Introduction: Asthma is a common debilitating disease of the airways that afflicts an estimated 300 million worldwide, causing reduction in physical activity, lost school/work days, and even death. There are many known and suspected risk factors of asthma; however, there is much controversy over prior and current cigarette smoking. Approximately 25% of the United States population currently smokes, with a quarter of these being asthma patients. Another 22 to 43 percent of asthmatics are ex-smokers. Objectives: (1) To estimate the prevalence for lifetime asthma in the adult US population; (2) to determine prevalence odds ratios (POR) of lifetime asthma based on questionnaire (smoking status, tobacco consumption) after adjustment of potential confounding variables; (3) to determine POR of lifetime asthma based on laboratory values (serum cotinine); and (4) to assess the validity of self-reported measures (smoking status and tobacco consumption) using serum cotinine as the gold standard.Methods: The National Health and Nutrition Examination Survey (NHANES) 1999-2002 is a proportional cross-sectional sample that uses weights to be representative. Crude odds ratios were obtained through univariate analysis; multiple logistic regression analysis was used to obtain adjusted odds ratios of asthma. Interactions for age, gender, and race/ethnicity were explored. Validity measures included sensitivity and specificity tests for self-reported smoking and non-parametric correlation of tobacco consumption with serum cotinine levels.Results: The overall prevalence of lifetime asthma among n=10,252 adults was 11.56% (95%CI 10.45-12.66). Analyses were stratified by race/ethnicity due to significant interaction. After adjusting for age, gender, body mass index, and family history of asthma, ex-smoking non-Hispanic Whites, non-Hispanic Blacks, and other races had odds ratios of 1.57 (95%CI 1.26-1.97), 1.52 (95%CI 1.01-2.27), and 1.97 (95%CI 1.01-3.83), respectively, relative to never smokers within their respective race/ethnic groups. Sample persons with a family history of asthma and increasing body mass index were significant predictors for lifetime asthma among all race/ethnic groups. Based on laboratory values, non-Hispanic White respondents with serum cotinine levels of 0.011 to Discussion: Self-reported smoking and tobacco consumption are valid measures of tobacco use. The present study found no significant relationship between current smoking and lifetime asthma. Despite the limited findings, asthmatic smokers make up a distinct, difficult-to-treat subgroup for which future treatment research should address.

Pediatric obesity has reached epidemic proportions. Reducing obesity among children is expected to lower their likelihood of being obese as adults and, therefore, lower their cardiovascular and metabolic risk profile in adulthood including hypertension, dyslipidemia, type II diabetes, heart disease, and stroke. Pediatric obesity among ages 2–19 is defined as a body mass index (BMI) greater than or equal to the 95th percentile for age and gender as defined according to the CDC BMI-for-age growth charts. Risk factors for obesity are present as early as birth, suggesting exposures at different stages of the life cycle are important to study. The primary objective of this thesis was to evaluate exposures throughout childhood and evaluate their association with both weight and metabolic status. Study 1 examined the relationship between physical activity and metabolic syndrome in overweight and obese youth ages 12–19. We found that even modest amounts of moderate to vigorous physical activity were associated with a reduction in risk of metabolic syndrome, with time spent in vigorous physical activity driving the association. Study 2 explored the relationship between environmental tobacco smoke (ETS) exposure and childhood overweight and obesity in 3–6 year old children. We observed that ETS has a positive association with risk of overweight/obesity, with a dose-response effect observed. Study 3 examined the relationship between maternal antibiotic use during pregnancy and infant birthweight. We did not observe any association between maternal antibiotic use and birthweight or BW/GA-z (birthweight adjusted for gestational age z-score), but we did observe a reduction in risk of SGA (small for gestational age) for infants exposed to antibiotics during gestation. This association was most evident among third trimester users. / 2019-06-09T00:00:00Z