The rising tide of end-stage renal disease: what can be done?

Epidemiological Transition of End-Stage Kidney Disease in Oman

INTRODUCTION

The number of persons receiving renal replacement therapy (RRT) is estimated at more than 2.5 million worldwide, and is growing by 8% annually. Registries in the developing world are not up to standards compared to the United States Renal Data System (USRDS). Herein we examine the causes, progression, and magnitude of end-stage kidney disease (ESKD) over 3 decades in Oman.

METHODS

We examined ESKD data from 1983 to 2013. Data from 1998 to 2013 were obtained through an Information Management System. Data before 2008 were collected from patients' files. A questionnaire based on USRDS form 2728 was completed by nephrologists once a citizen reached ESKD.

RESULTS

A total of 4066 forms were completed, with a response rate of 90% (52% male). The mean (SD) age was 50.1 (14.0) years. By 31 December 2013, there were 2386 patients alive on RRT, of whom 1206 were on hemodialysis (50.5%), 1080 were living with a functioning kidney transplant (45.3%), and 100 were receiving peritoneal dialysis (4.2%). The incidence of ESKD on RRT was 21, 75, and 120 per million population in 1983, 2001, and 2013, respectively. Similarly, the prevalence of ESKD was 49, 916, and 2386 in 1983, 2001, and 2013 respectively. Among patients with ESKD on RRT, a progressive rise was seen in diabetic nephropathy, with 5.8%, 32.1%, and 46% in 1983, 2001, and 2013 respectively.

DISCUSSION

The incidence and prevalence of ESKD has increased progressively over last 30 years. This is anticipated to continue at an even higher rate in view of the progressive rise in noncommunicable diseases. Continuous improvement in registries is required to improve capturing of ESKD patients for providing accurate data to health authorities, and enhancing public awareness of the magnitude, future trends, treatments, and outcomes regarding ESKD.

Renal tissue oxygenation in essential hypertension and chronic kidney disease

Animal studies suggest that renal tissue hypoxia plays an important role in the development of renal damage in hypertension and renal diseases, yet human data were scarce due to the lack of noninvasive methods. Over the last decade, blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI), detecting deoxyhemoglobin in hypoxic renal tissue, has become a powerful tool to assess kidney oxygenation noninvasively in humans. This paper provides an overview of BOLD-MRI studies performed in patients suffering from essential hypertension or chronic kidney disease (CKD). In line with animal studies, acute changes in cortical and medullary oxygenation have been observed after the administration of medication (furosemide, blockers of the renin-angiotensin system) or alterations in sodium intake in these patient groups, underlining the important role of renal sodium handling in kidney oxygenation. In contrast, no BOLD-MRI studies have convincingly demonstrated that renal oxygenation is chronically reduced in essential hypertension or in CKD or chronically altered after long-term medication intake. More studies are required to clarify this discrepancy and to further unravel the role of renal oxygenation in the development and progression of essential hypertension and CKD in humans.

Not all inflammatory markers are linked to kidney function: results from a population-based study

BACKGROUND

Several studies have reported increased levels of inflammatory biomarkers in chronic kidney disease (CKD), but data from the general population are sparse. In this study, we assessed levels of the inflammatory markers C-reactive protein (hsCRP), tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-6 across all ranges of renal function.

METHODS

We conducted a cross-sectional study in a random sample of 6,184 Caucasian subjects aged 35-75 years in Lausanne, Switzerland. Serum levels of hsCRP, TNF-α, IL-6, and IL-1β were measured in 6,067 participants (98.1%); serum creatinine-based estimated glomerular filtration rate (eGFR(creat), CKD-EPI formula) was used to assess renal function, and albumin/creatinine ratio on spot morning urine to assess microalbuminuria (MAU).

RESULTS

Higher serum levels of IL-6, TNF-α and hsCRP and lower levels of IL-1β were associated with a lower renal function, CKD (eGFR(creat) <60 ml/min/1.73 m(2); n = 283), and MAU (n = 583). In multivariate linear regression analysis adjusted for age, sex, hypertension, smoking, diabetes, body mass index, lipids, antihypertensive and hypolipemic therapy, only log-transformed TNF-α remained independently associated with lower renal function (β -0.54 ±0.19). In multivariate logistic regression analysis, higher TNF-α levels were associated with CKD (OR 1.17; 95% CI 1.01-1.35), whereas higher levels of IL-6 (OR 1.09; 95% CI 1.02-1.16) and hsCRP (OR 1.21; 95% CI 1.10-1.32) were associated with MAU.

CONCLUSION

We did not confirm a significant association between renal function and IL-6, IL-1β and hsCRP in the general population. However, our results demonstrate a significant association between TNF-α and renal function, suggesting a potential link between inflammation and the development of CKD. These data also confirm the association between MAU and inflammation.

Glomerulonephritis and managing the risks of chronic renal disease

The rising global burden of chronic renal disease, the high cost of providing renal replacement therapies, and renal disease also being a risk factor for cardiovascular disease is increasing focus on renal disease prevention. This article focuses on the aspects of renal disease (specifically poststreptococcal glomerulonephritis [PSGN] and chronic kidney disease [CKD]) in Indigenous populations in Australia, New Zealand, Canada, and the United States that diverge from those typically seen in the general population of those countries. The spectrum of renal and many other diseases seen in Indigenous people in developed countries is similar to that seen in developing countries. Diseases like PSGN that have largely disappeared in developed countries still occur frequently in Indigenous people. CKD during the childhood years is due to congenital anomalies of the kidney and urinary tract in up to 70% of cases and occurs later in polycystic kidney disease and childhood-onset diabetes. Several risk factors for CKD in adulthood are already present in childhood.

Relationship between metabolic syndrome (MS) and coronary heart disease (CHD) in an aged group

Our study aimed at investigating the relationship between metabolic syndrome (MS) and coronary heart disease (CHD) in aged patients, including 125 patients (age> or =60 years). Of them 78 cases belonged to the CHD group, which were subdivided into the CHD-MS group (38 cases) and the simple CHD group (40 cases); the other 47 patients without CHD belonged to the non-CHD group, which were subdivided again into the MS group (11 cases) and the control group (36 cases). Body mass index (BMI), blood lipids, blood uric acid, plasma fibrinogen, blood glucose and blood pressure of every patient were detected. The anatomy of coronary vessels was analyzed by selective coronary angiography to evaluate the relationship between MS and CHD. We found that the prevalence of MS in CHD group was significantly higher as compared to the groups not suffering from CHD (p<0.01). The CHD-MS group showed a higher prevalence of multivessel disease (p<0.05), unstable lesions (p<0.05) and needed more revascularization procedures (p<0.05) than the simple CHD group. The prevalence of CHD and the number of blocked coronary vessels were directly correlated with MS by Spearman correlation analysis (r=0.225, p<0.05; r=0.361, p<0.01). Logistic regression analysis demonstrated that both the risk of having future CHD and the number of blocked coronary vessels were directly correlated with MS (p<0.01; p<0.01), suggesting that MS can predict the prevalence and extent of future CHD in the elderly.

Measuring the burden of illness for end-stage renal disease: some heavy lifting required

Estimates for the burden of illness (BOI) attributable to end-stage renal disease (ESRD) in Canada are presented in the article by Zelmer. This Commentary describes the methodology of BOI analysis, its role in formulating public policy, and the potential application to improving care for ESRD.

Predictors of diabetic end-stage renal disease in Japan

Diabetes mellitus (DM) has been the leading cause of incident dialysis in Japan since 1998, according to the Japanese Society for Dialysis Therapy (JSDT). In particular, the number of male DM dialysis patients is increasing. DM is becoming a worldwide epidemic in both developed and developing countries. Strategies to detect individuals at high-risk of developing CKD and end-stage renal disease (ESRD) are needed that can be implemented on a population-basis. Among the commonly measured variables, dipstick urinalysis (proteinuria, haematuria), blood pressure, serum creatinine, body mass index (BMI), and serum uric acid are significant predictors of ESRD. Recently, we evaluated the effect of DM as a risk factor of developing ESRD. DM was diagnosed when the fasting plasma glucose (FPG) was 126 mg/dL or more in participants (n = 78529) of the 1993 screening program in Okinawa. The prevalence of DM was 5.2%. The odds ratio (95% CI) of DM for developing ESRD was 3.098 (1.738-5.525, P = 0.0001) after adjusting for possible confounding variables. Early detection and treatment of DM might prevent DM-related ESRD. We examined 7125 non-DM screenees who underwent a 1-day health check between April 1997 and March 1998. They were followed-up until March 2000 to determine whether they developed DM. Over the 2 years, the cumulative incidence of DM was 2.3%, 2.9% in men and 1.3% in women. Proteinuria was the most robust predictor of the development of DM; the adjusted relative risk (95% CI) was 1.90 (1.14-3.17). Obesity, per se, is also recognized as a risk factor for developing proteinuria. The higher the BMI, the higher the risk of developing ESRD; the adjusted odds ratio (95% CI) was 1.273 (1.121-1.446, P = 0.0002) for men. Other than being overweight (BMI = 25.0 kg/m2), a smoking habit was a significant predictor of developing proteinuria. The prevalence of obesity and DM is increasing in Japan. It is possible that the impact of obesity and complications of DM are different among races and ethnicities. Public relations regarding the risk of DM and its complications are especially important in Asian countries. Asians have more fat than non-Asians, even at the same BMI levels. Knowledge of the predictors of DM-ESRD is crucial as a first step toward prevention. Consistent with this notion, initiatives on the management of CKD and ESRD were recently organized in Japan and internationally.

Type 2 diabetes mellitus: a cardiovascular perspective

Diabetes mellitus is a disease, which is at the epitome of cardiovascular risk factors causing considerable morbidity and mortality. In addition to microvascular complications, there is two- to six-fold increased risk of macrovascular diseases, such as coronary artery disease, peripheral artery disease and stroke. While the mortality from coronary artery disease in patients without diabetes has declined over the past 20 years, the mortality in men with type 2 diabetes mellitus has not changed. Furthermore, the prevalence of diabetes in the UK has increased by 30% since 1991 and the same among the world population in 2010 is expected to be twice in 1990. This dramatic increase has serious implications from a cardiovascular perspective and thus the aggressive management of blood pressure, dyslipidaemia and blood glucose in diabetes is of vital importance. The aim of this review is to evaluate the current evidence and to discuss the implications of type 2 diabetes and its relevance to clinical practice in cardiology. We address this broad subject in discussing (i) the pathophysiology of cardiovascular disease in the setting of type 2 diabetes and (ii) the prevalence of cardiovascular risk, complications and prognostic implications in type 2 diabetes, with a discussion of current therapeutic interventions for the prevention or delay of these consequences where relevant.