Cystatin C Levels in Patients with Dipper and Nondipper Hypertension

OBJECTIVE: Subjects with nondipper hypertension carry a higher risk of cardiovascular events than their normotensive counterparts. The present study was designed to investigate cystatin C levels in patients with dipper and nondipper hypertension. METHODS: Eighty-eight consecutive patients who had been treated with antihypertensive drugs for at least 6 months were included in the study. Dipping and nondipping patterns were detected with ambulatory blood pressure monitoring. Clinical, laboratory, and ambulatory blood pressure monitoring data of patient groups with nondipper and dipper hypertension were compared. RESULTS: Patients in the nondipper group were older than those in the dipper group. Serum cystatin C level was higher in the patients in the nondipper group. Cystatin C was negatively correlated with the rate of systolic blood pressure fall at night (r = -0.41; P < 0.001). Linear regression analyses revealed that only cystatin C level was a significant correlate of nocturnal systolic blood pressure decrease. Logistic regression analyses also showed that cystatin C was an independent predictor of nondipping pattern (odds ratio, 3.586; 95% confidence interval, 1.432-8.98; P = 0.006]). CONCLUSION: The present study showed that cystatin C is higher in patients with nondipper hypertension patients.