Association Between Body Weight Changes and Subsequent Development of Out-of-Hospital Cardiac Arrest: A Population-Based Nested Case-Control Study

BACKGROUND: Body weight is a modifiable demographic factor. Although the association of body mass index (BMI) categories with sudden cardiac death was reported, dynamic changes of BMI and the risk of cardiac arrest remain unknown. This study aimed to evaluate the association between the out-of-hospital cardiac arrest (OHCA) occurrence within a year and the percent changes of BMI preceding the OHCA. METHODS: This population-based nested case-control study used the National Health Insurance Service Data of Korea. In all, 24,465 patients with non-traumatic OHCA between 2010 and 2018, who underwent national health check-up twice (one within a year and the other within 2–4 years before OHCA) and 32,434 controls without OHCA, were matched for age and sex. The association between the risk of OHCA and BMI percent change stratified by sex was investigated. RESULTS: All the BMI percent changes of ≥ 5% significantly increased the OHCA occurrence with a reverse J-shaped association. Compared to individuals with a stable weight, those with severe (> 15%) BMI decrease had the highest odds ratio (OR) of 4.29 (95% confidence intervals [CIs], 3.72–4.95) for OHCA occurrence followed by those with moderate (10–15%) weight loss (OR, 2.80; 95% CI, 2.55–3.08) and those with severe (> 15%) weigh gain (OR, 2.24; 95% CI, 1.96–2.57), respectively. The impact of weight loss on the cardiac arrest occurrence was more prominent in men, while the impact of weight gain was more prominent in women. CONCLUSION: Significant weight changes increase the risk of OHCA within a year with a reverse J-shaped association. Significant weight loss might be a warning sign for OHCA especially for men.