Twelve-Year Trajectory of Disease Burden and Mortality by Obesity Level in Korea: Analysis of the National Health Insurance Service Database

Introduction Despite increases in obesity prevalence, awareness of obesity as a disease requiring active treatment remains lacking in Korea. We investigated differences in medical problems and expenditures and mortality across obesity categories using 12-year data from the National Health Insurance Service. Materials and Methods Individuals aged 40–79 years who underwent medical examinations during 2003–2004 ( n = 415,201) were divided based on Asian body mass index (kg/m 2 ) criteria: normal weight (18.5 to < 23.0, 36.4%), overweight (23.0 to < 25.0, 28.3%), obesity (25.0 to < 30.0, 32.5%), and severe obesity (≥ 30.0, 2.8%). Medical problems and expenditures were fitted to linear mixed models. Mortality was analyzed via Cox proportional-hazards model. Results More severe obesity was associated with a higher rate of medical problems, relative to normal weight: coefficient = 0.31 (95% confidence interval [CI], 0.30–0.32) for overweight, 0.61 (0.60–0.61) for obesity, and 1.07 (1.04–1.09) for severe obesity. A similar association was observed for medical expenditure: coefficient = 8.85 (95%CI, 6.80–10.89) for overweight, 20.04 (18.07–22.01) for obesity, and 48.76 (43.66–53.86) for severe obesity. Relative to overweight participants, those with normal weight and severe obesity exhibited a higher mortality risk (hazard ratio [HR] 1.21 [95%CI, 1.18–1.25] for normal; 1.27 [1.19–1.36] for severe obesity). In age-specific analyses, mortality risk was the highest for participants with severe obesity, aged < 60 years (HR, 1.58 [95%CI, 1.41–1.77]). Conclusion Disease burden including medical problems and expenditure, and mortality in middle-aged adults, increased proportionally to the degrees of obesity. Health policies and medical systems aimed at reducing the burden of obesity may help reduce the burden of disease on society. Graphical abstract