Relationship Between CD4 Counts, Hypertension in Patients with HIV

Christian Aken Dimala, MD, Public Health Researcher at the Johns Hopkins Bloomberg School of Public Health

Christian Aken Dimala, MD

With the more recent availability of highly active antiretroviral therapy (HAART), patients living with HIV/AIDS are living longer, healthier lives. This increase in life expectancy is also associated with an increase in noncommunicable diseases among patients with HIV/AIDS, including cardiovascular disease (CVD).

Hypertension in patients with HIV/AIDS is a complex disease state. While low CD4 counts have been associated with hypertension, HAART, which will ultimately result in higher CD4 counts, has been linked to accelerated atherosclerotic changes the could also lead to hypertension.

Body mass index (BMI) is another potentially confounding variable, with higher BMIs correlating with increased incidence of hypertension in immunocompetent patients. Patients living with HIV/AIDS, however, tend to have lower BMIs, further complicating the relationship between HIV/AIDS, CD4 counts, BMI and hypertension.

Christian Aken Dimala, MD, Public Health Researcher at the Johns Hopkins Bloomberg School of Public Health, conducted a recent study to further elucidate this relationship.

“The aim of this study was therefore to assess if there is an independent relationship between CD4 cell count and hypertension in HIV/AIDS patients and if this association is modified or confounded by the BMI,” wrote Dimala.

This study was a secondary analysis of data from a cross-sectional study of HIV-infected patients receiving care at the HIV treatment center affiliated with the Limbe Regional Hospital in Cameroon. Patients were included in the study if they were 21 years or older and had no previous history of hypertension, diabetes or renal disease. Half of the patients had been on HAART for at least 12 months, while the other half were HAART-naïve. Patients were excluded from the study if they were nonadherent to HAART for more than 6 months or if they were taking corticosteroids, oral contraceptives or any medications known to affect blood pressure.

A total of 200 patients were included in the study, 70% were female, and the mean age was 39.1 years. Each patient underwent a physical examination, took part in a face-to-face interview, and completed a structured questionnaire to collect sociodemographic and clinical characteristics. Patients self-reported some data while other information was acquired from medical records.

Contrary to expectation, the study revealed no linear relationship between CD4 count and blood pressure after adjusting for BMI, and there was no statistically significant difference in the CD4 count between patients with and without hypertension.

“These observed discrepancies in the study findings suggest hypertension results from a more complex interplay of several environmental and genetic predisposing factors,” noted Dimala.

Dimala noted that the cross-sectional nature of the study limited their ability to ascertain causality. He suggested that a prospective cohort would be a superior study design for future investigations into the relationship with CD4 count, BMI and hypertension. In addition, Dimala pointed out that it might not be possible to generalize the study results to other demographically different populations.

The study, “Association between CD4 Cell Count and Blood Pressure and Its Variation with Body Mass Index Categories in HIV-Infected Patients,” was published in January in the International Journal of Hypertension.