Associations Among Cigarette Smoking, Weight Status and Mortality and Morbidities Among US Adults [electronic resource]

다국어 초록 (Multilingual Abstract)

Background: In the United States (US), cigarette smoking and weight status have been considered the main public health concerns in recent years due to a higher incidence of all-cause mortality and respiratory diseases such as asthma and COPD among those with past 30 day smoking or have an underweight or obesity weight status than those who do not smoke cigarettes or have a weight status of normal weight or overweight. The health burden associated with cigarette smoking and weight status in the US adult population has not been consistent across sociodemographic factors such as sex/gender, socioeconomic status (SES), and race/ethnicity. The association among cigarette smoking, weight status and all-cause mortality; cigarette smoking, weight status and asthma; and cigarette smoking, weight status and COPD are not entirely understood, or how disparities may contribute to these associations. Each of this dissertation's three aims addresses a specific research question about the associations among cigarette smoking and weight status with all-cause mortality, asthma, and COPD as well as which factors may contribute to health disparities of these associations. The first aim sought to determine whether weight status was a mediator between cigarette smoking and all-cause mortality among adults with past 30 days smoking in the US. The second aim sought to determine whether weight status is a mediator between cigarette smoking and asthma, and cigarette smoking and COPD. The third aim sought to determine which factors were a source of health disparities in the associations among cigarette smoking and weight status with all-cause mortality, asthma, or COPD. Methods: The study population included adults in the US with past 30 day smoking, with nationally representative samples for the National Health and Nutrition Examination Survey (NHANES). For all three aims, cigarette smoking, asthma, and COPD were self-reported, while weight status was measured on-sites and all-cause mortality was collected through death records. The first and second studies included causal mediation analyses with weight status as the mediator of the associations between cigarette smoking and all-cause mortality, cigarette smoking and asthma and cigarette smoking and COPD using the NHANES dataset from 2003-2018 and 2013-2018, respectively. For the third study Structural Equation Models (SEM) were implemented to determine which factors related to health disparities may contribute to the associations among cigarette smoking, weight status, all-cause mortality, asthma, or COPD using the NHANES 2003-2018 dataset (for all-cause mortality) and the NHANES 2013-2018 (for asthma and COPD).Results: In the mediation analysis between cigarette smoking and all-cause mortality with weight status as a mediator, the total effect (TE) for the model with only physiological factors was -1.94 (95% CI=-2.67, -0.04; p<0.001), with an average direct effect (DE) of -1.82 (95% CI=-2.51, -0.56; p<0.001) and an average indirect effect (IE) of -0.118 (95% CI= -0.19, -0.03; p =0.004). The TE for the model adjusted for physiological and sociodemographic factors was -1.54 (95% CI = -2.20, 0.01; p = 0.048), an average DE of -1.49 (95% CI = -2.18, -0.01; p = 0.048) and an average IE of -0.049 (95% CI = -0.052, 0.02; p = 0.518). For the mediation analysis between cigarette smoking and asthma and cigarette smoking and COPD having as mediator weight status, it was obtained that for asthma, the TE was 0.0009; p=0.016, with an average DE 0.0009; p=0.016 and an average IE of 0.00003; p=0.232. For COPD, the TE was 0.00166; p<0.001. The average DE was 0.00174; p<0.001; the average IE was -0.00008; p=0.46. The Prevalence Ratio (PR) of having asthma and COPD was 1.03 (95% CI=1.00, 1.06; p<0.1032) and 1.04 (95% CI: 1.03, 1.05; p<0.001), respectively. For the third aim, sex/gender was a significant factor in the associations among cigarette smoking, weight status and all-cause mortality; cigarette smoking, weight status and asthma and cigarette smoking, weight status, and COPD. Race/ethnicity was only significant in the association of cigarette smoking, weight status, and all-cause mortality, and cigarette smoking, weight status, and COPD among Hispanic Mexican and Non-Hispanic White individuals. Conclusions: Findings from this dissertation showed that weight status was not a mediator between cigarette smoking and all-cause mortality; cigarette smoking and asthma, or cigarette smoking and COPD when considering physiological and sociodemographic factors. The findings also indicated that sex/gender contribute to health disparities of these associations. Smoking cessation and harm reduction interventions to reduce the incidence of all-cause mortality, asthma, and COPD due to cigarette smoking should be tailored by sex/gender.