Validation of the SMH Equations for the Estimation of the Total Body Water Volume in Hemodialysis Patients.

Background: Online dialysis clearance monitors typically provide an accurate value for Kt. A value for V (total body water [TBW]) is required to calculate Kt/V, the measure of the adequacy of the delivered dialysis in hemodialysis (HD) patients. Using bioimpedance spectroscopy (BIS), we previously developed 2 sex-specific equations for the estimation of the TBW, which we have chosen to name the St Michael's Hospital (SMH) equations.

Effects of coadministration of DHA and vitamin E on spermatogram, seminal oxidative stress, and sperm phospholipids in asthenozoospermic men: a randomized controlled trial.

Background: It is unknown which compounds in spermatozoa or seminal plasma may be involved in the regulation of sperm motility.

Objectives: The aim of this study was to investigate the effects of DHA (22:6n-3), vitamin E, and their probable interactions in men with asthenozoospermia.

Methods: A factorial, randomized, double-blind, placebo-controlled trial was conducted in infertility clinics in Tehran, Iran.

Volume Estimates in Chronic Hemodialysis Patients by the Watson Equation and Bioimpedance Spectroscopy and the Impact on the Kt/V calculation.

Background: Accurate assessment of total body water (TBW) is essential for the evaluation of dialysis adequacy (Kt/V). The Watson formula, which is recommended for the calculation of TBW, was derived in healthy volunteers thereby leading to potentially inaccurate TBW estimates in maintenance hemodialysis recipients. Bioimpedance spectroscopy (BIS) may be a robust alternative for the measurement of TBW in hemodialysis recipients.

Frailty and the Quality of Life in Hemodialysis Patients: The Importance of Waist Circumference.

Objective: Frailty among the end-stage renal disease (ESRD) population is highly prevalent and has been associated with mortality. Little is known about the relation of different aspects of body composition, a modifiable risk factor, with the risk of frailty in ESRD population.

Design And Methods: One hundred and fifty-one patients including 85 men and 66 women, aged ≥18 years with ESRD who had been receiving conventional maintenance hemodialysis (HD) for at least 3 months were included.

Nutritional status after conversion from conventional to in-centre nocturnal hemodialysis.

Introduction: Recipients of conventional hemodialysis (CHD; 3-4 h/session, 3 times/week) experience volume expansion and nutritional impairment which may contribute to high mortality. Prolongation of sessions with in-centre nocturnal hemodialysis (INHD; 7-8 h/session, 3 times/week) may improve clinical outcomes by enhancement of ultrafiltration and uremic toxin removal.

Materials And Methods: In this prospective cohort study, 56 adult patients who were receiving maintenance CHD for at least 90 days were assigned to CHD (patients who remained in CHD) and INHD (patients who switched to INHD) groups.

Reduction of carbamylated albumin by extended hemodialysis.

Introduction Among conventional hemodialysis (CHD) patients, carbamylated serum albumin (C-Alb) correlates with urea and amino acid deficiencies and is associated with mortality. We postulated that reduction of C-Alb by intensive HD may correlate with improvements in protein metabolism and cardiac function. Methods One-year observational study of in-center nocturnal extended hemodialysis (EHD) patients and CHD control subjects.

Urinary lithogenic risk profile in recurrent stone formers with hyperoxaluria: a randomized controlled trial comparing DASH (Dietary Approaches to Stop Hypertension)-style and low-oxalate diets.

Background: Patients with nephrolithiasis and hyperoxaluria generally are advised to follow a low-oxalate diet. However, most people do not eat isolated nutrients, but meals consisting of a variety of foods with complex combinations of nutrients. A more rational approach to nephrolithiasis prevention would be to base dietary advice on the cumulative effects of foods and different dietary patterns rather than single nutrients.

Effects of combined lipoic acid and pyridoxine on albuminuria, advanced glycation end-products, and blood pressure in diabetic nephropathy.

This study was designed to investigate the effects of combined administration of lipoic acid and pyridoxine on albuminuria, oxidative stress, blood pressure, serum advanced glycation end-products, nitric oxide (NO), and endothelin-1 in patients with diabetic nephropathy. Thirty-four patients were randomly assigned to either a supplement group or a placebo group. The patients in the supplement group received 800 mg lipoic acid and 80 mg pyridoxine daily for 12 weeks, whereas the placebo group received corresponding placebos.

Serum creatinine as a marker of muscle mass in chronic kidney disease: results of a cross-sectional study and review of literature.

Background: Higher muscle mass is associated with better outcomes and longevity in patients with chronic disease states. Imaging studies such as dual-energy X-ray absorptiometry (DEXA) are among the gold standard methods for assessing body fat and lean body mass (LBM), approximately half of which is comprised of skeletal muscle mass. Elaborate imaging devices, however, are not commonly available in routine clinical practice and therefore easily accessible and cost-effective, but reliable muscle mass biomarkers are needed.

Novel lipoprotein subfraction and size measurements in prediction of mortality in maintenance hemodialysis patients.

Background And Objectives: Conventional lipid profiles usually cannot predict cardiovascular outcomes in chronic disease states. We hypothesized that novel lipoprotein subfraction concentrations and LDL particle size measurements better predict mortality in maintenance hemodialysis (MHD) patients.

Design, Setting, Participants, & Measurements: Mortality-predictability of LDL particle diameter and lipoprotein subfraction concentrations, measured by novel ion mobility, was examined in a cohort of 235 hemodialysis patients who were followed for up to 6 years using Cox models with adjustment for important covariables.

Examining associations of circulating endotoxin with nutritional status, inflammation, and mortality in hemodialysis patients.

Objective: Lipopolysaccharide or endotoxin constitutes most part of the outer portion of the cell wall in the gram-negative bacteria. Subclinical endotoxemia could contribute to increased inflammation and mortality in hemodialysis (HD) patients. Endotoxin level and clinical effect are determined by its soluble receptor sCD14 and high-density lipoprotein.

Dietary omega-3 fatty acid, ratio of omega-6 to omega-3 intake, inflammation, and survival in long-term hemodialysis patients.

Background: Mortality in long-term hemodialysis patients is high, mostly attributed to cardiovascular events, and may be related to chronic inflammation. We hypothesized that the anti-inflammatory benefits of higher dietary intake of omega-3 compared with omega-6 polyunsaturated fatty acids may modulate the inflammatory processes and decrease death risk.

Study Design: Prospective cohort study using linear and Cox proportional regressions.

Quality-of-life and mortality in hemodialysis patients: roles of race and nutritional status.

Background And Objectives: Maintenance hemodialysis (MHD) patients often have protein-energy wasting, poor health-related quality of life (QoL), and high premature death rates, whereas African-American MHD patients have greater survival than non-African-American patients. We hypothesized that poor QoL scores and their nutritional correlates have a bearing on racial survival disparities of MHD patients.

Design, Setting, Participants, & Measurements: We examined associations between baseline self-administered SF36 questionnaire-derived QoL scores with nutritional markers by multivariate linear regression and with survival by Cox models and cubic splines in the 6-year cohort of 705 MHD patients, including 223 African Americans.

Glycemic control and survival in peritoneal dialysis patients with diabetes mellitus.

Background And Objectives: The optimal target for glycemic control has not been established for diabetic peritoneal dialysis (PD) patients.

Design, Setting, Participants, & Measurements: We examined mortality-predictability of hemoglobin A1c random serum glucose in a contemporary cohort of diabetic PD patients treated in DaVita dialysis clinics July 2001 through June 2006 with follow-up through June 2007.

Results: We identified 2798 diabetic PD patients with A1c data.

Racial and ethnic differences in mortality of hemodialysis patients: role of dietary and nutritional status and inflammation.

Background: Racial/ethnic disparities prevail among hemodialysis patients. We hypothesized that significant differences exist between Black and non-Hispanic and Hispanic White hemodialysis patients in nutritional status, dietary intake and inflammation, and that they account for racial survival disparities.

Methods: In a 6-year (2001-2007) cohort of 799 hemodialysis patients, we compared diet and surrogates of nutritional-inflammatory status and their mortality-predictabilities between 279 Blacks and 520 Whites using matched and regression analyses and Cox with cubic splines.

Novel equations to estimate lean body mass in maintenance hemodialysis patients.

Background: Lean body mass (LBM) is an important nutritional measure representing muscle mass and somatic protein in hemodialysis patients, for whom we developed and tested equations to estimate LBM.

Study Design: A study of diagnostic test accuracy.

Setting & Participants: The development cohort included 118 hemodialysis patients with LBM measured using dual-energy x-ray absorptiometry (DEXA) and near-infrared (NIR) interactance.

The obesity paradox and mortality associated with surrogates of body size and muscle mass in patients receiving hemodialysis.

Objective: To determine whether dry weight gain accompanied by an increase in muscle mass is associated with a survival benefit in patients receiving maintenance hemodialysis (HD).

Patients And Methods: In a nationally representative 5-year cohort of 121,762 patients receiving HD 3 times weekly from July 1, 2001, through June 30, 2006, we examined whether body mass index (BMI) (calculated using 3-month averaged post-HD dry weight) and 3-month averaged serum creatinine levels (a likely surrogate of muscle mass) and their changes over time were predictive of mortality risk.

Results: In the cohort, higher BMI (up to 45) and higher serum creatinine concentration were incrementally and independently associated with greater survival, even after extensive multivariate adjustment for available surrogates of nutritional status and inflammation.

Mid-arm muscle circumference and quality of life and survival in maintenance hemodialysis patients.

Background And Objectives: Maintenance hemodialysis (MHD) patients with larger body or fat mass have greater survival than normal to low mass. We hypothesized that mid-arm muscle circumference (MAMC), a conveniently measured surrogate of lean body mass (LBM), has stronger association with clinical outcomes than triceps skinfold (TSF), a surrogate of fat mass.

Design, Settings, Participants, & Measurements: The associations of TSF, MAMC, and serum creatinine, another LBM surrogate, with baseline short form 36 quality-of-life scores and 5-year survival were examined in 792 MHD patients.

Survival predictability of lean and fat mass in men and women undergoing maintenance hemodialysis.

Background: Larger body size is associated with greater survival in maintenance hemodialysis (MHD) patients. It is not clear how lean body mass (LBM) and fat mass (FM) compare in their associations with survival across sex in these patients.

Objective: We examined the hypothesis that higher FM and LBM are associated with greater survival in MHD patents irrespective of sex.

Design and development of a dialysis food frequency questionnaire.

Objectives: Periodic assessment of dietary intake across a given dialysis population may help to improve the clinical outcomes related to nutrients such as dietary protein, phosphorus, or potassium. Although dietary recalls and food records are used to assess dietary intake at individual level and over shorter periods, food frequency questionnaires (FFQ) are used to rank subjects of a given population according to their nutrient intake over longer periods.

Design: To modify and refine the conventional Block FFQ to develop a specific FFQ for dialysis patients.

Dietary protein intake in patients with advanced chronic kidney disease and on dialysis.

Many patients with chronic kidney disease (CKD), particularly those with stage 5 CKD, have protein wasting. The degree to which increased morbidity and mortality seen in these patients is due to protein depletion rather than to the often accompanying comorbidity is not clear. High protein diets lead to the accumulation of metabolites of protein that are potentially toxic.

Dietary assessment of individuals with chronic kidney disease.

Examining the quality and quantity of food intake by appropriate methods is critical in the management of patients with chronic kidney disease (CKD). The four commonly used dietary assessment methods in CKD patients include short-term dietary recalls, several days of food records with or without dietary interviews, urea kinetic based estimates such as protein nitrogen appearance calculation, and food histories including food screeners and food frequency questionnaires (FFQ). There are a number of strengths and limitations of these dietary assessment methods.

Dietary potassium intake and mortality in long-term hemodialysis patients.

Background: Hyperkalemia has been associated with higher mortality in long-term hemodialysis (HD) patients. There are few data concerning the relationship between dietary potassium intake and outcome.

Study Design: The mortality predictability of dietary potassium intake from reported food items estimated using the Block Food Frequency Questionnaire (FFQ) at the start of the cohort was examined in a 5-year (2001-2006) cohort of 224 HD patients in Southern California using Cox proportional hazards regression.

Effect of diabetes mellitus on protein-energy wasting and protein wasting in end-stage renal disease.

Protein wasting (PW) or protein-energy wasting (PEW) occurs commonly in patients with diabetes mellitus who have end-stage renal disease (ESRD) and are undergoing maintenance dialysis (MD) therapy. Some but not all studies indicate that PW or PEW is more prevalent in diabetic when compared with nondiabetic MD patients and that diabetic patients commencing maintenance hemodialysis (MHD) are more likely to lose fat-free, edema-free weight than are incident nondiabetic MHD patients. The causes of PW and PEW in diabetic MD patients are probably largely similar to those of nondiabetic MD patients.