Association Between C-Reactive Protein-Triglyceride Glucose Index and All-Cause Mortality and Exacerbation in Adult Asthma: NHANES, 1999–2010 and 2015–2018
Abstract
Purpose This study investigates the association between the C-reactive protein-triglyceride-glucose index (CTI), indicative of systemic inflammation and insulin resistance, and all-cause mortality as well as asthma exacerbations in adults with asthma. Methods Data from eight cycles of the US National Health and Nutrition Examination Survey (1999–2010 and 2015–2018) were analyzed. Adults aged ≥ 20 years were included, excluding those who were missing key variables. This resulted in 13,972 participants, of whom 1,832 had asthma. Participants were grouped into CTI tertiles. Participants self-reported exacerbations, and survival status was linked with the National Death Index. Complex survey weighting was applied to ensure national representativeness. Weighted multivariate logistic regression and Cox proportional hazards models assessed associations while adjusting for demographics, socioeconomic factors, body mass index, smoking, alcohol consumption, comorbidities, and laboratory indicators. Results The fully adjusted model revealed no significant association between CTI and asthma prevalence (odds ratio [OR], 1.07; 95% confidence interval [CI], 0.99–1.16; P = 0.078) but showed a strong association with all-cause mortality (hazard ratio [HR], 1.43; 95% CI, 1.12–1.81; P = 0.004). Patients in the highest CTI tertile exhibited a more than two-fold higher risk of mortality compared to those in the lowest tertile (HR, 2.22; 95% CI, 1.24–3.98; P = 0.007). Furthermore, higher CTI was associated with asthma exacerbation (OR, 1.23; 95% CI, 1.01–1.50; P = 0.039). Conclusions In this nationally representative sample, higher CTI was associated with higher all-cause mortality and higher odds of recent asthma exacerbations among adults with asthma, while no significant association with asthma prevalence was observed. CTI may help inform prognostic stratification in asthma and prospective studies are warranted.