Gender Disparities of Heart Disease and the Association with Smoking and Alcohol Drinking Behavior Among the Middle-Aged and Older Population in the US and China, a Cross-Sectional Study of CHARLS and HRS Data

Background
Heart disease remains the leading cause of death globally with substantial variabilities in mortalities by gender and region. Smoking and alcohol drinking are
known modifiable health behaviors associated with heart disease. This study aims to estimate the prevalence of heart disease and to examine the association
with smoking and drinking behavior for men and women in the United States (US) and China.
Methods
This study utilized the Harmonized data from the US Health and Retirement Study (HRS) and the China Health and Retirement Longitudinal Study (CHARLS),
which are sister surveys as part of the Gateway to Global Aging Data (https://g2aging.org/). We performed cross-sectional comparisons using the 2016 wave
HRS and 2015 wave CHARLS data. Age was categorized into four groups (50–59, 60–69, 70–79, and 80 years or older) and smoking and drinking behavior
were combined to neither, smoking only, drinking only and both behaviors. Weighted analyses were conducted to estimate the prevalence and prevalence
ratios (PRs) of heart disease accounting for complex survey design.
Results
The overall prevalence of heart disease was higher in men (24.5%) than in women (20.6%) in the US. In contrast, women had higher prevalence (22.9%) than
men (16.1%) in China. The prevalence of heart disease increased by age with increasing gender gap in the US, while in China, the highest prevalence was
observed in the 70–79 age group and gender difference were more apparent before 80 years of age. Adjusting for socio-demographic variables and health
conditions, smoking only was associated with a higher prevalence of heart disease in both countries and the associations were stronger among women (US:
PR = 1.39, 95%CI: 1.26 to 1.54; China: PR = 1.49, 95%CI: 1.30 to 1.72) than among men (US: PR = 1.20, 95%CI: 1.04 to 1.38; China: PR = 1.37, 95%CI: 0.94 to
1.98).
Conclusions
Findings from this study will improve present understanding of heart disease etiology and provide essential insights for future prevention, treatment, and
control. Better management of smoking behaviors by gender might be beneficial for reducing the burden of heart disease in both countries and worldwide.