Underweight and the Risk of Atrial Fibrillation in the Asian Population

While previous studies suggest a higher incidence of atrial fibrillation (AF) among underweight individuals, this association remains underexplored in Asian populations. We aimed to systematically assess this relationship in Asians.

The association between genetically predicted underweight (using summary GWAS data from the Korean Genome and Epidemiology Study Consortium) and AF (using data from BioBank Japan) was assessed using a two-sample Mendelian randomization analysis. A pooled analysis of cohort studies from PubMed, EMBASE, and Web of Knowledge was conducted to examine the relationship between underweight [body mass index (BMI) <18.5 kg/m2] and AF risk in Asians.

The genetically predicted underweight showed a significant causal relationship with AF (odds ratio: 1.91, 95% CI: 1.51, 2.42, p value = 7.51E-08). The meta-analysis included six cohort studies involving 427,844 participants, 27,273 of whom were classified as underweight. Compared with normal weight, underweight was associated with a 31 percent greater risk of AF (RR: 1.31; 95% CI: 1.13, 1.51). The dose-response analysis revealed that each 1-unit decrease in BMI was associated with a 6 percent higher risk of AF (95% CI: 1.04, 1.09) in individuals who were underweight.

Our findings, supported by both genetic and observational results, suggest that underweight is a risk factor for AF. Further research is needed to determine whether these results apply to populations outside of Asia. Additional clinical trials are required to explore whether addressing underweight can help prevent new-onset AF or recurrence after ablation.

Our findings suggest that in Asian populations, underweight individuals have a higher risk of AF.