Combined alcohol use and weight status effects on mortality risk among adults: Analysis of the National Health Interview Survey linked mortality files, 2001-2015.

BACKGROUND: Both alcohol use and weight status have been linked to increased mortality risk, but evidence of their joint effect is limited. The goal of this study was to examine the combined effects of alcohol and weight status (BMI classes: underweight, normal, overweight, obesity) on mortality using nationally representative data.

METHODS: Using data from public-use National Health Interview Survey-Linked Mortality Files (NHIS-LMF), 2001-2011, linked to prospective mortality follow-up through December 2015, we used age-period-cohort Cox proportional hazards models to examine all-cause and cause-specific mortality associated with the joint effects of alcohol use and BMI on 209,317 individuals aged 35-85.

RESULTS: Individuals with an underweight BMI status had higher all-cause and cause-specific mortality risks than those with a normal BMI status and light/moderate alcohol intake. All-cause mortality risks were 148% (hazard ratio [HR] 2.48, 95% CI 1.60-3.83) higher in underweight heavy drinkers than light/moderate drinkers with normal BMI status. Obese heavy drinkers had a 16% higher chance of dying from all-cause mortality (HR 1.16, 95% CI 1.00-1.35). Individuals in the unknown alcohol and BMI category have a higher chance of death from all-cause (HR 1.35, 95% CI 1.14-1.59) or cause-specific (CVD HR 1.75, 95% CI 1.14-2.69 and Cancer HR 1.33, 95% CI 1.01-1.76).

CONCLUSIONS: Alcohol drinking levels result in heightened all-cause and cause-specific mortality risks; the risks are compounded among underweight, obese, and unknown BMI individuals across all or cause-specific mortality.