Association of socioeconomic status and a broad combination of lifestyle factors with adult-onset asthma: a cohort study

Background The prevalence of asthma is gradually increasing worldwide and there are socioeconomic inequalities in the risk of developing asthma. Objective This study aimed to evaluate whether the lifestyle is associated with asthma in adults, as well as whether and to what extent healthy lifestyles may modify socioeconomic status (SES) inequities in asthma. Methods This study included a total of 223951 participants from the UK Biobank. Smoking, physical activity, alcohol consumption, healthy diet patterns, sedentary time, and sleep duration items were used to construct the lifestyle score. Income, education, and occupation were used to assess SES. Cases of adult-onset asthma were identified based on electronic health records. The Cox proportional hazards regression was used to explore the association of socioeconomic inequality and lifestyle factors with asthma. Results Compared with the most healthy lifestyle category, the HRs (95% CIs) of the moderately healthy lifestyle and least healthy lifestyle categories for asthma were 1.08 (1.01-1.15) and 1.29 (1.20-1.39), respectively. A significant interaction (P interaction< 0.05) was found between lifestyle categories and socioeconomic status, and the association between them was more pronounced in participants with low socioeconomic status (HR least healthy vs most healthy: 1.58, 95%CI: 1.40-1.80). The joint analysis revealed that the risk of asthma was highest among participants with the lowest SES and the least healthy lifestyles (HR: 2.02, 95%CI: 1.74-2.33). Conclusions Unhealthy lifestyle factors are associated with an increased risk of asthma in adults, and socioeconomically disadvantaged groups are more negatively affected by unhealthy lifestyles. Public health strategies for asthma prevention may need to be tailored according to socioeconomic status, and social policies to reduce poverty are needed alongside lifestyle interventions in areas of deprivation.