Rising Obesity Prevalence and Weight Gain Among Adults Starting Antiretroviral Therapy in the United States and Canada

Abstract

The proportion of overweight and obese adults in the United States and Canada has increased over the past decade, but temporal trends in body mass index (BMI) and weight gain on antiretroviral therapy (ART) among HIV-infected adults have not been well characterized. We conducted a cohort study comparing HIV-infected adults in the North America AIDS Cohort Collaboration on Research and Design (NA-ACCORD) to United States National Health and Nutrition Examination Survey (NHANES) controls matched by sex, race, and age over the period 1998 to 2010. Multivariable linear regression assessed the relationship between BMI and year of ART initiation, adjusting for sex, race, age, and baseline CD4(+) count. Temporal trends in weight on ART were assessed using a generalized least-squares model further adjusted for HIV-1 RNA and first ART regimen class. A total of 14,084 patients from 17 cohorts contributed data; 83% were male, 57% were nonwhite, and the median age was 40 years. Median BMI at ART initiation increased from 23.8 to 24.8 kg/m(2) between 1998 and 2010 in NA-ACCORD, but the percentage of those obese (BMI ≥30 kg/m(2)) at ART initiation increased from 9% to 18%. After 3 years of ART, 22% of individuals with a normal BMI (18.5-24.9 kg/m(2)) at baseline had become overweight (BMI 25.0-29.9 kg/m(2)), and 18% of those overweight at baseline had become obese. HIV-infected white women had a higher BMI after 3 years of ART as compared to age-matched white women in NHANES (p = 0.02), while no difference in BMI after 3 years of ART was observed for HIV-infected men or non-white women compared to controls. The high prevalence of obesity we observed among ART-exposed HIV-infected adults in North America may contribute to health complications in the future.

FIG. 1.

Estimated mean BMI at ART initiation (and 95% confidence interval) for HIV-infected NA-ACCORD participants and age-matched NHANES participants, stratified by sex and race. NA-ACCORD model adjusted for age, CD4⁺ T cell count at treatment initiation, and cohort. *NHANES data reported in 2-year intervals and weighted to match the NA-ACCORD cohort according to CDC guidelines. ART, antiretroviral therapy; BMI, body mass index; NHANES, National Health and Nutrition Examination Survey. Light gray shading represents females and dark gray shading represents males.

FIG. 2.

Predicted mean weight (and 95% confidence intervals) over 3 years after ART initiation, stratified by sex and race in NA-ACCORD, 1998–2010. Model adjusted for age, initial antiretroviral regimen, year of treatment initiation, cohort, and baseline weight, CD4⁺ T cell count, and log₁₀ HIV RNA.

FIG. 3.

Estimated mean weight over the initial 3 years following ART initiation, stratified by year of treatment initiation in NA-ACCORD, 1998–2010. Model adjusted for age, sex, race, initial antiretroviral regimen, cohort, and baseline weight, CD4⁺ T cell count, and log₁₀ HIV RNA. Participants starting ART in 2010 were truncated at 1 year of follow-up.