Associations between socioeconomic status and rates of blood pressure changes among Chinese older adults: a longitudinal community-based cohort study

Objectives The relationships between socioeconomic status (SES) and blood pressure changes among older adults in China remain unclear. This study aimed to examine the associations between SES and rates of blood pressure changes among Chinese older adults. Study design Community-based, prospective, longitudinal cohort study. Methods This study included 13,541 participants aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey between 2002 and 2018. SES was assessed by educational level, occupation, household yearly per capita income, and financial support. The estimated annual changes (EACs) of blood pressure were computed as the difference in blood pressure levels between any two adjacent surveys divided by the time interval. Associations between SES and EACs of blood pressure were evaluated using generalised estimating equations. Results Lower SES was significantly associated with greater annual increases of blood pressure among Chinese older adults. The effect of SES on EACs of blood pressure was more pronounced among non-hypertensive participants. Compared to EACs among non-hypertensive participants with high SES, multivariable-adjusted EACs among those with low SES increased by 0.57 mmHg (95% confidence interval [CI]: 0.16, 0.99), 0.32 mmHg (95% CI: 0.07, 0.57), and 0.40 mmHg (95% CI: 0.13, 0.66) for systolic blood pressure, diastolic blood pressure, and mean arterial pressure, respectively. Conclusions This study revealed strong associations between SES and EACs of blood pressure among Chinese older adults, especially in the non-hypertensive population. Findings suggest that prevention strategies for hypertension should pay more attention to the older population with low SES.