Obesity may have negative effect on CD4 counts in patients with HIV

Patients with HIV who are obese may be at an increased risk for low CD4 cell counts, according to new research presented at the 47th Annual Meeting of the Infectious Diseases Society of America, held this week in Philadelphia.

The study results seem to contradict previous assumptions about the association between body mass index and CD4 cell counts from the pre-HAART era. At that time, patients with a higher BMI were less likely to experience reduction in their CD4 cell counts over time. But this is not seen among patients treated with HAART. In contrast, the researchers said, patients treated with HAART who were obese had an increased risk of lower CD4 cell counts.

Nancy Crum-Cianflone, MD, MPH, from the Infectious Disease Clinical Research Program in Bethesda, Md., and colleagues examined a cohort of 1,119 patients with HIV who seroconverted between 1986 and 2008. The patients were categorized by BMI: underweight (BMI < 18.5), normal (BMI 18.5 to 24.9), overweight (BMI 25 to 29.9) and obese (BMI > 30). Patients were followed for an average of 4.5 years; changes in BMI and CD4 cell counts during this time were recorded.

Four hundred forty-one (39%) patients in the cohort were overweight at HIV diagnosis; 96 (9%) were obese. Mean CD4 counts at HIV diagnosis were 526, 551, 542 and 499 cells/m3 for underweight, normal, overweight and obese patients, respectively. Results were similar within the pre-HAART and HAART eras.

The results showed that for patients diagnosed in the pre-HAART era, mean post-diagnosis decrease in CD4 count was less as BMI category increased: -158, -125, -95 and -50 cells/mm3, respectively. Among patients diagnosed in the HAART era, the mean post-diagnosis change in CD4 count was -1, +103, +116 and +69 cells/mm3, respectively. The researchers said that compared with normal weight patients with HIV, patients with HIV who were obese had significantly smaller increases in CD4 cell counts.