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

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.