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

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. 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. 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. 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. •Syndemic drinking, smoking, and depression affected nearly 10 % of MSM.•The syndemic was associated with 4x the mortality risk compared to no syndemic.•The syndemic mortality risk was greater than that of any one condition.•The interaction between syndemic phenotype and HIV on mortality risk was significant.