Nutrition and chronic inflammatory rheumatic disease

Assessment of causal relationships between omega-3 and omega-6 polyunsaturated fatty acids in autoimmune rheumatic diseases: a brief research report from a Mendelian randomization study

Background

Currently, the association between the consumption of polyunsaturated fatty acids (PUFAs) and the susceptibility to autoimmune rheumatic diseases (ARDs) remains conflict and lacks substantial evidence in various clinical studies. To address this issue, we employed Mendelian randomization (MR) to establish causal links between six types of PUFAs and their connection to the risk of ARDs.

Methods

We retrieved summary-level data on six types of PUFAs, and five different types of ARDs from publicly accessible GWAS statistics. Causal relationships were determined using a two-sample MR analysis, with the IVW approach serving as the primary analysis method. To ensure the reliability of our research findings, we used four complementary approaches and conducted multivariable MR analysis (MVMR). Additionally, we investigated reverse causality through a reverse MR analysis.

Results

Our results indicate that a heightened genetic predisposition for elevated levels of EPA (ORIVW: 0.924, 95% CI: 0.666-1.283, P IVW = 0.025) was linked to a decreased susceptibility to psoriatic arthritis (PsA). Importantly, the genetically predicted higher levels of EPA remain significantly associated with an reduced risk of PsA, even after adjusting for multiple testing using the FDR method (P IVW-FDR-corrected = 0.033) and multivariable MR analysis (P MV-IVW < 0.05), indicating that EPA may be considered as the risk-protecting PUFAs for PsA. Additionally, high levels of LA showed a positive causal relationship with a higher risk of PsA (ORIVW: 1.248, 95% CI: 1.013-1.538, P IVW = 0.037). It is interesting to note, however, that the effects of these associations were weakened in our MVMR analyses, which incorporated adjustment for lipid profiles (P MV-IVW > 0.05) and multiple testing using the FDR method (P IVW-FDR-corrected = 0.062). Moreover, effects of total omega-3 PUFAs, DHA, EPA, and LA on PsA, were massively driven by SNP effects in the FADS gene region. Furthermore, no causal association was identified between the concentrations of other circulating PUFAs and the risk of other ARDs. Further analysis revealed no significant horizontal pleiotropy and heterogeneity or reverse causality.

Conclusion

Our comprehensive MR analysis indicated that EPA is a key omega-3 PUFA that may protect against PsA but not other ARDs. The FADS2 gene appears to play a central role in mediating the effects of omega-3 PUFAs on PsA risk. These findings suggest that EPA supplementation may be a promising strategy for preventing PsA onset. Further well-powered epidemiological studies and clinical trials are warranted to explore the potential mechanisms underlying the protective effects of EPA in PsA.

Diets and Joint Symptoms: A Survey of Moroccan Patients With Chronic Inflammatory Rheumatic Disease

Introduction The role of diet in the onset or aggravation of chronic diseases, especially chronic inflammatory rheumatic disease (CIRD), such as rheumatoid arthritis (RA) or spondyloarthritis (SpA), is a question frequently asked by patients. Our study aims to investigate whether Moroccan patients report a relationship between certain diets and disease symptoms and to study whether patients adopt specific dietary behaviours in order to relieve their symptoms. Methods This is a cross-sectional survey that included all patients followed for CIRD. The questionnaire has three parts, patients' sociodemographic and clinical data, patients' beliefs and attitudes regarding diet in relation to their joint symptoms, and a list of 24 foods for which patients were asked to indicate whether they aggravate, improve, or leave their joint symptoms unchanged. Results Thirty-four percent of the patients reported that the food had an effect on their symptoms, with 25% of them reporting an aggravation. Honey, garlic, and olive oil were the foods most often reported to improve joint symptoms, while red meat, fish, and legumes were most often reported to worsen symptoms. Age and type of rheumatism were factors associated with reporting that food affects joint symptoms. Twenty-three percent of the patients stated that they had already had discussions about diet with their rheumatologists, while 85.7% showed interest in such discussions. Experience with a food that improves joint symptoms was the only factor associated with discussing the diet with a rheumatologist. Conclusion Nearly one-third of the patients with CIRD reported an effect of diet on their joint symptoms.

Serum Fatty Acid Profiles Are Associated with Disease Activity in Early Rheumatoid Arthritis: Results from the ESPOIR Cohort

Background: Long-chain omega-3 and omega-6 fatty acids (n-3, n-6 FAs) may modulate inflammation and affect the risk of developing rheumatoid arthritis (RA). However, whether n-3/n-6 FA status affects RA after disease onset is unknown. This study aimed to assess whether FA profiles are independently associated with disease activity in a large prospective cohort of patients with early RA. Methods: Baseline serum FAs were quantified in 669 patients in the ESPOIR cohort. Principal component analysis identified three serum FA patterns that were rich in n-7–9, n-3 and n-6 FAs (patterns ω7–9, ω3 and ω6), respectively. The association of pattern tertiles with baseline variables and 6-month disease activity was tested using multivariable logistic regression. Results: Pattern ω3 was associated with low baseline and pattern ω6 with high baseline C-reactive protein level and disease activity. Both patterns ω3 and ω6 were associated with reduced odds of active disease after 6 months of follow-up (pattern ω3: odds ratio, tertile three vs. one, 0.49 [95% CI 0.25 to 0.97] and pattern ω6: 0.51 [0.28 to 0.95]; p = 0.04 and 0.03, respectively). Conclusions: In a cohort of early RA patients, a serum lipid profile rich in n-3 FAs was independently associated with persistently reduced disease activity between baseline and 6-month follow-up. An n-6 FA profile was also associated with lower 6-month disease activity.

Mendelian randomization study on the causal effects of omega-3 fatty acids on rheumatoid arthritis

OBJECTIVES

To resolve the ongoing debate on the role of plasma omega-3 fatty acids in rheumatoid arthritis (RA), we attempted to identify the association between omega-3 intake and the risk of RA.

METHODS

We analyzed data from the largest genome-wide association study (GWAS) for omega-3 fatty acids (N = 114,999 of European ancestry) and RA (14,361 cases and 43,923 controls of European ancestry). Mendelian randomization-egger_intercept, MR-PRESSO, and Cochran's Q test were used to determine pleiotropy and heterogeneity. Egger, weighted median, inverse variance weighted (IVW), simple mode, and weighted mode were used to evaluate the causal association of plasma omega-3 levels on RA.

RESULTS

We found no significant pleiotropy, heterogeneity, and bias among the omega-3 genetic instrumental variables (IVs) in RA GWAS datasets. MR analysis demonstrated that as omega-3 levels genetically increased, the risk of MS increased using MR-egger (Beta = 0.137, p = 0.037; OR = 1.146, 95% CI: [1.014, 1.296]), weighted median (Beta = 0.162, p = 0.001; OR = 1.176, 95% CI: [1.070, 1.292]), IVW (Beta = 0.102, p = 0.025; OR = 1.108, 95% CI: [1.013, 1.211]), simple mode (Beta = 0.219, p = 0.149; OR = 1.245, 95% CI: [0.931, 1.665]), and weighted mode (Beta = 0.146, p = 0.006; OR = 1.157, 95% CI: [1.051, 1.274]).

CONCLUSIONS

Our analysis suggested a causal association between genetically increased plasma omega-3 levels and the increased risk of RA in populations with European ancestry. Thus, to reduce the risk of RA, those of European descent should reduce omega-3 intake. Key Points • No significant pleiotropy or heterogeneity among the omega-3 genetic IVs in RA GWAS datasets. • Genetically increased plasma omega-3 levels enhanced the risk of RA in European lineages.

Dietary Recommendations of the French Society for Rheumatology for Patients with Chronic Inflammatory Rheumatic Diseases

This article presents the 1^st set of dietary recommendations of the French Society for Rheumatology for patients suffering from chronic inflammatory rheumatic diseases (IRD) made by a working group consisting of 12 rheumatology experts, 3 physician nutrition specialists, 1 internal medicine specialist, 1 registered dietician and 3 representatives from patient associations. This group relied on a systematic literature review and on expert opinions, while taking into consideration not only the joint effects of diet in IRD but also the extra-articular ones. Eight general principles and nine recommendations were established. The general principles emphasize that nutritional advice is not a substitute for pharmacological treatment of IRD and that it is an integral part of the patients' overall care, which could help the patient actively participate in their care. The recommendations propose supporting weight loss in subjects who are overweight or obese, a Mediterranean-type diet and supplementation in polyunsaturated fatty acids, mainly omega-3. Conversely, gluten-free diets (in the absence of celiac disease), vegetarian/vegan diets, fasting and elimination of dairy products should not be proposed. Supplementation with vitamins or trace elements is not indicated for controlling chronic IRD activity, while the use of probiotics or spices is not recommended given the limited or disparate data.

Dietary interventions with or without omega-3 supplementation for the management of rheumatoid arthritis: a systematic review protocol

Background: Rheumatoid arthritis (RA) is an autoimmune disease characterised by swollen and painful joints. It is hypothesised that changes in lifestyle factors such as consuming a healthier diet may  reduce the severity of RA symptoms. People living with RA commonly make alterations to their dietary intake with the hope of improving their symptoms. This systematic review aims to discuss the effects of dietary interventions with and without omega-3 supplementation for the management of rheumatoid arthritis. Methods: A systematic review of randomised controlled trials (RCTs) and non-randomised controlled trials (NRCTs) will be conducted. MEDLINE, EMBASE, The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Methodology Register) and CINAHL will be searched from inception without using date restrictions. Primary outcomes will include measures of disease activity, inflammation and quality of life among adults living with RA. Study selection will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the methodological appraisal of the studies will be assessed independently by two different reviewers (TR and AG) using the Cochrane Risk-of-Bias Tool for RCTs, and Risk-of-Bias In Non-Randomised Studies Tool for NRCTs. Ethics and dissemination: Ethical approval is not required for this systematic review. Only publically available data from previously published studies will be used. The findings of this systematic review will be submitted for publication in a peer-reviewed journal and presented at relevant conferences. PROSPERO registration: CRD42020147415 (11/02/2020).

Management of inflammatory rheumatic conditions in the elderly

The number of elderly people with chronic inflammatory rheumatic diseases is increasing. This heterogeneous and comorbid population is at particular risk of cardiovascular, neoplastic, infectious and iatrogenic complications. The development of biotherapies has paved the way for innovative therapeutic strategies, which are associated with toxicities. In this review, we have focused on the scientific and therapeutic changes impacting the management of elderly patients affected by RA, SpA or PsA. A multidimensional health assessment resulting in an integrated therapeutic strategy was identified as a major research direction for improving the management of elderly patients.

Association Between Mediterranean Anti-inflammatory Dietary Profile and Severity of Psoriasis: Results From the NutriNet-Santé Cohort

Importance

Psoriasis is a chronic inflammatory disease. The Mediterranean diet has been shown to reduce chronic inflammation and has a positive effect on the risk of metabolic syndrome and cardiovascular events. Thus, we hypothesized a positive effect on the onset and/or severity of psoriasis.

Objective

To assess the association between a score that reflects the adhesion to a Mediterranean diet (MEDI-LITE) and the onset and/or severity of psoriasis.

Design, Setting, and Participants

The NutriNet-Santé program is an ongoing, observational, web-based questionnaire cohort study launched in France in May 2009. The present study was performed within the framework of the NutriNet-Santé program, with data collected and analyzed between April 2017 and June 2017. Patients with psoriasis were identified via a validated online self-completed questionnaire and then categorized by disease severity: severe psoriasis, nonsevere psoriasis, and psoriasis-free. Data on dietary intake (including alcohol) were gathered during the first 2 years of participation in the cohort to calculate the MEDI-LITE score (ranging from 0 for no adherence to 18 for maximum adherence). Potentially confounding variables (eg, age, sex, physical activity, body mass index, tobacco use, and a history of cardiovascular disease) were also recorded. Analyses used adjusted multinomial logistic regression to estimate the risk of having severe psoriasis or nonsevere psoriasis compared with being psoriasis-free.

Results

Of the 158 361 total NutriNet-Santé participants, 35 735 (23%) replied to the psoriasis questionnaire. The mean (SD) age of the respondents was 47.5 (14.0) years; 27 220 (76%) of the respondents were women. Of these 35 735 respondents, 3557 (10%) individuals reported having psoriasis. The condition was severe in 878 cases (24.7%), and 299 (8.4%) incident cases were recorded (those arising more than 2 years after participant inclusion in the cohort). After adjustment for confounding factors, a significant inverse relationship was found between the MEDI-LITE score and having severe psoriasis: odds ratio (OR), 0.71; 95% CI, 0.55-0.92 for the MEDI-LITE score's second tertile (score of 8 to 9); and OR, 0.78; 95% CI, 0.59-1.01 for the third tertile (score of 10 to 18).

Conclusions and Relevance

Patients with severe psoriasis displayed low levels of adherence to the Mediterranean diet; this finding supports the hypothesis that the Mediterranean diet may slow the progression of psoriasis. If these findings are confirmed, adherence to a Mediterranean diet should be integrated into the routine management of moderate to severe psoriasis.

Remote Sensing between Liver and Intestine: Importance of Microbial Metabolites

Recent technological advancements including metagenomics sequencing and metabolomics have allowed the discovery of critical functions of gut microbiota in obesity, malnutrition, neurological disorders, asthma, and xenobiotic metabolism. Classification of the human gut microbiome into distinct "enterotypes" has been proposed to serve as a new paradigm for understanding the interplay between microbial variation and human disease phenotypes, as many organs are affected by gut microbiota modifications during the pathogenesis of diseases. Gut microbiota remotely interacts with liver and other metabolic organs of the host through various microbial metabolites that are absorbed into the systemic circulation.

PURPOSE OF REVIEW

The present review summarizes recent literature regarding the importance of gut microbiota in modulating the physiological and pathological responses of various host organs, and describes the functions of the known microbial metabolites that are involved in this remote sensing process, with a primary focus on the gut microbiota-liver axis.

RECENT FINDINGS

Under physiological conditions, gut microbiota modulates the hepatic transcriptome, proteome, and metabolome, most notably down-regulating cytochrome P450 3a mediated xenobiotic metabolism. Gut microbiome also modulates the rhythmicity in liver gene expression, likely through microbial metabolites, such as butyrate and propionate that serve as epigenetic modifiers. Additionally, the production of host hormones such as primary bile acids and glucagon like peptide 1 is altered by gut microbiota to modify intermediary metabolism of the host.

SUMMARY

Dysregulation of gut microbiota is implicated in various liver diseases such as alcoholic liver disease, non-alcoholic steatohepatitis, liver cirrhosis, cholangitis, and liver cancer. Gut microbiota modifiers such as probiotics and prebiotics are increasingly recognized as novel therapeutic modalities for liver and other types of human diseases.