HP-574-04 ASSOCIATIONS BETWEEN OBESITY PARAMETERS AND THE RISK OF INCIDENT ATRIAL FIBRILLATION AND ISCHEMIC STROKE IN DIFFERENT AGE GROUPS: A NATIONWIDE POPULATION-BASED STUDY

Abstract

Atrial fibrillation (AF) and ischemic stroke (IS) are two representative cardiovascular diseases. They share common metabolic risk factors such as obesity and ageing is an important predisposing factor. Limited data comprehensively evaluated the relationship between obesity measurements - body mass index (BMI) and waist circumference (WC) - and incident AF and IS in the different age groups. We investigated the risk of AF and IS according to body mass index (BMI) and waist circumference (WC) stratified by age. We included 9,432,332 adults who underwent a health examination in 2009 from the Korean National Health Insurance Service database. The age of individuals was categorised into six subgroups by an increase in every decade from the twenties. In each age group, BMI (kg/m2) was categorised into five groups: underweight (<18.5), normal (18.5-22.9), overweight (23-24.9), obese class I (25-29.9), and obese class II (≥30). WC was categorised into six groups with distinctive points of 80, 85, 90, 95, and 100 cm for men and 75, 80, 85, 90, and 95 cm for women. Primary outcomes were incident AF and IS. Across age, BMI-AF presented a J-shaped association. The hazard ratio (HR) of obese class II was the highest in subjects aged 30-39 years (HR 1.80, 95% confidence interval (CI) 1.63 to 1.98, p<0.001). The increased risk of AF in the underweight group was only statistically significant in adults over 60 years of age. The risk of IS increased in those with a BMI over the normal range in early and midlife, but was not significant in adults aged >60 years. The highest HR of obese class II was observed in subjects aged 20-29 years (HR 3.00, 95% CI 2.34 to 3.84, p<0.001). Positive linear correlations of WC-AF and WC-IS were observed, but the WC-IS association was weak in the population aged ≥40 years. There was a J-shaped association between BMI-AF and BMI-IS, and a positive linear correlations between WC-AF and WC-IS. The higher risks of AF and IS according to an increment of BMI and WC were most apparent among the young ages; hence, more attention should be directed to weight management in early life. The association between IS and obesity was not significant in the elderly, implicating that several other factors contribute to IS in this age group.