The difference between cystatin C- and creatinine-based estimated glomerular filtration rate and risk of hypertension: a population-based study in middle-aged and elderly Chinese

Aim: The difference between cystatin C-based and creatinine-based estimated glomerular filtration rate (eGFRdiff) has been suggested to reflect factors distinct from kidney function that are associated with cardiovascular risk. This study aims to investigate the association between eGFRdiff and hypertension (HP) among the middle-aged and elderly population in China. Methods: This study utilized a cross-sectional design based on retrospective data from the China Health and Retirement Longitudinal Study (CHARLS) cohort. We conducted a cross-sectional analysis of CHARLS data collected from 2011 to 2020. Hypertension was identified through self-reports or the use of antihypertensive medications. Participants younger than 45 years, those with kidney diseases, or individuals missing data on eGFRdiff, hypertension records, or baseline information were excluded from the study. Participants were categorized into three groups based on eGFRdiff: negative (< -15 mL/min/1.73 m2), midrange (-15 to 15 mL/min/1.73 m2), and positive (≥ 15 mL/min/1.73 m2). The primary outcome of interest was the prevalence of HP. We employed weighted multivariable-adjusted logistic regression to examine the association between eGFRdiff and HP. Results: Among 12,621 participants, after adjusting for covariates, a lower eGFRdiff was found to be independently associated with a higher prevalence of hypertension. In comparison to the negative eGFRdiff group, the midrange group exhibited an odds ratio (OR) of 0.79 (95%CI, 0.70-0.90; P < 0.001), while the positive group demonstrated an OR of 0.52 (95%CI, 0.44-0.61; P < 0.001). Our findings further underscore the significance of specific factors, such as age, gender, body mass index (BMI), and alcohol consumption, in influencing the association between eGFRdiff and hypertension prevalence. Conclusion: In the middle-aged and elderly population of CHARLS in China, lower eGFRdiff values were associated with a higher prevalence of hypertension, which may be influenced by specific factors such as age, gender, BMI, and alcohol consumption. These findings may have implications for the risk management of hypertension in the middle-aged and elderly population.