Nephrotic proteinuria as a result of essential hypertension.

BACKGROUND

The presence of nephrotic-range proteinuria in a nondiabetic hypertensive patient is generally indicative of an underlying glomerular disease. A few published reports have noted nephrotic proteinuria in some patients with hypertensive nephrosclerosis. The frequency of this association is unknown.

METHODS

We retrospectively reviewed renal biopsy reports on all cases of nephrotic syndrome over an 8-year period (1993-2000). We excluded all cases of diabetes mellitus, lupus, hepatitis, human immunodeficiency virus, and chronic use of nonsteroidal anti-inflammatory drugs. Biopsy specimens showing glomerular eosinophilic hyalinosis lesions, positive immunofluorescence staining, or dense deposits on electron microscopy were also excluded. Thirteen of the remaining 237 (5.5%) biopsy specimens satisfied the standard histological criteria for hypertensive nephrosclerosis.

RESULTS

All patients were African-Americans with a mean age of 47.5 +/- 13 years and an average mean arterial blood pressure of 122 +/- 19 mm Hg. The mean values for urinary protein excretion, serum creatinine, albumin, and cholesterol were 8.9 g/day, 3.3 mg/dl, 3.1 g/dl, and 245 mg/dl, respectively. Optimal blood pressure control required at least three antihypertensive agents. Progression to end-stage renal disease occurred over a mean duration of 8.3 +/- 6.5 months. Multivariate regression showed a strong but nonsignificant association between the level of proteinuria at the time of biopsy, duration of hypertension, and number of blood pressure medications (R(2) = 0.56, p = 0.38).

CONCLUSIONS

Nephrotic syndrome may be more common in poorly controlled essential hypertension than previously realized. In African-American patients, the differential diagnosis of nephrotic syndrome should include hypertensive nephrosclerosis, but abrogation of renal biopsy is not implied.