Dietary omega-3 fatty acid, ratio of omega-6 to omega-3 intake, inflammation, and survival in long-term hemodialysis patients

Impact of dietary n-6/n-3 fatty acid ratio of atherosclerosis risk: A review

Atherosclerosis is a causative factor associated with cardiovascular disease (CVD). Over the past few decades, extensive research has been carried out on the relationship between the n-6/n-3 fatty acid ratio of ingested lipids and the progression of atherosclerosis. However, there are still many uncertainties regarding the precise nature of this relationship, which has led to challenges in providing sound dietary advice to the general public. There is therefore a pressing need to review our current understanding of the relationship between the dietary n-6/n-3 fatty acid ratio and atherosclerosis, and to summarize the underlying factors contributing to the current uncertainties. Initially, this article reviews the association between the n-6/n-3 fatty acid ratio and CVDs in different countries. A summary of the current understanding of the molecular mechanisms of n-6/n-3 fatty acid ratio on atherosclerosis is then given, including inflammatory responses, lipid metabolism, low-density lipoprotein cholesterol oxidation, and vascular function. Possible reasons behind the current controversies on the relationship between the n-6/n-3 fatty acid ratio and atherosclerosis are then provided, including the precise molecular structures of the fatty acids, diet-gene interactions, the role of fat-soluble phytochemicals, and the impact of other nutritional factors. An important objective of this article is to highlight areas where further research is needed to clarify the role of n-6/n-3 fatty acid ratio on atherosclerosis.

Higher ratio of plasma omega-6/omega-3 fatty acids is associated with greater risk of all-cause, cancer, and cardiovascular mortality: A population-based cohort study in UK Biobank

Background

Circulating omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) have been associated with various chronic diseases and mortality, but results are conflicting. Few studies examined the role of omega-6/omega-3 ratio in mortality.

Methods

We investigated plasma omega-3 and omega-6 PUFAs and their ratio in relation to all-cause and cause-specific mortality in a large prospective cohort, the UK Biobank. Of 85,425 participants who had complete information on circulating PUFAs, 6461 died during follow-up, including 2794 from cancer and 1668 from cardiovascular disease (CVD). Associations were estimated by multivariable Cox proportional hazards regression with adjustment for relevant risk factors.

Results

Risk for all three mortality outcomes increased as the ratio of omega-6/omega-3 PUFAs increased (all Ptrend <0.05). Comparing the highest to the lowest quintiles, individuals had 26% (95% CI, 15-38%) higher total mortality, 14% (95% CI, 0-31%) higher cancer mortality, and 31% (95% CI, 10-55%) higher CVD mortality. Moreover, omega-3 and omega-6 PUFAs in plasma were all inversely associated with all-cause, cancer, and CVD mortality, with omega-3 showing stronger effects.

Conclusions

Using a population-based cohort in UK Biobank, our study revealed a strong association between the ratio of circulating omega-6/omega-3 PUFAs and the risk of all-cause, cancer, and CVD mortality.

Funding

Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institute of Health under the award number R35GM143060 (KY). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Higher ratio of plasma omega-6/omega-3 fatty acids is associated with greater risk of all-cause, cancer, and cardiovascular mortality: a population-based cohort study in UK Biobank

Background

Circulating omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) have been associated with various chronic diseases and mortality, but results are conflicting. Few studies examined the role of omega-6/omega-3 ratio in mortality.

Methods

We investigated plasma omega-3 and omega-6 PUFAs and their ratio in relation to all-cause and cause-specific mortality in a large prospective cohort, the UK Biobank. Of 85,425 participants who had complete information on circulating PUFAs, 6,461 died during follow-up, including 2,794 from cancer and 1,668 from cardiovascular disease (CVD). Associations were estimated by multivariable Cox proportional hazards regression with adjustment for relevant risk factors.

Results

Risk for all three mortality outcomes increased as the ratio of omega-6/omega-3 PUFAs increased (all Ptrend < 0.05). Comparing the highest to the lowest quintiles, individuals had 26% (95% CI, 15-38%) higher total mortality, 14% (95% CI, 0-31%) higher cancer mortality, and 31% (95% CI, 10-55%) higher CVD mortality. Moreover, omega-3 and omega-6 PUFAs in plasma were all inversely associated with all-cause, cancer, and CVD mortality, with omega-3 showing stronger effects.

Conclusions

Using a population-based cohort in UK Biobank, our study revealed a strong association between the ratio of circulating omega-6/omega-3 PUFAs and the risk of all-cause, cancer, and CVD mortality.

Association of the dietary inflammation index (DII) with the prevalence of chronic kidney disease in patients with type-2 diabetes mellitus

Chronic kidney disease (CKD) is a major complication of diabetes mellitus (DM). Inflammation is an essential component in the process of CKD progression in patients with DM. Diet is a significant determinant of systemic inflammation levels. However, the association between the dietary inflammatory index (DII) and CKD in individuals with DM remains largely unknown; therefore, the aim of this study was to explore whether the DII is linked to the prevalence of CKD in patients with DM. The research method was as follows: first, data from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2018 were obtained. There were 7,974 participants in our study. These individuals were then classified into three groups according to DII tertiles (T1-T3), with each group consisting of 2,658 participants. Logistic regression analysis was employed to examine whether there was a connection between the DII and CKD. We observed a significant association between the DII and the prevalence of CKD in individuals with DM. After full adjustment for age, sex, ethnicity, smoking, drinking, body mass index (BMI), triglyceride (TG), total cholesterol (TC), metabolic equivalents (METs), energy intake, hypoglycemic medications, hypertension, and cardiovascular disease (CVD), the group with a higher DII had a greater frequency of CKD (T2 group: OR: 1.40; 95% CI: 1.10-1.76; p = 0.006; T3 group: OR: 1.67; 95% CI: 1.29-2.17; p < 0.001). The implementation of an anti-inflammatory diet could serve as an intervention strategy for patients with DM to prevent the onset of CKD.

Distinct associations between dietary omega-3 and omega-6 fatty acids intake with chronic kidney disease in adults with and without diabetes: A cross-sectional study

OBJECTIVE

We explored the relationship of dietary intake of fatty acids with chronic kidney disease (CKD) according to glycemic status in Japanese people.

METHODS

A total of 1031 participants aged ≥40 y were included in this population-based, cross-sectional study. A validated self-administered diet history questionnaire was used to measure the dietary intakes of fat and fatty acids, including omega-3 and omega-6 polyunsaturated fatty acids. CKD was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m2 and diabetes as the use of antidiabetic medication, fasting plasma glucose ≥ 126 mg/dL, or hemoglobin A1c of ≥6.5%. Urine biomarkers of kidney injury (liver-type fatty acid-binding protein, β2-microglobulin, and albumin) were also examined.

RESULTS

The mean age of the participants was 62.5 ± 11.2 y, and 482 (46.8%) of them were men. Overall, 177 (17.2%) participants had CKD. In the multivariable model, low omega-3 intake (odds ratio = 0.109; 95% CI, 0.019-0.645) and high omega-6-to-omega-3 ratio (odds ratio = 2.112; 95% CI, 1.167-3.822) were associated with CKD in participants with diabetes but not in those without. In selected participants with diabetes, a substantial trend of urinary liver-type fatty acid-binding protein and β2-microglobulin level elevation along with an increase in the dietary ratio of omega-6 to omega-3 was observed.

CONCLUSIONS

Low dietary omega-3 intake and high omega-6-to-omega-3 ratio were associated with CKD in middle-aged and older Japanese people with diabetes but not in those without diabetes. These results may provide insight into the more tailored approaches for dietary polyunsaturated fatty acids to prevent CKD.

Dietary fatty acids intake and all-cause and cardiovascular mortality in patients on peritoneal dialysis

BACKGROUND & AIMS

The relationship between dietary fatty acids (FA) and clinical outcomes are relatively lacking in non-dialyzed and dialyzed chronic kidney disease (CKD) population, resulting in insufficient guide about the dietary FA intake in this population. In this study, we aimed to observe the association between the intake of total or different types of FA and all-cause and cardiovascular (CV) mortality in patients undergoing peritoneal dialysis (PD).

METHODS

This is a prospective cohort study with data retrospectively analyzed in 881 patients undergoing PD. Dietary FA intake measured by 3-day dietary records. The outcomes were defined as all-cause and CV death. Baseline FA intake and time-averaged FA intake were categorized by tertiles based on the distribution among the study population. We used univariate and multivariate Cox proportional regression models to determine the association between amounts and types of FA and all-cause and CV mortality.

RESULTS

During a median follow up of 45 months, 93 patients were still being maintained on PD, 467 had died, including 189 (40.5%) attributable to CV death. Compared to patients in the low tertile of total FA (TFA) intake at baseline group, the middle or/and high tertile groups were more likely to be male, younger, well-educated and better nutritional status (P < 0.05). At the baseline, no association was found between all-cause and CV death in either total or different types of FA after adjusting for nutritional variables. As for time-averaged analyses, the associations of TFA, saturated FA (SFA), monounsaturated FA (MUFA), ω-3 and ω-6 polyunsaturated FA (PUFA) and all-cause mortality were weakened after adjustment for laboratory and nutrients variables. However, PUFA independently reduced 5% of mortality even after adjustment for laboratory and nutrients variables [HR 0.95 (0.91, 0.99), P = 0.023], and the ratio of MUFA/PUFA was positively associated with the risk for all-cause mortality [HR 1.05 (1.01, 1.09), P = 0.008]. Furthermore, each 10% increase of the ratio of ω-6/ω-3 was only weakly associated with the risk for all-cause mortality [HR 1.02 (1.00, 1.04), P = 0.034]. As for CVD mortality, the impacts of total and each type of FA disappeared after adjustment for laboratory or nutrients variables.

CONCLUSIONS

Time-averaged PUFA intake was independently associated with a lower risk for all-cause mortality in our PD cohort, while the higher ratio of MUFA/PUFA and ω-6/ω-3 increased all-cause mortality. More observational and interventional researches are needed to determine these associations.

Interaction between ω-6 fatty acids intake and blood cadmium on the risk of low cognitive performance in older adults from National Health and Nutrition Examination Survey (NHANES) 2011-2014

Background

Identifying preventable diets and environmental exposure is essential to ensuring the health of the aging population. This study evaluated the interaction effect between blood cadmium and ω-6 fatty acids intake on low cognitive performance in Americans.

Method

The data of this cross-sectional study were obtained from the 2011–2012 and 2013–2014 National Health and Nutritional Examination Survey (NHANES). Cognitive performance was measured by the Consortium to Establish a Registry for Alzheimer’s Disease test, Animal Fluency Test, and Digit Symbol Substitution Test. Multivariate logistic regression models were used.

Results

A total of 1,918 individuals were included, with 467 (24.35%) low cognitive performance. Compared with participants with normal-level blood cadmium, those with high-level blood cadmium had a higher risk of low cognitive performance [odds ratio (OR) was 1.558 with 95% confidence interval (CI): 1.144–2.123]. Low-level ω-6 fatty acids intake was positively associated with low cognitive performance [OR = 1.633 (95%CI: 1.094–2.436)] compared with normal-level intake. Moreover, there was a significant interaction between low-level ω-6 fatty acids intake and high-level blood cadmium on the risk of low cognitive performance (relative excess risk due to interaction: 0.570, 95%CI: 0.208-0.932; the attributable proportion of interaction: 0.219, 95%CI: 0.102‐0.336; synergy index: 1.552, 95%CI: 1.189‐2.027).

Conclusions

There was a synergistic interaction between low-level ω-6 fatty acids intake and high-level blood cadmium on low cognitive performance. Low-level ω-6 fatty acids intake may amplify the adverse effects of long-term exposure to cadmium on cognitive performance. This may have a certain significance for the prevention of cognitive decline in the elderly.

Supplementary information

The online version contains supplementary material available at 10.1186/s12877-022-02988-7.

Dietary Omega-3 Fatty Acid Intake and Mortality in CKD Population: A 1999-2014 NHANES Analysis

INTRODUCTION

High risk of early death, especially contributed to cardiovascular disease, exists in patients who have chronic kidney disease (CKD). And the burden of cardiovascular disease is able to be lightened by an increase in omega-3 polyunsaturated fatty acid (omega-3 PUFA). A diet high in omega-3 PUFA in the general population is protective, although it is inconclusive about its beneficial role in the CKD population.

METHODS

From the 1999 to 2014 National Health and Nutrition Examination Surveys (NHANES), we can collect 2,990 participants who suffered from CKD, who were classified into 4 groups: <0.86, 0.87-1.30, 1.31-1.92, and 1.93-9.65 g/day based on NHANES 24-h dietary recall questionnaire dietary omega-3 PUFA. Moreover, their mortality details were available to be obtained by linking NHANES to the National Death Index. The associations between dietary omega-3 PUFA and mortality were evaluated by constructing multivariable Cox proportional hazards models.

RESULTS

Over 8 years of a median follow-up, 864 deaths were recorded. The adjusted hazard ratios (95% confidence interval) for all-cause mortality of the diseased people with CKD in the 2nd (0.87-1.30 g/day), 3rd (0.87-1.30 g/day), and 4th (1.93-9.65 g/day) quartiles of dietary omega-3 PUFA were 0.94 (0.72, 1.23), 0.74 (0.54, 1.02), and 0.67 (0.48, 0.93), respectively, versus those with the lowest quartile of dietary omega-3 PUFA intake (<0.86 g/day) (p for trend = 0.011).

CONCLUSION

There may be a inverse relation of dietary omega-3 PUFA intake and all-cause mortality in patients with CKD. Therefore, an increase of dietary omega-3 PUFA may be encouraged to be used clinically in patients with CKD.

Can an anti-inflammatory diet be effective in preventing or treating viral respiratory diseases? A systematic narrative review

Respiratory Viruses infections (RVI) such as rhinovirus, coronavirus, influenza virus, and adenovirus affect the respiratory and the immune systems. The role of nutrition in the respiratory and immune systems has been studied in some studies, and its importance is undeniable. In addition, one of the key findings in this disease is high inflammation that affects almost all patients. This systematic narrative review aims to answer the question, "Can an anti-inflammatory diet be effective in preventing or treating viral respiratory diseases?" A systematic review search was used for the articles extraction. All studies published in English from 1999 to 2020 investigating dietary inflammatory conditions and RVI were included. Food items with anti-inflammatory properties were selected based on the definition of the dietary inflammatory index (DII). We used Google Scholar, Pub Med, Scopus, Web of Science, Springer, Science Direct, Directory of Open Access Journals, Elsevier, Taylor and Francis, ProQuest, EBSCO, MEDLINE, and SciELO databases for extracting articles. Keywords were restricted by DII. Based on DII, food items/nutrients are involved in inflammation, some of which have anti-inflammatory and some inflammatory properties. Some foods/nutrients, in addition to their anti-inflammatory properties, have antioxidant, antiviral, and immune-enhancing properties. Considering the immune system's involvement, increased inflammation, and involvement of the pulmonary system in RVI and the remarkable role of the anti-inflammatory foods for counteracting them, it is recommended to use a predominantly anti-inflammatory diet along with prevention/control and treatment protocols. An anti-inflammatory diet (based on DII) includes turmeric, ginger, garlic, onions, saffron, dietary vitamin C, vitamin D, zinc, and omega-3 are recommended to reduce infection symptoms and duration.

Anti-Photoaging and Potential Skin Health Benefits of Seaweeds

The skin health benefits of seaweeds have been known since time immemorial. They are known as potential renewable sources of bioactive metabolites that have unique structural and functional features compared to their terrestrial counterparts. In addition, to the consciousness of green, eco-friendly, and natural skincare and cosmetics products, their extracts and bioactive compounds such as fucoidan, laminarin, carrageenan, fucoxanthin, and mycosporine like amino acids (MAAs) have proven useful in the skincare and cosmetic industries. These bioactive compounds have shown potential anti-photoaging properties. Furthermore, some of these bioactive compounds have been clinically tested and currently available in the market. In this contribution, the recent studies on anti-photoaging properties of extracts and bioactive compounds derived from seaweeds were described and discussed.

Circulating fatty acid profiles are associated with protein energy wasting in maintenance hemodialysis patients: a cross-sectional study

The metabolic impact of circulating fatty acids (FAs) in patients requiring hemodialysis (HD) is unknown. We investigated the associations between plasma triglyceride (TG) FAs and markers of inflammation, insulin resistance, nutritional status and body composition. Plasma TG-FAs were measured using gas chromatography in 341 patients on HD (age = 55.2 ± 14.0 years and 54.3% males). Cross-sectional associations of TG-FAs with 13 markers were examined using multivariate linear regression adjusted for potential confounders. Higher levels of TG saturated fatty acids were associated with greater body mass index (BMI, r = 0.230), waist circumference (r = 0.203), triceps skinfold (r = 0.197), fat tissue index (r = 0.150), serum insulin (r = 0.280), and homeostatic model assessment of insulin resistance (r = 0.276), but lower malnutrition inflammation score (MIS, r =  − 0.160). Greater TG monounsaturated fatty acid levels were associated with lower lean tissue index (r =  − 0.197) and serum albumin (r =  − 0.188), but higher MIS (r = 0.176). Higher levels of TG n-3 polyunsaturated fatty acids (PUFAs) were associated with lower MIS (r =  − 0.168) and interleukin-6 concentrations (r =  − 0.115). Higher levels of TG n-6 PUFAs were associated with lower BMI (r =  − 0.149) but greater serum albumin (r = 0.112). In conclusion, TG monounsaturated fatty acids were associated with poor nutritional status, while TG n-3 PUFAs were associated with good nutritional status. On the other hand, TG saturated fatty acids and TG n-6 PUFAs had both favorable and unfavorable associations with nutritional parameters.

Development and optimization of spray-dried functional oil microcapsules: Oxidation stability and release kinetics

This study aimed to optimize the microencapsulation method for a functional oil using high amylose corn starch (HACS) and assessed its structure and antioxidant capacity. The results showed that the optimal microencapsulation condition is achieved by using 28.5% of functional oil, 15.75% of HACS, and 57.86% of proportion of monoglyceride in emulsifier with 94.86% microencapsulation efficiency. Scanning electron microscopy and particle size measurement showed that the functional oil microcapsules were uniform size, smooth surface, spherical shape, and without cracks in the wall of the capsules. In vitro oil release of microencapsulates results showed that microencapsulated functional oil containing HACS has a better sustained release effect. The microcapsules containing HACS exhibited a lower lipid oxidation rate during storage. In conclusion, microencapsulation of HACS as wall material improved the stability of functional oil and this formulation of microcapsules was satisfactorily applied in powdered food for diabetic patients.

Production of Trans-free fats by chemical interesterified blends of palm stearin and sunflower oil

In this study, production of trans-free fats through chemical interesterification of binary blends of palm stearin (PS) and sunflower oil (SFO) and their physicochemical changes after the process was investigated. Analyzed responses included fatty acid and triacylglycerol composition, iodine value, free fatty acid (FFA), soap content, peroxide value (PV), plastic range, slip melting point (SMP), solid fat content (SFC), and oxidative stability along with potential applications of the interesterified fats. Transfatty acid content of PS/SFO blends was lower than 0.36%. Chemical interesterification increased the FFA and soap content and also decreased PV and oxidative stability index (at 110°C). After the process, SMP and SFC were reduced, also the plastic range transferred to the lower temperatures. All the interesterified blends melted completely at the body temperature, and their SFC was <32%. The melting characteristics of the PS/SFO-interesterified blends were suitable for many fat-based products.

Ketogenic Diet and Microbiota: Friends or Enemies?

Over the last years, a growing body of evidence suggests that gut microbial communities play a fundamental role in many aspects of human health and diseases. The gut microbiota is a very dynamic entity influenced by environment and nutritional behaviors. Considering the influence of such a microbial community on human health and its multiple mechanisms of action as the production of bioactive compounds, pathogens protection, energy homeostasis, nutrients metabolism and regulation of immunity, establishing the influences of different nutritional approach is of pivotal importance. The very low carbohydrate ketogenic diet is a very popular dietary approach used for different aims: from weight loss to neurological diseases. The aim of this review is to dissect the complex interactions between ketogenic diet and gut microbiota and how this large network may influence human health.

Omega-3 intake is associated with attenuated inflammatory response and cardiac remodeling after myocardial infarction

BACKGROUND

Myocardial infarction (MI) elicits an intense acute inflammatory response that is essential for cardiac repair. However, an excessive inflammatory response also favors myocardial apoptosis, cardiac remodeling, and cardiovascular mortality. Omega-3 polyunsaturated fatty acids (ω-3) bear anti-inflammatory effects, which may mitigate the inflammatory response during MI. This study investigated whether ω-3 intake is associated with attenuation of the MI-related inflammatory response and cardiac remodeling.

METHODS

ST-elevation MI (STEMI) patients (n = 421) underwent clinical, biochemical, nutritional, 3D echocardiogram, Cardiac Magnetic Resonance imaging (CMRi) at 30 days and 3D echocardiogram imaging at six months after the MI. Blood tests were performed at day one (D1) and day five (D5) of hospitalization. Changes in inflammatory markers (ΔD5-D1) were calculated. A validated food frequency questionnaire estimated the nutritional consumption and ω-3 intake in the last 3 months before admission.

RESULTS

The intake of ω-3 below the median (< 1.7 g/day) was associated with a short-term increase in hs-C-reactive protein [OR:1.96(1.24-3.10); p = 0.004], Interleukin-2 [OR:2.46(1.20-5.04); p = 0.014], brain-type natriuretic peptide [OR:2.66(1.30-5.44); p = 0.007], left-ventricle end-diastolic volume [OR:5.12(1.11-23.52)]; p = 0.036] and decreases in left-ventricle ejection fraction [OR:2.86(1.47-6.88); p = 0.017] after adjustment for covariates. No differences were observed in the extension of infarcted mass obtained by CMRi.

CONCLUSION

These findings suggest that a reduced daily intake of ω-3 may intensify outcome-determining mechanisms after STEMI, such as acute inflammatory response and late left ventricular remodeling.

TRIAL REGISTRATION

Clinical Trial Registry number and website: NCT02062554 .

Dietary fatty acid intake in hemodialysis patients and associations with circulating fatty acid profiles: A cross-sectional study

OBJECTIVES

The aims of this study were threefold: first, to assess the dietary fatty acid (FA) intake and blood FA status in Malaysian patients on hemodialysis (HD); second, to examine the association between dietary FA intakes and blood FA profiles in patients on HD; and third, to determine whether blood FAs could serve as a biomarker of dietary fat intake quality in these patients.

METHODS

Using 3 d of dietary records, FA intakes of 333 recruited patients were calculated using a food database built from laboratory analyses of commonly consumed Malaysian foods. Plasma triacylglycerol (TG) and erythrocyte FAs were determined by gas chromatography.

RESULTS

High dietary saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) consumption trends were observed. Patients on HD also reported low dietary ω-3 and ω-6 polyunsaturated fatty acid (PUFA) consumptions and low levels of TG and erythrocyte FAs. TG and dietary FAs were significantly associated respective to total PUFA, total ω-6 PUFA, 18:2 ω-6, total ω-3 PUFA, 18:3 ω-3, 22:6 ω-3, and trans 18:2 isomers (P < 0.05). Contrarily, only dietary total ω-3 PUFA and 22:6 ω-3 were significantly associated with erythrocyte FAs (P < 0.01). The highest tertile of fish and shellfish consumption reflected a significantly higher proportion of TG 22:6 ω-3. Dietary SFAs were directly associated with TG and erythrocyte MUFA, whereas dietary PUFAs were not.

CONCLUSION

TG and erythrocyte FAs serve as biomarkers of dietary PUFA intake in patients on HD. Elevation of circulating MUFA may be attributed to inadequate intake of PUFAs.

Stearidonic acid combined with alpha-linolenic acid improves lipemic and neurological markers in a rat model subject to a hypercaloric diet

In this study, we hypothesized that terrestrial plant oils, rich in alpha linolenic acid (ALA) and stearidonic acid (SDA) relative to fish oil, rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), prevent negative effects on cardiovascular and neurological function using a rat model fed a hypercaloric diet. Results showed effects on the FA profile, namely, eicosapentaenoic, EPA, and docosahexaenoic, DHA, levels. There were also effects on neural aspects (cAMP response element-binding protein, CREB, gene expression, at least, doubled) and the pro-inflammatory/anti-inflammatory balance (TNF-α, tumor necrosis factor alpha reduced by 30-50%). The most positive impact of ALA and SDA was the beneficial reduction of total lipids (from 395 ± 3 to 352-361 mg/dL), VLDL-cholesterol (from 21.8 ± 0.2 to 14.1-17.8 mg/dL), and triacylglycerols (from 109 ± 1 to 71-89 mg/dL) in both LIN (diet enriched in linseed oil) and BUG (diet enriched in Buglossoides oil) groups. Overall, data indicate that ALA- and SDA-rich lipid sources may counteract the undesirable cardiovascular effects of a hypercaloric diet based on milk fat.

Dietary n-3 polyunsaturated fatty acid intake and all-cause and cardiovascular mortality in adults on hemodialysis: The DIET-HD multinational cohort study

BACKGROUND & AIMS

Patients on hemodialysis suffer from high risk of premature death, which is largely attributed to cardiovascular disease, but interventions targeting traditional cardiovascular risk factors have made little or no difference. Long chain n-3 polyunsaturated fatty acids (n-3 PUFA) are putative candidates to reduce cardiovascular disease. Diets rich in n-3 PUFA are recommended in the general population, although their role in the hemodialysis setting is uncertain. We evaluated the association between the dietary intake of n-3 PUFA and mortality for hemodialysis patients.

METHODS

The DIET-HD study is a prospective cohort study (January 2014-June 2017) in 9757 adults treated with hemodialysis in Europe and South America. Dietary n-3 PUFA intake was measured at baseline using the GA²LEN Food Frequency Questionnaire. Adjusted Cox regression analyses clustered by country were conducted to evaluate the association of dietary n-3 PUFA intake with cardiovascular and all-cause mortality.

RESULTS

During a median follow up of 2.7 years (18,666 person-years), 2087 deaths were recorded, including 829 attributable to cardiovascular causes. One third of the study participants consumed sufficient (at least 1.75 g/week) n-3 PUFA recommended for primary cardiovascular prevention, and less than 10% recommended for secondary prevention (7-14 g/week). Compared to patients with the lowest tertile of dietary n-3 PUFA intake (<0.37 g/week), the adjusted hazard ratios (95% confidence interval) for cardiovascular mortality for patients in the middle (0.37 to <1.8 g/week) and highest (≥1.8 g/week) tertiles of n-3 PUFA were 0.82 (0.69-0.98) and 1.03 (0.84-1.26), respectively. Corresponding adjusted hazard ratios for all-cause mortality were 0.96 (0.86-1.08) and 1.00 (0.88-1.13), respectively.

CONCLUSIONS

Dietary n-3 PUFA intake was not associated with cardiovascular or all-cause mortality in patients on hemodialysis. As dietary n-3 PUFA intake was low, the possibility that n-3 PUFA supplementation might mitigate cardiovascular risk has not been excluded.

Diet quality in patients with end-stage kidney disease undergoing dialysis

BACKGROUND

People on haemodialysis (HD) are at risk of consuming a poor quality diet. This includes inadequate intake of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA).

OBJECTIVE

This study aims to investigate diet quality, with a particular focus on n-3 LCPUFA intake, in a population of incentre HD patients.

DESIGN

Dietary intake was measured using three 24 hour recalls; the Polyunsaturated food frequency questionnaire (PUFA FFQ) and the Total Diet Score (TDS). Dietary intake was also compared to evidence based practice guidelines (EBPG). Nutritional status was assessed using the Patient Generated Subjective Global Assessment (PG SGA).

SUBJECTS

A total of 32 dialysis patients were recruited, from two regional HD centres in New South Wales, Australia.

MAIN OUTCOME MEASURE

Diet quality was the main outcome measure.

RESULTS

Diet quality of study participants was poor, with the majority not meeting the EBPG for energy, protein and potassium. All participants exceeded the recommended amount of saturated fat. The mean TDS of the dialysis cohort was 10.2, which was significantly higher than the TDS of 9.3 of a healthy disease free cohort (p < 0.05). Positive correlations were found between TDS and LC omega-3 intake (r = 0.392) and TDS and total omega-6 intake (r = 0.363). Only 22% of participants met the suggested dietary target for n-3 LCPUFA intake.

CONCLUSION

Dialysis patients in this study had suboptimal diet quality. Improvements are required for better adherence to the EBPG. Increased consumption of n-3 LCPUFA fatty acids may also be of benefit.

Diet and enteral nutrition in patients with chronic kidney disease not on dialysis: a review focusing on fat, fiber and protein intake

The clinical data available on dietary requirements of patients with chronic kidney disease (CKD) not on dialysis are limited and largely inconclusive in terms of the renal, cardiovascular and nutritional outcomes achievable through dietary modifications. Restriction of protein intake during the early stages of CKD may in fact slow its progression, but at the same time this approach may also lead to protein-energy wasting, if energy intake is not adequate and properly monitored. Unfortunately, compliance to dietary recommendations is traditionally low in this patient population. A switch from saturated to mono- and polyunsaturated fats is generally recognized as advantageous for cardiac health; however, the benefits in term of renal function are largely unknown. Similarly, the association between dietary fiber intake and kidney disease is largely unknown. In fact, while there is evidence on the positive health effects of dietary fibers in the general population, nutritional guidelines for CKD lack formal recommendations concerning fiber intake. This paper reviews data and evidence from clinical trials and meta-analyses on renal and cardiovascular outcomes related to modifications in protein, fat and fiber intake. Suggestions for maintaining nutritional status through patient-oriented dietary patterns and enteral supplementation in CKD patients on conservative therapy are also presented.

Dietary Metabolites and Chronic Kidney Disease

Dietary contents and their metabolites are closely related to chronic kidney disease (CKD) progression. Advanced glycated end products (AGEs) are a type of uremic toxin produced by glycation. AGE accumulation is not only the result of elevated glucose levels or reduced renal clearance capacity, but it also promotes CKD progression. Indoxyl sulfate, another uremic toxin derived from amino acid metabolism, accumulates as CKD progresses and induces tubulointerstitial fibrosis and glomerular sclerosis. Specific types of amino acids (d-serine) or fatty acids (palmitate) are reported to be closely associated with CKD progression. Promising therapeutic targets associated with nutrition include uremic toxin absorbents and inhibitors of AGEs or the receptor for AGEs (RAGE). Probiotics and prebiotics maintain gut flora balance and also prevent CKD progression by enhancing gut barriers and reducing uremic toxin formation. Nrf2 signaling not only ameliorates oxidative stress but also reduces elevated AGE levels. Bardoxolone methyl, an Nrf2 activator and NF-κB suppressor, has been tested as a therapeutic agent, but the phase 3 clinical trial was terminated owing to the high rate of cardiovascular events. However, a phase 2 trial has been initiated in Japan, and the preliminary analysis reveals promising results without an increase in cardiovascular events.

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.

Potential Role of Vegetarianism on Nutritional and Cardiovascular Status in Taiwanese Dialysis Patients: A Case-Control Study

Background & Objectives

Cardiovascular disease remains the most common cause of death for patients on chronic dialysis. End stage renal disease patients undergoing dialysis imposed to reduce phosphorus intake, which likely contributes to development of vegetarian diet behaviors. Vegetarian diets are often lower in protein content, in contradiction to the recommendation that a high protein diet is followed by patients undergoing dialysis. The purpose of the study was to investigate the effects of a vegetarian diet on the nutritional and cardiovascular status of dialysis patients.

Design, Setting, Participants, Measurements

A study of 21 vegetarian dialysis patients and 42 age- and sex-matched non-vegetarian dialysis patients selected as controls was conducted in the Kaohsiung Veterans General Hospital. Brachial-ankle pulse wave velocity and biochemistry data including total homocysteine levels, serum lipid profiles, high-sensitivity C-reactive protein, vitamin D levels, albumin, and normalized protein catabolic rate were measured.

Results

Compared with the non-vegetarian control group, vegetarian subjects had lower body weight, body mass index, serum phosphate, blood urea nitrogen, serum creatinine, vitamin D, uric acid, albumin, and normalized protein catabolic rate (p < 0.05). The vegetarian group showed higher brachial-ankle pulse wave velocity than the non-vegetarian group (1926.95 ± 456.45 and 1684.82 ± 309.55 cm/sec, respectively, p < 0.05). After adjustment for age, albumin, pre-dialysis systolic blood pressure, and duration of dialysis, vegetarian diet remained an independent risk factor for brachial-ankle pulse wave velocity.

Conclusions

The present study revealed that patients on dialysis who follow vegetarian diets may experience subclinical protein malnutrition and vitamin D deficiency that could offset the beneficial cardiovascular effects of vegetarianism.

Ratio of dietary ω-3 and ω-6 fatty acids-independent determinants of muscle mass-in hemodialysis patients with diabetes

OBJECTIVE

ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) are essential nutrients in the human diet and possibly affect muscle mass. We evaluated the association between the dietary ratios of ω-3 and ω-6 PUFAs and muscle mass, indicated as skeletal muscle mass (SMM) and appendicular skeletal muscle mass (ASM), in patients with diabetes undergoing hemodialysis (HD).

METHODS

In this cross-sectional study, data on 69 patients with diabetes who underwent standard HD therapy were analyzed. For estimating muscle mass, anthropometric and bioelectrical impedance analyses were conducted following dialysis. In addition, routine laboratory and 3-d dietary data were obtained. The adequate intake (AI) cut-off for ω-3 PUFAs was 1.6 g/d and 1.1 g/d for male and female patients, respectively.

RESULTS

The average age of the participants was 63.0 ± 10.4 y. The mean ratios of ω-3/ω-6 PUFA intake, ω-6/ω-3 PUFA intake, SMM, and ASM of the patients were 0.13 ± 0.07, 9.4 ± 6.4, 24.6 ± 5.4 kg, and 18.3 ± 4.6 kg, respectively. Patients who had AI of ω-3 PUFAs had significantly higher SMM and ASM than did their counterparts. Linear and stepwise multivariable adjustment analyses revealed that insulin resistance and the ω-6/ω-3 PUFA ratio were the independent deleterious determinants of ASM normalized to height in HD patients.

CONCLUSIONS

Patients with AI of ω-3 PUFAs had total-body SMM and ASM that were more appropriate. A higher dietary ratio of ω-6/ω-3 PUFAs was associated with reduced muscle mass in HD patients.

Metabolic Changes Precede the Development of Pulmonary Hypertension in the Monocrotaline Exposed Rat Lung

There is increasing interest in the potential for metabolic profiling to evaluate the progression of pulmonary hypertension (PH). However, a detailed analysis of the metabolic changes in lungs at the early stage of PH, characterized by increased pulmonary artery pressure but prior to the development of right ventricle hypertrophy and failure, is lacking in a preclinical animal model of PH. Thus, we undertook a study using rats 14 days after exposure to monocrotaline (MCT), to determine whether we could identify early stage metabolic changes prior to the manifestation of developed PH. We observed changes in multiple pathways associated with the development of PH, including activated glycolysis, increased markers of proliferation, disruptions in carnitine homeostasis, increased inflammatory and fibrosis biomarkers, and a reduction in glutathione biosynthesis. Further, our global metabolic profile data compare favorably with prior work carried out in humans with PH. We conclude that despite the MCT-model not recapitulating all the structural changes associated with humans with advanced PH, including endothelial cell proliferation and the formation of plexiform lesions, it is very similar at a metabolic level. Thus, we suggest that despite its limitations it can still serve as a useful preclinical model for the study of PH.

Effect of the omega-3 fatty acid plus vitamin E supplementation on subjective global assessment score, glucose metabolism, and lipid concentrations in chronic hemodialysis patients

SCOPE

This study was conducted to determine the effects of omega-3 fatty acid plus vitamin E supplementation on subjective global assessment (SGA) score and metabolic profiles in chronic hemodialysis (HD) patients.

METHODS AND RESULTS

This randomized double-blind placebo-controlled clinical trial was conducted among 120 chronic HD patients. Participants were randomly divided into four groups to receive: (i) 1250 mg/day omega-3 fatty acid containing 600 mg eicosapentaenoic acid and 300 mg docosahexaenoic acid + vitamin E placebo (n = 30), (ii) 400 IU/day vitamin E + omega-3 fatty acids placebo (n = 30), (iii) 1250 mg omega-3 fatty acids/day + 400 IU/day vitamin E (n = 30), and (iv) omega-3 fatty acids placebo + vitamin E placebo (n = 30) for 12 wk. Fasting blood samples were taken at baseline and after 12-wk intervention to measure metabolic profiles. Patients who received combined omega-3 fatty acids and vitamin E supplements compared with vitamin E, omega-3 fatty acids, and placebo had significantly decreased SGA score (p < 0.001), fasting plasma glucose (p = 0.01), serum insulin levels (p = 0.001), homeostasis model of assessment insulin resistance (p = 0.002), and improved quantitative insulin sensitivity check index (p = 0.006).

CONCLUSION

Omega-3 fatty acids plus vitamin E supplementation for 12 wk among HD patients had beneficial effects on SGA score and metabolic profiles.

A review of recent evidence in human studies of n-3 and n-6 PUFA intake on cardiovascular disease, cancer, and depressive disorders: does the ratio really matter?

Polyunsaturated fatty acids (PUFAs) have been considered of great interest for human health due to their potential anti-inflammatory action that may protect from a number of chronic-degenerative diseases with an inflammatory pathogenesis. This review aimed to report the most updated evidence of both n-3 and n-6 PUFAs effect on cardiovascular disease, cancer, and depression in humans. Attention has been also paid to those studies exploring the effects of the ratio intake. Results from pooled analyses of human studies reported a general positive effect of n-3 PUFAs intake on all outcomes considered. In contrast, the role of n-6 PUFAs on human health needs to be better assessed in order to clearly identify which compound exerts beneficial/harmful effects. Only a limited number of clinical studies considered the n-3:n-6 PUFAs ratio, rather reporting contrasting results. A number of limitations when considering the ratio between these two families of PUFAs have risen.

Associations of fish oil and vitamin B and E supplementation with cardiovascular outcomes and mortality in people receiving haemodialysis: a review

Background

Cardiovascular complications are the leading cause of mortality in patients with end-stage kidney disease. Research indicates that the Mediterranean diet is protective of cardiovascular disease in the general population. Components of this diet have been trialled in haemodialysis patients with the aim of reducing the risk of cardiovascular disease and improving associated risk factors. Components include fish, fruit and vegetables in the form of fish oil supplements and vitamin and antioxidant supplements. This narrative review provides an overview of observational studies, and interventional and randomised controlled trials examining the association of these supplements with cardiovascular outcomes in haemodialysis patients.

Methods

We reviewed the relevant literature by searching English-language publications in Web of Science and references from relevant articles published since 1992. Eight-seven abstracts were reviewed and 38 relevant articles were included.

Results

The extant literature suggests that risk of mortality is reduced in patients with a higher fish intake and those with higher serum omega-3 fatty acid levels. However, the pathways by which risk of mortality is reduced have not been fully extrapolated. While only a few studies have examined the effect of vitamin B supplementation in haemodialysis patients, these studies suggest that supplementation alone does not reduce the risk of mortality. Finally, studies examining vitamin E supplementation have drawn inconsistent conclusions regarding its pro-oxidant or antioxidant effects. Differences between studies are likely due to methodological variations in regards to dose, route of administration and treatment duration.

Conclusions

Nutritional and dietary supplementation in haemodialysis patients is an area which requires larger, more methodologically robust randomised controlled trials to determine if risk of cardiovascular outcomes can be improved.

Dietary restrictions in dialysis patients: is there anything left to eat?

A significant number of dietary restrictions are imposed traditionally and uniformly on maintenance dialysis patients, whereas there is very little data to support their benefits. Recent studies indicate that dietary restrictions of phosphorus may lead to worse survival and poorer nutritional status. Restricting dietary potassium may deprive dialysis patients of heart-healthy diets and lead to intake of more atherogenic diets. There is little data about the survival benefits of dietary sodium restriction, and limiting fluid intake may inherently lead to lower protein and calorie consumption, when in fact dialysis patients often need higher protein intake to prevent and correct protein-energy wasting. Restricting dietary carbohydrates in diabetic dialysis patients may not be beneficial in those with burnt-out diabetes. Dietary fat including omega-3 fatty acids may be important caloric sources and should not be restricted. Data to justify other dietary restrictions related to calcium, vitamins, and trace elements are scarce and often contradictory. The restriction of eating during hemodialysis treatment is likely another incorrect practice that may worsen hemodialysis induced hypoglycemia and nutritional derangements. We suggest careful relaxation of most dietary restrictions and adoption of a more balanced and individualized approach, thereby easing some of these overzealous restrictions that have not been proven to offer major advantages to patients and their outcomes and which may in fact worsen patients' quality of life and satisfaction. This manuscript critically reviews the current paradigms and practices of recommended dietary regimens in dialysis patients including those related to dietary protein, carbohydrate, fat, phosphorus, potassium, sodium, and calcium, and discusses the feasibility and implications of adherence to ardent dietary restrictions and future research.

Plasma renin activity and its association with ischemic heart disease, congestive heart failure, and cerebrovascular disease in a large hypertensive cohort

Plasma renin activity (PRA) may be a surrogate for vascular damage. The authors hypothesize that PRA is associated with cardiovascular and cerebrovascular disease (CED). A cross-sectional study (January 1, 1998, to December 31, 2009) was performed on hypertensive individuals 18 years and older using multivariable logistic regression models to estimate odds ratios (ORs) for ischemic heart disease (IHD), congestive heart failure (CHF), and CED based on PRA quartiles controlling for age, sex, race, diabetes mellitus (DM), and medication use. Among 7887 individuals (60% women; 34% whites, 23% blacks, and 19% Hispanics; and 29% with DM), the adjusted ORs (95% CI) for IHD were 0.94 (0.80-1.10), 1.09 (0.92-1.29), and 1.18 (1.00-1.39); for CHF were 1.23 (0.99-1.53), 1.27 (1.01-1.61), and 1.41 (1.13-1.77); and for CED were 0.95 (0.78-1.17), 0.77 (0.61-0.97), and 0.97 (0.78-1.20) for the second, third, and fourth quartiles compared with the first quartile. Higher PRA was associated with greater likelihood for prevalent IHD and CHF but not CED in this large ethnically diverse population of hypertensive individuals.

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.

Depressive symptoms and the relationship of inflammation to physical signs and symptoms in heart failure patients

BACKGROUND

Depressive symptoms in patients with heart failure can affect the relationship between physical signs and symptoms and inflammation.

OBJECTIVE

To examine the relationship between soluble tumor necrosis factor receptor I and physical signs and symptoms and the effects of depressive symptoms on this relationship in patients with heart failure.

METHODS

Data on physical signs and symptoms (Symptom Status Questionnaire-Heart Failure), depressive symptoms (Beck Depression Inventory-II), and levels of the receptor (blood samples) were collected from 145 patients with heart failure. Data on the receptor were square root transformed to achieve normality. Patients were divided into 2 groups according to their scores for depressive symptoms (nondepressed <14 and depressed ≥14). Hierarchical multiple regression was used to analyze the data.

RESULTS

In the total sample, with controls for covariates, higher levels of the receptor were significantly related to more severe physical signs and symptoms (F = 7.915; P < .001). In subgroup analyses, with controls for covariates, levels of the receptor were significantly related to physical signs and symptoms only in the patients without depression (F = 3.174; P = .005).

CONCLUSION

Both depressive symptoms and inflammation should be considered along with physical signs and symptoms in patients with heart failure. Further studies are needed to determine the effects of improvement in inflammation on improvement in physical signs and symptoms, with consideration given to the effects of depressive symptoms.

Evidence for the use of glomerulomegaly as a surrogate marker of glomerular damage and for alpha-linolenic acid-rich oils in the treatment of early obesity-related glomerulopathy in a diet-induced rodent model of obesity

Obesity-related glomerulopathy (ORG) is a unique and emerging condition that can lead to renal failure. Early detection, aided by an earlier diagnostic marker, would improve patient outcomes; this could be facilitated by an accurate model. Such a model would be useful to examine interventions like dietary fatty acids, which are known to influence renal diseases in later stages. In this study, obese-prone rats were provided high-fat (55% of energy) diets for 12 weeks to generate a model of diet-induced obesity. The rats were subsequently provided dietary oils with various levels of alpha-linolenic acid (ALA) and linoleic acid (LA) for 8 weeks, as follows: (g ALA:LA per 100 g oil): canola/flax (20:18), canola (8:18), soy (9:53), high-oleic canola/canola (5:16), high-oleic canola (2:15), lard/soy (1:8), and safflower (0.2:73). The model developed obesity, glomerulomegaly, proteinuria, and scarce glomerular damage with an indolent course. Morphometry and histology revealed glomerulomegaly as the first renal structural alteration. The utility of this marker as a predictor for the presence of ORG and renal injury was evidenced by its correlation to visceral adiposity (p < 0.0001, r = 0.44), proteinuria (p < 0.0001, ρ = 0.55), change in proteinuria (p = 0.0092, ρ = 0.42), and glomerular damage (p < 0.0001, ρ = 0.48). Renal triglyceride ALA:LA was strongly correlated with dietary ALA:LA (p < 0.0005, ρ = 0.96), and inversely associated with mean glomerular volume (p = 0.02, ρ = -0.82). The diet-induced obese model accurately represents early ORG, and implicates glomerulomegaly as an early surrogate diagnostic marker. Early intervention with ALA-rich dietary oils slowed glomerular enlargement; these findings warrant further clinical investigation to promote optimal patient outcomes.

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.

Chronic kidney disease: considerations for nutrition interventions

Chronic kidney disease (CKD) is highly prevalent and has major health consequences for patients. Caring for patients with CKD requires knowledge of the food supply, renal pathophysiology, and nutrition-related medications used to work synergistically with diet to control the signs and symptoms of the disease. The nutrition care process and International Dietetic and Nutrition Terminology allow for systematic, holistic, quality care of patients with this complex, progressive disease. Nutrition interventions must be designed with the individual patients needs in mind while prioritizing factors with the largest negative impact on health outcomes and mortality risk. New areas of nutrition treatment are emerging that involve a greater focus on micronutrient needs, the microbiome, and vegetarian-style diets. These interventions may improve outcomes by decreasing inflammation, improving energy and protein delivery, and lowering phosphorus, electrolytes, and fluid retention.

Comparison of plasma and erythrocyte membrane fatty acid compositions in patients with end-stage renal disease and type 2 diabetes mellitus

BACKGROUND

In this study, we aimed to compare the serum lipid profile and fatty acid (FA) compositions of erythrocyte membrane (EM) and plasma in three different patient groups (group 1: type 2 diabetes mellitus (T2DM)+end-stage renal disease (ESRD), group 2: ESRD, group 4: T2DM) and healthy controls (group 3) simultaneously.

METHODS

40 ESRD patients treated with hemodialysis (HD) in Gulhane School of Medicine (20 with T2DM) and 32 controls (17 with T2DM, 15 healthy controls) were included in the study. Plasma and EM FA concentrations were measured by gas chromatography-flame ionization detector (GC-FID).

RESULTS

Plasma and EM palmitic acid (PA) and stearic acid (SA) levels were significantly higher in T2DM patients compared to controls (p=0.040 and p=0.002 for plasma, p=0.001 and p=0.010 for EM, respectively). EM docosahexaenoic acid (DHA) levels were also significantly lower in patients with ESRD+T2DM and ESRD compared to controls (p=0.004 and p=0.037, respectively).

CONCLUSIONS

Patients with insulin resistance display a pattern of high long chain saturated FAs (PA, SA and arachidic acids). However, while there are no recognized standards for normal EM DHA content, decreased levels of EM DHA in ESRD patient groups (groups 1 and 2) suggest that there may be reduced endogenous synthesis of DHA in HD subjects, due to the decreased functionality of desaturase and elongase enzymes. Because membrane PUFA content affects membrane fluidity and cell signaling, these findings are worthy of further investigation.

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.

Endogenous synthesis of n-3 PUFA modifies fatty acid composition of kidney phospholipids and eicosanoid levels in the fat-1 mouse

The goal of the present study was to determine whether endogenous synthesis of n-3 polyunsaturated fatty acids (PUFA) in the fat-1 mouse is comparable to fish oil feeding with respect to kidney n-3 PUFA composition and eicosanoid levels. Wild-type and heterozygous fat-1 mice, capable of synthesizing n-3 PUFA endogenously, were given diets enriched in either n-3 or n-6 PUFA in a 2×2 factorial design and terminated after 12 weeks. Kidney phospholipid fatty acids were analysed by gas chromatography. Kidney eicosanoids were analysed by liquid chromatography tandem mass spectrometry. Relative to control mice fed n-6 PUFA, n-3 PUFA fed and fat-1 mice had higher levels of kidney phospholipid n-3 PUFA, and lower levels of n-6 PUFA and eicosanoids. However, mice fed n-3 PUFA mice had higher levels of n-3 PUFA and lower levels of eicosanoids as compared to fat-1 mice. In conclusion, diet feeding had a greater impact on kidney fatty acid composition and eicosanoid levels than the genetic effect of the fat-1 gene. However, the fat-1 mouse remains a close approximation that can be used as a complementary model to study the role of n-3 PUFA in the kidney.

Let them eat during dialysis: an overlooked opportunity to improve outcomes in maintenance hemodialysis patients

In individuals with chronic kidney disease, surrogates of protein-energy wasting, including a relatively low serum albumin and fat or muscle wasting, are by far the strongest death risk factor compared with any other condition. There are data to indicate that hypoalbuminemia responds to nutritional interventions, which may save lives in the long run. Monitored, in-center provision of high-protein meals and/or oral nutritional supplements during hemodialysis is a feasible, inexpensive, and patient-friendly strategy despite concerns such as postprandial hypotension, aspiration risk, infection control and hygiene, dialysis staff burden, diabetes and phosphorus control, and financial constraints. Adjunct pharmacologic therapies can be added, including appetite stimulators (megesterol, ghrelin, and mirtazapine), anabolic hormones (testosterone and growth factors), antimyostatin agents, and antioxidative and anti-inflammatory agents (pentoxiphylline and cytokine modulators), to increase efficiency of intradialytic food and oral supplementation, although adequate evidence is still lacking. If more severe hypoalbuminemia (<3.0 g/dL) not amenable to oral interventions prevails, or if a patient is not capable of enteral interventions (e.g., because of swallowing problems), then parenteral interventions such as intradialytic parenteral nutrition can be considered. Given the fact that meals and supplements during hemodialysis would require only a small fraction of the funds currently used for dialysis patients this is also an economically feasible strategy.

Inverse relationship between long-chain n-3 fatty acids and risk of sudden cardiac death in patients starting hemodialysis

Experimental and clinical evidence suggests that long chain n-3 fatty acids may protect against sudden cardiac death, the leading cause of mortality in hemodialysis patients. Here we investigated whether long chain n-3 fatty acids have a protective relationship with sudden cardiac death in 100 patients who died of sudden cardiac death during the first year of starting hemodialysis and 300 patients who survived. Individuals were selected from a nationally representative cohort of over 1000 U.S. hemodialysis units in 2004–2005. The odds of sudden cardiac death were calculated by quartile of long chain n-3 fatty acids levels over the first year. There was a significant inverse relationship between long chain n-3 fatty acids and the risk of sudden cardiac death even after adjusting for relevant co-morbid conditions, biochemical values, and dietary fats. The odds of sudden cardiac death at 1 year for the second, third, and fourth quartile groups of long chain n-3 fatty acids were 0.37, 0.22, and 0.20, respectively, compared to the lowest quartile. This significant inverse relationship was maintained even during the highest-risk first few months on hemodialysis. Thus, long chain n-3 fatty acids are strongly and independently associated with a lower risk of sudden cardiac death in hemodialysis patients throughout the first year of hemodialysis.

Serum and adipose tissue fatty acid composition as biomarkers of habitual dietary fat intake in elderly men with chronic kidney disease

BACKGROUND

Fatty acid (FA) composition in serum cholesterol esters (CE) and adipose tissue (AT) reflect the long-term FA intake in the general population. Because both dietary intake and FA biomarkers associate with renal function, our aim was to identify which CE and AT FAs are useful biomarkers of habitual FA intake in individuals with chronic kidney disease (CKD).

METHODS

Cross-sectional analysis was performed in 506 men (aged 70 years) with a glomerular filtration rate (GFR) of <60 mL/min per 1.73 m(2) from the Uppsala Longitudinal Study of Adult Men cohort. Dietary habits were evaluated with a 7-day dietary record. FA compositions in CE and AT were analyzed by gas-liquid chromatography in two random subsamples of 248 and 318 individuals, respectively.

RESULTS

Both CE and AT linoleic acid and docosahexaenoic acid (DHA) were strongly associated with their corresponding intake, after adjustments for non-dietary factors. The proportions of eicosapentaenoic acid (EPA) and palmitic acid in CE and AT moderately correlated with dietary intake, whereas correlations of other FAs were weaker or absent. Proportions of EPA and DHA in CE and AT were positively associated with the total energy-adjusted fish intake. Results were confirmed in adequate reporters as identified by the Goldberg cutoff method. These relationships held constant, regardless of a GFR above or below 45 mL/min per 1.73 m(2) or the prevalence of microalbuminuria.

CONCLUSIONS

Proportions of EPA, DHA, palmitic and linoleic acid in serum CE and AT are good indicators of their dietary intake in men with CKD. They can be considered valid biomarkers for epidemiological studies and assessment of compliance.

Low blood levels of long-chain n-3 polyunsaturated fatty acids in US hemodialysis patients: clinical implications

BACKGROUND

Cardioprotective and other clinical benefits of long-chain n-3 polyunsaturated fatty acids (PUFA) are inversely related to dietary intake and hence blood content. We therefore investigated, in the first study of its kind, the blood content and distribution of these fatty acids in a large representative population of US hemodialysis patients.

METHODS

Frozen sera were obtained from 400 individuals who were part of a large, contemporary, representative cohort of US incident hemodialysis patients. Long-chain n-3 PUFA were measured in total serum lipids and in the neutral and polar serum fractions using gas chromatography and solid phase extraction techniques. Mean long-chain n-3 PUFA levels were compared to levels in other dialysis and nondialysis populations from published reports.

RESULTS

The study population was qualitatively similar to the overall US hemodialysis population in terms of major clinical characteristics. Long-chain n-3 PUFA were present in the serum polar fraction, with essentially none being detected in the neutral fraction (p < 0.0001 for polar vs. neutral fractions for all three long-chain n-3 PUFA). Mean serum long-chain n-3 PUFA levels (weight percent (±SD): total 1.55 ± 0.95, polar 3.99 ± 1.45) were low compared to nondialysis and most other non-US hemodialysis cohorts.

CONCLUSIONS

While US hemodialysis patients have a blood distribution of long-chain n-3 PUFA that is similar to that in the general population, blood content is among the lowest recorded in the medical literature. This has implications for renal dietary recommendations and makes US patients an ideal group for testing the clinical effects of long-chain n-3 PUFA supplementation.

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.