An Epidemiologic Study On Changes And Patterns Of Smoking Behavior And Its Genetic Score In An Elderly Population

Objective:The study aims to explore the patterns and changes of active and passive smoking in the elderly population, compare the difference of tobacco exposure in elderly between Beijing and Guangzhou, test and verify the SNPs from GWAS for smoking behavior in Chinese population, and develop a genetic score to quantify the genetic susceptibility to smoking in Chinese population.Methods:1. Two cross-sectional surveys with representative samples aged between 60 and 95 years old from the urban areas were conducted in 2001 and 2010 in Beijing. We analyzed the baseline cross-sectional data from the Guangzhou Biobank Cohort Study (GBCS) and 2010 data from Beijing to compare the difference in smoking exposure between the two cities. We used respective percentages of age and gender in Beijing and Guangzhou in 2001 and 2010 as a reference and standardized our data to improve the representativeness, and we used propensity score matching to increase the comparability of our data.2. Through literature review, we searched for the significant SNPs from GWAS related to smoking behavior, tested and verified the SNPs in our sample, screened significant SNPs and used their ? to establish a genetic score to estimate the genetic susceptibility to smoking behavior.Results:The prevalence of passive smoking was 30.5%(95%CI:28.6-32.4%) in 2001 and 30.0%(95%CI:28.1-32.0%) in 2010. The main source of secondhand smoke switched from a spouse in 2001 to offspring in 2010. This trend was observed in both sexes. Passive smoking in males from a smoking spouse decreased from 5.7% to 2.4%(P<0.001), while that from smoking offspring increased from 7.3 to 14.5% (P<0.001). Passive smoking in females from a spouse decreased from 30.6 to 17.6%, while that from offspring increased from 5.3 to 15.4%(P<0.001).2. Compared with Beijing, older adults from Guangzhou had higher rate of being exposed to second-hand smoke at work (49.5%) and public place (13.6%).3. After adjustment for covariates, compared with the population with the first tertile genetic score (low), participants with the third tertile genetic score (high) have 34% (95% CI:8%-67%) higher risk of being a smoker, and a 43%(95%CI:14%-80%) higher risk of SI (age of smoking initiation)?18ys.Conclusion:Offspring became the main source of secondhand smoke for the elderly. Our findings demonstrated the importance of implementing smoking prevention programs for elderly. Compared with Guangzhou, the smoking rate among light physical laborers in Beijing is lower, as well as the passive smoking prevalence at work and public place. We established a genetic score to estimate the genetic susceptibility to smoking behavior in Chinese population. This score could help determine the high-risk population who are sensitive to the dangers of tobacco exposure.