24-hour blood pressure monitoring and renal function in patients with type 1 diabetes

Background and aims. Dipping profile in ambulatory blood pressure monitoring (ABPM) may be a good predictor of target organ damage in patients with type 1 diabetes. The aim of the study was to analyze the correlation between the blood pressure profile in ABPM and other predictors of early kidney damage in type 1 diabetes. Material and methods. We examined 132 type 1 diabetes patients with normal blood pressure and 22 type 1 diabetes patients treated with antihypertensive drugs. ABPM was performed in each patient. Urine albumin to creatinine ratio (UACR) was assessed and estimated glomerular filtration rate (eGFR) was estimated based on serum cystatin C concentration. The association between blood pressure profile in ABPM and renal function was analyzed. Results. In normotensive patients dipper status did not have any impact on renal function. Non-dippers had lower day systolic and diastolic blood pressure and higher night systolic and diastolic blood pressure than dippers. Day systolic blood pressure was negatively correlated with eGRF estimated with cystatin C. In hypertensive patients non-dippers had higher urine albumine to creatinine ratio than dippers. Conclusions. In normotensive type 1 diabetic patients non-dipping status does not seem to be good predictor of early renal complications. However, in type 1 diabetics treated for hypertension, non-dipping could reflect probable kidney damage. GFR estimated with cystatin C could be more sensitive than albuminuria predictor of early kidney damage in type 1 diabetes.