How Smoking, SES Are Linked With Allergic, Nonallergic Asthma Risk

In addition to independent risk factors, the interaction between smoking and socioeconomic status (SES) was found to be associated with risk of respiratory illnesses, such as asthma, according to a new study.

“This study found putative interactions between smoking and different measures of SES in relation to the probability of having respiratory diseases,” wrote the study researchers. “Education and occupational classification, as different measures of SES, presented different patterns of smoking association with asthma, when the latter is divided by allergic status.”

The results of this population-based analysis were published in Respiratory Medicine.

The researchers used data from the West Sweden Asthma Study (WSAS), which included 23,753 participants, and the Obstructive Lung Disease in Northern (OLIN) studies, which included 6519 participants. All participants included in the analysis were randomly selected adults aged 20 to 75 years living in Sweden in 2016.

All participants received a questionnaire that consisted of 3 parts, with questions pertaining to the following:

• Respiratory symptoms, age, sex, smoking status, and education
• Occupations, airborne occupational and environmental exposures, SES, and health status
• Rhinitis, eczema, height, and weight

In total, the finaly analysis sample included 30,123 participants:

• Most participants with current asthma were female (60.7%), highly educated, and had a high prevalence of comorbidities
• Manual service workers (20.8%) had the highest prevalence of allergic asthma cases with hereditary lung diseases and at-home smoking exposure (23.3%)
• Participants with nonallergic asthma were mostly nonmanual workers (19.5%) and manual service workers who were highly educated.
• Individuals with chronic obstructive pulmonary disease and/or chronic bronchitis were significantly older, industry workers, had low education attainment, and had a high prevalence of comorbidities and obesity (26.6%)

As a result, the study found education and occupation presented different smoking associations between allergic and nonallergic asthma status.

Respiratory problems associated with smoking and allergic asthma was more profound among manual workers in service and intermediate nonmanual employees than in high professional and executive workers. However, the prevalence of allergic asthma was higher among highly educated groups compared with lower-educated groups.

In contrast, adverse smoking effects and nonallergic asthma were more prevalent among high occupational workers compared with manual and home workers. However, nonallergic asthma status was more prevalent among low0-educated groups compared with highly educated groups.

The results of this study suggest that certain high-risk social and occupational groups may benefit from individualized smoking cessation interventions more than others. In addition, the researchers believe that more research is needed to fully understand the mechanism behind the interaction of smoking and occupation exposures to reduce the risk of asthma among different SES and occupational settings.

“In conclusion, this study showed that beyond the independent role of smoking and SES in respiratory diseases, in high-income countries such as Sweden, SES as measured using different socioeconomic classification systems and smoking interact in defining the risk of respiratory diseases in adults,” wrote the researchers. “Better understanding of this interaction can be of help when identifying social and occupational risk groups at higher need of preventive intervention.”

Reference

Bashir MB, Basna R, Hedman L, et al. Interaction of smoking and social status on the risk of respiratory outcomes in a Swedish adult population: a nordic epilung study. Respiratory Medicine. Published online March 9, 2023. doi:10.1016/j.rmed.2023.107192