Coffee and autoimmunity: More than a mere hot beverage!

Rheumatoid arthritis and thyroid dysfunction: A cross-sectional study and a review of the literature

Thyroid dysfunction appears to show increased prevalence in many autoimmune diseases; however, this comorbidity has not been properly investigated in patients with RA. This issue was addressed in this cross-sectional study. Using the database of the Clalit Health Services (CHS) in Israel, RA patients were paired with age- and sex-matched controls to compare the prevalence of hypothyroidism and hyperthyroidism. Chi-squared and t-tests were used for univariate analysis and a logistic regression model was used for multivariate analysis. The study included 11,782 patients with RA and 57,973 controls. The rate of thyroid dysfunction diseases in RA patients was increased compared with the prevalence in controls (16.0% and 11.7%, p < 0.001, for hypothyroidism; and 2.33% and 1.81%, p < 0.001 in hyperthyroidism, respectively). In a multivariate analysis, RA was associated with hypothyroidism (OR = 1.42, 95% CI 1.34-1.50) and hyperthyroidism (OR = 1.26, 95% CI 1.10-1.45). RA is associated with thyroid dysfunction. Therefore, physicians treating patients with RA should be aware of the possibility of comorbid thyroid dysfunction and treat accordingly.

Environmental (Lifestyle) Risk Factors for LADA

BACKGROUND

In order to prevent diabetes it is important to identify common, modifiable risk factors in the population. Such knowledge is extensive for type 2 diabetes but limited for autoimmune forms of diabetes.

OBJECTIVE

This review aims at summarizing the limited literature on potential environmental (lifestyle) risk factors for LADA.

METHODS

A PubMed search identified 15 papers estimating the risk of LADA in relation to lifestyle. These were based on data from two population-based studies; one Swedish case-control study and one Norwegian cohort study.

RESULTS

Studies published to date indicate that the risk of LADA is associated with factors promoting insulin resistance and type 2 diabetes such as overweight, physical inactivity, smoking, low birth weight, sweetened beverage intake and moderate alcohol consumption (protective). Findings also indicate potential effects on autoimmunity exerted by intake of coffee (harmful) and fatty fish (protective). This supports the concept of LADA as being a hybrid form of diabetes with an etiology including factors associated with both insulin resistance and autoimmunity.

CONCLUSION

LADA may in part be preventable through the same lifestyle modifications as type 2 diabetes including weight loss, physical activity and smoking cessation. However, current knowledge is hampered by the small number of studies and the fact that they exclusively are based on Scandinavian populations. There is a great need for additional studies exploring the role of lifestyle factors in the development of LADA.

DNA Damage Response Signals Transduce Stress From Rheumatoid Arthritis Risk Factors Into T Cell Dysfunction

Rheumatoid arthritis (RA) is an autoimmune-mediated disease that is associated with significant cartilage damage and immunosenescence. Despite decades of research, the major signal pathways that initiate RA are still unclear. The DNA damage response (DDR) is a specific and hierarchical network that includes cell cycle checkpoints, DNA repair, and DNA-damage tolerance pathways. Recent studies suggest that this condition is associated with deficits in telomere maintenance and overall genomic instability in the T cells of RA patients. Analysis of the underlying mechanisms has revealed defects in DDR pathways. Particularly, the DNA repair enzyme, ataxia telangiectasia mutated (ATM), is downregulated, which leaves the damaged DNA breaks in RA-associated T cells unrepaired and pushes them to apoptosis, exhausts the T cell pool, and promotes the arthritogenesis effector function of T cells. This review discusses recent advancements and illustrates that risk factors for RA, such as viral infections, environmental events, and genetic risk loci are combat with DDR signals, and the impaired DDR response of RA-associated T cells, in turn, triggers disease-related phenotypes. Therefore, DDR is the dominant signal that converts genetic and environmental stress to RA-related immune dysfunction. Understanding the orchestration of RA pathogenesis by DDR signals would further our current knowledge of RA and provide novel avenues in RA therapy.

Psychological stress and type 1 diabetes mellitus: what is the link?

INTRODUCTION

Type 1 diabetes mellitus (T1DM) is a chronic disease characterized by the destruction of insulin-producing β-cells of the pancreas. The current paradigm in this disease's etiopathogenesis points toward the interplay of genetic and environmental factors. Among the environmental variables, dietary factors, intestinal microbiota, toxins, and psychological stress have been implicated in disease onset. Areas covered: This review aims to investigate the relationship between psychological stress and T1DM by presenting evidence from epidemiological studies, animal models, and to provide the mechanism involved in this association. The literature search was conducted through PubMed to identify studies that investigate the connection between stress and T1DM. Experimental designs, such as case-control, and retrospective and prospective cohorts studies, were included. Expert commentary: A wide array of evidence, ranging from epidemiological to animal models, points toward the role of psychological stressors in T1DM pathogenesis. Various mechanisms have been proposed, including the hypothalamic-pituitary-adrenal (HPA) axis, influence of the nervous system on immune cells, and insulin resistance. Further research could investigate the gene-stress interactions to evaluate the risk of T1DM development.

The role of dietary sodium in autoimmune diseases: The salty truth

Autoimmune diseases are a group of heterogeneous condition that occur secondary to the intrinsic loss of tolerance to self- antigens. In genetically susceptible individuals, the complex interplay of environmental factors and epigenetic deregulations have been proposed to drive disease etiopathogenesis. Various environmental variables have been identified including viral infections, exposure to pollutants, stress and dietary factors. Sodium, a major constituent of salt is essential for mammalian physiology. However, high salt intake may play a role in the development of autoimmune diseases. Several lines of evidence point toward the role of high sodium intake in reversing the suppressive effects of Regulatory T cells (Tregs) and instead promoting cellular shift toward T-helper (Th)-1 and Th17 pro-inflammatory phenotypes. These effects have been attributed to cascade of events that ultimately results in downstream activation of serum glucocorticoid kinase 1 (Sgk1). In vivo, various autoimmune animal models have confirmed the role of high sodium diet in the emergence and the exacerbation of autoimmune conditions including for instance Experimental Autoimmune Encephalomyelitis model for multiple sclerosis, MRL/lpr mouse model for lupus nephritis, collagen induced arthritis model for rheumatoid arthritis, and dextran sulfate sodium induced colitis, and TNBS-induced colitis models for Crohn's disease. Clinical epidemiological studies are scarce. High sodium intake was associated with increased risk of rheumatoid arthritis disease emergence. In multiple sclerosis, some studies suggest a relation to clinical exacerbation rates however other studies did not corroborate these results. Taken together, high dietary salt intake plays a role in the spectrum of autoimmune disease etiology. Further research is warranted to better characterize such relationship and assist in identifying individuals that would benefit from dietary salt restriction.

Coffee consumption and the risk of rheumatoid arthritis and systemic lupus erythematosus: a Mendelian randomization study

We aimed to analyze the causal association between coffee consumption and the risk of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We performed a two-sample Mendelian randomization (MR) analysis using the inverse-variance weighted (IVW), MR-Egger regression, and weighted median methods. We used publicly available summary statistics datasets of coffee consumption genome-wide association studies (GWASs) as an exposure variable and RA and SLE GWASs as outcomes. Four single-nucleotide polymorphisms (SNPs) from GWASs of coffee consumption were selected as instrumental variables (IVs) to improve inference: NCARD (rs16868941), POR (rs17685), CYP1A1 (rs2470893), and LAMB4 (rs382140). The IVW method showed a causal association between coffee consumption and RA (beta = 0.770, SE = 0.279, p = 0.006). MR-Egger regression revealed that directional pleiotropy was unlikely to be biasing the result (intercept = - 0.145, p = 0.451). While the MR-Egger analysis showed no causal association between coffee consumption and RA (beta = 2.744, SE = 1.712, p = 0.355), the weighted median approach demonstrated a causal association between coffee consumption and RA (beta = 0.751, SE = 0.348, p = 0.031). However, the associations based on the weighted median analyses after the Bonferroni correction were not significant (adjusted p values = 0.091). The IVW, MR-Egger analysis, and weighted median methods showed no causal association between coffee consumption and SLE risk (beta = 0.594, SE = 0.437, p = 0.209; beta = 3.100, SE = 3.632, p = 0.550; beta = 0.733, SE = 0.567, p = 0.196). MR analysis results do not support causal associations between coffee consumption and the development of RA and SLE.

The role of stress in the mosaic of autoimmunity: An overlooked association

Stress is defined as the pscyophysiological reaction in which the steady state is disturbed or threatened. Stress is not always perceived as a negative response. Stress results when environmental demands exceed an individuals' adaptive capacities. Autoimmune diseases are heterogeneous group of chronic diseases which occur secondary to loss of self antigen tolerance. The etiopathogenesis of autoimmune disease is uncertain. Genetic factors as well as environmental factors appear to interplay, leading to a cascade of events resulting in disease onset. Stress has been postulated to play a role in disease onset in the genetically susceptible patients. During the stress response, catecholamines and glucocorticoids are released from locus coeruleus and adrenal gland. These biomolecules exert control over various immune cells in the innate and adaptive arms of the immune system, thereby altering the cytokine profile released. The increase of IL-4 promotes T-helper 2 (T_h2) cell differentiation, while the decrease in IL-12 and the increased IL-10 production reduce the number of T-helper 1 (T_h1) cells. The relationship between stress and autoimmune diseases is intricate. Stress has been shown to be associated with disease onset, and disease exacerbations in rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, multiple sclerosis, Graves' disease as well as other autoimmune conditions. In certain conditions such as psoriasis, stress has been implicated in delaying lesion clearance upon the application of standard treatment regimes. Finally, psychological therapy and cognitive behavioral therapy aimed to reduce stress levels was shown to be effective in influencing better outcomes in many autoimmune diseases. The purpose of this paper is to closer inspect the clinical evidence regarding the role of stress on influencing the various aspects of disease entities.

The impact of dietary habits on the pathogenesis of rheumatoid arthritis: a case-control study

It has not been clear what kinds and how much nutrients could be harmful, preventive, or healthful for development of rheumatoid arthritis. This study aimed to determine the impact of dietary habits on the pathogenesis of rheumatoid arthritis. This case-control study was conducted on a total of 500 rheumatoid arthritis patients and 500 healthy controls refereed to three clinics of Shiraz University of Medical Sciences in 2015-2016. Convenience sampling was used for data collection in both case and control groups. An approved valid and reliable questionnaire including information about the intake of different kinds of beverages, and nutritious and non-nutritious diet was used. Data were analyzed by SPSS, version 20, using t test, chi-square and Multiple Logistic Regression model. The associations between rheumatoid arthritis development and variables including drinking 1-7 cups of coffee (OR = .44, CI .25-.76), ≥ 8 cups of coffee (OR = .50, CI .28-.90), full-fat milk (OR = 1.01, CI 1.003-1.03) per month, and intake of green tea (OR = .65, CI .45-.93) and solid oils (OR = 2.29, CI:1.57-3.34) were significant. Based on the findings, coffee consumption more than one cup per month and green tea might have preventive effects on developing rheumatoid arthritis. On the other hand, patients who consumed more full-fat milk per month and solid oil might be at risk of development of rheumatoid arthritis. Therefore, modification of diet based on these findings is suggested. Performing a cohort study to determine the causality effect of dietary habits and development and prevention of rheumatoid arthritis is recommended.

Coffee consumption, metabolic syndrome and clinical severity of psoriasis: good or bad stuff?

Despite the wide consumption of coffee, its anti-inflammatory effect on clinical severity of psoriasis is still debatable. The aim of this study was to evaluate the association between the coffee consumption and clinical severity of psoriasis in a sample of patients stratified according to the presence of the metabolic syndrome (MetS) and smoking. This cross-sectional case-control observational study was conducted on 221 treatment-naïve psoriatic patients. Lifestyle habits, anthropometric measures, clinical and biochemical evaluations were obtained. Clinical severity of psoriasis was assessed by Psoriasis Area and Severity Index (PASI) score. Data on energy caloric intake and coffee consumption were collected using a 7-day food diary record. The coffee consumption was analyzed as coffee intake (consumers and non-consumers) and daily servings (range 0-4 servings/day). Coffee consumers have a lower PASI score vs non-consumers (p < 0.001). The lowest PASI score and MetS prevalence were found in patients consuming 3 cups of coffee/day (p < 0.001), which was also the most common daily serving (34.8%), whereas the highest PASI score was found among those drinking ≥ 4 cups/day. Grouping the case patients according to smoking and MetS, the best odds of PASI score was observed in those drinking 3 cups of coffee per day and no smokers, after adjusting for total energy intake (OR 74.8; p < 0.001). As a novel finding, we reported a negative association between coffee intake, MetS prevalence and clinical severity of psoriasis. The evaluation of the anti-inflammatory effect of coffee on clinical severity of psoriasis, whose metabolic risk increases along with its clinical severity, could be of great importance from a public health perspective.

Physical activity and autoimmune diseases: Get moving and manage the disease

Physical activity, by definition, is any skeletal muscle body movement that results in energy expenditure. In the last few decades, a plethora of scientific evidences have accumulated and confirmed the beneficial role of physical activity as a modifiable risk factor for a wide variety of chronic diseases including cardiovascular diseases (CVDs), diabetes mellitus and cancer, among others. Autoimmune diseases are a heterogeneous group of chronic diseases, which occur secondary to loss of self-antigen tolerance. With the advent of biological therapies, better outcomes have recently been noted in the management of autoimmune diseases. Nonetheless, recent research highlights the salient role of modifiable behaviors such as physical inactivity on various aspects of the immune system and autoimmune diseases. Physical activity leads to a significant elevation in T-regulatory cells, decreased immunoglobulin secretion and produces a shift in the Th1/Th2 balance to a decreased Th1 cell production. Moreover, physical activity has been proven to promote the release of IL-6 from muscles. IL-6 released from muscles functions as a myokine and has been shown to induce an anti-inflammatory response through IL-10 secretion and IL-1β inhibition. Physical activity has been shown to be safe in most of autoimmune diseases including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), inflammatory bowel diseases (IBD), as well as others. Additionally, the incidence of RA, MS, IBD and psoriasis has been found to be higher in patients less engaged in physical activity. As a general trend, patients with autoimmune diseases tend to be less physically active as compared to the general population. Physically active RA patients were found to have a milder disease course, better cardiovascular disease (CVD) profile, and improved joint mobility. Physical activity decreases fatigue, enhances mood, cognitive abilities and mobility in patients with MS. In SLE patients, enhanced quality of life and better CVD profile were documented in more physically active patients. Physically active patients with type 1 diabetes mellitus have a decreased risk of autonomic neuropathy and CVD. Both fibromyalgia and systemic sclerosis patients report decreased disease severity, pain, as well as better quality of life with more physical activity. Further, SSc patients improve their grip strength, finger stretching and mouth opening with increased level of exercise. The purpose of this paper is to review the clinical evidence regarding the safety, barriers to engagement, and impact of physical activity on autoimmune diseases.