Associations of serum carotenoids with asthma and mortality in the US adults.

Objective: This study was to investigate the association between serum carotenoid levels and the prevalence of asthma, as well as the relationship between serum carotenoid levels and the risk of mortality among individuals with asthma.

Methods: Data on five serum carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, and lycopene) were obtained from the National Health and Nutrition Examination Survey (NHANES) 2001-2006. Mortality data was extracted from the pertinent mortality records within the NHANES database, up to December 31, 2019. Logistic regression analysis was employed to investigate the association between serum carotenoid concentrations and asthma prevalence. Cox proportional hazards models were used to investigate the connection between serum carotenoids and mortality rates in asthma individuals.

Results: Among the study population, 1569 (12.63 %) individuals were diagnosed with asthma, while 25.01 % of asthma patients died within a median follow-up duration of 15.5 (13.8-17.3) years. After controlling for all other variables, greater serum levels of certain carotenoids, such asα-carotene, β-carotene, β-cryptoxanthin, and lutein/zeaxanthin, were found to be substantially linked with a decreased prevalence of asthma. Furthermore, persons with asthma who had greater levels of serum carotenoids in the fourth quartile had a significantly lower risk of all-cause death compared to those in the first quartile. Specifically, the presence of α-carotene, β-cryptoxanthin, and lutein/zeaxanthin was associated with reductions in all-cause mortality by 45 % (HR = 0.55 [0.36-0.84],  = 0.002), 38 % (HR = 0.62 [0.42-0.92],  = 0.004), and 45 % (HR = 0.55 [0.41-0.73], <0.001), respectively. The above relationships are mostly linear and remain robust in sensitivity analyses.

Conclusions: Our findings indicate that higher serum carotenoids are related with a reduced likelihood of mortality in asthmatic individuals.