Short‐term weight gain after antiretroviral therapy initiation and subsequent risk of cardiovascular disease and diabetes: the D : A : D study

Objectives The aim of the study was to assess the impact of the gain in body mass index ( BMI ) observed immediately after antiretroviral therapy ( ART ) initiation on the subsequent risk of cardiovascular disease ( CVD ) and diabetes. Methods We analysed data from the Data Collection on Adverse Events of Anti‐ HIV Drugs ( D : A : D ) cohort study. Outcomes were development of (i) CVD (composite of myocardial infarction/stroke/coronary procedure) and (ii) diabetes. The main exposure variable was change in BMI from ART initiation (pre‐ ART ) to 1 year after initiation (continuous variable) in treatment‐naïve individuals initiating ART with no history of CVD or diabetes (for respective outcomes). BMI [weight (kg)/(height (m)) 2 ] was categorized as underweight (< 18.5), normal (18.5–25), overweight (25–30) and obese (> 30). Poisson regression models were fitted stratified for each pre‐ ART BMI category to allow for category‐specific estimates of incidence rate ratio ( IRR ). Models were adjusted for pre‐ ART BMI and CD4 count, key known risk factors (time‐updated where possible) and calendar year. Results A total of 97 CVD events occurred in 43 982 person‐years ( n  = 9321) and 125 diabetes events in 43 278 person‐years ( n  = 9193). In fully adjusted analyses for CVD , the IRR /unit gain in BMI (95% confidence interval) in the first year of ART , by pre‐ ART BMI category, was: underweight, 0.90 (0.60–1.37); normal, 1.18 (1.05–1.33); overweight, 0.87 (0.70–1.10), and obese, 0.95 (0.71–1.28) ( P for interaction = 0.04). For diabetes, the IRR /unit gain in BMI was 1.11 (95% confidence interval 1.03 to 1.21), regardless of pre‐ ART BMI ( P for interaction > 0.05). Conclusions Short‐term gain in BMI following ART initiation appeared to increase the longer term risk of CVD , but only in those with pre‐ ART BMI in the normal range. It was also associated with increased risk of diabetes regardless of pre‐ ART BMI .