Impact of syndemic heavy drinking, smoking, and depression on mortality among MSM with and without HIV: A longitudinal study.

Background: Heavy drinking, smoking, and depression are common among men who have sex with men (MSM). The association of co-occurring longitudinal patterns of these conditions and mortality among MSM were tested, applying a syndemic framework - the interaction of two or more conditions that contribute to poor health outcomes.

Methods: Longitudinal data from 1999 to 2018 from the Multicenter AIDS Cohort Study of 3046 MSM were analyzed. Group-based trajectories models (GBTM) of alcohol use, smoking, and depressive symptoms were developed. Syndemic phenotypes were defined based on overlapping high-risk group membership in the GBTM for each condition (i.e., heavy drinking, current smoking, severe depressive symptoms). Cox proportional hazards models estimated confounder-adjusted associations of syndemic phenotypes with mortality (National Death Index, n = 395; median follow-up 16.0 years). An interaction between HIV and syndemic phenotypes on mortality was tested.

Results: Syndemic phenotypes included no high-risk conditions (63 %), heavy drinking only (3 %), smoking only (16 %), depressive symptoms only (10 %), and two or more high-risk trajectories (9 %, sustained syndemic). Among MSM, the syndemic was associated with greater mortality risk compared to no conditions (hazard ratio [HR] 4.48, 95 % confidence interval [CI] 3.21, 6.26) or any single condition (heavy drinking HR 1.84, CI 0.90, 3.75; smoking HR 2.70, CI 2.03, 3.59; depression HR 2.31, CI 1.69, 3.14). The interaction between syndemic phenotype and HIV on mortality risk was significant.

Conclusions: The long-term clustering of high-risk drinking, smoking, and depressive symptoms occurred in nearly 10 % of MSM and was associated with increased mortality risk, especially among MSM living with HIV.