Association between tobacco smoking and heart disease in older adults: a cross-sectional study based on the Chinese Longitudinal Healthy Longevity Survey

Abstract

Background The association between the risk of heart disease and tobacco smoking has been studied in previous work, but there are arguments among various population. We aimed to investigate the association between heart disease incidence and smoking status among older adults. Methods A cross-sectional analysis was conducted with 10,891 older adults in the 2 most recent waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), 2011–2014 and 2014–2018. The data included individual weighting variables to ensure they were nationally representative. The parameters consisted of age, sex, body mass index (BMI), smoking status, and disease history was collected. Smoking measures included current/former/never status, pack-years and the time to first cigarette. Heart disease included coronary artery disease, arrhythmias, heart failure, valve diseases and other heart conditions. Respondents with missed values were excluded. Multivariable logistic regression analyses were performed. Results Among the 10,006 respondents included in the analyses, 4,501 (44.9%) were men. The median age was 88 years old [interquartile range (IQR), 78–96]. A total of 6,713 respondents (67.1%) were nonsmokers, 1,695 respondents (16.9%) were former smokers, and 1,598 respondents (16.0%) were current smokers. The incidence of heart disease was significantly higher in smokers compared with nonsmokers (14.5% vs. 12.8%, P=0.018). Female smokers and those over 80 years old had higher morbidity than male smokers. After adjusting for sex, age, BMI, hypertension, diabetes, area of residency, alcohol status, and exercise status, smokers still had an increased risk of heart disease [odds ratio (OR) 1.29, 95% confidential interval (CI): 1.10–1.50, P=0.001]. The incidence of heart disease also increased with higher intensity of smoking for each additional pack-year (OR 1.01, 95% CI: 1.00–1.02, P=0.011). Conclusions For elderly adults, current or former smoking was largely associated with heart disease incidence, especially in females and those over 80 years old. These variables could be considered for inclusion in future heart disease risk prediction models.