Medical Ethics in Nephrology: A Jewish Perspective

Jewish medical ethics is arguably the oldest recorded system of bioethics still in use. It should be of interest to practicing nephrologists because of its influence on the ethical systems of Christianity, Islam, and Western secular society; because of the extensive written documentation of rabbinical response in addressing a broad range of bioethical dilemmas; and in understanding the values of patients who choose to adhere to religious Jewish law. The goal of this review is to provide a brief overview of the basic principles underlying mainstream traditional Jewish medical ethics, apply them to common clinical scenarios experienced in nephrology practice, and contrast them with that of secular medical ethics

Is Bariatric Surgery an Effective Treatment for Type II Diabetic Kidney Disease?

Type II diabetic kidney disease is devastating to patients and society alike. This review will evaluate bariatric surgery as a treatment for diabetic kidney disease primarily through its ability to induce and maintain regression of type II diabetes. The review begins by outlining the global challenge of diabetic kidney disease, its link to obesity, and the comparative benefits of bariatric surgery on weight and type II diabetes. It then surveys comprehensively the relevant literature, which reports that although bariatric surgery is associated with reductions in albuminuria, its effect on harder clinical end points like progression of diabetic kidney disease is not known. The review also includes a critical assessment of the risks and costs of bariatric surgery and concludes by acknowledging the major knowledge gaps in the field and providing research strategies to overcome them. Until these knowledge gaps are filled, clinicians will be forced to rely on their own subjective judgment in determining the benefit-risk ratio of bariatric surgery for patients with diabetic kidney disease

Life-threatening post-thrombectomy hypotension due to residual complications from a translumbar catheter

Translumbar catheters offer an alternative life-saving option in patients without conventional dialysis access, though their use and complication rates are poorly understood. We report the first case in the medical literature of a translumbar catheter inducing a central venous stenosis. This occult sequela converted what is usually a subclinical complication from an arteriovenous graft thrombectomy into a life-threatening one. This unusual clinical presentation highlights the need for clinicians to recognize the potential serious implications of translumbar catheter-induced occult central venous stenosis

Is Routine Multivitamin Supplementation Necessary in US Chronic Adult Hemodialysis Patients? A Systematic Review

Because of concern that United States (US) chronic hemodialysis patients are at high risk for the development of vitamin deficiencies, the great majority of such patients are routinely supplemented with a multivitamin. This policy is supported by major US dialysis providers and nonprofit organizations. Yet routine multivitamin supplementation expands hemodialysis patients' already large pill burden, probably accounts for many millions of dollars in annual costs, and in light of previous reports may even carry with it the possibility of increased risk of adverse outcomes. An analysis of the benefits of routine multivitamin supplementation in US patients is therefore in order. We performed a systematic review of the medical literature between 1970 and 2014 using the Ovid MEDLINE database to address this question. We conclude that there is insufficient evidence to support routine multivitamin use and recommend that the decision to supplement be made on an individual basis

Serum phospholipid fraction of polyunsaturated fatty acids is the preferred indicator for nutrition and health status in hemodialysis patients

Long chain (LC) polyunsaturated fatty acids (PUFA) are major components of cell membrane phospholipids (PL) and serve as precursors for numerous bioactive lipid derivatives. Fatty acids (FA) are routinely analyzed in biological samples to assess composition of tissues, cells, and lipid fractions. In human studies, serum or plasma is often used because of their easy procurement. However, the lipid pool in serum and plasma is a mixture of triacylglycerol (TG), PL, cholesterol and its esters, and other components. Herein, we report findings from a serum FA analysis after fractionation of polar and neutral lipids by solid phase extraction in a large cohort of 400 hemodialysis patients. LC PUFA were found concentrated in the polar fraction compared to the total or the neutral lipid fraction. When correlated with clinical markers of disease, a greater number of significant correlations were found for PUFA in polar compared to total or the neutral fraction. We also observed that polar lipids are a reliable reflection of LC PUFA status compared to the total or neutral fractions because the latter are diluted by non-essential FA. The relative amounts of LC PUFA in the total and neutral fractions reflect the contribution of TG in blood that varies with diet, age, and physiologic state. Our data indicate that LC PUFA in the polar fraction are superior indicators of bioactive FA-status than in the total or the neutral fraction and should be used to establish important links between PUFA status, their bioactive substrates in hemodialysis patients

Personal Attitudes Toward Weight in Overweight and Obese US Hemodialysis Patients

Objective Overweight and obesity have become increasingly common among end-stage renal disease patients on hemodialysis. Yet, little attention has been given to what hemodialysis patients themselves think of their weight, how they perceive it affects their health, and their attitudes about or desire for weight reduction. We explored these issues using a survey that we designed specifically for the dialysis population. Design and Methods Sixty-six chronic hemodialysis patients from a US urban center with a body mass index ≥25 kg/m2 and stable weight were recruited to participate in a cross-sectional study. The 12-question weight-related survey was validated by retesting a random portion of the study population. Results Based on test–retest results, the survey had good to excellent validity. Seventy-nine percent of patients were black, 49% were male, 29% were overweight, and 71% were obese. In general, the patients underestimated their weight excess though 73% were interested in weight loss, of whom nearly half reported attempting to do so mostly through diet and exercise. The majority of participants interested in losing weight felt that doing so would improve their physical and emotional health. The most common barrier to weight reduction was a belief that it was too difficult (55%), followed by a lack of motivation, money, time, resources, and knowledge. Diet was the most common weight loss strategy (85%) considered, whereas bariatric surgery was the least common (6.1%). Conclusions A majority of overweight and obese hemodialysis patients believe their excess weight is adversely impacting their health and quality of life and therefore wish to lose weight

Influence of dietary protein on glomerular filtration before and after bariatric surgery: a cohort study

BACKGROUND: Obesity-associated elevations in glomerular filtration rate (GFR) are common and may play a role in the development of kidney disease, so identifying the underlying mechanism is important. We therefore studied whether reductions in dietary protein intake, which is known to modulate GFR, explain why GFR decreases after bariatric surgery-induced weight loss. STUDY DESIGN: Cohort study with participants as their own controls. SETTING & PARTICIPANTS: 8 severely obese patients with normal kidney function were recruited from bariatric surgery centers in Indianapolis, IN. All participants were placed on a fixed-protein (50-g/d) diet for 1 week before and after a minimum of a 20-kg weight loss by bariatric surgery and were followed up closely by dieticians for adherence. PREDICTOR: Ad lib versus low-protein diet before versus after bariatric surgery. OUTCOME: Measured GFR, using repeated-measures analysis, was used to estimate the independent effects of diet and surgery. MEASUREMENT: GFR was measured using plasma iohexol clearance. RESULTS: A median of 32.9 (range, 19.5-54.4)kg was lost between the first presurgery visit and first postsurgery visit. Dietetic evaluations and urinary urea excretion confirmed that patients generally adhered to the study diet. GFRs on an ad lib diet were significantly higher before compared to after surgery (GFR medians were 144 (range, 114-178) and 107 (range, 85-147) mL/min, respectively; P=0.01). Although bariatric surgery (-26mL/min; P=0.005) and dietary sodium intake (+7.5mL/min per 100mg of dietary sodium; P=0.001) both influenced GFR, consuming a low-protein diet did not (P=0.7). LIMITATIONS: Small sample size; mostly white women; possible lack of generalizability. CONCLUSIONS: The decrease in GFR observed after bariatric surgery is explained at least in part by the effects of surgery and/or dietary sodium intake, but not by low dietary protein consumption

Predicting the glomerular filtration rate in bariatric surgery patients

BACKGROUND/AIMS: Identifying the best method to estimate the glomerular filtration rate (GFR) in bariatric surgery patients has important implications for the clinical care of obese patients and research into the impact of obesity and weight reduction on kidney health. We therefore performed such an analysis in patients before and after surgical weight loss. METHODS: Fasting measured GFR (mGFR) by plasma iohexol clearance before and after bariatric surgery was obtained in 36 severely obese individuals. Estimated GFR was calculated using the Modification of Diet in Renal Disease equation, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation using serum creatinine only, the CKD-EPI equation using serum cystatin C only and a recently derived equation that uses both serum creatinine and cystatin C (CKD-EPIcreat-cystC) and then compared to mGFR. RESULTS: Participants were primarily middle-aged white females with a mean baseline body mass index of 46 ± 9, serum creatinine of 0.81 ± 0.24 mg/dl and mGFR of 117 ± 40 ml/min. mGFR had a stronger linear relationship with inverse cystatin C before (r = 0.28, p = 0.09) and after (r = 0.38, p = 0.02) surgery compared to the inverse of creatinine (before: r = 0.26, p = 0.13; after: r = 0.11, p = 0.51). mGFR fell by 17 ± 35 ml/min (p = 0.007) following surgery. The CKD-EPIcreat-cystC was unquestionably the best overall performing estimating equation before and after surgery, revealing very little bias and a capacity to estimate mGFR within 30% of its true value over 80% of the time. This was true whether or not mGFR was indexed for body surface area. CONCLUSIONS: In severely obese bariatric surgery patients with normal kidney function, cystatin C is more strongly associated with mGFR than is serum creatinine. The CKD-EPIcreat-cystC equation best predicted mGFR both before and after surgery

Inquiry into the short- and long-term effects of Roux-en-Y gastric bypass on the glomerular filtration rate

Bariatric surgery is known to attenuate glomerular hyperfiltration over the long term and thereby protect the kidney from mechanical damage. Whether this effect is directly related to weight loss or is independent of weight as are some of its other beneficial metabolic effects is not known. We explored this question in a preliminary study that directly measured glomerular filtration rate (GFR) before, immediately after, and again many months after Roux-en-Y gastric bypass after large weight loss had occurred. We simultaneously measured stimulated circulating glucagon-like peptide-1, which is upregulated after Roux-en-Y gastric bypass and is a putative mediator of GFR after bariatric surgery. We found no weight-independent effect of Roux-en-Y gastric bypass on GFR nor an association between circulating GLP-1 levels and GFR. These findings, if confirmed in larger studies, will help steer future enquiries in this area