Association of the C-reactive protein-triglyceride-glucose (CTI) index with asthma prevalence: Evidence from dual...

The association between the C-reactive protein-triglyceride-glucose (CTI) index and prevalent asthma was examined in two national cohorts.

This cross-sectional study included 6809 participants from NHANES and 9148 from CHARLS. Multivariable logistic regression and restricted cubic spline models were used to assess associations between CTI and prevalent asthma. Receiver operating characteristic curves, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to compare CTI with CRP or TyG alone.

Higher CTI was associated with greater odds of prevalent asthma in both cohorts. In fully adjusted models, the odds ratio was 1.34 (95% CI, 1.11-1.51) in NHANES and 1.14 (95% CI, 1.05-1.23) in CHARLS. Participants in the highest CTI quartile had higher odds of asthma than those in the lowest quartile in both cohorts. There was no evidence of non-linearity in NHANES, whereas a non-linear association was observed in CHARLS. CTI yielded slightly higher AUCs than CRP or TyG alone, while the continuous NRI and IDI estimates were positive and statistically significant.

Higher CTI was positively associated with prevalent asthma in both cohorts, although association patterns differed. These findings should be considered exploratory and hypothesis-generating and warrant prospective evaluation using objective asthma assessment.