Pharmacological strategies for kidney function preservation: are there differences by ethnicity?

The prevalence of chronic kidney disease (CKD) is on the rise in all ethnic groups. This is because of the increased prevalence of obesity, diabetes mellitus, the metabolic syndrome, and the inadequate control of elevated blood pressure and other cardiovascular-renal risk factors, especially in ethnic minority populations. The implications of the aforementioned trends in risk factor prevalence and control are profound. Moreover, these trends negatively impact patient quality of life and place an enormous financial burden on the health care system for the provision of care to patients with CKD, end-stage renal disease (ESRD), and/or cardiovascular disease (CVD). Thus, it is of utmost importance to devise strategies that prevent kidney disease and delay progressive loss of kidney function in persons with CKD. Proven strategies include pharmacological interventions that lower blood pressure to less than target levels (<130/80 mm Hg), attainment of optimal glycemic control (Hb A1c <7%), and reducing urinary protein excretion. It is also possible, although yet unproven, that correction of anemia and aggressive treatment of dyslipidemia may forestall the loss of kidney function. In general, ethnic minorities are underrepresented in most large trials. Recently, a few outcome clinical trials in blacks have reinforced the lessons of kidney function preservation already learned in nonblack populations. That is, the reversible risk factors for CKD appear to be virtually identical and, at least in nondiabetic CKD, pharmacological targeting of the renin-angiotensin-aldosterone system (RAAS) with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers preserves kidney function better than non-RAAS blood pressure-lowering regimens, especially when significant proteinuria exists. Although more CKD studies in ethnic minorities are needed, until they become available, the best available evidence from the existing clinical trial database should be applied to minorities with CKD-even when specific data are not available for a specific racial or ethnic group. Why this approach? First, there are no known unique risk factors for kidney disease in any ethnic group. Second, poor control of reversible risk factors for CKD is universal, particularly in blacks and other ethnic minorities. Thus, it is logical to predict that more efficient use of strategies proven to forestall loss of kidney function will reduce the excess of CKD and ESRD in ethnic minorities relative to non-minority populations. However, medical-based strategies alone are probably not enough. The global epidemic of obesity will fuel the growing population of persons, especially among ethnic minorities, with diabetes, the main cause of CKD, ESRD, and CVD. The obesity and diabetes epidemics are unlikely to abate without innovative and ultimately effective public health approaches.