Clinical features of benign hypertensive nephrosclerosis at time of renal biopsy

Although hypertension accounts for approximately 15-20% of end-stage renal disease and renal impairment occurs in 15% of patients with essential hypertension, there are few data available on the clinical features of patients with benign hypertensive nephrosclerosis, the histological consequence of hypertension on the kidney. To determine its prevalence on renal biopsy and its clinical features (including proteinuria and renal function), we used the U.K. MRC Glomerulonephritis Registry of 7339 biopsies from 20 centres to define all patients with benign hypertensive nephrosclerosis. In patients with no co-existing disease, 185 biopsies were classified solely as benign hypertensive nephrosclerosis (2.5%). Sixty-nine percent of patients were male and 72% aged over 50 years. Sixty-four percent had diastolic blood pressure above 90 mmHg and severe hypertension (diastolic > 120 mmHg) was present in 9%. Protein excretion of > 1.5 g/day was noted in 40%, with 22% excreting > 3 g/day. Eighteen percent had serum albumin values under 30 g/l. Eighty-one percent had serum creatinine > 120 mumol/l; in 51% this was > 250 mumol/l. There was significant correlation between serum creatinine and systolic blood pressure at time of biopsy (p = 0.01) and between serum creatinine and serum albumin (p = 0.001). Benign hypertensive nephrosclerosis accounts for 2.5% of all registered biopsies. Significant proteinuria is a common finding and proteinuria within the nephrotic range does occur. Systolic blood pressure appears to influence serum creatinine levels. Hypertensive nephropathy should be considered in all patients with heavy proteinuria and renal impairment.