The effects of omega-3 fatty acid on vitamin D activation in hemodialysis patients: a pilot study

Enhanced Metabolic Effects of Fish Oil When Combined with Vitamin D in Diet-Induced Obese Male Mice

Vitamin D (vit D) and fish oil (FO) both offer unique health benefits, however, their combined effects have not been evaluated in obesity and nonalcoholic fatty liver disease (NAFLD). Hence, we hypothesized that vit D and FO supplementation would have additive effects in reducing obesity-associated inflammation and NAFLD. Male C57BL6 mice were split into four groups and fed a high fat (HF) diet supplemented with a low (HF; +200 IU vit D) or high dose of vitamin D (HF + D; +1000 IU vit D); combination of vit D and FO (HF-FO; +1000 IU vit D); or only FO (HF-FO; +200 IU vit D) for 12 weeks. We measured body weight, food intake, glucose tolerance, and harvested epididymal fat pad and liver for gene expression analyses. Adiposity was reduced in groups supplemented with both FO and vit D. Glucose clearance was higher in FO-supplemented groups compared to mice fed HF. In adipose tissue, markers of fatty acid synthesis and oxidation were comparable in groups that received vit D and FO individually in comparison to HF. However, the vit D and FO group had significantly lower fatty acid synthesis and higher oxidation compared to the other groups. Vit D and FO also significantly improved fatty acid oxidation, despite similar fatty acid synthesis among the four groups in liver. Even though we did not find additive effects of vit D and FO, our data provide evidence that FO reduces markers of obesity in the presence of adequate levels of vit D.

Effects of omega-3 supplementation on serum albumin, pre-albumin and the CRP/albumin ratio in hospitalized patients: a systematic review and meta-analysis

CONTEXT

Low serum albumin and pre-albumin concentrations are associated with edema, infection, thrombosis, heart failure, and mortality.

OBJECTIVE

This comprehensive systematic review and meta-analysis of clinical trials was conducted to summarize the available findings on the impact of omega-3 supplementation on albumin, pre-albumin, and the C-reactive protein/albumin ratio in hospitalized patients.

DATA SOURCES

PubMed, Web of Science, Scopus, and Google Scholar databases were searched from January 1990 to October 2021.

DATA EXTRACTION

Extracted data from 50 randomized controlled trials (RCTs) with a total number of 3196 participants were analyzed using the random-effects model. The dose-dependent effect was also evaluated.

DATA ANALYSIS

Oral omega-3 supplementation significantly increased serum albumin concentrations in patients with cancer (weighted mean difference [WMD]: 0.19; 95% CI: 0.05, 0.33, P= 0.006), patients on dialysis (WMD: 0.14; 95% CI: 0.01, 0.28, P= 0.042), and those with hypoalbuminemia (WMD: 0.38; 95% CI: 0.03, 0.72, P = 0.033); however, there was no significant effect among patients with gastrointestinal or hepatologic diseases. Moreover, each 1000 mg/day increase in oral omega-3 supplementation resulted in elevated serum albumin levels in cancer patients (WMD: 0.15; 95% CI: 0.07, 0.24, P < 0.001). In addition, a favorable effect of oral omega-3 supplementation on pre-albumin levels was observed among patients with cancer (WMD: 33.87; 95% CI: 12.34, 55.39, P = 0.002). A similar significant effect of parenteral omega-3 supplementation on pre-albumin concentrations was seen among those with gastrointestinal and hepatologic diseases as well (WMD: 23.30; 95% CI: 13.58, 33.03, P < 0.001). No significant effect of oral omega-3 supplementation on the CRP/albumin ratio was found.

CONCLUSIONS

Overall, omega-3 fatty acids supplementation resulted in a favorable change in serum albumin and pre-albumin concentrations in hospitalized patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021285704.

The influence of dietary and supplemental omega-3 fatty acids on the omega-3 index: A scoping review

Introduction

The majority of the population do not consume adequate omega-3 fatty acids (n-3 FA), leading to global deficiencies, as evidenced by poor omega-3 status. An indicator of overall n-3 FA status, omega3-index (O3i) ≥8% has been associated with reduced risk of chronic disease, most notably cardiovascular disease. Thus, a synthesis of current research summarizing the effects of n-3 FA intake on O3i is warranted to develop and refine clinical recommendations. The purpose of this scoping review was to evaluate the effect of n-3 FA interventions and estimate sufficient n-3 FA intake to improve O3i to meet recommendations.

Methods

Search criteria were human studies published in English from 2004 to 2022 that assessed O3i at baseline and following an n-3 FA intervention.

Results

Fifty-eight studies that met inclusion criteria were identified. Protocols included fish consumption, fortified foods, combined eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplements, supplements of single n-3 FA (alpha linolenic acid (ALA), EPA, DHA, etc.), and supplements providing multiple n-3 FA. Dietary supplements varied in chemical composition; the most common were triglycerides or ethyl esters. The lowest supplementation protocol was 100 mg/d, and the largest was 4,400 mg/d EPA and DHA. Supplementation time period ranged from 3 weeks to 1 year. At baseline, three study samples had mean O3i >8%, although many intervention protocols successfully increased O3i.

Discussion

Generally, the lowest doses shown to be effective in raising O3i to recommended levels were >1,000 mg/d of combination DHA plus EPA for 12 weeks or longer. Supplements composed of triglycerides were more bioavailable and thus more effective than other formulas. Based on the data evaluated, practical recommendations to improve O3i to ≥8% are consumption of 1,000-1,500 mg/d EPA plus DHA as triglycerides for at least 12 weeks.

The Frequency of Vitamin D and Calcium Deficiencies Among Women of Reproductive Age in Wadi Etba, Southern Region of Libya

Background

Vitamin D (VD) is the sunshine vitamin. Its deficiency is widely spread worldwide and is implicated in various health problems that have serious financial, mental, and physical health burdens. In Libya, it also has a high incidence as many studies have been conducted on this issue, but the exact situation of VD deficiency in the southern region of Libya remains unclear.

Aim 

The aim of this study is to investigate the frequency of VD deficiency and calcium status among females of reproductive age in Wadi Etba (located in the southern region of Libya).

Material and methods

This study included 622 females aged 20-40 years attending the Rural Hospital and Private Clinics in Wadi Etba for various health issues during the last five years. The study population was further subdivided into two age groups; 20-30 years and 31-40 years. VD and calcium were measured to determine the VD status among the study population.

Results

In general, 489 females had sub-optimal VD (<30 ng/mL), representing 78.6% of the total subjects. Normal VD levels were represented only by 133 subjects (21.4%). VD deficiency was represented by 354 subjects (57%) of the total subjects. A total of 232 (37%) subjects were VD-deficient females (18.3 ± 5.5 ng/ml), 122 subjects (20%) were considered poor (severe deficient, VD <10 ng/ml) represented with a mean serum VD of 8.2 ± 0.6. Furthermore, deficiency cases dominated the older age group. Regarding calcium (Ca⁺²) levels, 31% had lower than the normal range, 68% had normal range, and only 1% showed high Ca⁺² levels. On the other hand, there was no correlation between serum levels of VD and Ca⁺² levels.

Conclusion

VD deficiency has become a widespread condition in the southern region of Libya. Therefore, we recommended making lifestyle changes, including extending the exposure time to the sunlight radiation, fortifying foods and drinks with VD, and taking supplementary doses of VD to reduce the high incidence of VD deficiency.

A Consistency Model for Identifying the Effects of n-3 and n-6 Fatty Acids on Lipoproteins in Dialysis Patients

Numerous randomized controlled trials (RCTs) and meta-analyses have assessed the effects of supplemental dietary polyunsaturated fatty acids (PUFAs) on levels of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) and the LDL/HDL ratio in patients receiving renal replacement therapy (RRT). However, results are ambiguous due to mixed reports of various nutrients used in the intervention group. We performed a network meta-analysis of RCTs to assess the effects of PUFAs on lipid profiles in patients undergoing RRT. RCTs performed before November 2021 were gathered from three databases. The means, standard deviations and the number of cases for each arm were independently extracted by two authors to form a network meta-analysis of LDL and HDL levels and the LDL/HDL ratio in a random effects model. Twenty-eight RCTs (n = 2017 subjects) were included in this study. The pooled results revealed that the combination of omega-3 fatty acids (n-3) and omega-6 fatty acids (n-6) produced significantly lower LDL (standardized mean difference (SMD) = −1.43, 95% confidence interval: −2.28 to −0.57) than the placebo. Both n-3 fatty acids (SMD = 0.78) and the combination of n-3 + n-6 (SMD = 1.09) benefited HDL significantly compared with placebo. Moreover, n-3 alone also exhibited a significantly lower LDL/HDL ratio than placebo. Collectively, PUFAs seem to be adequate nutrients for controlling lipoproteins in patients undergoing RRT. Specifically, n-3 + n-6 supplementation improved LDL levels, while n-3 improved HDL levels and the LDL/HDL ratio. However, our data provide limited information on specific dosages of PUFAs to form a concrete recommendation.

Effect of omega-3 and vitamin D co-supplementation on psychological distress in reproductive-aged women with pre-diabetes and hypovitaminosis D: A randomized controlled trial

PURPOSE

Psychological distresses and pre-diabetes are among the risk factors of developing type-II diabetes. The present study was conducted to determine the effectiveness of omega-3 and vitamin D co-supplementation on psychological distresses in women of reproductive age with pre-diabetes and hypovitaminosis D.

METHODS

The present factorial clinical trial was conducted on 168 women of reproductive age with pre-diabetes and hypovitaminosis D. These participants were selected by stratified random sampling and were assigned to four groups for 8 weeks: group 1 (placebo group), group 2 (omega-3 group), group 3 (vitamin D group), and group 4 (co-supplement group). The medication and placebo doses being two 1000-mg tablets each day for omega-3 and 50,000-IU pearls every 2 weeks for vitamin D. Fasting blood glucose and vitamin D were measured at the beginning of the study. The Depression Anxiety Stress Scale-21 and the Pittsburgh Sleep Quality Index were completed by the participants at the start and end of the intervention.

RESULTS

A significant difference was observed in terms of reduction in anxiety and improvement in sleep quality in the co-supplementation compared to the other three groups (p < .05). There was also a significant difference between the group receiving both supplements and the group receiving only placebos in terms of reduction in depression and stress (p < .05).

CONCLUSION

Vitamin D and omega-3 co-supplementation improved depression, anxiety, and sleep quality in women of reproductive age with pre-diabetes and hypovitaminosis D. Therefore, these two supplements can be recommended for improving the mental health of this group of women.

CLINICAL TRIAL REGISTRY

Iranian Registry of Clinical Trials Code: IRCT20100130003226N17. Registered on February 9, 2019.

Effects of Omega-3 Fatty Acid Intake in Patients Undergoing Dialysis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective: Fish oil supplementation has been shown to be beneficial for hemodialysis (HD) patients. The aim of this study was to evaluate the efficacy and safety of omega-3 fatty acid supplementation or dietary adjustment in dialysis patients.Methods: A systematic literature search was performed to identify relevant randomized controlled trials (RCTs) to study the effects of omega-3 supplementation on dialysis patients. The variables of interest included the levels of blood lipids, inflammatory indicators, proteins, parathyroid hormone (PTH), gastrointestinal adverse reactions, and all-cause mortality. The mean differences (MDs) and 95% confidence intervals (CIs) were calculated, and heterogeneity was assessed with the I² test. Subgroup and sensitivity analyses were performed to identify potential sources.Results: The systematic review included 49 RCTs and evaluated the efficacy and safety of omega-3 fatty acid supplementation in dialysis patients. Data synthesis showed that compared with the control group, the group receivingomega-3 supplementation exhibited significantly decreased serum triglyceride (TG) levels, decreased C-reactive protein (CRP) and TNF-alpha levels, increased hemoglobin levels, reduced serum phosphorus levels, increased PTH levels, and increased gastrointestinal adverse reactions to a certain extent. Furthermore, there was no effect on the blood total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), albumin or calcium levels and all-cause mortality.Conclusion: Omega-3 fatty acid supplementation is related to a reduction in serum TG, LDL and inflammation index levels and has few adverse reactions. Therefore, omega-3 fatty acid supplementation may be a useful nutrition therapy for dialysis patients.

Habitual use of fish oil supplements, genetic predisposition, and risk of fractures: a large population-based study

BACKGROUND

Epidemiologic studies have suggested an inverse association between circulating concentrations of long-chain ω-3 PUFAs and fracture risk. However, whether supplementation of long-chain ω-3 PUFA (i.e. fish oil) is associated with fracture risk, and whether the association is modified by genetic predisposition to fracture risk remain unclear.

OBJECTIVES

To evaluate the associations of habitual fish oil supplement use with fracture risk, and to explore the potential effect modification by genetic predisposition.

METHODS

This study included 492,713 participants from the UK Biobank who completed a questionnaire on habitual fish oil supplement use between 2006 and 2010. HRs and 95% CIs for fractures were estimated from multivariable Cox proportional hazards models. A weighted fracture-genetic risk score (GRS) was derived from 14 validated single nucleotide polymorphisms.

RESULTS

During a median follow-up of 8.1 y, 12,070 incident fractures occurred among participants free of fracture at baseline (n = 441,756). Compared with nonuse, habitual use of fish oil supplements was associated with a lower risk of total fractures (HR = 0.93; 95% CI: 0.89, 0.97), hip fractures (HR = 0.83; 95% CI: 0.75, 0.92), and vertebrae fractures (HR = 0.85; 95% CI: 0.72, 0.99). The inverse association for total fractures was more pronounced among participants having a higher fracture-GRS than among those with a lower fracture-GRS (P-interaction <0.001). Among participants with a history of fracture at baseline (n = 50,957), fish oil use was associated with a lower risk of total recurrent fractures (HR = 0.88; 95% CI: 0.82, 0.96) and vertebrae recurrent fractures (HR = 0.64; 95% CI: 0.46, 0.88) but not with hip fracture recurrence.

CONCLUSIONS

Our findings suggest that habitual fish oil supplement use is associated with lower risks of both incident and recurrent fractures. The inverse associations of fish oil use with total fractures appeared to be more pronounced among individuals at higher genetic risk of fractures than those with lower genetic risk.

The effect of fish oil on inflammation markers in adult patients undergoing hemodialysis: A meta-analysis

OBJECTIVE

This meta-analysis was to assess the effect of fish oil supplementation on inflammation markers in adult patients receiving hemodialysis.

METHODS

CENTRAL, EMBASE, MEDLINE databases were searched from inception to 10 April 2020. Two authors independently searched, selected, and screened the literature. The pooled results are represented by WMD or SMD with 95% confidence intervals. Subgroup analysis and meta-regression were used to explore sources of heterogeneity, and sensitivity analysis was used to assess the robustness of the pooled results. Funnel plots were used to assess publication bias.

RESULTS

Eleven RCT (randomized control trials) studies were included. The pooled results showed that fish oil supplementation caused a significant reduction of the CRP(C-reactive protein) level (random model: WMD, -3.36, 95%CI: -5.46 to -1.26, P = .002), especially in patients with baseline CRP ≥ 5 mg/L (random model: WMD, -4.43, 95%CI: -6.10 to -2.76, P = .00001, I²  = 41%). Meta-regression analyses showed that CRP baseline level (CRP < 5 mg/L) was the main source of heterogeneity (P = .036). Sensitive analyses revealed that the result was hardly changed. Fish oil supplementation might not reduce the level of IL-6 (random model: WMD, -2.26, 95%CI: -19.61 to 15.09, P = .80) in four studies or the level of TNF-α (random model: SMD, -2.51, 95%CI: -6.08 to 1.06, P = .17) in three studies.

CONCLUSIONS

Fish oil supplementation could reduce the level of CRP in hemodialysis patients, especially in patients with CRP ≥ 5 mg/L, but had no effects on IL-6 and TNF-α.

The Effect of Omega-3 Fatty Acids on Thromboxane, Brain-Derived Neurotrophic Factor, Homocysteine, and Vitamin D in Depressive Children and Adolescents: Randomized Controlled Trial

In the DEPOXIN project, we have found that a high ratio of omega-6/omega-3 fatty acids (FA) is associated with worsening of depressive symptoms in children and adolescents with depressive disorder (DD) and that the 12-week omega-3 FA supplementation modulates DD symptoms. Here we present our results of the secondary outcomes: the levels of thromboxane (TXB), brain-derived neurotrophic factor (BDNF), homocysteine (HCy) and vitamin D. Fifty-eight patients were randomized into two arms. One group received a fish oil emulsion enriched with omega-3 FA, and the other received a sunflower oil emulsion containing omega-6 FA, for 12 weeks. Depressive symptoms were evaluated, using the Child's Depressive Inventory (CDI). The patients with DD had elevated TXB levels and decreased vitamin D levels, as compared to healthy controls. Both CDI and omega-6/omega-3 ratio correlated positively with TXB and negatively with BDNF at baseline. Compared to the omega-6 FA group, the supplementation with omega-3 FA for 12 weeks significantly reduced plasma TXB (p = 0.024) and increased BDNF (p = 0.011) levels. No changes in HCy and vitamin D were observed. Our results demonstrate the possible role of TXB and BDNF in the pathophysiology of DD and the benefits of omega-3 FA supplementation. The study was registered with the ISRCTN registry (ISRCTN81655012).

Maternal vitamin D deficiency influences long-chain polyunsaturated fatty acids and pregnancy outcome in association with alterations in one-carbon metabolism

Preeclampsia is a pregnancy-specific disorder, leading to maternal and infant morbidity and mortality. Abnormal placentation has been reported in preeclampsia. Nutrients like vitamin D and long-chain polyunsaturated fatty acids (LCPUFA) are known to play a role in placental development. In an animal model, we have previously demonstrated that maternal vitamin D deficiency increases the thromboxane/prostacyclin ratio and contributes to inflammation and vasoconstriction. We hypothesize that maternal vitamin D status influences placental LCPUFA metabolism through alterations in one carbon metabolism in women with preeclampsia. To test this hypothesis, we recruited 69 normotensive control (NC) women and 50 women with preeclampsia. Women with preeclampsia had lower placental protein and mRNA levels of cystathionine-β-synthase (CBS), higher plasma malondialdehyde (MDA) levels and higher levels of arachidonic acid (AA) and total omega-6 fatty acids in the placenta. Women with preeclampsia also demonstrated higher placental mRNA levels of cyclooxygenase-2 (COX-2) as compared to NC women. Maternal 25(OH)D levels were negatively associated with maternal plasma MDA levels. Placental vitamin D receptor (VDR) levels were positively associated with CBS while maternal MDA levels were positively associated with serum levels of thromboxane-B2 (TXB2) levels. Our findings indicate that vitamin D deficiency increases oxidative stress through alterations in one carbon metabolism to influence pro-inflammatory omega-6 metabolic pathway in the placenta. This study demonstrates a possible mechanism through which vitamin D deficiency can result in an imbalance in the LCPUFA metabolites and contribute to placental inflammation and endothelial dysfunction in preeclampsia.

The influence of omega-3 supplementation on vitamin D levels in humans: a systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Inconsistencies exist with regard to the influence of omega-3 supplementation on 25-hydroxyvitamin D (25(OH)D) levels, which could be attributed to many factors, such as the duration and dose of omega-3 supplementation, and individuals' baseline 25(OH)D levels. Therefore, to address the inconsistencies, we conducted a systematic review and dose-response meta-analysis to accurately determine the effect of omega-3 supplementation on 25(OH)D levels in humans.

METHODS

We performed a comprehensive literature search in Web of Science, PubMed/Medline, Scopus, and Embase databases from inception up to January 2020. We included only randomized controlled trials (RCTs). We used weighted mean difference (WMD) with 95% confidence interval (CI) to assess the influence of omega-3 supplementation on serum 25(OH)D levels using the random-effects model.

RESULTS

Our pooled results of 10 RCTs demonstrated an overall significant increase in 25(OH)D levels following omega-3 intake (WMD = 3.77 ng/ml, 95% CI: 1.29, 6.25). In addition, 25(OH)D levels were significantly increased when the intervention duration lasted >8 weeks and when the baseline serum 25(OH)D level was ˂20 ng/ml. Moreover, omega-3 intake ≤1000 mg/day resulted in higher 25(OH)D levels compared to omega-3 intake >1000 mg/day.

CONCLUSION

In conclusion, omega-3 supplementation increased 25(OH)D concentrations, particularly with dosages ≤1000 mg/day and intervention durations >8 weeks.

Development, validation and utilisation of dish-based dietary assessment tools: a scoping review

Objective:

To summarise the existing evidence of development, validation and current status of utilisation of dish-based dietary assessment tools.

Design:

Scoping review.

Setting:

Systematic search using PubMed and Web of Science.

Results:

We identified twelve tools from seventy-four eligible publications. They were developed for Koreans (n 4), Bangladeshis (n 2), Iranians (n 1), Indians/Malays/Chinese (n 1), Japanese (n 3) and Chinese Americans (n 1). Most tools (10/12) were composed of a dish-based FFQ. Although the development process of a dish list varied among the tools, six studies classified mixed dishes based on the similarity of their characteristics such as food ingredients and cooking methods. Tools were validated against self-reported dietary information (n 9) and concentration biomarkers (n 1). In the eight studies assessing the differences between the tool and a reference, the mean (or median) intake of energy significantly differed in five studies, and 26–83 % of nutrients significantly differed in eight studies. Correlation coefficients for energy ranged from 0·15 to 0·87 across the thirteen studies, and the median correlation coefficients for nutrients ranged from 0·12 to 0·77. Dish-based dietary assessment tools were used in fifty-nine studies mainly to assess diet–disease relationships in target populations.

Conclusions:

Dish-based dietary assessment tools have exclusively been developed and used for Asian-origin populations. Further validation studies, particularly biomarker-based studies, are needed to assess the applicability of tools.

The effect of omega-3 and vitamin D co-supplementation on glycemic control and lipid profiles in reproductive-aged women with pre-diabetes and hypovitaminosis D: a randomized controlled trial

BACKGROUND

Prediabetes can predispose the individual to type 2 diabetes in the long-term. The present study was conducted to determine the effectiveness of vitamin D and omega-3 co-supplementation on glycemic control and serum lipid profiles in women of reproductive age with prediabetes and hypovitaminosis D.

METHODS

The present factorial, triple-blind, clinical trial was conducted on 168 women of reproductive age with prediabetes and hypovitaminosis D. The participants were assigned to four groups based on block randomization method: the placebo group received omega-3 and vitamin D placebos; the omega-3 group took omega-3 supplements and vitamin D placebos; the vitamin D group received omega-3 placebos and vitamin D supplements and the co-supplementation group. The groups received every 2 weeks 50,000 IU pearls of vitamin D and twice-daily doses of 1000-mg omega-3 tablets or placebos for 8 weeks. Dietary intake, physical activity, anthropometric indices and blood biochemical tests were measured at the beginning and end of the study. Analysis was performed using two-way mixed ANOVA.

RESULTS

A significant reduction was observed in fasting glucose, insulin, homeostasis model assessment-beta cell function, weight and waist circumference in the co-supplementation group compared to the other three groups (P < 0.05). Moreover, high-density lipoprotein-cholesterol levels increased significantly in the co-supplementation group compared to the other three groups (P < 0.05). Despite the fact that homeostasis model assessment-insulin resistance, total cholesterol, triglyceride and low-density lipoprotein-cholesterol levels decreased after intervention in the co-supplementation group, there was no significant difference between the groups in these outcomes.

CONCLUSION

Vitamin D and omega-3 co-supplementation improved fasting serum glucose, insulin, high-density lipoprotein-cholesterol level, homeostasis model assessment-beta cell function, weight and waist circumference in women of reproductive age with prediabetes and hypovitaminosis D. This co-supplementation can therefore be recommended for glycemic control in these women.Trial registration Iranian Registry of Clinical Trials Code: IRCT20100130003226N17. Registered on 9 Feb. 2019.

Efficacy of Polyunsaturated Fatty Acids on Inflammatory Markers in Patients Undergoing Dialysis: A Systematic Review with Network Meta-Analysis of Randomized Clinical Trials

The effects of polyunsaturated fatty acids (PUFAs) on inflammatory markers among patients receiving dialysis have been discussed for a long time, but previous syntheses made controversial conclusion because of highly conceptual heterogeneity in their synthesis. Thus, to further understanding of this topic, we comprehensively gathered relevant randomized clinical trials (RCTs) before April 2019, and two authors independently extracted data of C-reactive protein (CRP), high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6) for conducting network meta-analysis. Eighteen eligible RCTs with 962 patients undergoing dialysis were included in our study. The result showed that with placebo as the reference, PUFAs was the only treatment showing significantly lower CRP (weighted mean difference (WMD): −0.37, 95% confidence interval (CI): −0.07 to −0.68), but the CRP in PUFAs group was not significantly lower than vitamin E, PUFAs plus vitamin E, or medium-chain triglyceride. Although no significant changes were noted for hs-CRP and IL-6 levels, PUFAs showed the best ranking among treatments according to surface under the cumulative ranking. Therefore, PUFAs could be a protective option for patients receiving dialysis in clinical practice.

Assessing the effect of omega-3 fatty acid combined with vitamin D3 versus vitamin D3 alone on estradiol levels: a randomized, placebo-controlled trial in females with vitamin D deficiency

Purpose

Outcomes investigating the effect of vitamin D3 (VD3) and omega-3 fatty acids (Omega-3FA) on serum estradiol (E2) are scarce and conflicting. No previous study has investigated the effect of VD3 combination with Omega-3FA on E2 levels. This study was designed to investigate the effect of VD3, Omega-3FA and VD3 plus Omega-3FA on serum E2 levels in premenopausal females diagnosed with vitamin D deficiency (VDD).

Subjects and methods

This randomized, placebo-controlled clinical trial was designed to evaluate the effects of 50,000 IU VD3 taken weekly, 300 mg Omega-3FA taken daily and their combination by the study participants for 8 weeks. The mid-follicular serum levels of E2 and 25-hydroxy vitamin D (25OHD) were assessed at 8 weeks. The study was conducted during winter on a convenience sample of healthy premenopausal Jordanian females with diagnosed VDD. Fasting serum levels for 25OHD and E2 were assessed at baseline and the end of the trial (after 8 weeks). Data were entered into SPSS and analyzed.

Results

Healthy premenopausal Jordanian females (N=86) with diagnosed VDD, mean age 32.8±8.9 years, were recruited into the study. Supplementation of VD3 alone resulted in a significant increase in serum 25OHD (13.4±7.9–28.2±7.1 ng/mL, P<0.001) and a significant decrease in E2 levels (85.7±16.5–60.3±20.6 pg/mL, P=0.001). Omega-3FA intake led to a significant decrease in serum 25OHD levels (21.2±12.8–13.6±9.2 ng/mL, P=0.001) and a significant increase in E2 levels (56.3±19.2–78.4±23.7 pg/mL, P=0.006). Combination therapy (VD3 plus Omega-3FA) resulted in a significant increase in both 25OHD (12.0±4.7–35.1±9.5 ng/mL, P<0.001) and E2 (43.0±23.4–57.3±31.5 pg/mL, P=0.028) levels.

Conclusion

Results of this study provide vital insight into the effects of D3, Omega-3FA and a combination of their supplementation on premenopausal Jordanian females with diagnosed VDD. Eight weeks of therapy led to decreased E2 level by VD3 and increased level by Omega-3FA supplementation. With regard to 25OHD, its level was increased by VD3 and decreased by Omega-3FA supplementation. Combination of VD3 plus Omega-3FA increased the levels of both E2 and 25OHD.

Trial registration

This trial was registered at clinicaltrials.gov as NCT03333564.

Blood Fatty Acid Status and Clinical Outcomes in Dialysis Patients: A Systematic Review

Blood fatty acids (FAs) are derived from endogenous and dietary routes. Metabolic abnormalities from kidney dysfunction, as well as cross-cultural dietary habits, may alter the FA profile of dialysis patients (DP), leading to detrimental clinical outcomes. Therefore, we aimed to (i) summarize FA status of DP from different countries, (ii) compare blood FA composition between healthy controls and DP, and (iii) evaluate FA profile and clinical endpoints in DP. Fifty-three articles from 1980 onwards, reporting FA profile in hemodialysis and peritoneal DP, were identified from PubMed, Embase, and the Cochrane library. Studies on pediatric, predialysis chronic kidney disease, acute kidney injury, and transplant patients were excluded. Moderate to high levels of n-3 polyunsaturated fatty acids (PUFA) were reported in Japan, Korea, Denmark, and Sweden. Compared to healthy adults, DP had lower proportions of n-3 and n-6 PUFA, but higher proportion of monounsaturated fatty acids. Two studies reported inverse associations between n-3 PUFAs and risks of sudden cardiac death, while one reported eicosapentaenoic acid + docosahexaenoic acid)/arachidonic acid ratio was inversely associated with cardiovascular events. The relationship between all-cause mortality and blood FA composition in DP remained inconclusive. The current evidence highlights a critical role for essential FA in nutritional management of DP.

Efficacy of Nutritional Interventions on Inflammatory Markers in Haemodialysis Patients: A Systematic Review and Limited Meta-Analysis

Low-grade chronic inflammation is prevalent in patients undergoing haemodialysis (HD) treatment and is linked to the development of premature atherosclerosis and mortality. The non-pharmacological approach to treat inflammation in HD patients through nutritional intervention is well cited. We aimed to assess the efficacy of different nutritional interventions at improving inflammatory outcomes in HD patients, based on markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α). We searched PubMed, Cochrane Library, and Embase for randomized controlled trials (RCT) published before June 2017. Inclusion criteria included RCTs on adult patients on maintenance HD treatment with duration of nutritional interventions for a minimum 4 weeks. Risk of bias was assessed using the Jadad score. In total, 46 RCTs experimenting different nutritional interventions were included in the review and categorized into polyphenols rich foods, omega-3 fatty acids, antioxidants, vitamin D, fibres, and probiotics. Meta-analyses indicated significant reduction in CRP levels by omega-3 fatty acids (Random model effect: -0.667 mg/L, p < 0.001) and vitamin E (fixed model effect: -0.257 mg/L, p = 0.005). Evidence for other groups of nutritional interventions was inconclusive. In conclusion, our meta-analysis provided evidence that omega-3 fatty acids and vitamin E could improve inflammatory outcomes in HD patients.

The polyunsaturated fatty acid balance in kidney health and disease: A review

Epidemiological studies show that circulating polyunsaturated fatty acids contribute to preserve renal function. In renal disease states there is generally a lack of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) as measured in biological samples, but despite intense research for more than 30 years, it is still unclear how and to what extent their supplementation would benefit kidney disorders. Studies evaluating the n-6 series and the kidney are less frequent. The last compilation of clinical trials with n-3 LCPUFA supplements focusing on renal function and damage dates back to 2012. We here discuss n-3 and n-6 fatty acids in relation to the kidney summarizing single- and double blind randomized controlled trials performed between 2012 and 2016. Nine were sub-studies/post-hoc analyses of previous parent trials. Twelve out of the twenty trials reported on fatty acid profile or fatty acid species. Factors that may explain inconsistent results obtained after supplementation with the n-3 LCPUFA EPA and DHA in kidney disease are discussed such as baseline levels determining response, drug interaction. The need of evaluating fatty acid status before and after intervention is emphasized, to match changes in outcome measure with changes of any fatty acid potentially involved.

The effects of vitamin D and omega-3 fatty acid co-supplementation on glycemic control and lipid concentrations in patients with gestational diabetes

OBJECTIVE

This study was performed to evaluate the effects of vitamin D and omega-3 fatty acids co-supplementation on glucose metabolism and lipid concentrations in gestational diabetes (GDM) patients.

METHODS

This randomized double-blind placebo-controlled clinical trial was done among 140 GDM patients. Participants were randomly divided into 4 groups to receive: (1) 1000 mg omega-3 fatty acids containing 360 mg eicosapentaenoic acid and 240 mg docosahexaenoic acid (DHA) twice a day + vitamin D placebo (n = 35); (2) 50,000 IU vitamin D every 2 weeks + omega-3 fatty acids placebo (n = 35); (3) 50,000 IU vitamin D every 2 weeks + 1000 mg omega-3 fatty acids twice a day (n = 35), and (4) vitamin D placebo + omega-3 fatty acids placebo (n = 35) for 6 weeks.

RESULTS

After 6 weeks of intervention, patients who received combined vitamin D and omega-3 fatty acids supplements compared with vitamin D, omega-3 fatty acids, and placebo had significantly decreased fasting plasma glucose (-7.3 ± 7.8, -6.9 ± 6.6, -4.0 ± 2.5, and +1.0 ± 11.4 mg/dL, respectively, P < .001), serum insulin levels (-1.9 ± 1.9, -1.3 ± 6.3, -0.4 ± 6.3, and +2.6 ± 6.5 μIU/mL, respectively, P = .005), homeostatic model of assessment for insulin resistance (-0.7 ± 0.6, -0.5 ± 1.4, -0.2 ± 1.5, and +0.6 ± 1.5, respectively, P < .001) and increased quantitative insulin sensitivity check index (+0.01 ± 0.01, +0.008 ± 0.02, +0.002 ± 0.02, and -0.005 ± 0.02, respectively, P = .001). In addition, changes in serum triglycerides (-8.2 ± 41.0, +7.6 ± 31.5, +3.6 ± 29.9, and +20.1 ± 29.6 mg/dL, respectively, P = .006) and very low-density lipoprotein cholesterol (-1.6 ± 8.2, +1.5 ± 6.3, +0.8 ± 6.0, and +4.0 ± 5.9 mg/dL, respectively, P = .006) in the vitamin D plus omega-3 fatty acids group were significantly different from the changes in these indicators in the vitamin D, omega-3 fatty acids, and placebo groups.

CONCLUSION

Overall, vitamin D and omega-3 fatty acids co-supplementation for 6 weeks among GDM patients had beneficial effects on fasting plasma glucose, serum insulin levels, homeostatic model of assessment for insulin resistance, quantitative insulin sensitivity check index, serum triglycerides, and very low-density lipoprotein cholesterol levels.

Effect of omega-3 fatty acid supplementation on serum lipids and vascular inflammation in patients with end-stage renal disease: a meta-analysis

Omega-3 fatty acids (O3FAs) are associated with lower cardiovascular disease (CVD) risk in adults. However, this association in patients with end-stage renal disease (ESRD) remains controversial prompting the need for investigation into the role of O3FAs on serum lipids and vascular inflammation markers. The present meta-analysis summarized the effects of O3FA supplementation on serum lipids and vascular inflammatory markers in patients with ESRD. PubMed, EmBase, and the Cochrane Library were searched to identify randomized controlled trials (RCTs) focused on serum lipids and vascular inflammation markers in patients with ESRD. Standard mean differences (SMD) were used to measure the effect of O3FA supplementation on serum lipids and vascular inflammatory markers. The final pooled analysis included 20 RCTs involving 1,461 patients with ESRD. The results indicated that O3FA supplementation reduced TG by 0.61, LDL by 0.35 and CRP by 0.56. However, O3FA had no significant effect on TC, HDL, albumin, hemoglobin, homocysteine, DBP, glucose, lipoprotein(a), and ferritin. O3FA supplementation is associated with lower several serum lipids and vascular inflammation markers in patients with ESRD.