⁹ Another issue is the disproportionate number of elderly women compared to men, and it is not unusual for an older man to have multiple sexual partners.⁶ Heterosexual women are one of the fastest growing groups of AIDS patients nationwide, and this trend is similarly observed in the older female population.¹⁰ At risk older adults are approximately one-fifth as likely as at-risk younger adults to have undergone HIV testing and about one-sixth as likely to use a condom during sex.¹¹

It was also reported that progression to AIDS in this population was quicker and the initial mortality greater.^4,12,13 The immune alterations that occur in normal aging were proposed to explain these observations that older HIV infected patients often presented with more advanced disease, a more rapid course and a shorter survival time after diagnosis.^12,14 Normal aging of the immune system does include a loss of T-cell proliferation ability, a loss of delayed hypersensitivity skin reaction to antigens, a decrease of antibody diversity and avidity and a change in the elaboration of certain lymphokines.¹² The trends are still suggested by current data that report older adults are more likely to be reported with an AIDS opportunistic infection then just with severe immunosuppression without an opportunistic infection; and that they are more likely to die within 1 month of their AIDS diagnosis compared to younger adults.⁵

The aging immune system is not the only reason for this group generally having worse disease. The failure to identify and test in this group because of perceived low risk by both the patient and physician is another major factor.^6,7,10,15 Older persons may be less knowledgeable about HIV and AIDS with the mistaken belief that HIV is a disease of the young or middle aged. Physician awareness that the elderly are also at risk for this infection is also lacking,⁹ and the disease is misdiagnosed in older people.⁶ This lack of recognition is dangerous, as older Americans are the most rapidly increasing population subgroup in the US.

HIV testing is usually performed under three circumstances: 1) as part of a targeted population survey; 2) in individuals with risky behavior (e.g. substance abuse, homosexual and bisexual men, those with multiple sexual partners, and those with sexual contact with an HIV-infected individual); and 3) in individuals with clinical presentations consistent with HIV infection.¹⁵ This strategy has been successful for the younger at risk adults, but may miss the atypical presentations of the older at risk population. Often the clinical presentation of HIV infection in the elderly does not differ from that of younger adults, but the symptoms of fatigue, anorexia, weight loss, and memory problems are nonspecific and mimic other common geriatric problems.^8,12 The characteristic AIDS-defining opportunistic infections have similar prevalence rates regardless of age. The most frequent cause of morbidity and mortality in older patients with HIV is bacterial pneumonia. This pneumonia is usually caused by encapsulated organisms such as Haemophilus influenzae and Streptococcus pneumoniae.⁹ There is also an increased age-specific infection rate for Mycobacterium tuberculae^9,16 as well as the varicella zoster virus in the elderly.^9,16 Besides infection, the most significant cause of morbidity in elderly AIDS patients is neurological disease.⁹ Often confused with Alzheimer's disease, HIV-related dementia may be the presenting manifestation of HIV infection. AIDS dementia complex is a subcortical dementia characterized by decreased attention and concentration, apathy and social withdrawal, and psychomotor retardation. It progresses more rapidly (over months) compared to Alzheimer's disease and is more often associated with peripheral neuropathies, myelopathies, and general physical complaints. HIV-associated cognitive abnormalities may improve with anti-retroviral therapy.

Epidemiologic trends in the South indicate that Florida accounts for 34% of the 641,086 AIDS reported cases through 1997, and that rural AIDS cases and those among men of lower socioeconomic status are susbstantial in this region.¹⁷ Sexual behavior is still the most common risk for exposure to HIV.^16,17 Data are available for the older US population from 1991 through 1996,⁵ and of the 68,473 adults reported with AIDS, 7,459 (11%) were aged greater than or equal to 50 years. Males accounted for 85% of cases, and blacks accounted for the highest proportion (43%) by race/ethnicity. The highest proportion of cases by risk category was for men who have sex with men (36%). Of particular concern for this older population is the proportion that had no risk reported (26%). This may indeed highlight the ongoing lack of awareness of risk behavior by older patients and possibly their providers. Furthermore, many patients may present after long incubation periods.¹⁸

The demographics of HIV in the elderly of Duval County are somewhat reflective of state and national trends. At Boulevard Comprehensive Care Center (BCCC), The Infectious and Communicable Diseases Clinic of the University of Florida and Duval County Health Department, of 1350 HIV positive patients followed, 201 or 14.9% are over age 50. As shown in Figure 1, 56% of the elderly patients are black men, 21% black women, 19% white men and 4% white women. Figure 2 shows the risk factors identified for acquiring HIV by sex and race. In black men and women, it can be seen that the most frequent identified risk is heterosexual or unknown (heterosexual or non-admitted IVDU or homosexual) transmission.

Figure 1. Racial Demographics of 201 Elderly HIV+ Patients at BCCC	Figure 2. Risk Factors for HIV Acquisition in the Elderly HIV Population at BCCC

With the development of new anti-retroviral agents and the initiation of HAART as the standard of care, the pharmacologic considerations in the older HIV-infected adults taking numerous other medications are often complex. Some researchers have suggested that HIV may soon be considered a chronic process much like diabetes or hypertension. Likewise, targeted information about HIV disease in this population is also lacking. As effective therapies keep HIV infected adults alive longer, the complications of long -term antiretrovirals will be seen in an aging adult population. One such effect has been noted with protease inhibitors in the development of hyperglycemia, hyperlipidemia, and the lipodystrophy syndrome. The side effects tolerated in the young may complicate the care of the elderly with existing diabetes, hypertension, peripheral vascular disease and coronary artery disease.

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Jacksonville Medicine / August, 1999