The role of hypertension, obesity, and diabetes in causing renal vascular disease.

The Jackson Heart Study will be an epidemiological study of African Americans in Jackson, Mississippi, to identify risk factors for development and progression of cardiovascular disease. One of the potential risk factors to be assessed in this study is renal vascular disease. Atherosclerotic renal vascular disease is a disease of the elderly, is predominantly seen in white people, and is strongly associated with diffuse atherosclerotic disease and high-grade hypertensive retinopathy. Patients with ischemic nephropathy may constitute up to 16% of new dialysis patients and die more quickly while on renal replacement therapy. Although often not present, hypertension is a commonly observed consequence (but probably not a cause) of renal vascular disease, and the control of blood pressure may not halt the progression of the disease. Approximately 20-25% of patients with moderate to severe renal artery stenosis will be diabetic. Diabetic patients fair less well with intervention and have a higher progression to end-stage renal disease or death. Obesity is not commonly seen in patients with renal vascular disease. The Jackson Heart Study may be able to assess the true incidence of atherosclerotic renal vascular disease in African Americans and its impact of cardiovascular morbidity and mortality.

Hypertension and renal disease in Puerto Ricans.

Hypertension and end-stage renal disease (ESRD) constitute a major health threat to Puerto Ricans in the United States and in the Commonwealth. In the Hispanic population of the United States, Puerto Ricans seem to have a worse health status than Mexican- and Cuban Americans. Poverty, language, and lack of education increase the risk of less-than-adequate diagnosis and treatment of hypertension. In the Commonwealth, hypertension is a common problem. Deaths caused by heart disease continue to increase on the island. Although the health care system in Puerto Rico continues to improve, changes in diet, increased social stress, and the high prevalence of diabetes mellitus and obesity may add to the increased death rate from cardiovascular causes. The incidence and prevalence of ESRD in Puerto Rico is as high as in the United States; however, diabetes mellitus seems to be the primary diagnosis in a larger number of patients with ESRD than in the U.S. Preventive and control measures must be urgently taken by public health officials to minimize the impact of these disorders in the health of Puerto Ricans.

Renal artery repair in African-Americans.

PURPOSE: This retrospective review examines the results of atherosclerotic renal artery (RA) repair in consecutive hypertensive African-Americans treated at our center and compares these results with Caucasians treated during the same period. METHODS: From Jan. 1987 through Sep. 1996, a total of 485 patients underwent operative RA repair. Of these, 28 African-Americans and 370 Caucasians were managed for atherosclerotic renovascular disease. These cohorts were compared on the basis of preoperative blood pressure and renal function, extent of renal disease, extrarenal atherosclerosis, response to operation, and estimated survival. RESULTS: The African-American cohort included nine men and 19 women (mean age, 62 years) with hypertension (mean blood pressure, 204 +/- 31/109 +/- 20 mm Hg) for an average of 10.2 +/- 7.5 years. Ischemic nephropathy (serum creatinine level, > 1.3 mg/dl) was present in 82% (n = 23) of the African-American group. RA reconstructions were unilateral in nine patients and bilateral in 19 patients (including repair to two solitary kidneys), for a total of 45 RA reconstructions (30 RA bypass procedures; eight transrenal/transaortic RA endarterectomy procedures; two RA reimplantations; five nephrectomies). Nine patients underwent combined aortic procedures (four abdominal aortic aneurysm; five occlusive disease). There was one perioperative death in the African-American group as a result of sepsis and multiple organ failure. Among surgical survivors, 20 African-American patients (74%) had a beneficial hypertension response (7% cured, 67% improved). Mean estimated glomerular filtration rate improved significantly from 34 to 42 ml/min/1.73 m2 (p < 0.001). In the 23 patients with ischemic nephropathy, 13 (57%) demonstrated greater than 20% decrease in serum creatinine level. In comparison with the 370 Caucasians (191 men, 179 women), the African-American cohort had significantly more preoperative heart disease (congestive heart failure or left ventricular hypertrophy; 68% vs 46%; p = 0.03) and tended toward more severe renal dysfunction (mean serum creatinine level, 2.5 vs 2.1 mg/dl; p = 0.25). However, African-Americans demonstrated a beneficial blood pressure and renal function response after operation, similar to Caucasians. CONCLUSIONS: Our results indicate that the majority of selected African-Americans have a favorable blood pressure and renal function response to operative renal artery repair. This beneficial clinical response appears equivalent to the response observed in Caucasian patients and supports the search for RA disease in hypertensive African-Americans.

Takayasu's arteritis as a cause of renovascular hypertension in a non-Asian population.

Takayasu's disease (TD) is a chronic inflammatory arteritis which affects the aorta and its main branches and occasionally the pulmonary artery. Its cause is not known. Clinical manifestations are due to the intensity and location of arterial inflammation in the acute phase, as well as chronic arterial stenosis over time; 50% of patients have hypertension. Although TD appears to be more common in Asia, increasing numbers of patients of different races are observed in Western countries. The most important pathogenetic mechanism of hypertension seems to be through renal artery stenosis. We show here seven Caucasian hypertensive patients with TD and renovascular stenosis and arterial hypertension. One case was diagnosed in the acute phase of the disease, while in the others diagnosis was established in an advanced occlusive phase. Basic diagnosis was established by angiographic study, with biopsy confirmation in two cases. All patients had at least three of the six criteria listed as diagnostic of TD (by the American College of Reumatology). All patients had the following criteria: age of disease onset before 40 years (symptoms or findings related to TD), vascular bruits in different areas and all patients also had aortic and renal arterial stenosis with some lesions of the main aortic branches. Six of them had claudication of the extremities. We describe their clinical, analytical and angiographic features and also the therapeutic approach. We discuss the aetiopathogenic mechanisms of hypertension in this disease and suggest that TD is not an unusual cause of vasculorenal hypertension.

Similar prevalence of renovascular hypertension in selected blacks and whites.

Renovascular hypertension is a potentially curable form of high blood pressure that is thought to be extremely rare among blacks. We demonstrate, however, that in a clinically selected population, the prevalence of renovascular hypertension is similar in blacks and whites. We prospectively evaluated 167 hypertensive subjects who had one or more clinical features known to be associated with renovascular hypertension. All subjects had captopril-stimulated peripheral renin measurements and conventional renal arteriography. All significant renal artery stenoses (greater than 50% luminal narrowing) were treated with percutaneous transluminal angioplasty or surgery. Renovascular hypertension was diagnosed if there was a blood pressure response to interventional therapy, according to the criteria established by the Cooperative Study of Renovascular Hypertension. Of the total group evaluated, 24% (39 of 167) had renal artery stenosis and 14% (23 of 167) had renovascular hypertension. Renal artery stenosis or occlusion was found in 27% (26 of 97) of whites and 19% (13 of 67) of blacks (p = 0.27). Renovascular hypertension was diagnosed in 18% (17 of 97) of whites and 9% (6 of 67) of blacks evaluated (p = 0.25). Renovascular hypertension was associated with severe or refractory hypertension and with smoking, but there were no racial differences in these associations. Blacks with renovascular hypertension tended to have low captopril-stimulated peripheral renin activity. We conclude that blacks with clinical features suggestive of renovascular hypertension should be evaluated with angiography. Captopril-stimulated plasma renin may not be useful in detecting blacks with renovascular hypertension, but this and other potential screening tests require further evaluation.

Renal vascular disease in African-Americans and other racial minorities.

Hypertensive end-stage renal disease is about 10-fold more common nationwide in African-Americans than in Caucasians and 17-fold higher in some sections of the United States. These figures are alarming and require a much greater effort in understanding the causes of this disparity and improving blood pressure control in this population to prevent catastrophic renal damage. More information is also needed about the renovascular status of other minorities. Financial obstacles to antihypertensive care appear to be an important contributing factor to the disparities of end-stage renal disease in African-Americans and perhaps other minorities.