Clinical implication of an impaired fasting glucose and prehypertension related to new onset atrial fibrillation in a healthy Asian population without underlying disease: a nationwide cohort study in Korea

Aims For healthy populations without comorbidities, whether prehypertension and impaired fasting glucose (IFG) are associated with new onset atrial fibrillation (AF) is not well known. Methods and results We included 366 507 subjects (age >= 20 years) not diagnosed with non-valvular AF from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC) from 2003 to 2008. In total, 139 306 subjects diagnosed with AF-related comorbidities were excluded, and a 227 102 healthy population was followed up until 2013. The body mass index (BMI), blood pressure (BP), and fasting blood glucose (BG) level were acquired during National health check-ups. Subjects with IFG [hazard ratio (HR) 1.16, P = 0.017] had a higher AF risk and the diastolic BP (HR 1.11, P = 0.045) was a stronger indicator for an AF incidence than the systolic BP. After dividing the subjects into two mutually exclusive groups, AF incidence was increased dramatically by the combination effect of both prehypertension and an IFG in BMI <25 kg/m(2) group, but, in BMI >= 25 kg/m(2) group, did not show this tendency. An IFG related to AF risk was more prominent in the BMI <25 kg/m(2) population (HR 1.18, P = 0.025) than those with a BMI >= 25 kg/m(2), and subjects with both an IFG and prehypertension had a greater AF risk (HR 1.27, P = 0.016) than those without. Conclusion Even in a healthy Asian populations without comorbidities, prehypertension and IFG were important risk factors of AF. Specifically, when prehypertension, including systolic and diastolic BPs, was finally combined with the IFG, the risk of new onset AF was increased especially in the BMI <25 kg/m(2) group.