Underweight is a major risk factor for atrial fibrillation in Asian people with type 2 diabetes mellitus

Background Atrial fibrillation (AF) is prevalent in patients with type 2 diabetes mellitus (T2DM). Obesity commonly accompanies T2DM, and increases the risk of AF. However, the dose-relationship between body mass index (BMI) and AF risk has seldom been studied in patients with diabetes. Methods This cohort study utilized a database from National Taiwan University Hospital, a tertiary medical center in Taiwan. Between 2014 and 2019, 64,339 adult patients with T2DM were enrolled for analysis. BMI was measured and categorized as underweight (BMI < 18.5), normal (18.5 <= BMI < 24), overweight (24 <= BMI < 27), obesity class 1 (27 <= BMI < 30), obesity class 2 (30 <= BMI < 35), or obesity class 3 (BMI >= 35). Multivariate Cox regression and spline regression models were employed to estimate the relationship between BMI and the risk of AF in patients with T2DM. Results The incidence of AF was 1.97 per 1000 person-years (median follow-up, 70.7 months). In multivariate Cox regression, using normal BMI as the reference group, underweight (HR 1.52, 95% CI 1.25-1.87, p < 0.001) was associated with a significantly higher risk of AF, while overweight was associated with significantly reduced risk of AF (HR 0.82, 95% CI 0.73-0.89, p < 0.001). Kaplan-Meier analysis showed AF risk was highest in the underweight group, followed by obesity class 3, while the overweight group had the lowest incidence of AF (log-rank test, p < 0.001). The cubic restrictive spline model revealed a J-shaped or L-shaped relationship between BMI and AF risk. Conclusions Underweight status confers the highest AF risk in Asian patients with T2DM.

Automated summary

The study revealed that underweight status is associated with the highest risk of AF in Asian patients with T2DM, while overweight status is linked to reduced AF risk. The relationship between BMI and AF risk was found to be J-shaped or L-shaped.