Effect of Olmesartan on serum cystatin C levels in the patients with essential hypertension

Aim: We aimed to investigate whether Olmesartan had an effect on cystatin C levels in hypertensive patients, and evaluate its correlation with blood pressure (BP). Materials and Methods: Seventy-two patients essential hypertension patients with a known for, at most, the last 3 years were enrolled to the study. Patients were divided in three groups (group 1; receives 20 mg/day olmesartan; group 2, receives 40 mg/day olmesartan; group 3, receives Olmesartan plus hydrochlorothiazide), according to their BP measurements. Blood samples (serum urea, creatinine, sodium, potassium and cystatin C) were collected initially and at the end of the study from all patients and the correlation of these parameters with BP and drug use was investigated. Results: There were no significantly difference between the groups in terms of age, gender, serum urea, creatinine, cystatin C and diastolic BP levels (p > 0.05); while, systolic BP was significantly higher in group 3 at baseline (p = 0.001). After 3 months of olmesartan treatment, the mean serum cystatin C (p: 0.001, 0.023 and 0.018 respectively), systolic (p: 0.001, 0.001 and 0.001 respectively) and diastolic BP levels (p: 0.001, 0.001 and 0.001 respectively) decreased in all groups. However, there was no significant difference in serum creatinine levels (p > 0.05). There were not found correlation between the changes of systolic and diastolic BP and cystatin C levels. Conclusions: Cystatin C is a more sensitive marker to detect of early kidney dysfunction compared to serum creatinine level. Olmesartan treatment led to a decrease of cystatin C level. Therefore, olmesartan can be used to prevent the renal damage in patients with hypertensive and it is independent of drop in blood pressure.