Chronic obstructive pulmonary disease among lung cancer-free smokers: The importance of healthy controls.

BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) in smokers enrolled as "healthy" controls in studies is 10-50%. The COPD status of ideal smoker populations for lung cancer case-control studies should be checked via spirometry; however, this is often not feasible, because no medical indications exist for asymptomatic smokers to undergo spirometry prior to study enrollment. Therefore, there is an unmet need for robust, cost effective assays for identifying undiagnosed lung disease among asymptomatic smokers. Such assays would help excluding unhealthy smokers from lung cancer case-control studies. METHODS: We used the cytokinesis-blocked micronucleus (CBMN) assay (a measure of genetic instability) to identify undiagnosed lung disease among asymptomatic smokers. We used a convenience population from an on-going lung cancer case-control study including smokers with lung cancer (n = 454), smoker controls (n = 797), and a self-reported COPD (n = 200) contingent within the smoker controls. RESULTS: Significant differences for all CBMN endpoints were observed when comparing lung cancer to All controls (which included COPD) and Healthy controls (with no COPD). The risk ratio (RR) was increased in the COPD group vs. Healthy controls for nuclear buds (RR 1.28, 95% confidence interval 1.01-1.62), and marginally increased for micronuclei (RR 1.06, 0.98-1.89) and nucleoplasmic bridges (RR 1.07, 0.97-1.15). CONCLUSION: These findings highlight the importance of using truly healthy controls in studies geared toward assessment of lung cancer risk. Using genetic instability biomarkers would facilitate the identification of smokers susceptible to tobacco smoke carcinogens and therefore predisposed to either disease.

Using a Community-Engaged Approach to Develop a Bilingual Survey about Psychosocial Stressors among Individuals of Mexican Origin.

Hypertension is on the rise among Hispanics and is highest among those of Mexican origin. Recent studies have found a positive association between air pollution and blood pressure and hypertension. Moreover, a link between hypertension and adverse socioeconomic conditions is well established. However, less is known about psychosocial stressors, although their impact on coronary heart disease has been shown. To address this gap in the literature, community perspectives of the health consequences of environmental exposures and psychosocial stressors experienced among the Mexican-origin population in Houston, Texas were obtained through participation in focus groups, the establishment of a Neighborhood Council of Advisors (NCA), and the testing of a pilot questionnaire. Taken together, the findings from the community were used to develop a culturally sensitive, bilingual questionnaire for an investigation of the combined effects of environmental and psychosocial stressors on hypertension among individuals of Mexican origin.