Body Mass Index and The Risk of Serious Non-Aids Events and All Cause Mortality in Treated Hiv-Positive Individuals: D: A: D Cohort Analysis

BACKGROUND: The relationship between body mass index (BMI) (weight (kg)/ height(m)) and serious non-AIDS events is not well understood.

METHODS: We followed D:A:D study participants on antiretroviral therapy from their first BMI measurement to the first occurrence of the endpoint or end of follow-up (N=41,149 followed for 295,147 person-years). The endpoints were cardiovascular disease (CVD); diabetes; non-AIDS-defining cancers (NADCs) and BMI-NADCs (cancers known to be associated with BMI in general population); and all-cause mortality. Using poisson regression models, we analysed BMI as time-updated, lagged by 1 year, and categorized at: 18.5, 23, 25, 27.5 and 30 kg/m.

RESULTS: Participants were largely male (73%) with the mean age of 40 years (SD 9.7) and baseline median BMI of 23.3 (IQR: 21.2-25.7). Overall, BMI showed a statistically significant J-shaped relationship with the risk of all outcomes except diabetes. The relative risk (RR) for the BMI of <18.5 and >30 (95% CI) compared to 23-25, respectively, was as follows: CVD: 1.46(1.15-1.84) and 1.31(1.03-1.67); NADCs: 1.78(1.39-2.28) and 1.17(0.88-1.54); 'BMI-NADCs': 1.29(0.66-2.55) and 1.92(1.10-3.36). For all-cause mortality, there was an interaction by gender (P<0.001): RR in males: 2.47(2.12-2.89) and 1.21(0.97-1.50); and in females: 1.60(1.30-1.98) and 1.02(0.74-1.42). RR remained around 1 for intermediate categories of BMI. The risk of diabetes linearly increased with increasing BMI (P<0.001).

CONCLUSIONS: Risk of CVD, a range of cancers, and all-cause mortality increased at low BMI (<18.5) and then tended to increase only at BMI>30 with a relatively low risk at BMI of 23-25 and 25-30. High BMI was also associated with risk of diabetes.