Abstract
Population-based studies of cardiovascular disease markers, such as high-sensitivity C-reactive protein (hs-CRP), are crucial. However, studies exploring the effect of metabolic indices on hs-CRP while controlling for confounding variables adequately in middle-aged adults are limited. Using Wave 5 public-use biomarkers data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), we examined the impact of various metabolic indices on hs-CRP in adults aged 32-42, controlling for eight allergic and infectious factors that may elevate hs-CRP levels. We used multiple linear regression analysis to determine which factors predict hs-CRP levels after the log transformation of the dependent variable. The total number of participants was N = 1839 (weighted N = 1,390,763), with a mean age of 38.1 (SD = 2.0) and 46.4% having obesity. Among the controlled variables, recent surgery was the only confounder to significantly predict increased hs-CRP levels [ P = 0.029; exponentiated estimate (EE) = 1.61; 95% confidence interval (Cl), 1.31-1.91]. Notably, current smoking and altered low-density lipoprotein levels did not show a significant association with hs-CRP levels ( P > 0.05). However, a significant increase in hs-CRP levels was observed in females compared with males ( P < 0.001; EE = 1.43; 95% Cl, 1.35-1.51). Similar findings were noted for diabetic HbA1c levels ( P = 0.001; EE = 1.6; 95% CI, 1.42-1.78), high waist circumference ( P = 0.015; EE = 1.25; 95% CI, 1.15-1.35), and stage 3 obesity ( P = 0.006; EE = 7.62; 95% CI, 2.86-12.38). Although not statistically significant, hs-CRP levels exhibited a gradual increase with rising body mass index after controlling for other variables. These findings will improve the clinical application of hs-CRP in predicting coronary artery disease, especially in younger adults.