Omega-3 fatty acid supplementation as an adjunctive therapy in the treatment of chronic kidney disease: a meta-analysis

The Nephroprotective Effects of the Allogeneic Transplantation with Mesenchymal Stromal Cells Were Potentiated by ω3 Stimulating Up-Regulation of the PPAR-γ

Mesenchymal stromal cells (MSCs) obtained from bone marrow are a promising tool for regenerative medicine, including kidney diseases. A step forward in MSCs studies is cellular conditioning through specific minerals and vitamins. The Omega-3 fatty acids (ω3) are essential in regulating MSCs self-renewal, cell cycle, and survival. The ω3 could act as a ligand for peroxisome proliferator-activated receptor gamma (PPAR-γ). This study aimed to demonstrate that ω3 supplementation in rats could lead to the up-regulation of PPAR-γ in the MSCs. The next step was to compare the effects of these MSCs through allogeneic transplantation in rats subjected to unilateral ureteral obstruction (UUO). Independent of ω3 supplementation in the diet of the rats, the MSCs in vitro conserved differentiation capability and phenotypic characteristics. Nevertheless, MSCs obtained from the rats supplemented with ω3 stimulated an increase in the expression of PPAR-γ. After allogeneic transplantation in rats subjected to UUO, the ω3 supplementation in the rats enhanced some nephroprotective effects of the MSCs through a higher expression of antioxidant enzyme (SOD-1), anti-inflammatory marker (IL-10), and lower expression of the inflammatory marker (IL-6), and proteinuria.

Causal associations between polyunsaturated fatty acids and kidney function: A bidirectional Mendelian randomization study

BACKGROUND

PUFAs were suggested to be beneficial for kidney function in observational studies. However, whether these associations are causal remains unclear.

OBJECTIVES

This study explores the causality between PUFAs and chronic kidney disease (CKD) or estimated glomerular filtration rate (eGFR) using bidirectional 2-sample Mendelian randomization (MR).

METHODS

Single nucleotide polymorphisms associated with PUFAs and kidney function were obtained from the largest and most recent genome-wide association studies with sample sizes of 13,544, 13,506, 13,499, 13,527, and 13,549 for omega-3 fatty acids, omega-6 fatty acids, DHA, LA, and other PUFAs than 18:2 (otPUFA), and 480,698 and 1,201,909 for CKD and eGFR, respectively. MR inverse-variance weighted (IVW) and pleiotropy residual sum and outlier test (MR-PRESSO) were used for data analysis, supplemented with a weighted median estimator, MR-Egger regression, and multivariable MR, giving β or OR and their 95% CIs.

RESULTS

There was suggestive evidence that higher omega-6 fatty acids were associated with increased eGFR using MR-PRESSO [β: 0.005 log(mL/min/1.73 m²) per SD increase in omega-6 fatty acids; 95% CI: 0.002, 0.008; P = 0.008]. Higher LA level was also associated with higher eGFR [β: 0.005 log(mL/min/1.73 m²) per SD increase in LA; 95% CI: 0.003, 0.007; P = 0.0007] using MR-PRESSO. Neither association of the other PUFAs, i.e., omega-3 fatty acids, DHA, and otPUFA, with CKD or eGFR nor the association of CKD and eGFR with PUFAs was found. Similar results were found in sensitivity analyses.

CONCLUSIONS

Our results suggest that higher omega-6 fatty acids and LA may increase eGFR levels. Although the estimated effects were relatively small, the results provide public health and research relevance, indicating the need for further longitudinal cohorts or randomized controlled trials on omega-6 fatty acids in improving kidney function.

Crocodile Oil Disrupts Mitochondrial Homeostasis and Exacerbates Diabetic Kidney Injury in Spontaneously Diabetic Torii Rats

Diabetic nephropathy is currently the leading cause of end-stage renal disease (ESRD) in type 2 diabetes. Studies have suggested that supplementation with some fatty acids might reduce the risk and delay the progression to ESRD in patient with chronic kidney disease. Crocodile oil (CO) contains a variety of fatty acids, especially omega-3, -6 and -9, that have been reported to be beneficial to human health. This study examined the impact of long-term CO supplementation on the development of diabetic nephropathy in spontaneously diabetic Torii (SDT) rats. After diabetic verification, SDT rats were assigned to receive vehicle or CO at 500 and 1000 mg/kg BW, respectively, by oral gavage. Age-matched nondiabetic Sprague–Dawley rats were given vehicle or high-dose CO. After 28 weeks of intervention, CO failed to improve hyperglycemia and pancreatic histopathological changes in SDT rats. Unexpectedly, CO dose-dependently exacerbated the impairment of kidney and mitochondrial functions caused by diabetes. CO also disturbed the expressions of proteins involved in mitochondrial biogenesis, dynamics, and mitophagy. However, no significant alterations were observed in nondiabetic rats receiving high-dose CO. The findings reveal that CO has deleterious effects that aggravate diabetic kidney injury via disrupting mitochondrial homeostasis, possibly due to its improper omega-6: omega-3 ratio.

Glomerular Biomechanical Stress and Lipid Mediators during Cellular Changes Leading to Chronic Kidney Disease

Hyperfiltration is an important underlying cause of glomerular dysfunction associated with several systemic and intrinsic glomerular conditions leading to chronic kidney disease (CKD). These include obesity, diabetes, hypertension, focal segmental glomerulosclerosis (FSGS), congenital abnormalities and reduced renal mass (low nephron number). Hyperfiltration-associated biomechanical forces directly impact the cell membrane, generating tensile and fluid flow shear stresses in multiple segments of the nephron. Ongoing research suggests these biomechanical forces as the initial mediators of hyperfiltration-induced deterioration of podocyte structure and function leading to their detachment and irreplaceable loss from the glomerular filtration barrier. Membrane lipid-derived polyunsaturated fatty acids (PUFA) and their metabolites are potent transducers of biomechanical stress from the cell surface to intracellular compartments. Omega-6 and ω-3 long-chain PUFA from membrane phospholipids generate many versatile and autacoid oxylipins that modulate pro-inflammatory as well as anti-inflammatory autocrine and paracrine signaling. We advance the idea that lipid signaling molecules, related enzymes, metabolites and receptors are not just mediators of cellular stress but also potential targets for developing novel interventions. With the growing emphasis on lifestyle changes for wellness, dietary fatty acids are potential adjunct-therapeutics to minimize/treat hyperfiltration-induced progressive glomerular damage and CKD.

Association of polyunsaturated fatty acids with improved heart rate variability and cardiovascular events in patients with end-stage renal disease receiving maintenance dialysis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Apart from dietary restriction and medical therapy, the benefits of cardiovascular protection offered by polyunsaturated fatty acid (PUFA) supplements in patients with ESRD receiving maintenance dialysis remain unclear. This systematic review and meta-analysis examined the effects of PUFAs on blood pressure, heart rate (HR), HR variability (HRV), and cardiovascular disease (CVD) prognosis.

METHODS

We identified randomized controlled trials (RCTs) from Embase, PubMed (including MEDLINE), and Web of Science. We included seven RCTs that involved 724 patients with ESRD receiving dialysis and PUFA supplements.

RESULTS

The data indicated that compared with the control group, the PUFA group demonstrated decreased cardiovascular events (Peto odds ratio = 0.52, 95% confidence interval [CI] = 0.32 to 0.85, P = 0.009) and HRV (changes in the mean HR [mean difference = -2.59, 95% CI = -4.91 to -0.26, P = 0.03, I² = 0%]; mean RR interval [MD = 29.03, 95% CI = 5.43 to 52.63, P = 0.02, I² = 0%]; mean of the standard deviation of all normal RR intervals for all 5 min segments [MD = 2.73, 95% CI = 0.48 to 4.99, P = 0.02, I² = 0%], and square root of the mean of the sum of the squares of differences between adjacent intervals [MD = 2.03, 95% CI = 0.04 to 4.03, P = 0.05, I² = 0%]).

CONCLUSION

PUFA supplements appeared to improve CVD prognosis in patients receiving dialysis. Additional RCTs with longer follow-up periods need to clarify the benefits of PUFA supplements in this patient population.

Animal Fat Intake Is Associated with Albuminuria in Patients with Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome

Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS) are associated with chronic kidney disease (CKD). Diet could play a predisposing role in the development of increased albuminuria in patients with NAFLD and MetS; however, published evidence is still limited. The aim of this cross-sectional analysis was to assess whether dietary fats are associated with changes in urinary albumin-to-creatinine ratio (UACR) in 146 patients aged 40–60-years with NAFLD and MetS. Dietary data were collected by food frequency questionnaire; UACR was measured in a single first morning void. Sources and types of dietary fats used in the analysis were total fat, fats from animal and vegetable sources, saturated, monounsaturated, polyunsaturated, and trans fats. One-way analysis of variance was performed to assess differences in dietary fats intakes across stages of UACR. The association between dietary fats and UACR was assessed by Pearson’s correlation coefficient and multivariable linear regression. Patients with increased UACR showed a worse cardiometabolic profile and higher intakes of animal fat, as compared to patients with normal levels of albuminuria. Animal fat intake was associated with mean UACR, independent of potential covariates.

Enumerating the role of properdin in the pathogenesis of IgA nephropathy and its possible therapies

BACKGROUND

IgA nephropathy (IgAN) has become the most prevalent form of glomerulonephritis affecting almost 1.3% of the total population worldwide. It is an autoimmune disorder where the host autoantibody forms an immune complex with the defective galactose-deficient IgA1 and gets deposited at the mesangium and endocapillary region of glomeruli. IgA has the capability to activate alternative and lectin complement cascades which even aggravates the condition. Properdin is directly associated with IgAN by activating and stabilising the alternative complement pathway at the mesangium, thereby causing progressive renal damage.

OBJECTIVE

The present review mainly focuses on correlating the influence of properdin in activating the complement cascade at glomeruli which is the major cause of disease exacerbation. Secondly, we have described the probable therapies and new targets that are under trials to check their efficacy in IgAN.

METHODS

An in-depth research was carried out from different peer-reviewed articles till December 2020 from several renowned databases like PubMed, Frontier, and MEDLINE, and the information was analysed and written in a simplified manner.

RESULTS

Co-deposition of properdin is observed along with IgA and C3 in 75%-100% of the patients. It is not yet fully understood whether properdin inhibition can attenuate IgAN, as many conflicting reports have revealed worsening of IgAN after impeding properdin.

CONCLUSION

With no specific cure still available, the treatment strategies are of great concern to find a better target to restrict the disease progression. More research and clinical trials are required to find out a prominent target to combat IgAN.

Systematic Review of Nutrition Supplements in Chronic Kidney Diseases: A GRADE Approach

Chronic kidney disease (CKD) is cumulative worldwide and an increasing public health issue. Aside from the widely known protein restriction and medical therapy, less evident is the renal protection of nutrition supplements in CKD patients. This systematic review (SR), using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, aims to summarize and quantify evidence about the prevention effects of vitamin D and analogues, omega-3 polyunsaturated fatty acid (omega-3 PUFA), dietary fiber, coenzyme Q10 (CoQ10), and biotics on CKD progression. This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to examine SRs and/or meta-analysis of clinical controlled trials identified from PubMed, Embase, and the Cochrane Library. Finally, seventeen SRs were included in the qualitative analysis. The beneficial effects of these nutrition supplements in CKD patients mostly seem to be at low to very low evidence on proteinuria, kidney function, and inflammations and did not appear to improve CKD prognosis. The recommendation of nutrition supplements in CKD patients needs to discuss with physicians and consider the benefits over the adverse effects. Longer follow-up of larger randomized trials is necessary to clarify the benefits of nutrition supplements in CKD patients.

Omega 3 Supplementation Can Regulate Inflammatory States in Gas Station Workers: A Double-Blind Placebo-Controlled Clinical Trial

Environmental exposure to diesel particulate matter and commercial gasoline in gas station workers might induce oxidative stress and changes in the balance of the immune system. In this study, the immunomodulatory impacts of omega 3 fatty acid (ω3FA) supplement were assessed on inflammatory and anti-inflammatory markers in gas station workers in a double-blind placebo-controlled clinical trial. Fifty-three men working in gas stations were treated with ω3FA (n = 29) or placebo (n = 24) for 60 days. C-reactive protein, interleukin-12 (IL-12), transforming growth factor β (TGF-β), interferon γ (IFN-γ), tumor necrosis factor α, IL-10, and IL-17 levels were measured by enzyme-linked immunosorbent assay method before and after the completion of the trial. The concentrations of IFN-γ and IL-17 were significantly decreased in ω3FA group compared with the placebo group (P < 0.001). Moreover, the levels of inhibitory cytokines including TGF-β and IL-10 significantly were increased in ω3FA group (P < 0.001). Overall, ω3FA nutritional supplementation can be useful in reducing inflammatory immune responses and maintaining immune tolerance in people with high exposure to inflammation-inducing factors. [Figure: see text].

Management of dyslipidaemia in patients with chronic kidney disease: a position paper endorsed by the Italian Society of Nephrology

Chronic kidney disease (CKD) represents a major public health issue worldwide and entails a high burden of cardiovascular events and mortality. Dyslipidaemia is common in patients with CKD and it is characterized by a highly atherogenic profile with relatively low levels of HDL-cholesterol and high levels of triglyceride and oxidized LDL-cholesterol. Overall, current literature indicates that lowering LDL-cholesterol is beneficial for preventing major atherosclerotic events in patients with CKD and in kidney transplant recipients while the evidence is less clear in patients on dialysis. Lipid lowering treatment is recommended in all patients with stage 3 CKD or worse, independently of baseline LDL-cholesterol levels. Statin and ezetimibe are the cornerstones in the management of dyslipidaemia in patients with CKD, however alternative and emerging lipid-lowering therapies may acquire a central role in near future. This position paper endorsed by the Italian Society of Nephrology aims at providing useful information on the topic of dyslipidaemia in CKD and at assisting decision making in the management of these patients.

The effects of omega-3 fatty acids on diabetic nephropathy: A meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the effects of omega-3 long-chain polyunsaturated fatty acids on proteinuria, estimated glomerular filtration rate (eGFR) and metabolic biomarkers among patients with diabetes.

STUDY DESIGN

Meta-analysis of randomized controlled clinical trials (RCTs).

SETTING & SUBJECTS

Patients with diabetes.

SELECTION CRITERIA FOR STUDIES

We conducted electronic searches in PubMed, Embase and Cochrane Central Register of Controlled Trials from January 1960 to April 2019 to identify RCTs, which examined the effects of omega-3 fatty acids on proteinuria, eGFR and metabolic biomarkers among diabetic patients.

RESULTS

Ten RCTs with 344 participants were included in our meta-analysis. Omega-3 fatty acids reduced the amount of proteinuria among type 2 diabetes mellitus (type 2 DM) and type 1 diabetes mellitus (type 1 DM). This association was only significant among type 2 DM (SMD = -0.29 (95% CI: -0.54, -0.03; p = 0.03). Only studies with duration of intervention of 24 weeks or longer demonstrated a significant lower proteinuria among omega-3 fatty acids compared to control group (SMD = -0.30 (95% CI: -0.58, -0.02; p = 0.04). There was a higher eGFR for both type 1 and type 2 DM groups among omega-3 fatty acids compared to control group, however, the effect was not statistically significant. Regarding serum total cholesterol, LDL-cholesterol and HbA1C, there was no significant difference comparing omega-3 fatty acids to control group. There was a non-significant systolic blood pressure reduction in the omega-3 fatty acids supplementation group compared to control.

CONCLUSION

Omega-3 fatty acids could help ameliorate proteinuria among type 2 DM who received omega-3 supplementation for at least 24 weeks without adverse effects on HbA1C, total serum cholesterol and LDL-cholesterol.

Dietary omega-3 PUFA improved tubular function after ischemia induced acute kidney injury in mice but did not attenuate impairment of renal function

BACKGROUND

Acute kidney injury (AKI) is an important complication after major surgery and solid organ transplantation. Here, we present a dietary omega-3 polyunsaturated fatty acid (n3-PUFA) supplementation study to investigate whether pre-treatment can reduce ischemia induced AKI in mice.

METHODS

Male 12-14 week old C57BL/6 J mice received a linoleic acid rich sunflower oil based standard diet containing 10 % fat (STD) or the same diet enriched with n3-PUFA (containing 1 % EPA and 1 % DHA) (STD + n3). After 14 days of feeding bilateral 30 min renal ischemia reperfusion injury (IRI) was conducted to induce AKI and mice were sacrificed at 24 h. Serum creatinine and blood urea nitrogen (BUN) as well as liver enzyme elevation were measured. Kidney damage was analyzed by histology and immunohistochemistry. Furthermore, pro-inflammatory cytokines (IL-6, MCP-1) were determined by qPCR. FA and oxylipin pattern were quantified in blood and kidneys by GC-FID and LC-MS/MS, respectively.

RESULTS

n3-PUFA supplementation prior to renal IRI increased systemic and renal levels of n3-PUFA. Consistently, eicosanoids and other oxylipins derived from n3-PUFA including precursors of specialized pro-resolving mediators were elevated while n6-PUFA derived mediators such as pro-inflammatory prostaglandins were decreased. Feeding of n3-PUFA did not attenuate renal function impairment, morphological renal damage and inflammation characterized by IL-6 and MCP-1 elevation or neutrophil infiltration. However, the tubular transport marker alpha-1 microglobulin (A1M) was significantly higher expressed in proximal tubular epithelial cells of STD + n3 compared to STD fed mice. This indicates a better integrity of proximal tubular epithelial cells and thus significant protection of tubular function. In addition, heme oxygenase-1 (HO-1) which protects tubular function was also up-regulated in the treatment group receiving n3-PUFA supplemented chow.

DISCUSSION

We showed that n3-PUFA pre-treatment did not affect overall renal function or renal inflammation in a mouse model of moderate ischemia induced AKI, but tubular transport was improved. In conclusion, dietary n3-PUFA supplementation altered the oxylipin levels significantly but did not protect from renal function deterioration or attenuate ischemia induced renal inflammation.

Omega-3 attenuates high fat diet-induced kidney injury of female rats and renal programming of their offsprings

Context: Maternal diet composition could influence fetal organogenesis. Objective: We investigated effects of high fat diet (HFD) intake alone or combined with omega 3 during pregnancy, lactation and early days of weaning on nephrogenesis of pups and maternal renal function and morphology. Material and methods: Mothers and their pups included in each group were supplied with the same diet composition. Rats were divided into group I, II and III supplied with chow of either 10 kcal%, 45 kcal% or 45 kcal% from fat together with omega-3 respectively. Results: Group II showed increased serum urea and creatinine, renal TNF-α, IL1β. Structural injury was observed in mothers and their pups as Bowman's capsule and tubular dilatation and increased expression of PCNA that were decreased following omega-3 supplementation added to down regulation of Wnt4, Pax2 gene and podocin expression. Discussion and conclusion: Omega-3 supplementation improves lipid nephrotoxicity observed in mothers and their pups.

Icosapent ethyl reduces atherogenic markers in high-risk statin-treated patients with stage 3 chronic kidney disease and high triglycerides

Objective: Patients with chronic kidney disease (CKD) have increased cardiovascular disease (CVD) risk, likely driven by atherogenic and inflammatory markers beyond low-density lipoprotein cholesterol (LDL-C). The objective of this hypothesis-generating post hoc subgroup analysis was to explore the effects of icosapent ethyl at 2 or 4 g/day (prescription pure ethyl ester of the omega-3 fatty acid eicosapentaenoic acid [EPA]) on atherogenic lipid, apolipoprotein, inflammatory parameters (high-sensitivity C-reactive protein [hsCRP], lipoprotein-associated phospholipase A₂ [Lp-PLA₂]), and oxidative parameters (oxidized-LDL [ox-LDL]) in statin-treated patients from ANCHOR with stage 3 CKD.Methods: The 12-week ANCHOR study evaluated icosapent ethyl in 702 statin-treated patients at increased CVD risk with triglycerides (TG) 200-499 mg/dL despite controlled LDL-C (40-99 mg/dL). This post-hoc analysis included patients from ANCHOR with stage 3 CKD (estimated glomerular filtration rate [eGFR] ≤60 mL/min/1.73 m² for ≥3 months) randomized to icosapent ethyl 4 g/day (n = 19), 2 g/day (n = 30), or placebo (n = 36).Results: At the prescription dose of 4 g/day, icosapent ethyl significantly reduced TG (-16.9%; P = 0.0074) and other potentially atherogenic lipids/lipoproteins, ox-LDL, hsCRP, and Lp-PLA₂, and increased plasma and red blood cell EPA levels (+879% and +579%, respectively; both P < 0.0001) versus placebo. Icosapent ethyl did not significantly alter eGFR or serum creatinine. Safety and tolerability were similar to placebo.Conclusions: In patients with stage 3 CKD at high CVD risk with persistent high TG despite statins, icosapent ethyl 4 g/day reduced potentially atherogenic and other cardiovascular risk factors without raising LDL-C, with safety similar to placebo. These findings suggest prospective investigation may be warranted.

Plasma marine n-3 polyunsaturated fatty acids and cardiovascular risk factors: data from the ACE 1950 study

PURPOSE

A high intake of marine n-3 polyunsaturated fatty acids (PUFAs) might improve cardiovascular (CV) health. We conducted a cross-sectional study to investigate associations between plasma phospholipid levels of marine n-3 PUFAs and CV risk factors, educational level, physical activity and smoking habits.

METHODS

A total of 3706 individuals from a general population, all born in 1950 and residing in Akershus County, Norway, were included in this study. The main statistical approach was multivariable adjusted linear regression.

RESULTS

Plasma marine n-3 PUFA levels ranged from 2.7 to 20.3 wt%, with a median level of 7.7 wt% (interquartile range 4.3-11.1 wt%). High levels of plasma marine n-3 PUFAs were associated with lower serum triglycerides [Standardized regression coefficient (Std.β-coeff.) - 0.14, p < 0.001], body mass index (Std. β-coeff. -0.08, p < 0.001), serum creatinine (Std. β-coeff. -0.03, p = 0.05), C-reactive protein levels (Std. β-coeff. - 0.03, p = 0.04), higher levels of serum high-density lipoprotein cholesterol (Std. β-coeff. 0.08, p < 0.001) and low-density lipoprotein cholesterol (Std. β-coeff. 0.04, p = 0.003). High levels of plasma marine n-3 PUFAs were also associated with lower glycated hemoglobin (Std. β-coeff. - 0.04, p = 0.01), however, only in individuals without diabetes. We found no associations between plasma marine n-3 PUFA levels and fasting plasma glucose or carotid intima-media thickness. High levels of plasma marine n-3 PUFAs were associated with higher educational level, more physical activity and lower prevalence of smoking.

CONCLUSION

In this cross-sectional study of Norwegian individuals born in 1950, high levels of plasma marine n-3 PUFAs were favourably associated with several CV risk factors, suggesting that fish consumption might improve CV health.

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.

Polyunsaturated fatty acid food frequency questionnaire validation in people with end stage renal disease on dialysis

AIM

To validate the polyunsaturated food frequency questionnaire (PUFA FFQ) and test for reproducibility in people with end stage renal disease on dialysis treatment.

METHODS

Participants (n = 32) completed the PUFA FFQ and three 24-hour recalls. Erythrocyte samples (n = 29) were used for erythrocyte fatty acid analysis. The triangular relationship between the PUFA FFQ, 24-hour recalls and the biomarker was assessed using the method of triads. Agreement between the two dietary methods was also assessed using Bland-Altman plots and classification by quintiles. Reproducibility was tested on a subset of the group (n = 8).

RESULTS

The PUFA FFQ was a valid measure of all PUFA except for docosapentaenoic acid (DPA) and arachidonic acid (AA). Strong validity coefficients were found for n-3 long-chain PUFA (LCPUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of 0.914 (95% CI: 0.665, 0.997) and 0.889 (95% CI: 0.706, 0.994), respectively. In the Bland-Altman plots 91-100% of observations fell between the limits of agreement for all PUFA. There were significant correlations between the initial FFQ and the repeat FFQ for all PUFA except DPA and AA.

CONCLUSIONS

The PUFA FFQ is a valid tool for assessing PUFA intake in people with end stage renal disease.

Effect of Vitamin D and Tacrolimus Combination Therapy on IgA Nephropathy

Background

To explore the effects and the mechanism of vitamin D (VD) and tacrolimus (TAC) combinatorial therapy in the treatment of IgA nephropathy (IgAN) in a rat model.

Material/Methods

IgAN rat models constructed by oral immunization with bovine serum albumin (BSA) and lipopolysaccharide (LPS) (n=30) and were treated with: saline (model group), TAC (TAC group), or TAC+VD therapy (TAC+VD group) through gavage daily for 14 days. Serum creatinine (Scr), albumin (ALB), blood urea nitrogen (BUN), and urinary protein (UAE) levels were determined. Histopathology of renal tissues was examined after hematoxylin and eosin (H&E) staining. The levels of cytokines TGF-β1, IL-5, IFN-γ, and IL-4 in serum were detected by enzyme-linked immunosorbent assay (ELISA). Changes in TLR4/NF-κB pathway were evaluated by western blot.

Results

Both TAC and TAC+VD treatment significantly restored the dysregulated Scr, ALB, BUN, and UAE levels in IgAN rats. TAC+VD therapy more prominently restored Scr and UAE levels (p<0.05). TAC+VD therapy demonstrated superior efficacy in reducing glomerular mesangial cells hyperplasia, reducing thickening of the glomerular basement membrane and glomerular infiltration of inflammatory cells. Thymus and spleen indexes were also increased (p<0.05). The levels of TGF-β1, IL-5, and IL-4 of the TAC+VD group were also lower than those of the TAC group (p<0.05). The TAC+VD group also demonstrated increased IFN-γ, and decreased p-P65/P65 and TLR4 compared to the TAC group.

Conclusions

TAC+VD combinatorial therapy can effectively alleviate renal tissue damage in IgAN rats by regulating immune response and the NF-κB/TLR4 pathway.