Morbidity and mortality in alcohol use disorder: the role of comorbid substance use disorder, age, sex, and the A1 allele of the Taq1A (rs1800497) polymorphism in the ANKK1 gene in an 18-year follow-up.

Abstract

Background and aims: The present study aimed to: (i) compare a patient group with solely alcohol use disorder (AUD) to a group with poly-substance use disorder (poly-SUD) regarding sociodemographic background, morbidity, mortality, and the prevalence of the A1 allele of the Taq1A polymorphism. (ii) Investigate whether gender, age, poly-SUD, and the prevalence of the A1 allele or interactions among these factors, are associated with mortality risk over an 18-year follow-up period.

Methods: This study comprised 360 individuals treated for severe alcohol withdrawal symptoms in 1997 at a treatment unit in Sweden. Genotyping was performed during their hospital stay, and participants were followed annually for up to 18 years using data from Swedish registers.

Results: Fifty-three percent of the participants had died over the 18 year period. Poly-SUD patients exhibited higher rates of psychiatric disorders, gastrointestinal diseases, and intoxication as the primary diagnosis. Patients with AUD exhibited a higher prevalence of cardiac diseases. Traumatic causes of death were more prevalent in the poly-SUD group, whereas somatic diseases were more common among individuals with AUD. Male sex and age were the strongest predictors of premature death among individuals with AUD. The A1 allele of the Taq1A polymorphism showed a borderline association with an increased hazard of death.

Conclusions: Male sex and age are the strongest predictors of premature death. Patients with poly-SUD may represent a distinct subgroup with different comorbidities and causes of death. To determine whether there is a genetic vulnerability as indicated by the findings, research using larger samples with sufficient statistical power is needed.