Metabolic syndrome in HD patients: association with body composition, nutritional status, inflammation and serum iron

Comparison of Inflammatory Markers in the Diagnosis of Metabolic Syndrome in Hemodialysis Patients: A Multicenter Observational Study

OBJECTIVE

The purpose of this study is to observe the correlation between high sensitivity C-reactive protein (hs-CRP) and metabolic syndrome (MetS) in hemodialysis patients, determine its optimal cut-off point value, and compare the diagnostic ability of different inflammatory markers for MetS.

METHODS

This cross-sectional study finally included 860 long-term hemodialysis patients (male 524, average age 61.5 years) from seven dialysis centers in Shanghai, China. The International Diabetes Federation metabolic syndrome guidelines were used to define MetS, including high waist circumference, elevated blood pressure, elevated fasting blood glucose, elevated triglycerides, and reduced HDL cholesterol. Serum hs-CRP was determined by the immunonephelometric assay. The association with MetS was observed according to the quartile of inflammatory markers, and then the optimal cut-off point value of the hs-CRP was determined by ROC analysis.

RESULTS

The overall prevalence of MetS was 55.1% (46.6% in males and 68.5% in females). In the final logistic regression model, there was a significant, graded positive association between hs-CRP and MetS (p for trend = 0.010). The traditional inflammatory markers leukocytes, neutrophils, lymphocytes, monocytes and neutrophil-to-lymphocyte ratio (NLR) were not associated with MetS. The results of the ROC analysis showed that the optimal cut point value of hs-CRP for the diagnosis of MetS was 1.58 mg/L. In the components of MetS and hs-CRP was significantly positively associated with high waist circumference, elevated TG and low HDL (p < 0.05).

CONCLUSION

The increase in hs-CRP concentration is significantly associated with the risk of MetS, and the diagnostic ability of hs-CRP for MetS is better than traditional inflammatory markers.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.

The interplay among iron metabolism, endothelium and inflammatory cascade in dysmetabolic disorders

PURPOSE

Metabolic syndrome (MetS) is considered as a proinflammatory and prothrombotic state with atherogenic risk factors including dyslipidemia, obesity and glucose intolerance. Oxidative stress is a unifying basis of several disorders including diabetes mellitus (DM) and MetS. We therefore designed this cross-sectional study to investigate the potential interaction among iron metabolism, inflammation and endothelial plexus in MetS and DM patients.

METHODS

A total of 62 patients [median age 54 (23-76) years; male/female 16/46] and 18 healthy controls [median age 38 (30-64) years; male/female 6/12] were included in the study. Patient population was classified as MetS (n = 30) and DM (n = 32).

RESULTS

Leukocyte count (p = 0.002) and osteopontin (OPN) levels (p = 0.008) were significantly higher, while C-reactive protein (CRP) (p = 0.056) and IL-6 (p = 0.059) represented a relative increase in the patient group. Leptin, endothelin 1 (ET1), hepcidin, nitric oxide synthase (NOS), erythrocyte sedimentation rate (ESR), iron, transferrin saturation (TS) and ferritin levels were not significantly different between the patient and control groups. Endothelin 1 was found to be higher in the DM group compared to MetS group (p = 0.15, p = 0.049). Leukocyte count, leptin, hepcidin, OPN, NOS, IL-6, ESR, CRP, iron, TS and ferritin levels were not different between DM and MetS groups. A positive correlation was demonstrated between leptin and OPN (p = 0.001, r = 0.360), ferritin and hepcidin (p < 0.01, r = 0.633), IL-6 and CRP (p = 0.023, r = 0.319), leptin and NOS (p = 0.005, r = 0.309) and OPN and NOS (p < 0.001, r = 0.803). There was a negative correlation between hepcidin and NOS (p = 0.009, r = -0.289). When the study cohort was divided into two particular groups based on median ferritin and hepcidin levels, hepcidin (p = 0.002), ALT (p = 0.001) and LDL (p = 0.049) levels were higher in the high-ferritin group. Nitric oxide synthase levels (p = 0.033) were lower, whereas ferritin levels (p = 0.004) were higher in the high-hepcidin group.

CONCLUSION

Mechanisms involved in the vicious circle of MetS including inflammation, endothelial vasculature and iron metabolism remain to be elucidated. The role of iron metabolism in this complex interaction should be confirmed with further studies.

Impact of metabolic disturbances and malnutrition-inflammation on 6-year mortality in Japanese patients undergoing hemodialysis

Metabolic syndrome confers an increased risk of cardiovascular disease (CVD) in the general population. The relationship between adiponectins, and clinical outcomes in patients undergoing hemodialysis remains controversial. We investigated whether adiponectins, biomarkers of inflammation, nutrition status and clinical features predict the mortality of patients undergoing hemodialysis for 6 years. We measured baseline plasma total and high-molecular-weight (HMW) adiponectins, tumor necrosis factor (TNF)-α, serum high sensitivity C-reactive protein (hsCRP), and clinical characteristics including visceral fat area (VFA) and the Geriatric Nutritional Risk Index (GNRI) in 133 patients undergoing chronic hemodialysis. Forty-one of the 133 patients died during follow-up. The deceased patients were significantly older, had more prior CVD and diabetes, higher TNF-α and hsCRP levels but lower GNRI. VFA, and total and HMW adiponectin did not significantly differ between the two groups. TNF-α and hsCRP levels and GNRI score were significant for predicting all-cause and cardiovascular mortality in receiver operating curve analyses. When stratified by a GNRI score of 96, Cox proportional hazards analyses identified TNF-α as a significant predictor of all-cause mortality (hazard ratio [HR] 1.23; P = 0.038) and hsCRP as a significant predictor of all-cause and cardiovascular mortality (HR, 2.32, P = 0.003; HR 2.30, P = 0.012, respectively) after adjusting for age, sex, diabetes mellitus, and prior CVD, only in malnourished patients. These results demonstrate that malnutrition and the inflammatory markers TNF-α and hsCRP, but not metabolic markers, including VFA and adiponectins have a significant impact on 6-year all-cause and cardiovascular mortality in Japanese patients undergoing hemodialysis.

Effects of alpha lipoic acid supplementation on serum levels of IL-8 and TNF-α in patient with ESRD undergoing hemodialysis

BACKGROUND

Chronic renal failure is a progressive and irreversible loss of kidney function, and the hemodialysis (HD) is one of the most common modalities in this regard. Oxidative stresses [like interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α)] and inflammation are the main risk factors associated with cardiovascular diseases and other complications in many organs in hemodialysis patients; meanwhile, antioxidants like alpha lipoic acid (ALA) may reduce the oxidative stress markers and the levels of inflammatory cytokines, so can improve of the patient's quality of life.

METHODS

In this randomized clinical trial study, 60 HD patients were randomly categorized in two case and control groups. Case group received a daily capsule of 600 mg of ALA supplementation for 8 weeks, and the control group received placebo capsules daily. The serum level of IL-8 and TNF-α was measured in both groups before and after the intervention.

RESULTS

There were no significant differences in age, gender, duration of dialysis, and causative factor for dialysis between both groups (P > 0.05). The mean of IL-8 and TNF-α after the intervention in case group was 26.20 ± 15.34 and 21.25 ± 9.61, respectively; the difference between both groups was not statistically significant (P > 0.05).

CONCLUSION

Based on the better feeling and other beneficial effects of ALA were found in our study; we can conclude that it is a beneficial and recommended supplement, especially, for diabetic and dialysis patients.

Insulin resistance and left ventricular mass in non-diabetic hemodialysis patients

BACKGROUND

Insulin resistance (IR) is frequently recognized in patients with uremia, and it is thought that IR has a basic role in the pathogenesis of cardiovascular disease.

OBJECTIVE

To evaluate the effect of IR on cardiovascular risk in non-diabetic patients receiving hemodialysis (HD).

METHODS

We performed a cross-sectional observational study that comprised 186 non-diabetic patients receiving HD (95 men; mean [SD] age, 46.4 [10.8] years; age range, 35-60 years) who had been receiving HD for 7.3 (3.5) years. Demographic variables and laboratory values were recorded. Insulin resistance was determined using the Homeostatic Model Assessment (HOMA), and the left ventricular mass index (LVMI) was calculated via echocardiography.

RESULTS

According to HOMA-IR levels, patients were categorized as having IR (HOMA-IR score ≥2.5; n = 53) or not having IR (HOMA-IR score <2.5; n = 133). Insulin resistance was determined in 28.4% of study patients. Compared with the non-IR group, the IR group had been receiving HD longer; had greater body mass index; and had higher serum creatinine, uric acid, triglyceride, insulin, and C-reactive protein concentrations, leukocyte count, and LVMI (P < 0.05). Patients with increased LVMI had significantly higher body mass index, systolic blood pressure, serum cholesterol and C-reactive protein concentrations, and HOMA score. At multivariate analysis, systolic blood pressure (β = 0.22; P = 0.03) and HOMA score (β = 0.26; P = 0.01) affected LVMI.

CONCLUSIONS

Insulin resistance and hypertension are independent risk factors for left ventricular hypertrophy in non-diabetic patients with uremia who are receiving HD. Further studies are needed to indicate the benefits of improving IR for cardiovascular mortality in this subgroup of patients with uremia.

Determination of anti-inflammatory activities of standardised preparations of plant- and mushroom-based foods

PURPOSE

Chronic inflammatory processes contribute to the pathogenesis of many age-related diseases. In search of anti-inflammatory foods, we have systematically screened a variety of common dietary plants and mushrooms for their anti-inflammatory activity.

METHODS

A selection of 115 samples was prepared by a generic food-compatible processing method involving heating. These products were tested for their anti-inflammatory activity in murine N11 microglia and RAW 264.7 macrophages, using nitric oxide (NO) and tumour necrosis factor-α (TNF-α) as pro-inflammatory readouts.

RESULTS

Ten food samples including lime zest, English breakfast tea, honey-brown mushroom, button mushroom, oyster mushroom, cinnamon and cloves inhibited NO production in N11 microglia, with IC50 values below 0.5 mg/ml. The most active samples were onion, oregano and red sweet potato, exhibiting IC50 values below 0.1 mg/ml. When these ten food preparations were retested in RAW 264.7 macrophages, they all inhibited NO production similar to the results obtained in N11 microglia. In addition, English breakfast tea leaves, oyster mushroom, onion, cinnamon and button mushroom preparations suppressed TNF-α production, exhibiting IC50 values below 0.5 mg/ml in RAW 264.7 macrophages.

CONCLUSION

In summary, anti-inflammatory activity in these food samples survived 'cooking'. Provided that individual bioavailability allows active compounds to reach therapeutic levels in target tissues, these foods may be useful in limiting inflammation in a variety of age-related inflammatory diseases. Furthermore, these foods could be a source for the discovery of novel anti-inflammatory drugs.

Association of inflammatory biomarkers with metabolic syndrome in hemodialysis patients

The relative importance of inflammatory markers in relation with metabolic syndrome (MeS) in hemodialysis (HD) patients is uncertain. This study investigated the association between MeS and high-sensitive C-reactive protein (hsCRP), hallmark of inflammation, and other inflammatory-related biomarkers. The study included 153 patients who were dialyzed at least for the last 3 months. The serum level of hsCRP was assessed by high-sensitive Enzyme-linked immunosorbent assay (ELISA). MeS was defined using the modified National Cholesterol Education Program Adult Treatment Panel III (ATP-III). Ninety-one HD patients (59.5%) were diagnosed as having MeS. Lower level of high-density lipoprotein-cholesterol (HDL-C) was the most prevalent MeS component (85.6%). The serum level of hsCRP in these patients was significantly higher than that in HD patients without MeS (2.3 ± 1.7 vs. 1.7 ± 1.6 mg/dL, p = 0.03). A significant linear increase in the hsCRP levels was found according to the number of MeS components (β = 0.09, p = 0.022). The study concluded that increasing inflammatory biomarkers, especially hsCRP, is associated with MeS in HD patients.

Abdominal obesity is the most significant metabolic syndrome component predictive of cardiovascular events in chronic hemodialysis patients

BACKGROUND

Five components of metabolic syndrome (MetS) have been identified as predictive of cardiovascular events (CVEs) in the general population: impaired fasting glucose, abdominal obesity, hypertriglyceridemia, hypertension and low high-density lipoprotein cholesterol. Whether MetS and its components are also predictive of CVEs in chronic hemodialysis (HD) patients remains unclear. We therefore investigated the role of MetS and its components in patients on chronic HD.

METHODS

MetS at baseline was diagnosed in 91 HD patients based on the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI) and the International Diabetes Federation (IDF) definitions. During a 3-year period, all hospitalizations, CVEs and deaths were recorded and analyzed using Kaplan-Meier survival analysis and Cox regression.

RESULTS

There were no differences in the number of CVEs, hospitalizations or deaths between patients with and without AHA/NHLBI-defined MetS; however, patients with IDF-defined MetS were found to be at a higher risk for CVEs (P = 0.006). Cox regression analysis showed that, of the MetS components, abdominal obesity was the single most significant predictor of CVEs (hazard ratio 6.25; 95% confidence interval: 1.65-23.6; P = 0.007).

CONCLUSIONS

IDF-defined MetS was more predictive of CVEs than AHA/NHLBI-defined MetS. Of the MetS components, abdominal obesity was the single most significant predictor of CVEs in chronic HD patients.

Metabolic syndrome predicts mortality in non-diabetic patients on continuous ambulatory peritoneal dialysis

BACKGROUND

Metabolic syndrome is associated with higher morbidity and mortality in the general population, but the corresponding effects in patients on dialysis have not been clearly defined. In this study, we prospectively investigated the effect of metabolic syndrome and its individual components on outcome in non-diabetic peritoneal dialysis (PD) patients. Method. The study subjects included 106 stable non-diabetic PD patients who had been on PD for >3 months. We measured baseline characteristics, blood pressure, fasting blood glucose, lipid profiles and high-sensitivity CRP (hsCRP), and defined metabolic syndrome using the modified National Cholesterol Education Program (Adult Treatment Panel III) criteria. Mortality, technical failure and hospitalization were evaluated during the follow-up period.

RESULTS

Metabolic syndrome was present in 50 patients (47.2%), and these showed higher baseline hsCRP levels (0.67; 95% CI: 0.50-0.94 versus 1.78 mg/dl; 95% CI: 1.21-2.57; P < 0.001). Patients with metabolic syndrome experienced significantly lower 5-year survival rates than patients without (90% versus 67%, P = 0.02), although these groups did not differ in peritonitis rates, technical failure or hospitalization. A Cox proportional hazards analysis identified the following as predictors of mortality: metabolic syndrome (RR: 3.39; 95% CI: 1.16-9.94; P = 0.02), baseline albumin (RR: 0.06; 95% CI: 0.01-0.30; P = 0.001) and baseline hsCRP levels (RR: 1.14; 95% CI: 1.07-1.22; P < 0.001).

CONCLUSION

Metabolic syndrome is prevalent and is a risk factor influencing long-term survival in non-diabetic PD patients.

Adipokines and nutritional status for patients on maintenance hemodialysis

OBJECTIVES

The aim of this study was to investigate the serum concentration of adipokines, such as leptin, adiponectin, and resistin, and assess its relation to nutritional and inflammatory parameters in both overweight and normal weight patients on maintenance hemodialysis.

METHODS

A total of 36 hemodialysis patients (27 M, 9 F; mean age 55.3 +/- 12 yr.) were examined and 23 additional healthy volunteers were recruited as the control group. The concentrations of leptin, leptin receptor, adiponectin, resistin, IL-6, TNFa and CRP were measured by ELISA. Assessment of nutritional status was determined by the levels of albumin, BMI, percentage of body fat (%F), lean body mass (LBM), and Subjective Global Assessment Score (SGA).

RESULTS

According to the SGA 7-points score and the albumin level, 20 patients were of good nutritional status (6-7 points), while 16 patients were mildly malnourished (4-5 points). The concentrations of CRP, resistin, adiponectin, and TNFa were statistically higher in hemodialysis patients than in the control group (p pound 0.05). The adiponectin level was inversely correlated with %F (R Spearman=-0.3; p pound 0.05). The level of leptin was positively correlated with %F as well as with BMI and SGA scores (R Spearman=0.4; p pound 0.05). Although there was no significant difference in the nutritional status between the nonoverweight (BMI 18.5-24.99) and overweight (BMI (3)25.0) groups of patients, in the nonoverweight group there were 12 patients (54.5%) with signs of mild malnutrition compared to 4 malnourished patients (28.5%) in the overweight group. Nonoverweight patients presented significantly lower leptin concentration (12.7 vs 27.8 ug/l) and higher adiponectin level (38.9 vs 32.5 ng/ml) when compared to overweight patients. The levels of IL-6 and TNFa were higher in the nonoverweight group of patients. Overweight patients also had shorter durations of stay in the hemodialysis program (30.5 vs. 87.6 months).

CONCLUSION

The results of our study indicate that lean hemodialysis patients are more prone to malnutrition and inflammation. The increased levels of leptin and decreased levels of adiponectin in the overweight hemodialysis patients support the idea of a reverse epidemiology phenomenon in this group of patients.

Does metabolic syndrome have an impact on the quality of life and mood of hemodialysis patients?

OBJECTIVE

Little is known about the association between metabolic syndrome (MetSyn), health-related quality of life (HRQoL), and depressive symptoms in hemodialysis (HD) patients. We hypothesized that MetSyn may be associated with lower HRQoL and depression in HD patients.

DESIGN

This was a cross-sectional study.

SETTING

The trial involved HD patients at a tertiary-care hospital.

PATIENTS

We evaluated 115 patients (41 women and 74 men; mean age, 48.4 +/- SD 11.9 years SD).

METHODS

MetSyn was defined according to National Cholesterol Education Panel criteria. The Medical Outcomes Study Short Form-36 (SF-36) and Beck Depression Inventory (BDI) were used to assess HRQoL and signs of depression, respectively. We compared HRQoL and clinical and psychosocial characteristics among participants with and without MetSyn.

RESULTS

Fifty patients (43.5%) had MetSyn, and 65 patients (56.5%) were free of MetSyn. Comparisons of SF-36 and BDI scores between HD patients with and without MetSyn revealed no statistically significant differences. The Physical Component Summary Score (PCS) of SF-36 was independently associated with HD duration (beta = -0.274, P = .002), age (beta = -0.206, P = .024), sleep disturbance (beta = -0.175, P = .045), albumin (beta = +0.252, P = .006), and hemoglobin (beta = +0.270, P = .002) in stepwise linear regression analysis. The MetSyn was not associated with PCS. The Mental Component Summary Score of SF-36 was independently associated with hemoglobin (beta = +0.235, P = .016) and BDI score (beta = -0.218, P = .025).

CONCLUSIONS

The presence of MetSyn was not associated with HRQoL according to the Mental Component Summary Score. In HD patients, HRQoL and depressive behaviors were not influenced by MetSyn, but by various other factors.