Study of Relationship between Kidney Function and Systolic Blood Pressure: New Insights from Cystatin C

Background: Control of hypertension is of utmost importance in treating chronic kidney disease (CKD). The relationship between renal function and blood pressure (BP) components has been studied in persons with diagnosed CKD, diabetes or hypertension. Whether renal function in such cases is associated with systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure is unclear. Methods: In the study we have evaluated the association between renal function test parameters and each BP component using cystatin C in 80 essential hypertensive patients and 80 age and sex matched normotensive healthy controls. Results: We observed that cystatin C showed significant positive correlation with SBP in both stage I (p<0.05 and r value 0.36) and stage II (p<0.00001 and r value 0.66) hypertensive patients. However cystatin C didn’t show any significant correlation with DBP. Conclusion: As SBP was significantly associated with kidney function across a wide range of cystatin C concentrations, even in subjects with presumably normal kidney function, this can provide a vital link in diagnosis of worsening of renal function at an early stage. For control of hypertension in patients undertaking anti-hypertensive medications this can also serve as an important marker.