Relation between blood pressure variability and early renal damage in hypertensive patients.

OBJECTIVE The objective of the present study was to observe the relation between blood pressure variability (BPV) and early renal damage in hypertensive patients. PATIENTS AND METHODS A total of 118 hypertensive patients were consecutively selected. General parameters including sex, age, duration, and grade of hypertension, antihypertensive drugs taken, smoking status, blood sugar, blood lipid level, body mass index, indexes of 24-h ambulatory blood pressure monitoring and renal function including cystatin C (CysC), serum creatinine (SCr), angiotensin II (Ang II), microalbuminuria (mALb), and urine creatinine (UCr) were measured. Glomerular filtration rate (eGFR), endogenous creatinine clearance rate (Ccr), and urine albumin/creatinine ratio (UACR) were calculated by CysC level, SCr level, and mALb and UCr level respectively. The 24-h ambulatory blood pressure monitoring indexes included 24-h mean systolic blood pressure variability (24h-SBPV), 24-h mean diastolic blood pressure variability (24h-DBPV), day mean systolic blood pressure variability (d-SBPV), day mean diastolic blood pressure variability (d-DBPV), night mean systolic blood pressure variability (n-SBPV), and night mean diastolic blood pressure variability (n-DBPV). RESULTS Sixty-four hypertensive patients (54.24%) were non-dipper, and the baseline data of the two groups were comparable. The 24h-SBPV, 24h-DBPV, d-DBPV, n-SBPV and SCr, eGFR, and Ccr of the two groups showed no significant differences. The d-SBPV, n-DBPV, CysC, and Ang II of the non-dipper group were significantly higher than those of the dipper group (p<0.05). The mALb in both groups increased and was more obvious in the non-dipper group. UACR of the non-dipper group was significantly higher than that of dipper group (p<0.05), while UCr showed no difference. By Pearson correlation, d-SBPV and n-DBPV correlated positively (p<0.05) with CysC, Ang II, mALb, and UACR. CONCLUSIONS BPV of hypersensitive patients, especially the d-SBPV and n-DBPV, was closely related to indexes of early renal damage including CysC, Ang II, mALb, and UACR.