Cross-national comparison of metabolic syndrome prevalence and related medication use in South Korea and the United States, 2007–2020: Evidence from KHANES and NHANES

Metabolic syndrome (MetS) is a major risk factor for cardiovascular disease and type 2 diabetes, yet comparative studies between countries are limited. Thus, we aim to compare trends in MetS prevalence, medication use, and component control in South Korea and the US. We analyzed data from the Korea National Health and Nutrition Examination Survey and the National Health and Nutrition Examination Survey from 2007 to 2020 for nonpregnant adults. MetS was defined by the National Cholesterol Education Program Adult Treatment Panel III criteria. Use of MetS-related medications was defined as the use of antihypertensive, antidiabetic, and lipid-lowering agents. The weighted prevalence with 95% confidence interval (CI) of MetS, its components, and their control among individuals on corresponding medications was analyzed, and adjusted odds ratios for component control by sociodemographic factors were estimated using weighted multivariable logistic regression. A total of 74,714 participants aged ≥20 years from Korea National Health and Nutrition Examination Survey (male, 43.59%) and 14,036 from National Health and Nutrition Examination Survey (male, 44.12%) were included in the analysis. MetS prevalence was higher in South Korea (18.47% [95% confidence interval, 18.09-18.85]) than in the United States (6.03% [5.54-6.53]). Among the components of MetS, low serum high-density lipoprotein cholesterol was the most prevalent in South Korea (35.04% [34.57-35.51]), whereas large waist circumference was most common in the United States (48.62% [47.05-50.20]). High prevalence of MetS was associated with older age, obesity, lower income, and nondrinkers in both populations. From 2007 to 2020, antidiabetic use declined in South Korea and increased in the United States, while antihypertensive and lipid-lowering agent use increased in both countries. Among medication users, MetS-related control rates were consistently lower in South Korea compared to the US: fasting glucose (12.76% [10.50-15.03] vs 56.07% [51.15-60.98]), triglycerides (64.39% [63.02-65.77] vs 87.87% [85.90-89.84]), and blood pressure (45.77% [44.72-46.82] vs 55.69% [53.13-58.25]). Significant differences exist in the MetS prevalence, pharmacologic treatment patterns, and control outcomes between South Korea and the US. Targeted strategies tailored to each country-specific context are needed to improve metabolic health.