Loss of significant association between high-sensitivity C-reactive protein (hs-CRP) and metabolic syndrome after adjustment for waist circumference found in 2022 Korea National Health and Nutrition Examination Survey data

Abstract Background Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that increase the risk of cardiovascular disease and type 2 diabetes. High-sensitivity C-reactive protein (hs-CRP) is a biomarker of systemic inflammation, but its relationship with MetS and its components remains unclear. This study investigates the association between hs-CRP and MetS in a representative Korean population. Methods Using data from the 2022 Korea National Health and Nutrition Examination Survey (KNHANES), we analyzed 4,823 adults. MetS was defined according to revised NCEP-ATP III criteria. Multivariate analyses were conducted, adjusting for confounders such as sex, age, income, education, smoking, alcohol consumption, physical activity, and waist circumference. Results Among the study population, 1,784 participants (37.0%) were diagnosed with MetS. hs-CRP levels were significantly higher in individuals with MetS (1.06 mg/L vs. 0.79 mg/L, p < 0.001) and increased with the number of MetS components (p for trend < 0.001). Significant associations were observed between hs-CRP and all MetS components. However, after adjusting for waist circumference, these associations lost statistical significance. Conclusion This study confirms a strong association between hs-CRP and MetS, primarily influenced by central obesity. The findings highlight abdominal obesity as a key contributor to systemic inflammation in MetS. Further longitudinal studies are needed to explore the causal relationship and underlying mechanisms.