Care of the aging HIV patient
ABSTRACTThanks to antiretroviral therapy, human immunodeficiency virus (HIV) infection has become a controllable chronic disease, and many infected patients are now living into their 60s and beyond. In addition, many patients with newly diagnosed HIV infection are over age 50. The subsequent rising prevalence of HIV infection in older adults presents several challenges for primary care clinicians. This article promotes increased HIV screening in older adults and highlights the need to recognize polypharmacy and the various comorbidities inherent in the aging HIV population.
KEY POINTS
- Today, nearly 20% of newly diagnosed HIV-infected people and more than 50% of all HIV-infected people in the United States are over age 50.
- The diagnosis and treatment of HIV tends to be delayed in elderly patients, with deleterious effects.
- Antiretroviral drugs have a number of interactions with drugs commonly used in elderly patients.
- Several diseases are more common in HIV-positive patients, including cardiovascular disease, diabetes mellitus, osteoporosis, dementia, and various malignant diseases. These merit aggressive screening and preventive measures.
ENDOCRINE DISEASE
Diabetes mellitus
The estimated prevalence of diabetes mellitus is 3% in HIV-infected people who have never received antiretroviral therapy, but glucose intolerance increases to the range of 10% to 25% in those who have started it.45 Glucose disorders are associated with traditional risk factors as well as with HIV-associated factors such as lipodystrophy and antiretroviral therapy, specifically long-term use of protease inhibitors.46 Although increasing age and obesity clearly play a role in the development of diabetes mellitus in this population, HIV-specific factors may also allow diabetes to develop at a lower level of adiposity than in people without HIV infection.47
Strategies for preventing type 2 diabetes mellitus in HIV-infected patients focus on avoiding excessive weight gain, especially after starting antiretroviral therapy; regularly screening for diabetes using hemoglobin A1c, both before and after starting antiretroviral therapy; and continuing to check hemoglobin A1c every 6 months. The target hemoglobin A1c should be less than 7.0%. This threshold should be increased to 8% in frail elderly adults if their anticipated life expectancy is less than 5 years, given their higher risk of hypoglycemia, polypharmacy, and drug interactions.48 In addition, as in HIV-negative patients, diabetes screening should be performed if systolic blood pressure exceeds 135/80 mm Hg.
Insulin sensitizers such as metformin and thiazolidinediones should be considered for treating diabetes in HIV-infected patients if no contraindications exist. Consideration may also be given to switching the antiretroviral regimen from a protease inhibitor-based regimen to a nonnucleoside reverse transcriptase inhibitor-based regimen.48
Take-home points
- Glucose intolerance has been associated with HIV-specific factors, including lipodystrophy and antiretroviral therapy.
- Avoiding excessive weight gain, use of insulin-sensitizing medications, and alteration in antiretroviral regimens should be considered for the treatment of diabetes mellitus in HIV infection.
Osteoporosis
Osteoporotic bone disease disproportionately affects patients with advanced HIV infection compared with patients of similar age.49 Bone mineral density is lower and the fracture rate is higher in HIV-infected individuals.
The pathogenesis of bone disease appears to be multifactorial. Traditional risk factors include hypogonadism, smoking, alcohol use, and low body weight, while HIV-related risk factors include chronic immune activation and antiretroviral therapy.50
Several antiretroviral regimens have been linked to clinically significant bone loss, including both tenofovir-based and protease inhibitor-based regimens.51 Most studies have shown that bone mineral density decreases by 2% to 6% in the first 2 years after starting these regimens52; however, long-term effects on bone loss are unknown.
Questions remain. For example, what are the exact mechanisms that lead to the acute decrease in bone mineral density after starting antiretroviral therapy? And why is vitamin D deficiency is so prevalent in HIV infection, with low vitamin D levels seen in up to 60% to 75% of elderly HIV-infected patients?53
Both the Work Group for the HIV and Aging Consensus Project54 and the European AIDS Clinical Society43 recommend screening for and treating causes of secondary low bone mineral density in HIV-infected men over age 50 and postmenopausal HIV-infected women. These causes include vitamin D deficiency. As of 2013, the National Osteoporosis Foundation guidelines include HIV infection and antiretroviral therapy as osteoporosis risk factors that should trigger screening for low bone mineral density with dual-energy x-ray absorptiometry (DXA).55
As in the general population, the preferred treatment for low bone mineral density in people with HIV is a bisphosphonate, in addition to ensuring adequate calcium and vitamin D intake. It is important to repeat DXA imaging every 2 years and to reassess the need for continued bisphosphonate therapy after 3 to 5 years because of a possible increased risk of fracture with prolonged use.
Take-home points
- Osteoporosis and vitamin D deficiency both appear to be more prevalent with HIV infection.
- HIV infection and antiretroviral therapy are risk factors that should prompt DXA screening to evaluate for osteoporosis.
