Epidemiologic and clinical comparison of renal artery stenosis in black patients and white patients.

OBJECTIVE

This study was undertaken to compare the epidemiologic and clinical features of renal artery stenosis (RAS) in black patients and white patients.

METHODS

Data on all patients identified with 50% or greater RAS from 1984 to 1990 were collected and analyzed. The study was conducted at the Cleveland Clinic Foundation, which is a referral center for patients with renal artery disease. Eight hundred nineteen patients with RAS were identified from an institutional registry that records information on patients with this disease. This group comprises 40 black patients (4.9%) and 779 white patients (95.1%). The presence of RAS was determined by abdominal aortography in all patients. Black patients and white patients with RAS were compared with respect to their age, sex, presence and severity of hypertension, renal function, type and extent of renal artery disease, extrarenal vascular disease, and risk factors such as history of smoking, diabetes, and hyperlipidemia.

RESULTS

The mean age of black patients and white patients was 62 years; however, a greater proportion of black patients were women (p = 0.01). RAS was due to atherosclerosis in 95% and 92% of blacks and whites, respectively. Although the extent and severity of RAS were equivalent in black patients and white patients, more blacks were diagnosed with severe (p = 0.01) or refractory (p = 0.05) hypertension. Extrarenal vascular disease was present in 95% and 70% of blacks and whites, respectively (p < 0.01). The incidence of coronary artery disease (p < 0.01), cerebrovascular disease (p < 0.01), and peripheral vascular disease (p < 0.01) was greater among black patients. A history of smoking was more common among black patients (p < 0.01). Serum total cholesterol and low-density lipoprotein cholesterol levels were equivalent among black patients and white patients; however, black patients had higher high-density lipoprotein cholesterol (p = 0.03) and lower triglyceride (p < 0.01) levels.

CONCLUSIONS

There are significant differences between black patients and white patients with RAS. The basis for these findings and their relationship to the cause and true prevalence of RAS in blacks requires further study.