OBJECTIVES The purpose of this study was to examine temporal trends in physical activity and metabolic syndrome (MetS) among Korean adults, and to evaluate secular trends in the association between physical activity and MetS from 2018 to 2023.METHODS This study utilized data from the Korea National Health and Nutrition Examination Survey (KNHANES) collected between 2018 and 2023. A total of 32,639 adults aged ≥ 19 years were included. Physical activity was dichotomized based on meeting the World Health Organization guidelines (≥ 150 minutes/week of moderate to vigorous physical activity). MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria with Asian-specific waist circumference cutoffs, as the presence of ≥ 3 of 5 metabolic components based on measured component values. All analyses accounted for the complex sampling design of KNHANES by applying survey weights and primary sampling units and strata. Temporal trends were tested using orthogonal polynomial contrasts. Secular changes in the association between physical activity and MetS were evaluated using random-effects meta-regression.RESULTS Physical activity levels showed no significant temporal trends from 2018 to 2023. Among MetS components, waist circumference and HDL-C showed significant linear and quadratic trends, fasting plasma glucose demonstrated a significant quadratic pattern peaking in 2021, and both triglycerides and diastolic blood pressure showed significant negative linear trends, whereas systolic blood pressure showed no significant temporal trend. Pooled analyses revealed that meeting physical activity guidelines was associated with a 25% lower odds of MetS (pooled OR = 0.75, 95% CI = 0.70–0.80). Meta-regression indicated no significant secular change in this association across survey years.CONCLUSIONS Meeting physical activity guidelines was consistently associated with lower odds of MetS among Korean adults from 2018 to 2023, with no evidence of secular change in this association. Despite stable physical activity, several MetS components showed partially unfavorable temporal trends, underscoring the need for prevention strategies beyond physical activity alone.
Kim et al. (Sat,) studied this question.