Serum Cystatin C, Creatinine-Based Estimated Glomerular Filtration Rate, and the Risk of Incident Hypertension in Middle-Aged Men

BACKGROUND The aim of this study was to examine the predictive value of serum cystatin C (CysC) and that of creatinine-based estimated glomerular filtration rate (eGFR(Creat)) for the risk of incident hypertension in a middle-aged male population. METHODS Serum CysC levels were measured in 904 nonhypertensive, Japanese male subjects (mean age = 44 +/- 6 years) who received an annual general health examination in a company. Serum creatinine levels were simultaneously measured, and eGFR(Creat) was calculated. Subjects were followed-up for a maximum period of 4 years, and annual blood pressure measurements were recorded. RESULTS During the follow-up period, 124 subjects developed hypertension, defined as systolic/diastolic blood pressure >= 140/90 mmHg or use of antihypertensive medications. In the Kaplan-Meier analysis, both the third quintile of CysC and that of eGFR(Creat) showed the lowest 4-year cumulative incident rate of hypertension. The multiadjusted hazard ratio for incident hypertension was significantly increased in the highest quintile of CysC compared with the third quintile (2.60; 95% confidence interval (CI) = 1.41-4.77; P = 0.002), as well as compared with the lowest 4 quintiles combined (1.89; 95% CI = 1.26-2.84; P = 0.002). However, eGFR(Creat) did not show significant hazard ratios for incident hypertension in any of the adjusted models. CONCLUSIONS Elevated serum CysC levels could predict the risk of incident hypertension in this study population with a maximum follow-up period of 4 years. In contrast, eGFR(Creat) did not show predictive value for the risk of incident hypertension.