Intermuscular adipose tissue accumulation is associated with higher tissue sodium in healthy individuals.

BACKGROUND AND AIMS: High tissue sodium accumulation and intermuscular adipose tissue (IMAT) are associated with aging, type 2 diabetes, and chronic kidney disease. In this study, we aim to investigate whether high lower-extremity tissue sodium accumulation relates to IMAT quantity and whether systemic inflammatory mediators and adipocytokines contribute to such association. METHODS: Tissue sodium content and IMAT accumulation (percentage of IMAT area to muscle area) were measured in 83 healthy individuals using sodium imaging (23Na-MRI) and proton (1H-MRI) imaging of the calf. Insulin sensitivity was assessed by glucose disposal rate (GDR) measured with the hyperinsulinemic-euglycemic clamp. RESULTS: Median (interquartile range) muscle and skin sodium contents were 16.6 (14.9, 19.0) and 12.6 (10.9, 16.7) mmol/L, respectively. Median IMAT was 3.69 (2.80, 5.37) %. In models adjusted for age, sex, BMI, GDR, adiponectin, and high-sensitivity C-reactive protein, increasing tissue sodium content was significantly associated with higher IMAT quantity (p = 0.018 and 0.032 for muscle and skin tissue sodium, respectively). In subgroup analysis stratified by sex, skin sodium was significantly associated with IMAT only among men. In interaction analysis, the association between skin sodium and IMAT was greater with increasing levels of high-sensitivity C-reactive protein and interleukin-6 (p for interaction = 0.022 and 0.006, respectively). CONCLUSIONS: Leg muscle and skin sodium are associated with IMAT quantity among healthy individuals. The relationship between skin sodium and IMAT may be mediated by systemic inflammation.

The relationship between changes in peritoneal membrane solute transfer characteristics and cardiac remodeling in patients with peritoneal dialysis.

INTRODUCTION: We aimed to determine the relationship between the dilatation of the heart chambers and the change in peritoneal membrane solute transfer characteristics (PMTC) in long-term peritoneal dialysis (PD) patients. METHODS: This is a retrospective, single-center study including the follow-up of maintenance PD patients. According to the changes in PMTC from baseline to the last visit, patients were divided into three groups; stable (n = 11), increased (n = 41), and decreased transporters (n = 35). RESULTS: Left atrium (LA) and Right ventricle (RV) dilatation were more prominent in the PMTC-decreased group compared to PMTC-increased and stable groups (p < 0.001 and p = 0.07, respectively). The Cox regression analysis showed that only decreased PMTC was associated with LA dilatation (HR 2.89 [CI 95%1.54, 5.45] p < 0.01) and RV dilatation (HR 3.01 [CI 95%1.40, 6.21] p < 0.01). CONCLUSION: PD can be associated with unfavorable dynamic changes in cardiac structure and functions even at the subclinical level.

How many blood pressure measurements should we take in the office?

No consensus has emerged among different guidelines concerning how many blood pressure (BP) measurements should be performed at office visits in the diagnosis of hypertension. The purpose of this study was to examine the compatibility of various multiple average office BP measurements and 24-h BP monitoring (ABPM) in patients followed up in the posthoc analysis of the Cappadocia hypertension cohort. A total 1158 office BP measurements by 207 patients were examined. The results were then classified as G1 (average of the 1st and 2nd BP), G2 (average of the 2nd and 3rd), G3 (average of the 2nd, 3rd, and 4th), G4 (average of the 2nd, 3rd, 4th, and 5th), and G5 (average of all five measurements). Compatibility between the average values in the groups and concomitant 24-h ABPM data was examined. While a significant difference was observed between daytime 24-h ABPM SBP and G1 (p = .002), no difference was found in the other groups. Office DBP approached the daytime 24-h ABPM values as the number of measurements in the five groups increased, although average office DBP data in all groups were higher than daytime 24-h ABPM DBP (p = .000 for all). In light of our study results, we recommend that three office BP measurements be performed and that the average of the 2nd and 3rd measurements be used for SBP, while in terms of DBP, we recommend that as many measurements as possible be taken without the 1st value being included in the average.

A randomized controlled pilot trial of anakinra and pioglitazone for protein metabolism in patients on maintenance haemodialysis.

BACKGROUND: Chronic inflammation and insulin resistance are highly prevalent in patients on maintenance haemodialysis (MHD) and are strongly associated with protein energy wasting. We conducted a pilot, randomized, placebo-controlled trial of recombinant human interleukin-1 receptor antagonist (IL-1ra) and pioglitazone to explore the safety, feasibility and efficacy for insulin-mediated protein metabolism in patients undergoing MHD. METHODS: Twenty-four patients were randomized to receive IL-1ra, pioglitazone or placebo for 12 weeks. Changes in serum inflammatory markers and insulin-mediated protein synthesis, breakdown and net balance in the whole-body and skeletal muscle compartments were assessed using hyperinsulinaemic-hyperaminoacidemic clamp technique at baseline and Week 12. RESULTS: Among 24 patients, median (interquartile range) age was 51 (40, 61), 79% were African American and 21% had diabetes mellitus. All patients initiated on intervention completed the study, and no serious adverse events were observed. There was a statistically significant decrease in serum high-sensitivity C-reactive protein in the pioglitazone group compared with placebo, but not in the IL-1ra group. No significant differences in the changes of whole-body or skeletal muscle protein synthesis, breakdown and net balance were found between the groups. CONCLUSIONS: In this pilot study, there were no statistically significant effects of 12 weeks of IL-1ra or pioglitazone on protein metabolism in patients on MHD. CLINICALTRIALS: gov registration: NCT02278562.

High tissue-sodium associates with systemic inflammation and insulin resistance in obese individuals.

BACKGROUND AND AIMS: High sodium intake is associated with obesity and insulin resistance, and high extracellular sodium content may induce systemic inflammation, leading to cardiovascular disease. In this study, we aim to investigate whether high tissue sodium accumulation relates with obesity-related insulin resistance and whether the pro-inflammatory effects of excess tissue sodium accumulation may contribute to such association. METHODS AND RESULTS: In a cross-sectional study of 30 obese and 53 non-obese subjects, we measured insulin sensitivity determined as glucose disposal rate (GDR) using hyperinsulinemic euglycemic clamp, and tissue sodium content using 23Na magnetic resonance imaging. Median age was 48 years, 68% were female and 41% were African American. Median (interquartile range) BMI was 33 (31.5, 36.3) and 25 (23.5, 27.2) kg/m2 in the obese and non-obese individuals, respectively. In obese individuals, insulin sensitivity negatively correlated with muscle (r = -0.45, p = 0.01) and skin sodium (r = -0.46, p = 0.01). In interaction analysis among obese individuals, tissue sodium had a greater effect on insulin sensitivity at higher levels of high-sensitivity C-reactive protein (p-interaction = 0.03 and 0.01 for muscle and skin Na+, respectively) and interleukin-6 (p-interaction = 0.024 and 0.003 for muscle and skin Na+, respectively). In interaction analysis of the entire cohort, the association between muscle sodium and insulin sensitivity was stronger with increasing levels of serum leptin (p-interaction = 0.01). CONCLUSIONS: Higher muscle and skin sodium are associated with insulin resistance in obese patients. Whether high tissue sodium accumulation has a mechanistic role in the development of obesity-related insulin resistance through systemic inflammation and leptin dysregulation remains to be examined in future studies. CLINICALTRIALS: gov registration: NCT02236520.

The association between geriatric nutritional risk index variability and mortality in peritoneal dialysis patients.

BACKGROUND: The objective of this study is to examine the association between the Geriatric Nutritional Risk Index (GNRI) and overall mortality in this population. METHODS: GNRI values were calculated by using the serum albumin levels and body weight and the GNRI variability reflects the changes in GNRI change slopes in the follow-up. RESULTS: GNRI values showed a decrease from the median baseline GNRI of 106.3 (IQR, 95.0,113.4) to 98.4 (interquartile range [IQR], 91.9108.9) (p < 0.001). The median GNRI variability was 4.7 (IQR, 2.5, 10.3). Both baseline GNRI levels (adjusted odds ratio [OR]: 0.96, 95% confidence interval [CI]: 0.93, 0.99, p = 0.04) and more profoundly GNRI variability (adjusted OR: 1.23, 95% CI: 1.01, 1.44, p = 0.03) were independently associated with mortality. CONCLUSION: The monitorization of the changes in GNRI values as a variability index is an easy tool that might improve the predictive accuracy of mortality in peritoneal dialysis patients.

Association of longitudinal high-sensitive C-reactive protein levels with changing membrane characteristics in peritoneal dialysis.

BACKGROUND: Increasing peritoneal permeability with ultrafiltration and solute removal inadequacy is a challenging issue in peritoneal dialysis (PD). Decreasing permeability is less frequent but also results in diminished solute clearance. We evaluated the association between longitudinal high-sensitive C-reactive protein (hs-CRP) values and the change in transport characteristics of the peritoneal membrane in PD patients. METHODS: This is a retrospective, single-center study of incident PD patients. An increase or decrease in peritoneal transport status is defined as two or more categories of a rise or decline in the peritoneal equilibration test (PET) from their baseline during follow-up. The 4-h dialysate/plasma creatinine ratio was used to classify transport characteristics. Hs-CRP values were obtained from the routine annual examinations of the patients. RESULTS: Baseline demographics, residual kidney function, frequency of high glucose-containing dialysate, and icodextrin use were similar between the groups. Total episodes of peritonitis within the first 5 years of follow-up were higher in stable transporters than in increased and decreased transporters (p = 0.009). Stable transporters' mean hs-CRP values did not change within 5 years (Wilks' λ = 0.873, F (2.317, 180.740) = 2.210, p = 0.10). Increased and decreased transporters' hs-CRP values significantly raised over the years (Wilks' λ = 0.422, F (1.979, 77.163) = 3.405, p = 0.04 and Wilks' λ = 0.558, F (3.673, 66.107) = 4.396, p = 0.001, respectively). CONCLUSIONS: Our study shows that the peritoneal membrane may change into different characteristics in many patients over time, despite very low peritonitis frequencies and similar baseline characteristics that may be significantly affected by systemic inflammation.

Comparison of geriatric nutritional risk index and creatinine index in short-term mortality prediction in maintenance hemodialysis patients.

BACKGROUND: The aim of this study is to analyze and compare the predictive values of the Geriatric Nutritional Risk Index (GNRI) and Creatinine Index (CI) in the short-term mortality of maintenance hemodialysis patients and to determine their best cut-offs. METHODS: A total of 169 adult hemodialysis patients were included in this retrospective, cross-sectional, and single-center study. The demographic, clinical, and laboratory data of the month in which the patients were included in the study were obtained from their medical files and computer records. All-cause death was the primary outcome of the study during a 12-month follow-up after baseline GNRI and CI calculations. RESULTS: The mean age of the study population was 57 ± 16 years (49.7% were women, 15% were diabetic). During the one-year observation period, 19 (11.24%) of the cases died (8 CV deaths). The optimal cut-off value for GNRI was determined as 104.2 by ROC analysis [AUC = 0.682 ± 0.06, (95% CI, 0.549-0.815), p = 0.01]. The low GNRI group had a higher risk for all-cause and CV mortality compared to the higher GNRI group (p = 0.02 for both in log-rank test). The optimal sex-specific cut-off was 12.18 mg/kg/day for men [AUC = 0.723 ± 0.07, (95% CI, 0.574-0.875), p = 0.03] and was 12.08 mg/kg/day for females [AUC = 0.649 ± 0.13, (95% CI, 0.384- 0.914), p = 0.01]. Patients with lower sex-specific CI values had higher all-cause and CV mortality (p = 0.001 and p = 0.009 in log-rank test, respectively). In multivariate cox models, both GNRI [HR = 4.904 (% 95 CI, 1.77-13.56), p = 0.002] and sex-specific CI [HR = 5.1 (95% CI, 1.38-18.9), p = 0.01] predicted all-cause mortality. The association of GNRI with CV was lost [HR = 2.6 (CI 95%, 0.54-13.455), p = 0.22], but low CI had a very strong association with CV mortality [HR = 11.48 (CI 95%, 1.25 -104), p = 0.03]. DISCUSSION: In hemodialysis patients, GNRI and CI have similar powers in predicting all-cause short-term mortality. The association of CI with all-cause death depends on gender. On the other hand, sex-specific CI predicts CV mortality better than GNRI.

Tissue Sodium in Patients With Early Stage Hypertension: A Randomized Controlled Trial.

Background Sodium (Na+) stored in skin and muscle tissue is associated with essential hypertension. Sodium magnetic resonance imaging is a validated method of quantifying tissue stores of Na+. In this study, we evaluated tissue Na+ in patients with elevated blood pressure or stage I hypertension in response to diuretic therapy or low Na+ diet. Methods and Results In a double-blinded, placebo-controlled trial, patients with systolic blood pressure 120 to 139 mm Hg were randomized to low sodium diet (<2 g of sodium), chlorthalidone, spironolactone, or placebo for 8 weeks. Muscle and skin Na+ using sodium magnetic resonance imaging and pulse wave velocity were assessed at the beginning and end of the study. Ninety-eight patients were enrolled to undergo baseline measurements and 54 completed randomization. Median baseline muscle and skin Na+ in 98 patients were 16.4 mmol/L (14.9, 18.9) and 13.1 mmol/L (11.1, 16.1), respectively. After 8 weeks, muscle Na+ increased in the diet and chlorthalidone arms compared with placebo. Skin sodium was decreased only in the diet arm compared with placebo. These associations remained significant after adjustment for age, sex, body mass index, systolic blood pressure, and urinary sodium. No changes were observed in pulse wave velocity among the different groups when compared with placebo. Conclusions Diuretic therapy for 8 weeks did not decrease muscle or skin sodium or improve pulse wave velocity in patients with elevated blood pressure or stage I hypertension. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02236520.

Does Blood Pressure Variability Affect Hypertension Development in Prehypertensive Patients?

BACKGROUND: Blood pressure variability (BPV) is associated with end organ damage and cardiovascular outcomes in hypertensive patients. Prehypertensive patients frequently develop hypertension (HT). The purpose of the present study was to evaluate the effect of BPV on the development of HT. METHODS: Two hundred and seven prehypertensive patients from the Cappadocia cohort were monitored over 2 years, and 24-hour ambulatory blood pressure monitoring (ABPM), office BP, and home BP measurements were subsequently performed at 4- to 6-month intervals. BPV was calculated as average real variability (ARV) from 24-h ABPM data, home BP, and office BP measurements at first visit. The relationship was evaluated between baseline ARV and the development of HT. RESULTS: HT was diagnosed in 25.60% of subjects. Baseline 24-hour ABPM systolic blood pressure (SBP)ARV and diastolic blood pressure (DBP)ARV and home SBPARV were significantly higher in patients who developed HT than the other patients (P 0.006, 0.001 and 0.006, respectively). Baseline 24-hour ABPM SBPARV and home SBPARV exceeding the 90th percentile were identified as parameters affecting development of HT at logistic regression analysis. CONCLUSION: In conclusion, our prospective observational cohort study showed that short-term BPV in particular can predict the development of HT in the prehypertensive population.

Tissue sodium stores in peritoneal dialysis and hemodialysis patients determined by 23-sodium magnetic resonance imaging.

BACKGROUND: Tissue sodium content in patients on maintenance hemodialysis (MHD) and peritoneal dialysis (PD) were previously explored using 23Sodium magnetic resonance imaging (23NaMRI). Larger studies would provide a better understanding of sodium stores in patients on dialysis as well as the factors influencing this sodium accumulation. METHODS: In this cross-sectional study, we quantified the calf muscle and skin sodium content in 162 subjects (10 PD, 33 MHD patients, and 119 controls) using 23NaMRI. Plasma levels of interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) were measured to assess systemic inflammation. Sixty-four subjects had repeat 23NaMRI scans that were analyzed to assess the repeatability of the 23NaMRI measurements. RESULTS: Patients on MHD and PD exhibited significantly higher muscle and skin sodium accumulation compared to controls. African American patients on dialysis exhibited greater muscle and skin sodium content compared to non-African Americans. Multivariable analysis showed that older age was associated with both higher muscle and skin sodium. Male sex was also associated with increased skin sodium deposition. Greater ultrafiltration was associated with lower skin sodium in patients on PD (Spearman's rho=-0.68, P = 0.035). Higher plasma IL-6 and hsCRP levels correlated with increased muscle and skin sodium content in the overall study population. Patients with higher baseline tissue sodium content exhibited greater variability in tissue sodium stores on repeat measurements. CONCLUSIONS: Our findings highlight greater muscle and skin sodium content in dialysis patients compared to controls without kidney disease. Tissue sodium deposition and systemic inflammation seen in dialysis patients might influence one another bidirectionally.

Effects of long-term intradialytic oral nutrition and exercise on muscle protein homeostasis and markers of mitochondrial content in patients on hemodialysis.

Patients with end-stage kidney disease on maintenance hemodialysis commonly develop protein-energy wasting, a syndrome characterized by nutritional and metabolic abnormalities. Nutritional supplementation and exercise are recommended to prevent protein-energy wasting. In a 6-mo prospective randomized, open-label, clinical trial, we reported that the combination of resistance exercise and nutritional supplementation does not have an additive effect on lean body mass measured by dual-energy X-ray absorptiometry. To provide more mechanistic data, we performed a secondary analysis where we hypothesized that the combination of nutritional supplementation and resistance exercise would have additive effects on muscle protein accretion by stable isotope protein kinetic experiments, muscle mass by MRI, and mitochondrial content markers in muscle. We found that 6 mo of nutritional supplementation during hemodialysis increased muscle protein net balance [baseline: 2.5 (-17.8, 13.0) µg·100 mL-1·min-1 vs. 6 mo: 43.7 (13.0, 98.5) µg·100 mL-1·min-1, median (interquartile range), P = 0.04] and mid-thigh fat area [baseline: 162.3 (104.7, 226.6) cm2 vs. 6 mo: 181.9 (126.3, 279.2) cm2, median (interquartile range), P = 0.04]. Three months of nutritional supplementation also increased markers of mitochondrial content in muscle. Although the study is underpowered to detected differences, the combination of nutritional supplementation and exercise failed to show further benefit in protein accretion or muscle cross-sectional area. We conclude that long-term nutritional supplementation increases the skeletal muscle anabolic effect, the fat cross-sectional area of the thigh, and markers of mitochondrial content in skeletal muscle.

Early Diagnostic Markers for Detection of Acute Kidney Injury in Allogeneic Hematopoietic Stem Cell Transplant Recipients.

OBJECTIVES: Acute kidney injury is a relatively frequent complication of allogenic hematopoietic stem cell transplant, resulting in increased risk of morbidity and mortality. Early diagnosis and management of acute kidney injury is of great importance for prevention of poor outcomes in these transplant recipients. MATERIALS AND METHODS: Fifty consecutive patients, hospitalized for allogenic hematopoietic stem cell transplant at the Bone Marrow Transplantation Unit of Gazi University Faculty of Medicine, were included in this prospective study. Serial measurements of serum creatinine and creatinine clearance were obtained before administration of conditioning regimen and at 0, 7, 14, 21, and 28 days after start of conditioning. Blood and urine samples were also obtained for the measurement of serum cystatin C and urine neutrophil gelatinase-associated lipocalin levels before conditioning and 24 hours before each serum creatinine measurement. RESULTS: During the median 25 days of follow-up, acute kidney injury developed in 19 patients: 10 patients had stage 1, 7 had stage 2, and 2 had stage 3 acute kidney injury according to the Acute Kidney Injury Network classification. There were significant positive correlations between serum cystatin C levels and serum creatinine levels and negative correlations with creatinine clearance levels at each time point (P < .001), whereas no statistically significant associations were observed with urinary neutrophil gelatinase-associated lipocalin levels. Both univariate and multivariate Cox regression models showed a statistically significant association between serum cystatin C levels and development of acute kidney injury, whereas urine neutrophil gelatinase-associated lipocalin levels did not show any significant associations. CONCLUSIONS: Serum cystatin C levels might be a useful marker for early detection of acute kidney injury in adult allogenic hematopoietic stem cell transplant recipients. Close monitoring of kidney function by sensitive biomarkers might provide early recognition and timely management of acute kidney injury in high-risk patient populations.

Determination of genotoxic effects in hemodialysis patients with chronic kidney disease and the role of diabetes mellitus and other biochemical parameters.

Chronic kidney disease (CKD) is a common health problem. The primary etiology of CKD is diabetes mellitus (DM). The aim of our study is to determine the possible role of DM and also effects of other factors such as hypertension, duration of hemodialysis (HD), age, sex, body mass index (BMI), and levels of hemoglobin (HB), intact parathormone (iPTH), and ferritin on genetic alterations in maintenance HD patients using chromosomal aberrations (CAs), sister chromatid exchanges (SCEs), and micronucleus (MN) tests. According to the results, the frequency of CAs (p = 0.001), SCEs (p < 0.001) and MN (p < 0.001) statistically increased in HD patients compared to controls. However, there was no significant effect of diabetes as well as other factors on CA, SCE (except at factor of age), and MN in HD patients compared to controls. The mitotic (MI), replication (RI) and nuclear division indices (NDI) significantly decreased in HD patients compared to controls (p < 0.001). In addition, RI (p < 0.001) and NDI (p = 0.047) were significantly decreased in diabetic HD patients than the non-diabetic HD patients. There was no relation between the frequency of CA, SCE and MN and duration of HD treatment with correlation analysis. According to univariate regression analyses, only having CKD was significantly associated with the values of CA, SCE and MN. However, in multivariate analyses, only having CKD remained as significantly associated with CA, SCE and MN values. Consequently, the clastogenic and mutagenic effects increased in HD patients compared to controls; unlike DM in which cell proliferation decreased.

Acute effects of insulin on circulating natriuretic peptide levels in humans.

BACKGROUND: The natriuretic peptide hormones play an important role in salt and blood pressure regulation. In observational studies, obesity and insulin resistance have been consistently associated with lower concentrations of natriuretic peptides. It has been proposed that insulin influences natriuretic peptide production. OBJECTIVE: We sought to determine the acute effects of insulin administration on natriuretic peptide concentrations. METHODS: 31 men and women (11 lean, 10 overweight, and 10 obese), ages 30-70 years, without cardiovascular disease or overt diabetes underwent a hyperinsulinemic-euglycemic insulin clamp. Plasma concentrations of N-terminal pro atrial natriuretic peptide (NT-proANP) and N-terminal pro B-type natriuretic peptide (NT-proBNP) were measured at baseline and steady-state (the final 30 minutes of the clamp protocol). RESULTS: From baseline to steady-state, insulin levels increased from a mean level of 9.5 to 176.7 µU/ml (p<0.001). Over this period, circulating NT-proANP concentrations decreased by 9% (-1933 ng/L, p = 0.01). The changes in NT-proANP did not differ between lean, overweight, and obese individuals. Steady-state NT-proANP levels, adjusted for baseline, were lower in individuals with greater insulin resistance, independent of BMI. In contrast to NT-proANP, NT-proBNP levels did not change significantly during the clamp (p = 0.41). CONCLUSION: Insulin administration was associated with a moderate decrease in circulating NT-proANP, but not NT-proBNP. The lowest NT-proANP concentrations were found in insulin-resistant individuals. Further investigations are warranted to elucidate potential mechanisms underlying the effects of insulin on the cardiac hormonal axis.

Tissue sodium accumulation and peripheral insulin sensitivity in maintenance hemodialysis patients.

BACKGROUND: Recent data suggest that sodium (Na+ ) is stored in the muscle and skin without commensurate water retention in maintenance hemodialysis (MHD) patients. In this study, we hypothesized that excessive Na+ accumulation would be associated with abnormalities in peripheral insulin action. METHODS: Eleven MHD patients and eight controls underwent hyperinsulinemic-euglycemic-euaminoacidemic clamp studies to measure glucose (GDR) and leucine disposal rates (LDR), as well as lower left leg 23 Na magnetic resonance imaging to measure Na+ concentration in the muscle and skin tissue. RESULTS: The median GDR and LDR levels were lower, and the median muscle Na+ concentration was higher in MHD patients compared with controls. No significant difference was found regarding skin Na+ concentration between group comparisons. Linear regression revealed inverse relationships between muscle Na+ concentration and GDR and LDR in MHD patients, whereas no relationship was observed in controls. There was no association between skin Na+ content and GDR or LDR in either MHD patients or controls. CONCLUSIONS: These data suggest that excessive muscle Na+ content might be a determinant of IR in MHD patients, although the causality and mechanisms remain to be proven.

Prevalence of Chronic Kidney Disease in Turkish Adults With Obesity and Metabolic Syndrome: A Post Hoc Analysis from Chronic Renal Disease in Turkey Study.

BACKGROUND: Obesity confers an increased risk of chronic kidney disease (CKD), which is increased further by accompanying metabolic abnormalities. OBJECTIVE: To investigate the relationship of the risk of CKD with obesity and metabolic syndrome (MS) in adults by means of post hoc analysis of data from the Chronic Renal Disease in Turkey (CREDIT) study. METHODS: The anthropometric measurements of a total of 9,100 adult participants in the CREDIT study were included in the analyses. Subjects were classified according to the presence or absence of obesity (body mass index [BMI] > 30) and MS. Logistic regression analyses were used to estimate odds ratio for CKD. Effect modification analyses were also performed. RESULTS: The prevalence of obesity was 20.6% and that of MS was 31.3%. The prevalence of CKD was higher among obese subjects compared to those with a normal BMI (20.5% vs. 14%; P < .001). The odds ratio (OR) for CKD was 1.296 (95% confidence interval [CI], 1.121-1.498) for subjects who were overweight, 1.718 (95% CI, 1.444-2.044) for those with class I obesity, 1.983 (95% CI, 1.489-2.641) for those with class II obesity and 2.799 (95% CI, 1.719-4.557) for subjects with extreme obesity (P < .001 for each subgroup) compared to subjects with a normal BMI. CKD was significantly more prevalent in subjects with MS (21.9% vs. 12.3%, P < .001). The OR for CKD was higher in obese subjects with MS (adjusted OR, 1.321; 95% CI, 1.109-1.573; P = .002). CONCLUSION: The stratification of obese individuals based on their metabolic phenotype is important for prevention and treatment of CKD.

High Dose Omega-3 Fatty Acid Administration and Skeletal Muscle Protein Turnover in Maintenance Hemodialysis Patients.

BACKGROUND AND OBJECTIVES: Protein energy wasting and systemic inflammation are prevalent in maintenance hemodialysis (MHD) patients. Omega-3 (ω-3) fatty acids have anti-inflammatory properties and have been shown to improve protein homeostasis. We hypothesized that administration of high-dose (2.9 g/d) ω-3 would be associated with decreased muscle protein breakdown in MHD patients with systemic inflammation. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS: This is a substudy from a randomized, placebo-controlled study (NCT00655525). Patients were recruited between September 2008 and June 2011. Primary inclusion criteria included signs of chronic inflammation (average C-reactive protein of ≥5 mg/L over three consecutive measurements), lack of active infectious or inflammatory disease, no hospitalization within 1 month prior to the study, and not receiving steroids (>5 mg/d) and/or immunosuppressive agents. The primary outcomes were forearm muscle and whole body protein breakdown and synthesis before and after the intervention. The patients received ω-3 (n=11) versus placebo (n=9) for 12 weeks. Analysis of covariance was used to compare outcome variables at 12 weeks. Models were adjusted for a propensity score that was derived from age, sex, race, baseline high sensitivity C-reactive protein, diabetes mellitus, and fat mass because the groups were not balanced for several characteristics. RESULTS: Compared with placebo, ω-3 supplementation was significantly associated with decreased muscle protein breakdown at 12 weeks (-31, [interquartile range, -98--13] versus 26 [interquartile range, 13-87] µg/100 ml per min; P=0.01), which remained significant after multivariate adjustment (-46, [95% confidence interval, -102 to -1] µg/100 ml per min). ω-3 Supplementation resulted in decreased forearm muscle protein synthesis while the rate in the placebo group increased; however, there is no longer a statistically significant difference in skeletal muscle protein synthesis or in net protein balance after multivariate adjustment. There was no statistically significant effect of ω-3 supplementation on whole body protein synthesis or breakdown. CONCLUSIONS: High-dose ω-3 supplementation over 12 weeks in MHD patients with systemic inflammation was associated with attenuation of forearm muscle protein breakdown but did not influence skeletal muscle protein synthesis, skeletal muscle net protein balance or any component of the whole-body protein balance. These results should be interpreted cautiously given the imbalance in the two groups and the short duration of the intervention.

DNA damage in hemodialysis patients with chronic kidney disease; a test of the role of diabetes mellitus; a comet assay investigation.

The incidence of chronic kidney disease (CKD) is increasing rapidly. Diabetes mellitus (DM) is the most important cause of CKD. We studied the possible role of DM in CKD patients with respect to DNA damage, as assessed by the comet assay in 60 CKD patients (with or without DM) undergoing hemodialysis and in 26 controls. Effects of other factors, such as age, sex, hypertension, duration of hemodialysis, body mass index (BMI), and levels of hemoglobin (HB), intact parathormone (iPTH), and ferritin (FER), were also examined. Primary DNA damage measured by the comet assay was significantly higher in CKD patients than in controls. Among CKD patients, the following correlations were observed. (1) There was no difference in comet tail length or tail intensity between diabetic and non-diabetic individuals. (2) Age, sex, hemoglobin, hypertension, duration of hemodialysis, and ferritin levels affected neither tail length nor intensity. (3) BMI values above 25kg/m(2) and iPTH levels above 300pg/ml were associated with significantly greater comet tail length. Our results indicate that primary DNA damage is increased in CKD patients undergoing hemodialysis, compared to controls; however, DM had no additional effect.

Measurement and Correlation of Indices of Insulin Resistance in Patients on Peritoneal Dialysis.

UNLABELLED: ♦ BACKGROUND: Insulin resistance (IR) is common in maintenance dialysis patients and is associated with excess mortality. Hyperinsulinemic euglycemic glucose clamp (HEGC) is the gold standard for measuring IR. There are limited studies using HEGC for comparison to other indirect indices of IR in peritoneal dialysis (PD) patients, nor have there been direct comparisons between patients receiving PD and those on maintenance hemodialysis (MHD) with regard to severity of IR, methods of measurement, or factors associated with the development of IR. ♦ METHODS: This is a cross-sectional, single-center study performed in 10 prevalent PD patients of median age 48 years (range 41 - 54); 50% were female and 60% were African American. Insulin resistance was assessed by HEGC (glucose disposal rate [GDR]), homeostatic model assessment of IR (HOMA-IR), HOMA-IR corrected by adiponectin (HOMA-AD), leptin adiponectin ratio (LAR), quantitative insulin sensitivity check index (QUICKI), McAuley's index, and oral glucose tolerance test (OGTT) at each time point for a total of 18 studies. Retrospective analysis compared this cohort to 12 hemodialysis patients who had previously undergone similar testing. ♦ RESULTS: The median GDR was 6.4 mg/kg/min (interquartile range [IQR] 6.0, 7.8) in the PD cohort compared with the MHD group, which was 5.7 mg/kg/min (IQR 4.3, 6.6). For both the PD and MHD cohorts, the best predictors of GDR by HEGC after adjusting for age, gender, and body mass index (BMI), were HOMA-AD (PD: r = -0.69, p = 0.01; MHD: r = -0.78, p = 0.03) and LAR (PD: r = -0.68, p < 0.001; MHD: r = -0.65, p = 0.04). In both groups, HOMA-IR and QUICKI failed to have strong predictive value. Eight of 10 PD patients had at least 1 abnormal OGTT, demonstrating impaired glucose tolerance. ♦ CONCLUSIONS: Insulin resistance is highly prevalent in PD patients. The adipokine based formulas, HOMA-AD and LAR, correlated well in both the PD and MHD populations in predicting GDR by HEGC, outperforming HOMA-IR. The use of these novel markers could be considered for large-scale, epidemiological outcome studies.