CardioRenal Medicine

Swift P.A., MacGregor G.A.

High blood pressure occurs commonly in individuals of African origin, leading to an increased risk of cardiovascular and end-stage renal disease (ESRD). Black individuals frequently have low plasma renin activity, and their blood pressure responds well to salt reduction, suggesting that abnormalities in renal sodium handling may be important in the etiology of hypertension in this population. The epithelial sodium channel (ENaC) has a central role in sodium transport across membranes, and in the kidney it contributes to the regulation of blood pressure via changes in sodium balance and blood volume. Rare monogenetic disorders have been described in association with hypertension, such as Liddle's syndrome. In addition, other ENaC polymorphisms have also been described, some of which are more common in black individuals. The T594M polymorphism of ENaC occurs exclusively in black individuals and is associated with hypertension in a black South London population. There is preliminary evidence that amiloride is effective as monotherapy in hypertensives with the T594M polymorphism, and a further study is underway to determine whether this is indeed a safe and specific treatment. If so, then amiloride may provide an important new strategy for blood pressure control in affected black hypertensives.

Hall J.E., Henegar J.R., Dwyer T.M., Liu J., da Silva A.A., Kuo J.J., Tallam L.

Excess weight gain is a major risk factor for essential hypertension and for end-stage renal disease (ESRD). Obesity raises blood pressure by increasing renal tubular sodium reabsorption, impairing pressure natriuresis, and causing volume expansion because of activation of the sympathetic nervous system and renin-angiotensin system and by physical compression of the kidneys, especially when visceral obesity is present. Obesity also causes renal vasodilation and glomerular hyperfiltration that initially serve as compensatory mechanisms to maintain sodium balance in the face of increased tubular reabsorption. In the long-term, however, these changes, along with the increased systemic arterial pressure, create a hemodynamic burden on the kidneys that causes glomerular injury. With prolonged obesity, there is increasing urinary protein excretion and gradual loss of nephron function that worsens with time and exacerbates hypertension. With the worsening of metabolic disturbances and the development of type II diabetes in some obese patients, kidney disease progresses much more rapidly. Weight reduction is an essential first step in the management of obesity, hypertension, and kidney disease. Special considerations for the obese patient, in addition to adequately controlling the blood pressure, include correction of the metabolic abnormalities and protection of the kidneys from further injury.

Burrowes J.D.

Medical nutrition therapy (MNT), nutrition education, and counseling are essential components for effective management of end-stage kidney disease (ESKD). Patients with ESKD have to alter their diets and to implement new eating behaviors, sometimes irrespective of ethnic and cultural food preferences because of their high content of specific nutrients. Ethnic and cultural factors influence dietary adherence. Therefore, assessing cultural issues surrounding food and food preferences may help improve dietary adherence. A large percentage of the ESKD population in the United States is black and Hispanic, with cultural food preferences that are particularly high in potassium, phosphorus, and sodium. This article provides an overview of the role of culture and ethnicity in food habits and dietary adherence, a list of cultural and ethnic foods that should be examined and incorporated in the development of an appropriate renal diet meal plan for black and Hispanic Americans with ESKD, and practical recommendations for cross-cultural nutrition counseling. If MNT is to be effective in the medical management of patients from different cultural and ethnic backgrounds, it must incorporate more traditional and customary foods in the renal diet meal plan.

Li S., McAlpine D.D., Liu J., Li S., Collins A.J.

In the United States, the age-and-gender-adjusted incident rate of end-stage renal disease (ESRD) for blacks has been 4 times higher than that for whites. We analyzed patient information and medical services contained in the Medicare 5% random sample database. White (n = 977,436) and black (n = 77,800) Medicare enrollees who were at least 65 years old on January 1, 1997, were followed from 1999 to 2001. Hierarchical Cox regression models were used to estimate the relative risk of ESRD for blacks (with reference to whites) after adjustment for age and gender, socioeconomic status, special health conditions (anemia, chronic obstructive pulmonary disease, cardiovascular disease), primary causal diseases of ESRD (eg, diabetes, hypertension), diabetes care and preventive care (eg, hemoglobin A1c or lipid testing), and physician visits for primary or specialty care. The relative risk of ESRD for blacks (with reference to whites) was 3.52 (95% confidence interval [CI], 3.25-3.80) after adjustment for age and gender; 2.90 (95% CI, 2.67-3.15) after adjustment for socioeconomic status and special health conditions; and 2.11 (95% CI, 1.94-2.30) after further adjustment for primary causal diseases of ESRD, diabetes care and preventive care, and physician visits. We conclude that a higher prevalence of primary causal diseases of ESRD and lower access to diabetes care, preventive care, and primary physician visits in blacks compared with whites partially accounts for the racial difference in the incidence of ESRD in the elderly Medicare population. Public health policy should focus on improving access to care, which may lower the burden of ESRD in minority and other at-risk populations.

Root L.

Many renal social workers are uncertain about what to expect when providing services to Hispanic patients. The Hispanic dialysis population is a growing minority with a diverse culture. The Hispanic patient's family members are a source of natural support and strength. This article profiles a review of the literature available regarding working with Hispanic patients and their families in a medical setting and provides implications for renal social work practice.

Lakkis J., Weir M.R.

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 (

Lopes A.A.

In the United States, the incidence of end-stage renal disease (ESRD) is much higher for blacks, Native Americans, and Asians than for whites. The incidence of kidney disease is also higher for populations of Hispanic ethnicity. ESRD attributed to diabetes (ESRD-DM), hypertension (ESRD-HT), and glomerulonephritis (ESRD-GN), in this order of frequency, are the major categories of ESRD in the United States for all race/ethnic groups. By using the incidence rates of ESRD, during the period from 1997 through 2000, and with whites as reference, the highest rate ratio (RR) was observed for ESRD-HT in blacks (RR = 5.96), ESRD-DM in Native Americans (RR = 5.11), and ESRD-GN in Asians (RR=2.20). The data suggest that the excess of ESRD observed for racial/ethnic minorities may be reduced by interventions aimed at prevention/control of hypertension and diabetes. The data suggest that before developing ESRD, patients with chronic renal failure from minority groups have to face more barriers to receive high-quality health care. This may explain why they see nephrologists later and are less likely to receive renal transplantation at initiation of renal replacement therapy (RRT). Improvements in quality of care after initiating RRT may explain the lower mortality and higher scores in heath-related quality of life observed for patients from racial/ethnic minorities.

Isaacs R.

Chronic kidney disease (CKD) is a major epidemic in underserved and minority populations largely due to excess rates of hypertensive and diabetic kidney disease. Multiple complex socioeconomic barriers to early diagnosis and optimal therapies as well as delayed referral for kidney transplantation have created disparities in CKD care provided to ethnic minorities. Disparities exist in wait list time and kidney transplant rates for Native Americans and blacks, independent of insurance status. Moreover, independent of genetic matching, long-term transplant outcomes in blacks remain significantly lower than all other ethnic groups, suggesting that poorly understood social factors contribute to these survival differences. The existence of these disparities raises ethical concerns of equity and social justice in terms of the allocation of scarce resources. Although current changes in allocation policies will improve some disparities, more efforts are ultimately needed to improve access to care and the overall health and survival for all individuals at risk for CKD, independent of their race, ethnicity, or socioeconomic status.

Hostetter T.H.

Several minority populations in the United States have higher risks for end-stage renal disease than does the white population. This article addresses some areas for research aimed at reducing the disproportionate risks. Four general areas are considered: health services, risk factors and causative agents, clinical trials, and awareness campaigns.

Coney P.J.

Nardi D.A., Rooda L.A.

The purpose of this article is to discuss current standards for preparing nurses to practice as culturally competent generalists in our rapidly shrinking world. Culturally competent care, transcultural nursing practice, and the nursing professions' standards of nursing care for diverse populations are applied to nursing education, renal nursing, and transplant nursing issues. Recommendations for breaking down health care gaps and barriers include ensuring, within the boundaries and control base of our own practice, that cultural, racial, economic, spiritual, and social diversity is respected and acknowledged.

Flack J.M.

Andreoli S.P.

Idiopathic focal segmental glomerulosclerosis (FSGS) is a common cause of nephrotic syndrome in pediatric and adult patients. Most children with FSGS do not respond to any form of therapy and progress to end-stage renal disease (ESRD). FSGS reoccurs in the transplanted kidney in approximately one third of initial transplants and in a substantially higher percentage of subsequent transplants once FSGS has recurred in an earlier transplant. Thus, FSGS is a disease with substantial morbidity. Over the past several years, the incidence of FSGS in adults and children appears to be increasing, particularly in certain racial groups and ethnic populations. Several recent studies in adult and pediatric patients suggest that the incidence of FSGS is increasing particularly in the black population. In addition, some studies have also demonstrated a more rapid progression of FSGS to ESRD in black patients compared to other ethnic groups. Racial and ethnic background is likely to have a substantial influence on the incidence and progression of FSGS in children and adults. It is likely that specific genes or a combination of genes influence the different clinical manifestations of FSGS in racial and ethnic groups. Genetic mutations in NPHS1 gene, which encodes nephrin, have been found to cause congenital nephrotic syndrome. Genetic mutations in the NPHS2 gene, which encodes podocin, recently have been shown to be strongly associated with a recessive form of steroid-resistant nephrotic syndrome. Mutations in the ACTN4 gene that encodes actinin 4 has also been associated with familial nephrotic syndrome. A role for ACE polymorphisms in the progression of FSGS has been found in some studies. Future investigations to identify polymorphisms that influence the development of FSGS, the progression of FSGS, and the response to therapy will greatly improve understanding of the pathogenesis and management of FSGS.