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.

The effect of omega-3 fatty acids on depressive symptoms and inflammatory markers in maintenance hemodialysis patients: a randomized, placebo-controlled clinical trial

PURPOSE

This study was designed to investigate the effects of omega-3 fatty acids on depression and chronic inflammation in hemodialysis patients.

METHOD

Fifty-four maintenance hemodialysis patients were randomized to ingest two omega-3 (each containing 180 mg eicosapentaenoic acid and 120 mg docosahexaenoic acid) or placebo capsules, three times daily for 4 months.

MAIN OUTCOME MEASURES

Beck Depression Inventory (BDI) score and serum levels of C-reactive protein (CRP), interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, ferritin, intact parathyroid hormone (iPTH), and ratios of IL-10 to IL-6 and IL-10 to TNF-α were measured at baseline and at the end of the study.

RESULTS

Omega-3 supplement lowered BDI score significantly after 4 months of intervention. Among pro- and anti-inflammatory mediators, only serum ferritin level and IL-10 to IL-6 ratio showed significant changes in favor of omega-3 supplement during the study. In linear regression model adjusted for baseline values, omega-3 treatment was a significant predictor of reduced serum CRP, ferritin, and iPTH levels, and increased IL-10 to IL-6 ratio. No significant association was found between the anti-inflammatory and anti-depressant effects of omega-3 supplement.

CONCLUSIONS

Supplemental use of omega-3 fatty acids decreases depressive symptoms in hemodialysis patients apart from their anti-inflammatory effects.

Low serum magnesium levels and diabetic foot ulcers

Objective: Magnesium plays an important role in glucose homeostasis and insulin sensitivity. The aim of this study was to investigate the association between serum magnesium levels and diabetic foot ulcers.

Methods: A total of 147 subjects were included in this study. The participants were divided into three groups, including a study group of 49 patients with diabetes and foot ulcers, a control group of patients with diabetes without foot ulcers and a control group of 49 healthy subjects. Measurements and comparisons were made of the participants’ magnesium levels, HBA1C percentages, serum fasting glucose levels, creatinine levels and serum lipid levels for all groups. MedCalc version 12.0 (MedCalc, Turkey) was used for the statistical analysis.

Results: The groups were similar in terms of age and sex (p=0.116 and 0.897, respectively). The magnesium levels of the patients with diabetes and foot ulcers were lower than those in the patients with diabetes without foot ulcers and the healthy subjects (p<0.001). There was a strong relationship between the serum magnesium levels and the incidence of diabetic foot ulcers (OR 5.9, Cl 95% 2.7-12.6, p<0.001).

Conclusions: A low serum magnesium level is associated with diabetic foot ulcers. Therefore, the magnesium levels should be controlled in patients with diabetes (with or without foot ulcers) and magnesium supplementation can be a complimentary treatment in such cases.

Effects of dietary milled seed mixture on fatty acid status and inflammatory markers in patients on hemodialysis

BACKGROUND

Plant seeds have gained interest for their health benefits due to their fatty acid content. The objective of this study was to determine the effects of dietary consumption of milled sesame/pumpkin/flax seed mixture on glycemic control, serum lipids, phospholipid fatty acid status, and inflammatory factors in patients on hemodialysis.

METHODS

Thirty patients with well nutrition status (18 male, 12 female) were enrolled in the study. Participants consumed 30 g of milled sesame/pumpkin/flax (6 g/6 g/18 g, resp.) seeds mixture added to their habitual diet.

RESULTS

Total n-6 and n-3 polyunsaturated fatty acids and levels of linoleic, dihomo-gamma-linolenic (DGLA), arachidonic, alpha-linolenic (ALA), eicosapentaenoic, docosapentaenoic, and docosahexaenoic (DHA) acid were increased after 12 weeks of supplementation. A significant decrease of the serum triglyceride level (P < 0.001), glucose, insulin, calculated IR HOMA (P < 0.05), and inflammatory markers (TNF-alpha, IL-6, and hs-CRP, P < 0.001) was observed after seed mixture treatment. The serum levels of CRP and TNF-alpha negative correlate with ALA, DHA, and DGLA.

CONCLUSION

Results of this study indicated that dietary milled sesame/pumpkin/flax seed mixture added to a habitual diet lowered triglyceride and CRP, TNF-alpha, IL-6 levels, affect glycemic control and improved fatty acid profile and pruritus symptoms in hemodialysis patients.

Potential effects of omega-3 fatty acids on anemia and inflammatory markers in maintenance hemodialysis patients

BACKGROUND

Anemia is a common complication among hemodialysis (HD) patients. Although intravenous iron and erythropoiesis-stimulating agents revolutionized anemia treatment, about 10% of HD patients show suboptimal response to these agents. Systemic inflammation and increased serum hepcidin level may contribute to this hyporesponsiveness. Considering the anti-inflammatory properties of omega-3 fatty acids, this study aimed to evaluate potential role of these fatty acids in improving anemia and inflammation of chronic HD patients.

METHODS

In this randomized, placebo-controlled trial, 54 adult patients with HD duration of at least 3 months were randomized to ingest 1800 mg of either omega-3 fatty acids or matching placebo per day for 4 months. Anemia parameters including blood hemoglobin, serum iron, transferrin saturation (TSAT), erythropoietin resistance index, and required dose of intravenous iron and erythropoietin, and serum concentrations of inflammatory/anti-inflammatory markers including interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-10, C-reactive protein (CRP), hepcidin, ferritin, intact parathyroid hormone (iPTH), and ratios of IL-10 to IL-6 and IL-10 to TNF-α were measured at baseline and after 4 months of the intervention.

RESULTS

45 subjects (25 in the omega-3 and 20 in the placebo group) completed the study. No significant changes were observed in blood hemoglobin, serum iron, TSAT, and required dose of intravenous iron in either within or between group comparisons. Additionally, erythropoietin resistance index as well as required dose of intravenous erythropoietin showed no significant change in the omega-3 group compared to the placebo group. Although a relative alleviation in inflammatory state appeared in the omega-3 group, the mean differences of inflammatory and anti-inflammatory markers between the two groups did not reach statistically significant level except for IL-10-to-IL-6 ratio and serum ferritin level which showed significant changes in favor of omega-3 treatment (P <0.001 and P = 0.003, respectively).

CONCLUSION

Omega-3 fatty acids relatively improved systemic inflammation of chronic HD patients without any prominent benefits on anemia. However, future well-designed studies on larger number of patients may determine utility of omega-3 fatty acids in HD patients with respect to inflammation and anemia.

Estradiol In Vivo Induces Changes in Cardiomyocytes Size in Obese Rats

We studied the in vivo effects of estradiol on size and biochemical parameters of cardiomyocytes in pathophysiological conditions such as obesity and insulin resistance. Male Wistar rats were normally fed (controls, n = 7) or fed with high-fat diet (obese, n = 14). Half of the obese rats (obese + estradiol, n = 7) were treated with a single dose of estradiol (40 μg/kg, intraperitoneally) and 24 hours after treatment all the rats were killed. Estradiol in vivo in obese rats resulted in a significant increase in protein kinase B (Akt) activation ( P < .05) and decrease in heart mass ( P < .05), ratio of the heart mass/body mass ( P < .05), transverse diameters of cardiomyocytes ( P < .001), concentration of serum high-sensitivity C-reactive protein ( P < .001), and total cholesterol ( P < .01) compared with obese nontreated rats. Our results suggest that estradiol in obese/IR rats affects the size of cardiomyocytes and its actions lead in vivo to a reduction in obesity-induced cardiac hypertrophy, via Akt.

Serum magnesium in the metabolically-obese normal-weight and healthy-obese subjects

BACKGROUND

Given that hypomagnesemia is related with hyperglycemia, hypertension, hypertriglyceridemia, and insulin resistance, the objective of this study was to determine whether serum magnesium levels are associated with the metabolically obese normal weight (MONW) and the metabolically healthy obese (MHO) phenotypes.

METHODS

Population-based cross-sectional study that enrolled 427 subjects, men and non-pregnant women aged 20 to 65years, to participate in the study. Subjects were allocated into groups with and without obesity; among non-obese individuals, the subgroup of MONW subjects was compared with a control group of healthy normal-weight individuals. Among obese individuals, the subgroup of MHO subjects was compared with a control group of obese subjects who exhibited at least one metabolic abnormality. In the absence of obesity, the presence of fasting hyperglycemia, insulin resistance, hypertriglyceridemia, and/or hypertension defined the presence of MONW phenotype. In the absence of hypertension, insulin resistance and metabolic abnormalities of fasting glucose and triglycerides levels, the phenotypically obese subjects were defined as MHO individuals.

RESULTS

The sex-adjusted prevalence of MONW and MHO phenotypes was 40.8% and 27.9%. The multivariate logistic regression model adjusted by family history of diabetes, age, body mass index, and waist-circumference, showed a positive association between hypomagnesemia and the MONW phenotype (OR 6.4; 95%CI 2.3-20.4) and negative relationship between serum magnesium and the MHO phenotype (OR 0.32; 95%CI 0.17-0.61).

CONCLUSIONS

Our results show that hypomagnesemia is positively associated with the presence of MONW phenotype, and the normomagnesemia negatively with the MHO phenotype.

Omega-3 fatty acids improve glucose metabolism without effects on obesity values and serum visfatin levels in women with polycystic ovary syndrome

OBJECTIVE

Polycystic ovary syndrome (PCOS) is the most common female endocrine disorder. Affected women present a higher risk of type 2 diabetes. The objectives of this study were to investigate the effects of omega-3 fatty acids on obesity status, insulin resistance, and serum levels of visfatin in PCOS patients.

METHODS

This double-blind, randomized, controlled clinical trial was conducted on 61 women who were diagnosed with PCOS, had a body mass index (BMI) between 25 and 40 kg/m(2), and were from 20-35 years old. Thirty of the subjects had taken four 1-g omega-3 fatty acids capsules per day, providing 1200 mg n-3 long chain polyunsaturated fatty acids (n-3 LC PUFA), and 31 were given a placebo over 8 weeks. Fasting blood samples, anthropometric measurements, and dietary intake data were collected at the baseline and at the end of the trial. Data were analyzed by independent t test, paired t test, Pearson correlation test, and analysis of covariance.

RESULTS

Omega-3 fatty acids had no significant effects on weight, BMI, waist circumference, and waist to hip ratio at the end of the study. Omega-3 fatty acids significantly decreased glucose (by 11.4%, p < 0.001), insulin (by 8.4%, p < 0.05), and homeostatic model assessment for insulin resistance (by 21.8%, p < 0.001) compared with placebo. Changes in serum visfatin levels were not significant in either of the groups.

CONCLUSION

Omega-3 fatty acids improved insulin sensitivity in PCOS patients. This beneficial effect was not associated with alteration in anthropometric measurements and serum visfatin levels.

Tryptophan-kynurenine metabolism and insulin resistance in hepatitis C patients

Chronic hepatitis C virus (HCV) infection is associated with 50% incidence of insulin resistance (IR) that is fourfold higher than that in non-HCV population. IR impairs the outcome of antiviral treatment. The molecular mechanisms of IR in HCV are not entirely clear. Experimental and clinical data suggested that hepatitis C virus per se is diabetogenic. However, presence of HCV alone does not affect IR. It was proposed that IR is mediated by proinflammatory cytokines, mainly by TNF-alpha. TNF-alpha potentiates interferon-gamma-induced transcriptional activation of indoleamine 2,3-dioxygenase, the rate-limiting enzyme of tryptophan- (TRP-) kynurenine (KYN) metabolism. Upregulation of TRP-KYN metabolism was reported in HCV patients. KYN and some of its derivatives affect insulin signaling pathways. We hypothesized that upregulation of TRP-KYN metabolism might contribute to the development of IR in HCV. To check this suggestion, we evaluated serum concentrations of TRP and KYN and HOMA-IR and HOMA-beta in 60 chronic HCV patients considered for the treatment with IFN-alpha. KYN and TRP concentrations correlated with HOMA-IR and HOMA-beta scores. Our data suggest the involvement of KYN and its metabolites in the development of IR in HCV patients. TRP-KYN metabolism might be a new target for prevention and treatment of IR in HCV patients.

Effects of obesity and estradiol on Na+/K+-ATPase and their relevance to cardiovascular diseases

Obesity is associated with aberrant sodium/potassium-ATPase (Na(+)/K(+)-ATPase) activity, apparently linked to hyperglycemic hyperinsulinemia, which may repress or inactivate the enzyme. The reduction of Na(+)/K(+)-ATPase activity in cardiac tissue induces myocyte death and cardiac dysfunction, leading to the development of myocardial dilation in animal models; this has also been documented in patients with heart failure (HF). During several pathological situations (cardiac insufficiency and HF) and in experimental models (obesity), the heart becomes more sensitive to the effect of cardiac glycosides, due to a decrease in Na(+)/K(+)-ATPase levels. The primary female sex steroid estradiol has long been recognized to be important in a wide variety of physiological processes. Numerous studies, including ours, have shown that estradiol is one of the major factors controlling the activity and expression of Na(+)/K(+)-ATPase in the cardiovascular (CV) system. However, the effects of estradiol on Na(+)/K(+)-ATPase in both normal and pathological conditions, such as obesity, remain unclear. Increasing our understanding of the molecular mechanisms by which estradiol mediates its effects on Na(+)/K(+)-ATPase function may help to develop new strategies for the treatment of CV diseases. Herein, we discuss the latest data from animal and clinical studies that have examined how pathophysiological conditions such as obesity and the action of estradiol regulate Na(+)/K(+)-ATPase activity.

A high ratio of dietary n-3/n-6 polyunsaturated fatty acids improves obesity-linked inflammation and insulin resistance through suppressing activation of TLR4 in SD rats

Dietary ratios of n-3/n-6 polyunsaturated fatty acids (PUFAs) have been implicated in controlling markers of metabolic disorders, including obesity, insulin resistance (IR), inflammation, and lipid profiles, which are also presumed to be partly related to type 2 diabetes mellitus (T2DM). However, molecular mechanisms of the different PUFAs related to metabolic disorders have not been systematically addressed. The present study aimed to investigate the impact of dietary n-3/n-6 PUFA ratios on obesity and IR and, further, to determine the underlying mechanisms. For 16 weeks, 32 SD male rats, randomly divided into four groups (n = 8 per group), received one of the following diets: normal chow, high saturated fatty acid (SFA), high n-3/n-6 PUFA ratio (1∶1, PUFA¹:¹), or low n-3/n-6 PUFA ratio (1∶4, PUFA¹:⁴). Following the experimental diet period, metabolic parameters related to obesity and IR were measured. Compared to SFA diet-fed rats, PUFA¹:¹ diet-fed rats exhibited decreased body and visceral fat weight, lowered blood lipids, and improved glucose tolerance and insulin sensitivity. Interestingly, these changes were accompanied with decreased expression levels of circulating pro-inflammatory cytokines, including tumor necrosis factor α, interleukin-6, and C-reactive protein. Moreover, the TLR4 protein and mRNA levels were markedly down-regulated by PUFA¹:¹ compared with SFA; however, PUFA¹:⁴ diet-fed rats failed to exhibit these changes. Cumulatively, our data highlight a role for a PUFA¹:¹ diet in the prevention of obesity and related metabolic disorders by suppressing the activation of TLR4, a critical modulator of pro-inflammatory cytokines.

Implication of insulin receptor A isoform and IRA/IGF-IR hybrid receptors in the aortic vascular smooth muscle cell proliferation: role of TNF-α and IGF-II

To assess the role of insulin receptor (IR) isoforms (IRA and IRB) in the proliferation of vascular smooth muscle cells (VSMCs) involved in the atherosclerotic process, we generated new VSMC lines bearing IR (wild-type VSMCs; IRLoxP(+/+) VSMCs), lacking IR (IR(-/-) VSMCs) or expressing IRA (IRA VSMCs) or IRB (IRB VSMCs). Insulin and different proatherogenic stimuli induced a significant increase of IRA expression in IRLoxP(+/+) VSMCs. Moreover, insulin, through ERK signaling, and the proatherogenic stimuli, through ERK and p38 signaling, induced a higher proliferation in IRA than IRB VSMCs. The latter effect might be due to IRA cells showing a higher expression of angiotensin II, endothelin 1, and thromboxane 2 receptors and basal association between IRA and these receptors. Furthermore, TNF-α induced in a ligand-dependent manner a higher association between IRA and TNF-α receptor 1 (TNF-R1). On the other hand, IRA overexpression might favor the atherogenic actions of IGF-II. Thereby, IGF-II or TNF-α induced IRA and IGF-I receptor (IGF-IR) overexpression as well as an increase of IRA/IGF-IR hybrid receptors in VSMCs. More importantly, we observed a significant increase of IRA, TNF-R1, and IGF-IR expression as well as higher association of IRA with TNF-R1 or IGF-IR in the aorta from ApoE(-/-) and BATIRKO mice, 2 models showing vascular damage. In addition, anti-TNF-α treatment prevented those effects in BATIRKO mice. Finally, our data suggest that the IRA isoform and its association with TNF-R1 or IGF-IR confers proliferative advantage to VSMCs, mainly in response to TNF-α or IGF-II, which might be of significance in the early atherosclerotic process.

Essential role of Pin1 via STAT3 signalling and mitochondria-dependent pathways in restenosis in type 2 diabetes

Type 2 diabetes (T2D) is associated with accelerated restenosis rates after angioplasty. We have previously proved that Pin1 played an important role in vascular smooth muscle cell (VSMC) cycle and apoptosis. But neither the role of Pin1 in restenosis by T2D, nor the molecular mechanism of Pin1 in these processes has been elucidated. A mouse model of T2D was generated by the combination of high-fat diet (HFD) and streptozotocin (STZ) injections. Both Immunohistochemistry and Western blot revealed that Pin1 expression was up-regulated in the arterial wall in T2D mice and in VSMCs in culture conditions mimicking T2D. Next, increased activity of Pin1 was observed in neointimal hyperplasia after arterial injury in T2D mice. Further analysis confirmed that 10% serum of T2D mice and Pin1-forced expression stimulated proliferation, inhibited apoptosis, enhanced cell cycle progression and migration of VSMCs, whereas Pin1 knockdown resulted in the converse effects. We demonstrated that STAT3 signalling and mitochondria-dependent pathways played critical roles in the involvement of Pin1 in cell cycle regulation and apoptosis of VSMCs in T2D. In addition, VEGF expression was stimulated by Pin1, which unveiled part of the mechanism of Pin1 in regulating VSMC migration in T2D. Finally, the administration of juglone via pluronic gel onto injured common femoral artery resulted in a significant inhibition of the neointima/media ratio. Our findings demonstrated the vital effect of Pin1 on the VSMC proliferation, cell cycle progression, apoptosis and migration that underlie neointima formation in T2D and implicated Pin1 as a potential therapeutic target to prevent restenosis in T2D.

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.

Mercury induces proliferation and reduces cell size in vascular smooth muscle cells through MAPK, oxidative stress and cyclooxygenase-2 pathways

Mercury exposure is known to increase cardiovascular risk but the underlying cellular mechanisms remain undetermined. We analyzed whether chronic exposure to HgCl2 affects vascular structure and the functional properties of vascular smooth muscle cells (VSMC) through oxidative stress/cyclooxygenase-2 dependent pathways. Mesenteric resistance arteries and aortas from Wistar rats treated with HgCl2 (first dose 4.6mgkg(-1), subsequent doses 0.07mgkg(-1)day(-1), 30days) and cultured aortic VSMC stimulated with HgCl2 (0.05-5μg/ml) were used. Treatment of rats with HgCl2 decreased wall thickness of the resistance and conductance vasculature, increased the number of SMC within the media and decreased SMC nucleus size. In VSMCs, exposure to HgCl2: 1) induced a proliferative response and a reduction in cell size; 2) increased superoxide anion production, NADPH oxidase activity, gene and/or protein levels of the NADPH oxidase subunit NOX-1, the EC- and Mn-superoxide dismutases and cyclooxygenase-2 (COX-2); 3) induced activation of ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized the proliferative response and the altered cell size induced by HgCl2. Blockade of ERK1/2 and p38 signaling pathways abolished the HgCl2-induced Nox1 and COX-2 expression and normalized the alterations induced by mercury in cell proliferation and size. In conclusion, long exposure of VSMC to low doses of mercury activates MAPK signaling pathways that result in activation of inflammatory proteins such as NADPH oxidase and COX-2 that in turn induce proliferation of VSMC and changes in cell size. These findings offer further evidence that mercury might be considered an environmental risk factor for cardiovascular disease.

Treatment of cachexia: melanocortin and ghrelin interventions

Cachexia is a condition typified by wasting of fat and LBM caused by anorexia and further endocrinological modulation of energy stores. Diseases known to cause cachectic symptoms include cancer, chronic kidney disease, and chronic heart failure; these conditions are associated with increased levels of proinflammatory cytokines and increased resting energy expenditure. Early studies have suggested the central melanocortin system as one of the main mediators of the symptoms of cachexia. Pharmacological and genetic antagonism of these pathways attenuates cachectic symptoms in laboratory models; effects have yet to be studied in humans. In addition, ghrelin, an endogenous orexigenic hormone with receptors on melanocortinergic neurons, has been shown to ameliorate symptoms of cachexia, at least in part, by an increase in appetite via melanocortin modulation, in addition to its anticatabolic and anti-inflammatory effects. These effects of ghrelin have been confirmed in multiple types of cachexia in both laboratory and human studies, suggesting a positive future for cachexia treatments.

The role of G protein coupled receptor kinases in neurocardiovascular pathophysiology

In coronary artery disease the G protein related kinases (GRKs) play a role in desensitization of β-adrenoreceptors (AR) after coronary occlusion. Targeted deletion and lowering of cardiac myocyte GRK-2 decreases the risk of post-ischemic heart failure (HF). Studies carried out in humans confirm the role of GRK-2 as a marker for the progression of HF after myocardial infarction (MI). The level of GRK-2 could be an indicator of β-AR blocker efficacy in patients with acute coronary syndrome. Elevated levels of GRK-2 are an early ubiquitous consequence of myocardial injury. In hypertension an increased level of GRK-2 was reported in both animal models and human studies. The role of GRKs in vagally mediated disorders such as vasovagal syncope and atrial fibrillation remains controversial. The role of GRKs in the pathogenesis of neurocardiological diseases provides an insight into the molecular pathogenesis process, opens potential therapeutic options and suggests new directins for scientific research.

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.

Effects of protein and omega-3 supplementation, provided during regular dialysis sessions, on nutritional and inflammatory indices in hemodialysis patients

Purpose

Malnutrition and chronic inflammation in dialysis patients negatively impacts prognosis. However, intervening to correct this problem (through nutritional supplementation) is often hampered by poor compliance due to both medical and socioeconomic barriers. We have therefore performed a pilot study to investigate the technical feasibility of “directly observed treatment” of nutritional supplementation (protein and omega-3 fatty acids), administered during regular dialysis sessions. Secondary end points included observation of nutritional and inflammatory status of hypoalbuminemic patients undergoing hemodialysis.

Methods

Main inclusion criteria were serum albumin ≤ 3.9 g/dL (3 months prior to the study). Sixty-three eligible patients agreed to participate. Two intervention groups received 30 mL of a liquid protein supplement plus either 2.4 g omega-3 (1800 mg eicosapentaenoic acid + 600 mg docosahexaenoic acid) or a placebo, three times per week after their routine dialysis session for 6 months. Serum albumin, plasma lipids, and other indicators of nutritional and inflammatory status were measured.

Results

Directly observed nutritional supplementation resulted in a significant improvement in the low density lipoprotein cholesterol/high density lipoprotein cholesterol ratio in the omega-3 group as compared to the placebo group (P = 0.043). For the omega-3 group, serum albumin was also marginally higher after 6 months as compared to baseline (P = 0.07). The observed increase in C-reactive protein in the placebo group over 6 months was not apparent in the omega-3 group, although there was no significant difference between groups. Nuclear factor kappa B, malnutrition-inflammation score, normalized protein nitrogen appearance, body mass index, and hemoglobin were unaffected by the intervention.

Conclusion

“Directly observed treatment” with an omega-3 based supplement (as opposed to a pure protein supplement) showed beneficial effects on the lipid profile, and C-reactive protein levels. Further studies using a combination of outpatient and inpatient “directly observed treatment” of omega-3 based supplementation is warranted.

The effects of fish oil supplementation on markers of inflammation in chronic kidney disease patients

OBJECTIVE

One prevalent characteristic of all stages of chronic kidney disease (CKD) is excessive production of proinflammatory cytokines. Fish oil (FO) supplementation has been reported to lower levels of proinflammatory cytokines. The benefits of FO for an extensive range of populations and a variety of health concerns are apparent, yet the anti-inflammatory benefits for nondialysis CKD patients are not as well documented. Therefore, the purpose of this study was to investigate the effects of the daily consumption of FO (1,400 mg eicosapentaenoic acid + 1,000 mg docosahexaenoic acid) on interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) for 8 weeks in nondialysis CKD patients.

DESIGN, SETTING, AND SUBJECTS

In this double-blind, randomized, placebo-controlled intervention, the effect of 8 weeks of FO administration on IL-1β, IL-6, and TNF-α levels in nondialysis CKD patients were evaluated.

INTERVENTION

Thirty-one nondialysis CKD patients (17 = FO; 14 = placebo) randomly received either FO dietary supplementation 2.4 g/day (1,400 mg eicosapentaenoic acid + 1,000 mg docosahexaenoic acid) or placebo (safflower oil) for 8 weeks.

MAIN OUTCOME MEASURES

IL-1β, IL-6, and TNF-α were all measured as markers of inflammation.

RESULTS

One-way analysis of variance revealed no significant differences in IL-6 (P = .06), IL-1β (P = .18), and TNF-α (P = .20) between groups in pretest values. Additionally, no pretest differences existed between groups for age (P = .549), weight (P = .324), waist circumference (P = .086), gender (P = .591), and ethnicity (P = .875). Covariance was calculated using compliance, age, gender, ethnicity, body weight, and waist circumference as covariates. No significant differences were discovered between groups after FO supplementation for IL-6 (P = .453) and TNF-α (P = .242). A significant difference was discovered for IL-1β (P = .050) with lower levels in the FO group.

CONCLUSIONS

The results of this study are in agreement with some previous studies that suggest that FO supplementation has no effect on plasma proinflammatory cytokines TNF-α or IL-6, but does have an effect on IL-1β in nondialysis CKD patients.

Fish oil -- how does it reduce plasma triglycerides?

Long chain omega-3 fatty acids (FAs) are effective for reducing plasma triglyceride (TG) levels. At the pharmaceutical dose, 3.4g/day, they reduce plasma TG by about 25-50% after one month of treatment, resulting primarily from the decline in hepatic very low density lipoprotein (VLDL-TG) production, and secondarily from the increase in VLDL clearance. Numerous mechanisms have been shown to contribute to the TG overproduction, but a key component is an increase in the availability of FAs in the liver. The liver derives FAs from three sources: diet (delivered via chylomicron remnants), de novo lipogenesis, and circulating non-esterified FAs (NEFAs). Of these, NEFAs contribute the largest fraction to VLDL-TG production in both normotriglyceridemic subjects and hypertriglyceridemic, insulin resistant patients. Thus reducing NEFA delivery to the liver would be a likely locus of action for fish oils (FO). The key regulator of plasma NEFA is intracellular adipocyte lipolysis via hormone sensitive lipase (HSL), which increases as insulin sensitivity worsens. FO counteracts intracellular lipolysis in adipocytes by suppressing adipose tissue inflammation. In addition, FO increases extracellular lipolysis by lipoprotein lipase (LpL) in adipose, heart and skeletal muscle and enhances hepatic and skeletal muscle β-oxidation which contributes to reduced FA delivery to the liver. FO could activate transcription factors which control metabolic pathways in a tissue specific manner regulating nutrient traffic and reducing plasma TG. This article is part of a Special Issue entitled Triglyceride Metabolism and Disease.

Whole grain products, fish and bilberries alter glucose and lipid metabolism in a randomized, controlled trial: the Sysdimet study

Background

Due to the growing prevalence of type 2 diabetes, new dietary solutions are needed to help improve glucose and lipid metabolism in persons at high risk of developing the disease. Herein we investigated the effects of low-insulin-response grain products, fatty fish, and berries on glucose metabolism and plasma lipidomic profiles in persons with impaired glucose metabolism.

Methodology/Principal Findings

Altogether 106 men and women with impaired glucose metabolism and with at least two other features of the metabolic syndrome were included in a 12-week parallel dietary intervention. The participants were randomized into three diet intervention groups: (1) whole grain and low postprandial insulin response grain products, fatty fish three times a week, and bilberries three portions per day (HealthyDiet group), (2) Whole grain enriched diet (WGED) group, which includes principally the same grain products as group (1), but with no change in fish or berry consumption, and (3) refined wheat breads (Control). Oral glucose tolerance, plasma fatty acids and lipidomic profiles were measured before and after the intervention. Self-reported compliance with the diets was good and the body weight remained constant. Within the HealthyDiet group two hour glucose concentration and area-under-the-curve for glucose decreased and plasma proportion of (n-3) long-chain PUFAs increased (False Discovery Rate p-values <0.05). Increases in eicosapentaenoic acid and docosahexaenoic acid associated curvilinearly with the improved insulin secretion and glucose disposal. Among the 364 characterized lipids, 25 changed significantly in the HealthyDiet group, including multiple triglycerides incorporating the long chain (n-3) PUFA.

Conclusions/Significance

The results suggest that the diet rich in whole grain and low insulin response grain products, bilberries, and fatty fish improve glucose metabolism and alter the lipidomic profile. Therefore, such a diet may have a beneficial effect in the efforts to prevent type 2 diabetes in high risk persons.

Trial Registration

ClinicalTrials.gov NCT00573781

Thrombin and vascular inflammation

Vascular endothelium is a key regulator of homeostasis. In physiological conditions it mediates vascular dilatation, prevents platelet adhesion, and inhibits thrombin generation. However, endothelial dysfunction caused by physical injury of the vascular wall, for example during balloon angioplasty, acute or chronic inflammation, such as in atherothrombosis, creates a proinflammatory environment which supports leukocyte transmigration toward inflammatory sites. At the same time, the dysfunction promotes thrombin generation, fibrin deposition, and coagulation. The serine protease thrombin plays a pivotal role in the coagulation cascade. However, thrombin is not only the key effector of coagulation cascade; it also plays a significant role in inflammatory diseases. It shows an array of effects on endothelial cells, vascular smooth muscle cells, monocytes, and platelets, all of which participate in the vascular pathophysiology such as atherothrombosis. Therefore, thrombin can be considered as an important modulatory molecule of vascular homeostasis. This review summarizes the existing evidence on the role of thrombin in vascular inflammation.

Regulation of Inducible Nitric Oxide Synthase (iNOS) and its Potential Role in Insulin Resistance, Diabetes and Heart Failure

Nitric oxide synthases (NOS) are the enzymes responsible for nitric oxide (NO) generation. NO is a reactive oxygen species as well as a reactive nitrogen species. It is a free radical which mediates several biological effects. It is clear that the generation and actions of NO under physiological and pathophysiological conditions are regulated and extend to almost every cell type and function within the circulation. In mammals 3 distinct isoforms of NOS have been identified: neuronal NOS (nNOS), inducible NOS (iNOS) and endothelial NOS (eNOS). The important isoform in the regulation of insulin resistance (IR) is iNOS. Understanding the molecular mechanisms regulating the iNOS pathway in normal and hyperglycemic conditions would help to explain some of vascular abnormalities observed in type 2 diabetes mellitus (T2DM). Previous studies have reported increased myocardial iNOS activity and expression in heart failure (HF). This review considers the recent animal studies which focus on the understanding of regulation of iNOS activity/expression and the role of iNOS agonists as potential therapeutic agents in treatment of IR, T2DM and HF.

Omega-3 fatty acids supplementation does not affect serum lipids in chronic hemodialysis patients

OBJECTIVE

The aim of this study was to test the hypothesis that omega-3 fatty acids have an effect on serum lipids and inflammation markers in chronic hemodialysis (HD) patients.

DESIGN

The study followed a single-blind, randomized, crossover design.

SETTING

The study was conducted at the Hemodialysis Unit of the Laikon General Hospital in Athens, Greece.

PATIENTS

A total of 25 chronic HD patients were included in the study (16 men, 9 women, age: 51 ± 15 years).

INTERVENTION

Patients were randomly assigned to one of the following 2 intervention groups: omega-3 fatty acids plus α-tocopherol (920 mg eicosapentaenoic Acid (EPA), 760 mg docosahexaenoic acid (DHA), 8 mg α-tocopherol in total per day) or α-tocopherol supplement (100 mg/week resulting in 14.2 mg/day) alone for 4 weeks. After a washout period of 4 weeks, the 2 groups were crossed.

MAIN OUTCOME MEASURES

Medical history data were collected and anthropometric and nutritional intake evaluation was performed at the beginning and at the end of both interventions. Hematological and biochemical parameters as well as C-reactive protein levels were measured.

RESULTS

No statistically significant results were recorded in the lipidemic profiles of the participants between baseline and the 2 interventions. C-reactive protein levels also did not change significantly between the 2 interventions (5.54 ± 3.33 to 6.70 ± 5.01 mg/L [P = .19] with vitamin E vs. 7.13 ± 5.04 to 6.87 ± 5.24 [P = .78] with omega-3, P overall = .53).

CONCLUSION

The results of this study do not provide support for the positive effects of omega-3 fatty acid supplementation 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.

The differential effects of EPA and DHA on cardiovascular risk factors

Compelling evidence exists for the cardioprotective benefits resulting from consumption of fatty acids from fish oils, EPA (20:5n-3) and DHA (22:6n-3). EPA and DHA alter membrane fluidity, interact with transcription factors such as PPAR and sterol regulatory element binding protein, and are substrates for enzymes including cyclooxygenase, lipoxygenase and cytochrome P450. As a result, fish oils may improve cardiovascular health by altering lipid metabolism, inducing haemodynamic changes, decreasing arrhythmias, modulating platelet function, improving endothelial function and inhibiting inflammatory pathways. The independent effects of EPA and DHA are poorly understood. While both EPA and DHA decrease TAG levels, only DHA appears to increase HDL and LDL particle size. Evidence to date suggests that DHA is more efficient in decreasing blood pressure, heart rate and platelet aggregation compared to EPA. Fish oil consumption appears to improve arterial compliance and endothelial function; it is not yet clear as to whether differences exist between EPA and DHA in their vascular effects. In contrast, the beneficial effect of fish oils on inflammation and insulin sensitivity observed in vitro and in animal studies has not been confirmed in human subjects. Further investigation to clarify the relative effects of consuming EPA and DHA at a range of doses would enable elaboration of current understanding regarding cardioprotective effects of consuming oily fish and algal sources of long chain n-3 PUFA, and provide clearer evidence for the clinical therapeutic potential of consuming either EPA or DHA-rich oils.

Dietary milled flaxseed and flaxseed oil improve N-3 fatty acid status and do not affect glycemic control in individuals with well-controlled type 2 diabetes

OBJECTIVE

To determine the effects of dietary consumption of milled flaxseed or flaxseed oil on glycemic control, n-3 fatty acid status, anthropometrics, and adipokines in individuals with type 2 diabetes.

DESIGN

Thirty-four participants were randomized into a parallel, controlled trial.

SUBJECTS

The participants were adults with type 2 diabetes (age 52.4 +/- 1.5 years, body mass index 32.4 +/- 1.0 kg/m(2), n = 17 men and 17 women).

INTERVENTIONS

Participants consumed a selection of bakery products containing no flax (control group [CTL], n = 9), milled flaxseed (FXS, n = 13; 32 g/d), or flaxseed oil (FXO, n = 12; 13 g/d) daily for 12 weeks. The FXS and FXO groups received equivalent amounts of alpha-linolenic acid (ALA; 7.4 g/day).

MEASURES OF OUTCOME

The primary outcome measures were fasting plasma hemoglobin A(1c), glucose, insulin, and phospholipid fatty acid composition. The secondary outcome measures were fasting circulating leptin and adiponectin, as well as body weight, body mass index, and waist circumference. Dietary intake assessment and calculations for homeostasis model assessment for insulin resistance and quantified insulin sensitivity check were also completed.

RESULTS

The FXS and FXO groups had increases in plasma phospholipid n-3 fatty acids (ALA, eicosapentaenoic acid [EPA], or decosapentaenoic acid [DPA], but not docosahexaenoic acid), and the FXO group had more EPA and DPA in plasma phospholipids compared to the FXS group. All groups had similar caloric intakes; however, the CTL group experienced a 4% weight gain compared to baseline (p < 0.05), while both flax groups had constant body weights during the study period. All other parameters, including glycemic control, were unchanged by dietary treatment.

CONCLUSIONS

Milled FXS and FXO intake does not affect glycemic control in adults with well-controlled type 2 diabetes. Possible prevention of weight gain by flax consumption warrants further investigation.

Omega-3 polyunsaturated fatty acids in the treatment of kidney disease

After more than 25 years of published investigation, including randomized controlled trials, the role of omega-3 polyunsaturated fatty acids in the treatment of kidney disease remains unclear. In vitro and in vivo experimental studies support the efficacy of omega-3 polyunsaturated fatty acids on inflammatory pathways involved with the progression of kidney disease. Clinical investigations have focused predominantly on immunoglobulin A (IgA) nephropathy. More recently, lupus nephritis, polycystic kidney disease, and other glomerular diseases have been investigated. Clinical trials have shown conflicting results for the efficacy of omega-3 polyunsaturated fatty acids in IgA nephropathy, which may relate to varying doses, proportions of eicosapentaenoic acid and docosahexaenoic acid, duration of therapy, and sample size of the study populations. Meta-analyses of clinical trials using omega-3 polyunsaturated fatty acids in IgA nephropathy have been limited by the quality of available studies. However, guidelines suggest that omega-3 polyunsaturated fatty acids should be considered in progressive IgA nephropathy. Omega-3 polyunsaturated fatty acids decrease blood pressure, a known accelerant of kidney disease progression. Well-designed, adequately powered, randomized, controlled clinical trials are required to further investigate the potential benefits of omega-3 polyunsaturated fatty acids on the progression of kidney disease and patient survival.

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.

Fish oil supplementation lowers C-reactive protein levels independent of triglyceride reduction in patients with end-stage renal disease

BACKGROUND

Inflammation has been identified as a marker for cardiovascular disease. The purpose of this study is to examine the effects of fish oil fatty acid supplementation on C-reactive protein (CRP) levels.

METHODS

The study uses a double-blind, permuted-randomized, and placebo-controlled experimental protocol. Patients are randomly placed into a fish oil group or a control group. Thirty-three patients in the experimental and control groups ingest 2 soft-gel pills (1 g each) of fish oil supplements containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) or placebo at each meal. Patients follow the supplementation protocol for 6 months. Analysis of variance (ANOVA) is used to measure pretest and posttest differences in the variable of interest. A Kolmogorov-Smirnov test for normality is used to test whether CRP levels are normally distributed.

RESULTS

The Kolmogorov-Smirnov test for CRP finds a P value of .273 (KS = .997), revealing that the distribution is normal. ANOVA reveals no statistically significant difference between groups at baseline for CRP (F = 4.118, P = .053). ANOVA reveals a significant main effect (F = 4.29, P = .048) for CRP, with the EPA/DHA group having a significant change in values from pretest (16 mg/dL, standard deviation [SD] = 13.80) to posttest (10.22 mg/dL, SD = 7.87). The placebo group's CRP levels do not change significantly from pretest (13.37, standard deviation [SD] = 7.94) to posttest (13.67, SD = 7.07). An observed power calculation using Cohen's D with a computed alpha of .05 is .588.

CONCLUSIONS

The study demonstrates that consuming 960 mg/d of EPA and 600 mg/d of DHA can lower CRP.

Fatty fish intake decreases lipids related to inflammation and insulin signaling--a lipidomics approach

Background

The evidence of the multiple beneficial health effects of fish consumption is strong, but physiological mechanisms behind these effects are not completely known. Little information is available on the effects of consumption of different type of fish. The aim of this study was to investigate how fatty fish or lean fish in a diet affect serum lipidomic profiles in subjects with coronary heart disease.

Methodology and Principal Findings

A pilot study was designed which included altogether 33 subjects with myocardial infarction or unstable ischemic attack in an 8-week parallel controlled intervention. The subjects were randomized to either fatty fish (n = 11), lean fish (n = 12) or control (n = 10) groups. Subjects in the fish groups had 4 fish meals per week and subjects in the control group consumed lean beef, pork and chicken. A fish meal was allowed once a week maximum. Lipidomics analyses were performed using ultra performance liquid chromatography coupled to electrospray ionization mass spectrometry and gas chromatography. Multiple bioactive lipid species, including ceramides, lysophosphatidylcholines and diacylglycerols, decreased significantly in the fatty fish group, whereas in the lean fish group cholesterol esters and specific long-chain triacylglycerols increased significantly (False Discovery Rate q-value <0.05).

Conclusions/Significance

The 8-week consumption of fatty fish decreased lipids which are potential mediators of lipid-induced insulin resistance and inflammation, and may be related to the protective effects of fatty fish on the progression of atherosclerotic vascular diseases or insulin resistance.

Trial Registration

ClinicalTrials.gov NCT00720655

Prevention of insulin resistance by n-3 polyunsaturated fatty acids

PURPOSE OF REVIEW

Review results from recent human and animal studies regarding the effects of n-3 polyunsaturated fatty acid (PUFA) in the prevention of insulin resistance.

RECENT FINDINGS

Overall, results from animal studies indicate that fish oil and individual n-3 PUFA [alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA)] prevented insulin resistance in animal models; results from two studies in mice showed that EPA increased insulin secretion. ALA, EPA, and DHA may act at different sites and involve different mechanisms. Fish oil or purified EPA reduced insulin resistance in some but not other human studies in normal weight and obese individuals. Discrepancies may be due to differences in health status of participants, macronutrient, fatty acid, and antioxidant nutrient composition of basal diet; amount, duration, and fatty acid composition of n-3 PUFA, and methods used to assess insulin resistance. Moderate amounts of n-3 PUFA did not improve or deteriorate glucose control in type 2 diabetics.

SUMMARY

n-3 PUFA supplementation has clinical significance in the prevention and reversal of insulin resistance. However, increased intake of n-3 PUFA should be part of an overall healthy lifestyle that includes weight control, exercise, and reduction in the intake of refined sugars, n-6, saturated, and trans fatty acids.

Effects of seafood consumption and weight loss on fasting leptin and ghrelin concentrations in overweight and obese European young adults

BACKGROUND

Energy restriction affects circulating leptin and ghrelin concentrations.

THE AIM OF THIS STUDY

To investigate whether seafood consumption affects fasting leptin and ghrelin concentrations in addition to weight loss.

METHODS

In this 8-week dietary intervention, subjects (324 Icelandic, Spanish and Irish subjects, 20-40 years, BMI 27.5-32.5 kg/m(2)) were randomized to energy-restricted diets (-30%) of identical macronutrient composition but different amount of seafood: control (no seafood); lean fish (150 g cod, three times per week); fatty fish (150 g salmon, three times per week); EPA&DHA [daily docosahexaenoic (DHA)/eicosapentaenoic acid (EPA) capsules]. Anthropometric data, ghrelin, leptin, and insulin were measured at baseline and endpoint. Linear models investigated the effects of seafood on fasting leptin, ghrelin and insulin.

RESULTS

Body weight (-5.2 +/- 3.0 kg), leptin (-34.8%) and insulin (-13.5%) decreased, while ghrelin increased (5.6%) (all P < 0.001). According to linear models endpoint insulin was significantly lower in the EPA&DHA group (-16.4%, P = 0.025) compared to control, endpoint leptin in men was lower in the salmon group (-22.9%, P = 0.026), and the EPA&DHA group tended to have higher endpoint ghrelin (5.6%, P = 0.060), an effect seen only in women indicated by a significant gender x EPA&DHA interaction. Weight loss explained the effects of fatty seafood on leptin and ghrelin, but not insulin.

CONCLUSIONS

Consumption of fatty seafood can modulate fasting insulin, ghrelin and leptin during an 8-week intervention. Effects are partly gender specific and are partly explained by weight loss. Consumption of lean fish does not affect circulating hormones in comparison to control. The most consistent effect on circulating hormones is mediated by weight loss.