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. Journal of Acquired Immune Deficiency Syndrome
Achhra et al. on behalf of the D:A:D Study Group aimed to assess the relationship between latest body mass index (BMI) and the subsequent risk of various serious non-AIDS events (SNAEs) and all-cause mortality. The endpoints were cardiovascular disease (CVD); diabetes; non–AIDS-defining cancers (NADCs) and BMI-NADCs (i.e., cancers known to be associated with BMI in general population), and all-cause mortality.
A total of 41’149 individuals with 295’147 person-years of follow-up (PYFU) for the all-cause mortality outcome were included. Participants were largely male (73%) with the mean age of 40 years and baseline median BMI of 23.3. 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 compared with 23–25, respectively, was as follows: CVD: 1.46 and 1.31; NADCs: 1.78 and 1.17 and “BMI-NADCs”: 1.29 and 1.92. For all-cause mortality, there was an interaction by sex (P <0.001): RR in males: 2.47 and 1.21 and in females: 1.60 and 1.02. RR remained around 1 for intermediate categories of BMI. The risk of diabetes linearly increased with increasing BMI (P <0.001).
In summary, the authors found that low BMI was associated with high risk of several individual SNAEs as well as all-cause mortality. The relative risk of SNAEs and mortality did not increase at intermediate/moderately high BMI (around 23–30) and only tended to increase at BMI >30. These findings suggest that BMI of 25–30, thought to be “overweight/mildly obese” in general population, may in fact confer some survival advantage in HIV-positive individuals. Also, these findings seem to suggest that obesity at BMI >30 is likely harmful in the long term even in HIV-positive individuals. Future studies should assess how short-term and long-term changes in BMI relate to the risk of SNAEs. Ultimately, whether change in BMI or weight gain or loss interventions (depending on current BMI) would actually improve outcomes in this population will need trials on carefully designed behavioral and nutritional interventions.