Omega-3 Fatty Acid Supplementation in Advanced Kidney Disease

Blood Levels of Endocannabinoids, Oxylipins, and Metabolites Are Altered in Hemodialysis Patients

Hemodialysis patients (HDPs) have higher blood pressure, higher levels of inflammation, a higher risk of cardiovascular disease, and unusually low plasma n-3 polyunsaturated fatty acid (PUFA) levels compared to healthy subjects. The objective of our investigation was to examine the levels of endocannabinoids (eCBs) and oxylipins (OxLs) in female HDPs compared to healthy matched female controls, with the underlying hypothesis that differences in specific PUFA levels in hemodialysis patients would result in changes in eCBs and OxLs. Plasma phospholipid fatty acids were analyzed by gas chromatography. Plasma was extracted and analyzed using ultra-performance liquid chromatography followed by electrospray ionization and tandem MS for eCBs and OxLs. The global untargeted metabolite profiling of plasma was performed by GCTOF MS. Compared to the controls, HDPs showed lower levels of plasma EPA and the associated OxL metabolites 5- and 12-HEPE, 14,15-DiHETE, as well as DHA derived 19(20)-EpDPE. Meanwhile, no changes in arachidonylethanolamide or 2-arachidonylglycerol in the open circulation were detected. Higher levels of multiple N-acylethanolamides, monoacylglycerols, biomarkers of progressive kidney disease, the nitric oxide metabolism-linked citrulline, and the uremic toxins kynurenine and creatine were observed in HDP. These metabolic differences in cCBs and OxLs help explain the severe inflammatory and cardiovascular disease manifested by HDPs, and they should be explored in future studies.

Recent Progress on Lipid Intake and Chronic Kidney Disease

The incidence of chronic kidney disease (CKD) is associated with major abnormalities in circulating lipoproteins and renal lipid metabolism. This article elaborates on the mechanisms of CKD and lipid uptake abnormalities. The viewpoint we supported is that lipid abnormalities directly cause CKD, resulting in forming a vicious cycle. On the theoretical and experiment fronts, this inference has been verified by elaborately elucidating the role of lipid intake and accumulation as well as their influences on CKD. Taken together, these findings suggest that further understanding of lipid metabolism in CKD may lead to novel therapeutic approaches.

Partitioning of Rumen-Protected n-3 and n-6 Fatty Acids is Organ-Specific in Growing Angus Heifers

Dietary polyunsaturated fatty acids (PUFA), especially n-3 and n-6 fatty acids (FA), play an important role in the regulation of FA metabolism in all mammals. However, FA metabolism differs between different organs, suggesting a distinct partitioning of highly relevant FA. For the present study in cattle, a novel technology was applied to overcome rumen biohydrogenation of dietary unsaturated FA. Angus heifers were fed a straw-based diet supplemented for 8 weeks with 450 g/day of rumen-protected oil, either from fish (FO) or sunflower (SO). The FA composition in blood and five important organs, namely heart, kidney, liver, lung, and spleen, was examined. In blood, proportions of polyunsaturated FA were increased by supplementing FO compared to SO. The largest increase of eicosapentaenoic acid (EPA) proportion was found with FO instead of SO in the kidney, the lowest in the lung. Docosahexaenoic acid (DHA) was increased more in the liver than in kidney, lung, and spleen. The heart incorporated seven times more EPA than DHA, which is more than all other organs and described here for the first time in ruminants. In addition, the heart had the highest proportions of α-linolenic acid (18:3n-3) and linoleic acid (18:2n-6) of all organs. The proportions of polyunsaturated FA in the lung and spleen were exceptionally low compared to heart, liver, and kidney. In conclusion, it was shown that the response to FO in the distribution of dietary n-3 FA was organ-specific while proportions of n-6 FA were quite inert with respect to the type of oil supplemented.

Lipid Accumulation and Chronic Kidney Disease

Obesity and hyperlipidemia are the most prevalent independent risk factors of chronic kidney disease (CKD), suggesting that lipid accumulation in the renal parenchyma is detrimental to renal function. Non-esterified fatty acids (also known as free fatty acids, FFA) are especially harmful to the kidneys. A concerted, increased FFA uptake due to high fat diets, overexpression of fatty acid uptake systems such as the CD36 scavenger receptor and the fatty acid transport proteins, and a reduced β-oxidation rate underlie the intracellular lipid accumulation in non-adipose tissues. FFAs in excess can damage podocytes, proximal tubular epithelial cells and the tubulointerstitial tissue through various mechanisms, in particular by boosting the production of reactive oxygen species (ROS) and lipid peroxidation, promoting mitochondrial damage and tissue inflammation, which result in glomerular and tubular lesions. Not all lipids are bad for the kidneys: polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seem to help lag the progression of chronic kidney disease (CKD). Lifestyle interventions, especially dietary adjustments, and lipid-lowering drugs can contribute to improve the clinical outcome of patients with CKD.

Wasting in Chronic Kidney Disease – a Complex Issue

Chronic kidney disease (CKD) has become a global health burden and is associated with increased morbidity and mortality. In particular, wasting is highly prevalent in later stages of the illness with muscle loss being a common problem. The aetiology and progression of this wasting is complex and multiple states have been identified linked to wasting in CKD. These include: ‘malnutrition’, ‘disease-related malnutrition’, ‘protein-energy wasting’, ‘cachexia’, ‘sarcopenia’, ‘frailty’ and ‘muscle wasting’. The purpose of this paper is to review these terms in the context of CKD. Common features include weight loss, loss of muscle mass and muscle function principally driven by CKD disease specific factors and inflammatory mediators. Disease-related malnutrition would appear to be a more appropriate term for CKD than malnutrition as it take in to consideration disease specific factors such as inflammation for example.  Frailty is commonly associated with age-related decline in physiological function. Development of novel screening tools measuring across multiple domains of nutritional status, muscle and physical function may be useful in CKD. Research into potential treatments are currently underway with focus on multi-modal therapies including nutrition, resistance training and anabolic drugs such as myostatin blockade and selective androgen receptor modulators. A better understanding of different states and terms may help guide assessment and treatment opportunities for patients.

Stirring the Pot: Can Dietary Modification Alleviate the Burden of CKD?

Diet is one of the largest modifiable risk factors for chronic kidney disease (CKD)-related death and disability. CKD is largely a progressive disease; however, it is increasingly appreciated that hallmarks of chronic kidney disease such as albuminuria can regress over time. The factors driving albuminuria resolution remain elusive. Since albuminuria is a strong risk factor for GFR loss, modifiable lifestyle factors that lead to an improvement in albuminuria would likely reduce the burden of CKD in high-risk individuals, such as patients with diabetes. Dietary therapy such as protein and sodium restriction has historically been used in the management of CKD. Evidence is emerging to indicate that other nutrients may influence kidney health, either through metabolic or haemodynamic pathways or via the modification of gut homeostasis. This review focuses on the role of diet in the pathogenesis and progression of CKD and discusses the latest findings related to the mechanisms of diet-induced kidney disease. It is possible that optimizing diet quality or restricting dietary intake could be harnessed as an adjunct therapy for CKD prevention or progression in susceptible individuals, thereby reducing the burden of CKD.

Therapeutic Effects of Omega-3 Fatty Acids on Chronic Kidney Disease-Associated Pruritus: a Literature Review

Uremic pruritus remains one of the most tormenting, frequent and potentially disabling problem in chronic kidney disease (CKD) patients. However, an area of substantial etiological interest with relation to uremic pruritus is the essential fatty acids deficiency. So we performed a literature review to elucidate the efficacy of omega-3 fatty acids on uremic pruritus. This review evaluated all of the studies published in English language, focusing on the clinical effects of omega-3 fatty acids on uremic pruritus. The literature review was conducted in December 2015 and carried out by searching Scopus, Medline, Cochrane central register of controlled trials, and Cochrane database of systematic reviews. The search terms were "kidney injury", "kidney failure", "chronic kidney disease", "end-stage renal disease", "dialysis", "hemodialysis", "peritoneal dialysis", "pruritus", "itch", "skin problems", "fish oil", "omega 3", "n-3 fatty acids", "polyunsaturated fatty acids", "docosahexaenoic acid", and "eicosapentaenoic acid". Four small studies investigating potential benefits of omega-3 fatty acids on symptoms of uremic pruritus were found. Among them, three small randomized controlled trials have shown a significant improvement in pruritus symptoms (evaluated by a standard questionnaire) in CKD patients who took omega-3 supplement compared to omega-6, omega-9, and placebo supplementation. Despite numerous limitations of the studies, it is worth noting that even minor reduction in itching symptoms may be clinically significant for CKD patients. Therefore, and considering multiple health benefits of omega-3 fatty acids in advanced CKD and negligible risk profile, omega-3 intake can wisely be applied to CKD patients with uremic pruritus.

Effects of a Novel Nutritional Formula Enriched With Eicosapentaenoic Acid and Docosahexaenoic Acid Specially Developed for Tube-Fed Hemodialysis Patients

OBJECTIVE

To evaluate the effects of a nutritional formula enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in tube-fed bedridden hemodialysis patients.

DESIGN

A prospective, multicenter, single-arm study.

SETTING

Koyukai Memorial Hospital, Orimoto Hospital, and Chofu Hospital, Japan.

SUBJECTS

Eleven tube-fed bedridden hemodialysis patients.

INTERVENTION

Patients were fed a nutritional formula enriched with EPA and DHA for 12 weeks.

MAIN OUTCOME MEASURES

Body weight; body mass index (BMI); serum levels of total protein, albumin, prealbumin, total cholesterol, triglyceride, and C-reactive protein (CRP); serum fatty acid composition.

RESULTS

Body weight; BMI; and serum levels of total protein, albumin, total cholesterol, triglyceride, and CRP at 12 weeks were not significantly different from baseline levels. Serum prealbumin, EPA, and DHA levels significantly increased after 12 weeks of treatment.

CONCLUSIONS

A nutritional formula enriched with EPA and DHA may be beneficial for nutritional management in tube-fed bedridden hemodialysis patients.

Treatment options for dyslipidemia in chronic kidney disease and for protection from contrast-induced nephropathy

Chronic kidney disease (CKD) is highly prevalent worldwide and represents a major cardiovascular risk factor. Dyslipidemia is present in most patients with CKD and further worsens CKD, creating a vicious cycle. The treatment of CKD-related dyslipidemia has been a controversial topic. The use of statins is recommended in all stages of CKD, but it appears to reduce cardiovascular and renal events only in the early CKD stages, up to stage 3. The use of atorvastatin has proven very beneficial; thus, the earliest we start statin treatment, the better for the patient. Atorvastatin and pitavastatin do not need dose adjustments at any level of renal function. Fibrates can be administered in mixed hyperlipidemia, combined with statins in early CKD stages. Omega-3 fatty acids are useful for treating hypertriglyceridemia in CKD. Antibodies against proprotein convertase subtilisin/kexin type 9 hold promise for a better control of dyslipidemia and a greater reduction of cardiovascular risk.

Pros and cons of fatty acids in bone biology

Despite the growing interest in deciphering the causes and consequences of obesity-related disorders, the mechanisms linking fat intake to bone behaviour remain unclear. Since bone fractures are widely associated with increased morbidity and mortality, most notably in elderly and obese people, bone health has become a major social and economic issue. Consistently, public health system guidelines have encouraged low-fat diets in order to reduce associated complications. However, from a bone point of view, mechanisms linking fat intake to bone alteration remain quite controversial. Thus, after more than a decade of dedicated studies, this timely review offers a comprehensive overview of the relationships between bone and fatty acids. Using clinical evidences as a starting-point to more complex molecular elucidation, this work highlights the complexity of the system and reveals that bone alteration that cannot be solved simply by taking ω-3 pills. Fatty acid effects on bone metabolism can be both direct and indirect and require integrated investigations. Furthermore, even at the level of a single cell, one fatty acid is able to trigger several different independent pathways (receptors, metabolites…) which may all have a say in the final cellular metabolic response.

Quantitative assessment of the degree of lipid unsaturation in intact Mortierella by Raman microspectroscopy

Fungi of the genus Mortierella can accumulate large amounts of unusual lipids depending on species, strain, and growth conditions. Fast and easy determination of key parameters of lipid quality for these samples is required. In this contribution, we apply Raman microspectroscopy to determine the degree of unsaturation for fungal lipids directly inside intact hyphae without elaborate sample handling. Six Mortierella species were grown under varying conditions, and Raman spectra of single lipid vesicles were acquired. From the spectra, we calculate a peak intensity ratio I(1270 cm(-1))/I(1445 cm(-1)) from the signals of =CH and -CH2/-CH3 groups, respectively. This ratio is linked to the iodine value (IV) using spectra of reference compounds with known IV. IVs of fungal samples are compared to gas chromatography results. Values from both methods are in good accordance. Lipid composition is found to vary between the investigated species, with Mortierella alpina having the most unsaturated lipid (IV up to 280) and Mortierella exigua the least unsaturated (IV as low as 70). We find Raman microspectroscopy a suitable tool to determine the IV reliably, fast, and easily inside intact hyphae without extensive sample handling or treatment. The method can also be transferred to other microscopic samples.

Omega-3 fatty acids inhibit the up-regulation of endothelial chemokines in maintenance hemodialysis patients

BACKGROUND

Chronic systemic inflammation is common in patients with chronic kidney disease on dialysis (CKD5D) and has been considered a key mediator of the increased cardiovascular risk in this patient population. In this study, we tested the hypothesis that supplementation of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) will attenuate the systemic inflammatory process in CKD5D patients.

METHODS

The design was a randomized, double-blinded, placebo controlled pilot trial (NCT00655525). Thirty-eight patients were randomly assigned in a 1 : 1 fashion to receive 2.9 g of eicosapentaenoic acid (C20:5, n-3) plus docosahexaenoic acid (C22:6, n-3) versus placebo for 12 weeks. The primary outcome was change in pro-inflammatory chemokines measured by lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs). Secondary outcomes were changes in systemic inflammatory markers. Analysis of covariance was used to compare percent change from baseline to 12 weeks.

RESULTS

Thirty-one patients completed 12 weeks and three patients completed 6 weeks of the study. Median age was 52 (interquartile range 45, 60) years, 74% were African-American and 79% were male. Supplementation of ω-3 PUFAs effectively decreased the LPS-induced PBMC expression of RANTES (Regulated upon Activation, Normal T cell Expressed and Secreted) and MCP-1 (Monocyte Chemotactic Protein-1; unadjusted P = 0.04 and 0.06; adjusted for demographics P = 0.02 and 0.05, respectively). There was no significant effect of the intervention on serum inflammatory markers (C-reactive protein, interleukin-6 and procalcitonin).

CONCLUSIONS

The results of this pilot study suggest that supplementation of ω-3 PUFAs is beneficial in decreasing the levels of endothelial chemokines, RANTES and MCP-1. Studies of larger sample size and longer duration are required to further evaluate effects of ω-3 PUFAs on systemic markers of inflammation, other metabolic parameters and clinical outcomes, particularly cardiovascular outcomes in CKD5D patients.

Effect of six different cooking techniques in the nutritional composition of two fish species previously selected as optimal for renal patient's diet

Benefits of fish consumption are widely known, but there is little information about nutrient values of raw and cooked fish. The aim was to study the impact that six cooking techniques have on the nutritional composition of two fish species with low content of adverse nutrients in renal diet. Raw and steamed, foiled with aluminum, foiled with banana leaf, gas oven-baked, microwave oven-coked and fried lightly samples were chemically analyzed to determine their protein, phosphorus and lipid content. Crevalle jack: all methods increased lipid and protein content and fatty acids (FA) varied in all cooking methods. Phosphorus decreased in the steamed and microwave oven-cooked samples. Red drum: foiled and fried lightly increased lipid content compared to the raw sample. FA concentration changed in all cooking methods. Protein increased with every technique and phosphorus decreased in the steamed and gas oven-baked samples. Renal patients should preferably consume crevalle jack steamed or microwave oven-cooked and red drum steamed or gas oven-baked.

Omega-3 intake in people with epilepsy under regular hemodialysis program: here to stay

Among the many risk factors suggested for sudden unexpected death in epilepsy (SUDEP), higher frequency of seizures is a very consistent issue. Furthermore, it has been established that hemodialysis-associated seizure is a complication of the dialysis procedure. Thus, since a possible relation between cardiovascular abnormalities and SUDEP among patients with chronic renal insufficiency in regular hemodialysis program should not be neglected, we propose in this paper that omega-3 fatty acids offer opportunities for prevention of sudden cardiac death or improved treatment in people with epilepsy under the regular hemodialysis program.

Obesity, immunomodulation and chronic kidney disease

Obesity-induced inflammation is associated with numerous pathologies and is an independent risk factor of chronic kidney disease (CKD). The prevalence of CKD is escalating and current therapeutic strategies are seriously lacking in efficacy, and immunomodulation has been suggested as a potential new therapeutic approach. Indeed, specialized pro-resolving mediators (SPMs), such as lipoxins (LXs), resolvins and protectins, have demonstrated protection in adipose inflammation, restoring insulin sensitivity and adiponectin production, while modulating leukocyte infiltration and promoting resolution in visceral adipose tissue. Furthermore, SPMs display direct renoprotective effect. Thus we review current evidence of immunomodulation as a potential strategy to subvert obesity-related CKD.

Application of polyunsaturated fatty acids in internal medicine: beyond the established cardiovascular effects

n-3 Polyunsaturated fatty acids (PUFAs) are organic acids, essential for mammals, whose deficiency is associated with different diseases. The American Heart Association recommends that all adults increase food-derived n-3 PUFA intake and also suggests that patients with documented coronary heart disease consume approximately 1 g of eicosapentaenoic acid and docosahexaenoic acid per day. However, recent evidence broadens their potential application to many other health disorders directly or indirectly associated with cardiovascular disease risk such as rheumatological diseases, mood depression, chronic kidney disease, chronic inflammatory lung diseases and others. These effects seem to be largely dependent on the dosages employed and on the characteristics of the selected patients. The cardiometabolic effects of PUFAs have been largely reviewed elsewhere, so the aim of our review is to point out the potential usefulness of such drugs with pleiotropic effects in the management of the actual typical aging patient, with co-morbidities and multidrug therapies.

Long-term fish intake preserves kidney function in elderly individuals: the Ikaria study

OBJECTIVES

The aim of this work was to evaluate the correlation between the amount of weekly fish intake and kidney function as measured by creatinine clearance (CCr) rate among elderly inhabitants of Ikaria Island, a place that has been related to an increased rate of longevity.

METHODS

From June to October of 2009, 673 males and females, aged 65-100 years and long-term residents of Ikaria Island were enrolled. Of those, 328 (75 ± 7 years) were males and 339 (75 ± 6 years) were females. Nutritional habits, including fish intake, were evaluated using a validated, semi-frequent food questionnaire and the MedDietScore. Urea and creatinine were measured, and CCr rate was estimated by the Cockcroft-Gault formula.

RESULTS

Eighty-four percent of participants reported fish consumption of more than 150 g/week; 35% had moderate to severe CCr (<60 mL). Crude analysis revealed that CCr rate was positively associated with fish intake (b ± SE per 100 g/day: 24 ± 9, P = .007); multiple linear regression analysis confirmed the previous finding (b ± SE per 100 g/day: 11 ± 2, P = .001) after adjusting for overall dietary habits through the MedDietScore and other potential confounders. Fish intake was positively associated with CCr. Furthermore, multi-adjusted logistic regression analysis showed that fish consumption of 100 g/day increased the likelihood by 121% of having a CCr greater than 60 mL (95% confidence interval 10%-343%).

CONCLUSIONS

Long-term fish consumption was independently associated with improved kidney function among elderly individuals, a finding that extends the current knowledge regarding the benefits of fish intake on human health.

Omega-3 polyunsaturated fatty acids reduce vascular endothelial growth factor production and suppress endothelial wound repair

Long-chain polyunsaturated omega-3 fatty acids (n-3 PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have diverse beneficial effects on cardiovascular diseases and have been used widely as supplements in reducing the risk of cardiovascular diseases. The beneficial effects are believed to be related to the anti-inflammatory and antioxidant action of n-3 PUFA. EPA and DHA can inhibit inflammatory cytokine-induced endothelial activation and reduce endothelial migration and proliferation. Revascularisation is the major therapeutic approach for end-stage cardiovascular diseases, and endothelial migration and proliferation are essential for the success of revascularisation. The aim of this study was to investigate the role of n-3 PUFAs on vascular endothelial wound repair. A scratch-wound repair assay was carried out in cultured human microvascular endothelial cells (HMEC-1) with and without different concentrations of DHA or EPA. The effect of DHA and EPA on HMEC-1 proliferation was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The effect of DHA and EPA on vegf mRNA expression was detected by real-time RT-PCR and vascular endothelial growth factor (VEGF) protein secretion by enzyme-linked immunosorbent assay. DHA and EPA dose-dependently suppressed HMEC-1 cell proliferation and wound repair. DHA and EPA treatment did not induce significant HMEC-1 cell death. The treatment, however, significantly suppressed vegf mRNA expression and protein secretion in both normoxia and hypoxia culture conditions. The addition of exogenous VEGF prevented DHA- and EPA-mediated suppression of HMEC-1 cell proliferation. DHA and EPA have anti-angiogenic effect partially through vegf suppression. The use of DHA and EPA may benefit angiogenic diseases, but may have potential side effects to patients undergoing revascularisation therapy. Further studies will be required to confirm the effect of n-3 PUFAs on vascular repair.

Essential polyunsaturated fatty acids, inflammation and mortality in dialysis patients

BACKGROUND

Polyunsaturated fatty acids (PUFA) are essential nutrients with anti-inflammatory and cardioprotective properties. We investigated the association of essential dietary PUFA intake, reflected by plasma fatty acid composition, with inflammation and mortality in dialysis patients.

METHODS

We recruited 222 Swedish dialysis subjects (39% women) with median age of 57 years and average 12 months of dialysis vintage. Plasma phospholipid PUFA were assessed by gas-liquid chromatography. Overall mortality was assessed after 18.4 (10th-90th percentiles: 2.3-60) months of follow-up.

RESULTS

Linoleic acid (LA), Mead acid (MA), α-linolenic acid (ALA) and long-chain n-3 PUFA (LC n-3; the sum of eicosapentaenoic, docosapentaenoic and docosahexaenoic acids) represented 19.7, 0.26, 0.26 and 7.64% of all fatty acids in plasma, respectively. This may reflect an adequate n-3 PUFA intake. LA was negatively (β = - 0.21, P = 0.004) but MA positively (β = 0.25, P < 0.001) associated with interleukin (IL)-6 in multivariate analyses. Neither ALA nor LC n-3 were independently associated with IL-6. During follow-up, 61 deaths and 115 kidney transplants occurred. Fully adjusted competing risk models showed that every percent increase in the proportion of plasma LA was associated with 12% reduction in mortality risk before transplantation (hazard ratio 0.88, 95% confidence interval 0.79-0.99). MA was directly associated with mortality. Neither ALA nor LC n-3 predicted outcome.

CONCLUSIONS

The proportion of plasma phospholipid LA is inversely associated with IL-6 and all-cause mortality in Swedish dialysis patients. We raise the hypothesis that dialysis patients could benefit from increased intake of vegetable oils, the primary source of LA in the Western-type diet.

The importance of the long-chain polyunsaturated fatty acid n-6/n-3 ratio in development of non-alcoholic fatty liver associated with obesity

Non-alcoholic fatty liver disease (NAFLD) is the most important cause of chronic liver disease that is characterized by hepatocyte triacylglycerol accumulation (steatosis), which can progress to inflammation, fibrosis, and cirrhosis (steatohepatitis). Overnutrition triggers the onset of oxidative stress in the liver due to higher availability and oxidation of fatty acids (FA), with development of hyperinsulinemia and insulin resistance (IR), and n-3 long-chain polyunsaturated FA (n-3 LCPUFA) depletion, with enhancement in the n-6/n-3 LCPUFA ratio favouring a pro-inflammatory state. These changes may lead to hepatic steatosis by different mechanisms, namely, (i) IR-dependent higher peripheral lipolysis and FA flux to the liver, (ii) n-3 LCPUFA depletion-induced changes in DNA binding activity of sterol regulatory element-binding protein 1c (SREBP-1c) and peroxisome proliferator-activated receptor α (PPAR-α) favouring lipogenesis over FA oxidation, and (iii) hyperinsulinemia-induced activation of lipogenic factor PPAR-γ. Supplementation with n-3 LCPUFA appears to reduce nutritional hepatic steatosis in adults, however, other histopathologic features of NAFLD remain to be studied.

The retrospective analysis of 343 Czech patients with IgA nephropathy--one centre experience

BACKGROUND

The aim of our study was to retrospectively analyse the clinical data and the histological findings of 343 patients (pts) followed up with IgA nephropathy (IgAN) in our department of nephrology. We have assessed the main demographic, clinical and histological data, and the medical treatment of IgAN pts.

METHODS

Multivariate analysis was used to evaluate the effect of different variables on ≥50% increase of plasma creatinine level from baseline during a median follow-up of 4 years.

RESULTS

In our group of IgAN pts, the male gender (68%) predominated over female gender (32%). At the time of renal biopsy, the median age of IgAN pts was 32.3 (18-90) years, the median level of serum creatinine was 119 μmol/L and the median level of proteinuria was 1.8 g/day. Most of the pts were found to have arterial hypertension (56.7%). The majority of the pts with arterial hypertension were treated with inhibitors of angiotensin-converting enzyme (80.4%) and the remaining pts (42.6%) were treated with angiotensin II receptor blockers. Fifty per cent of the pts (170 pts) were treated of corticosteroids, 21% of the pts (71 pts) used a combined immunosuppressive treatment of corticosteroids and cyclophosphamide, 8% of the pts (27 pts) took azathioprine, 1.5% of the pts (5 pts) took cyclosporine and 1.5% of the pts (5 pts) were given mycophenolate mofetil. Hypertension at presentation, fibrointimal proliferation of arterial vessels, interstitial fibrosis and interstitial inflammation were shown to be associated with ≥50% increase of plasma creatinine level from baseline in univariate analysis (P<0.05 for hypertension and fibrointimal proliferation; P<0.01 for interstitial fibrosis and inflammation). Using stepwise logistic regression presenting proteinuria>2 g/day [odds ratio (OR)=2.24, P<0.01], tubular atrophy (OR=4.97, P<0.01) and damage of tubular epithelium (OR=1.78, P<0.05) were found as risk factors for ≥50% increase of plasma creatinine level from baseline.

CONCLUSION

Our retrospective analysis found valuable information not only about the clinical, laboratory and histological findings in IgAN pts but also information about the risk factors influencing the progression of renal insufficiency.

The effect of n-3 polyunsaturated fatty acids on leukotriene B₄ and leukotriene B₅ production from stimulated neutrophil granulocytes in patients with chronic kidney disease

The proinflammatory leukotriene B₄ (LTB₄) may be of importance in the progression of chronic kidney disease (CKD). We investigated whether n-3 polyunsaturated fatty acids (PUFA) decrease LTB₄ and increase the formation of the less inflammatory leukotriene B₅ (LTB₅) in patients with CKD. Fifty-six patients with CKD stage 2-5 were randomised to 2.4 g n-3 PUFA or olive oil for 8 weeks. Compared to controls, n-3 PUFA significantly decreased release of LTB₄ (p<0.001) and 5-hydroxyeicosatetraenoic acid (5-HETE) (p<0.01) and significantly increased release of LTB₅ (p<0.001) and 5-hydroxyeicosapentaenoic acid (5-HEPE) (p<0.001) from stimulated neutrophil granulocytes. Kidney function evaluated by creatinine clearance and proteinuria did not improve. In conclusion, n-3 PUFA supplementation for 8 weeks in patients with CKD stage 2-5 significantly decreased LTB₄ and 5-HETE and significantly increased LTB₅ and 5-HEPE. No effect was seen on kidney function.