Hypertension in a Post-AIDS World
People living with HIV who successfully access care and are adherent to antiretroviral therapy (ART) decrease their risk for AIDS-related complications, and those who enter care with higher CD4 cell counts have the potential for near-normal life expectancy. Indeed, the proportion of people over age 50 years living with HIV is increasing: this group represents nearly 50% of HIV-positive persons in the United States and 10% in sub-Saharan Africa.

It is in this post-AIDS world that providers have to face a different spectrum of noncommunicable diseases -- a world of growing rates of multiple comorbidities of serious mental illness; cancer; and hepatic, renal, bone, and cardiovascular diseases. The need for an increased focus on comorbidities is clear: Although previous studies have shown that rates of many complications decrease with ART use, rates of such complications may increase with the duration of HIV survival. A presentation by Giovanni Guaraldi and colleagues at the 4th International Workshop on HIV and Aging suggested that the rates of multiple comorbidities and non-AIDS complications were higher in longer-term survivors of HIV.

There is considerable interest in cardiovascular disease (CVD) and HIV, because multiple cohort studies have revealed that HIV-positive populations have higher rates of CVD than do HIV-negative comparative groups. Specifically, studies have shown that about 1 in 5 people living with HIV have hypertension -- rates that are higher than those seen in the general age-matched population. As in the general population, the presence of hypertension in HIV patients is associated with increased risk for end-organ injury, including cardiovascular events, suggesting that methods to identify key risk factors and implement preventive strategies are sorely needed.

In this context, the report by Krauskopf and colleagues in the current issue of the Journal of the International Association of Providers of AIDS Care offers relevant insight. Using data from the Longitudinal Study of the Ocular Complications of AIDS, they set out to distinguish between HIV disease- or treatment-specific factors and general factors when considering the risk for hypertension among HIV-positive individuals.

The clinical value of this knowledge is clear: If HIV infection or ART affects the risk of developing noncommunicable diseases, then earlier initiation of ART or modification of the treatment regimen might affect the presence of the comorbidity. By contrast, if risk is independent of HIV or HIV therapies, then risk-reduction strategies recommended for the general population would also be appropriate interventions for the HIV-infected population.

The prospective, observational study was started in 1998; by the end of 2011, 2390 individuals with a previous Centers for Disease Control and Prevention category C AIDS diagnosis were enrolled. Patients were followed for a median of 6.5 years, with researchers systematically capturing clinical events about HIV course, AIDS-related and non-AIDS-related medical conditions, and ART use. Since 2005, data on weight, blood pressure, cigarette smoking, and cardiovascular events were also collected. Eighty percent of patients were male, 45% were non-Hispanic white, and about two thirds were between the ages of 40 and 59 years.

Across the study cohort, 22% of patients had hypertension. In adjusted models, the risk for prevalent hypertension increased about 2-fold with each 10 years of age, diabetes, hyperlipidemia, and black race. Of note, nadir CD4 count, ART class, hepatitis C infection, and history of cytomegalovirus infection were not associated with prevalent hypertension. Incident hypertension was about 64 cases per 1000 years and was associated in adjusted models with increasing age, black race, higher weight, and diabetes. Similar to prevalent hypertension, HIV-associated factors, including time since AIDS diagnosis, CD4 count, HIV viral load, ART use, and hepatitis C infection, were not associated with incident hypertension.

On the basis of these data, the authors concluded that hypertension was common in this population of people who survived an AIDS complication, but hypertension risk was associated with the same factors as seen in the general population, not with those associated with HIV or HIV therapies.

For practicing clinicians, the report by Krauskopf and colleagues suggests that in the case of hypertension, the principles of preventive medicine that apply to the HIV-negative population should also be applied to the HIV-positive population.