Dietary patterns and risk of systemic lupus erythematosus in women

The role of the intestinal microbiome in antiphospholipid syndrome

The antiphospholipid syndrome (APS) is a thrombotic autoimmune disease in which the origin of the disease-characterizing autoantibodies is unknown. Increased research effort into the role of the intestinal microbiome in autoimmunity has produced new insights in this field. This scoping review focusses on the gut microbiome in its relation to APS. EMBASE and MEDLINE were searched for original studies with relevance to the relation between the gut microbiome and APS. Thirty studies were included. Work on systemic lupus erythematosus, which strongly overlaps with APS, has shown that patients often display an altered gut microbiome composition, that the disease is transferable with the microbiome, and that microbiome manipulation affects disease activity in murine lupus models. The latter has also been shown for APS, although data on microbiome composition is less consistent. APS patients do display an altered intestinal IgA response. Evidence has accrued for molecular mimicry as an explanatory mechanism for these observations in APS and other autoimmune diseases. Specific gut microbes express proteins with homology to immunodominant APS autoantigens. The disease phenotype appears to be dependent on these mimicking proteins in an APS mouse model, and human APS B- and T-cells indeed cross-react with these mimics. Pre-clinical evidence furthermore suggests that diet may influence autoimmunity through the microbiome, as may microbial short chain fatty acid production, though this has not been studied in APS. Lastly, the microbiome has been shown to affect key drivers of thrombosis, and may thus affect APS severity through non-immunological mechanisms. Overall, these observations demonstrate the impact of the intestinal microbiome on autoimmunity and the importance of understanding its role in APS.

Systemic Lupus Erythematosus Risk: The Role of Environmental Factors

Systemic lupus erythematosus (SLE) is a complex, chronic autoimmune disease. The etiology of SLE is multifactorial and includes potential environmental triggers, which may occur sequentially (the "multi-hit" hypothesis). This review focuses on SLE risk potentially associated with environmental factors including infections, the microbiome, diet, respirable exposures (eg, crystalline silica, smoking, air pollution), organic pollutants, heavy metals, and ultraviolet radiation.

The association between dietary patterns and a doctor diagnosis of systemic lupus erythematosus: the Adventist Health Study-2

OBJECTIVE

The aim of our study was to assess the association between a diagnosis of Systemic Lupus Erythematosus (SLE) and dietary pattern as well as demographic factors among subjects in the Adventist Health Study-2 (AHS-2) cohort.

METHODS

Multivariable logistic regression modeling was used to assess the association between prevalence of self-reported SLE and dietary patterns (vegetarian, pesco-vegetarian and non-vegetarian). Potential confounding variables included were age, gender, race, education, and smoking history among 77,795 AHS-2 participants.

RESULTS

There was a dose-response association between the prevalence of SLE with vegetarian diets, ordered by content of animal meats. The stricter vegetarians had 25% lower odds of reporting that they were currently being treated for SLE (OR = 0.75, 95% CI 0.56, 1.02) with intermediate levels for the pesco-vegetarians who eat fish (OR 0.88, 95% CI 0.57, 1.36), compared to non-vegetarians. As expected, there were also significant associations between the prevalence of SLE with sex, race, age, and smoking. Significantly fewer men were diagnosed with SLE compared to women (OR = 0.14, 95% CI: 0.08, 0.22). Compared to non-Hispanic Whites, non-Hispanic Blacks were significantly more likely to report a diagnosis of SLE (OR 1.69, 95% CI 1.29, 2.21). A significantly lower proportion of 30-39 year olds (OR 0.51, 95% CI 0.29, 0.90) reported a diagnosis of SLE when compared to those 60 or older. Also, ever smokers were more likely to report prevalent SLE than those who had never smoked (OR 1.71, 95% CI 1.27, 2.31).

CONCLUSION

We found that vegetarians had lower odds of doctor-diagnosed SLE with an increasing trend in prevalence from stricter vegetarians to pesco-vegetarians to non-vegetarians. We also note that the association with other demographic factors in AHS-2 was similar to that found in other studies. Future studies may focus on assessing the incidence and severity of the disease among vegetarians and non-vegetarians.

Understanding the Concept of Pre-Clinical Autoimmunity: Prediction and Prevention of Systemic Lupus Erythematosus: Identifying Risk Factors and Developing Strategies Against Disease Development

There is growing evidence that preceding the diagnosis or classification of systemic lupus erythematosus (SLE), patients undergo a preclinical phase of disease where markers of inflammation and autoimmunity are already present. Not surprisingly then, even though SLE management has improved over the years, many patients will already have irreversible disease-related organ damage by time they have been diagnosed with SLE. By gaining a greater understanding of the pathogenesis of preclinical SLE, we can potentially identify patients earlier in the disease course who are at-risk of transitioning to full-blown SLE and implement preventative strategies. In this review, we discuss the current state of knowledge of SLE preclinical pathogenesis and propose a screening and preventative strategy that involves the use of promising biomarkers of early disease, modification of lifestyle and environmental risk factors, and initiation of preventative therapies, as examined in other autoimmune diseases such as rheumatoid arthritis and type 1 diabetes.

The role of environmental exposures and gene-environment interactions in the etiology of systemic lupus erythematous

Systemic lupus erythematosus (SLE) is a complex, chronic autoimmune disease, whose etiology includes both genetic and environmental factors. Individual genetic risk factors likely only account for about one-third of observed heritability among individuals with a family history of SLE. A large portion of the remaining risk may be attributable to environmental exposures and gene-environment interactions. This review focuses on SLE risk associated with environmental factors, ranging from chemical and physical environmental exposures to lifestyle behaviors, with the weight of evidence supporting positive associations between SLE and occupational exposure to crystalline silica, current smoking, and exogenous estrogens (e.g., oral contraceptives and postmenopausal hormones). Other risk factors may include lifestyle behaviors (e.g., dietary intake and sleep) and other exposures (e.g., ultraviolet [UV] radiation, air pollution, solvents, pesticides, vaccines and medications, and infections). Alcohol use may be associated with decreased SLE risk. We also describe the more limited body of knowledge on gene-environment interactions and SLE risk, including IL-10, ESR1, IL-33, ITGAM, and NAT2 and observed interactions with smoking, UV exposure, and alcohol. Understanding genetic and environmental risk factors for SLE, and how they may interact, can help to elucidate SLE pathogenesis and its clinical heterogeneity. Ultimately, this knowledge may facilitate the development of preventive interventions that address modifiable risk factors in susceptible individuals and vulnerable populations.

Association of a Combination of Healthy Lifestyle Behaviors With Reduced Risk of Incident Systemic Lupus Erythematosus

OBJECTIVE

While previous studies have demonstrated an association between individual factors related to lifestyle and the risk of systemic lupus erythematosus (SLE), it is unclear how the combination of these factors might affect the risk of incident SLE. This study was undertaken to prospectively evaluate whether a combination of healthy lifestyle factors is associated with a lower risk of incident SLE and its subtypes (anti-double-stranded DNA [anti-dsDNA]-positive and anti-dsDNA-negative SLE).

METHODS

The study included 185,962 women from the Nurses' Health Study (NHS) and NHSII cohorts, among whom there were 203 incident cases of SLE (96 with anti-dsDNA-positive SLE, 107 with anti-dsDNA-negative SLE) during 4,649,477 person-years of follow-up. The Healthy Lifestyle Index Score (HLIS) was calculated at baseline and approximately every 2 years during follow-up, with scores assigned for 5 healthy lifestyle factors: alcohol consumption, body mass index, smoking, diet, and exercise. A time-varying Cox proportional hazards regression model was used to estimate the adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) for the risk of SLE. In addition, the percentage of partial population attributable risk (PAR%) of SLE development was calculated.

RESULTS

A higher HLIS was associated with a lower risk of SLE overall (HR 0.81 [95% CI 0.71-0.94]) and a lower risk of anti-dsDNA-positive SLE (HR 0.78 [95% CI 0.63-0.95]). Women with ≥4 healthy lifestyle factors had the lowest risk of SLE overall (HR 0.42, 95% CI 0.25-0.70) and lowest risk of anti-dsDNA-positive SLE (HR 0.35, 95% CI 0.17-0.75) as compared to women with only 1 healthy behavior or no healthy behaviors. The PAR% of SLE development was 47.7% (95% CI 23.1-66.6%), assuming that the entire population had adhered to at least 4 healthy lifestyle behaviors.

CONCLUSION

These results indicate that the risk of developing SLE, a disease in which significant evidence of genetic involvement has been established, might be reduced by nearly 50% with adherence to modifiable healthy lifestyle behaviors.

Association of macronutrients and dietary patterns with risk of systemic lupus erythematosus in the Black Women's Health Study

BACKGROUND

Systemic lupus erythematosus (SLE) affects African-American (AA) women disproportionately. The few prospective studies assessing dietary intake in relation to risk of SLE have been conducted in predominantly white populations and have been null.

OBJECTIVES

The present study assessed associations of macronutrients and dietary patterns with risk of SLE in AA women.

METHODS

Data from the Black Women's Health Study was collected prospectively via biennial questionnaires starting in 1995. Participants completed a self-administered 68-item FFQ in 1995. Self-reported SLE was verified through medical record review. We used multivariable (MV) Cox regression models to estimate HRs and 95% CIs for macronutrients, carbohydrates, proteins, total fats, PUFAs, ω-3 fatty acids, ω-6 fatty acids, MUFAs, saturated fats, trans fatty acids, Alternative Healthy Eating Index score, vegetable/fruit and meat/fried food dietary patterns, and a reduced rank regression (RRR)-derived dietary pattern in relation to SLE risk.

RESULTS

We confirmed a total of 114 incident cases of SLE among 51,934 women during 1995-2015. MVHRs and 95% CIs for the highest quintile of intake versus the lowest were HR: 1.96, 95% CI: 1.02, 3.67 for carbohydrates; HR: 0.66, 95% CI: 0.37, 1.18 for protein; and HR: 0.54, 95% CI: 0.28, 1.01 for total fats. MUFAs, saturated fatty acids, and trans fatty acids were significantly associated with a lower risk of SLE. An RRR-derived factor, rich in fruits and sugar-sweetened drinks and low in margarines and butter, red and processed meats, fried chicken, poultry, and eggs, which explained 53.4% of the total variation of macronutrients, was the only food pattern associated with increased SLE risk (HR: 1.88, 95% CI: 1.06, 3.35).

CONCLUSION

These analyses suggest that a diet high in carbohydrates and low in fats is associated with increased SLE risk in AA women.

Association of Dietary Quality With Risk of Incident Systemic Lupus Erythematosus in the Nurses' Health Study and Nurses' Health Study II

OBJECTIVE

Knowledge remains scarce regarding diet and systemic lupus erythematosus (SLE) risk. Our objective was to investigate 4 dietary quality scores and SLE risk overall and by anti-double-stranded DNA (anti-dsDNA) positive versus negative subtypes.

METHODS

We studied 79,568 women in the Nurses' Health Study (1984-2014) and 93,554 in the Nurses' Health Study II (1991-2013). Using validated food frequency questionnaires, we calculated 4 dietary scores: the 2010 Alternative Healthy Eating Index (AHEI-2010), the Alternative Mediterranean Diet Score (aMed), the Dietary Approach to Stop Hypertension (DASH), and the Empirical Dietary Inflammatory Pattern (EDIP). Incident SLE was confirmed by medical record review. Time-varying Cox regression models estimated pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) of SLE risk, overall and by anti-dsDNA, for cumulative average dietary quality score tertiles and individual AHEI-2010 components.

RESULTS

We identified 194 incident SLE cases. SLE risk was similar in women with the highest (versus lowest) dietary scores (AHEI-2010 HR 0.78 [95% CI 0.54-1.14], aMed HR 0.82 [95% CI 0.56-1.18], DASH HR 1.16 [95% CI 0.81-1.66], EDIP HR 0.83 [95% CI 0.57-1.21]). No association was demonstrated for anti-dsDNA+ or anti-dsDNA- SLE risk. Women in the highest (versus lowest) AHEI-2010 tertile of nut/legume intake had a decreased SLE risk (HR 0.59 [95% CI 0.40-0.87]). No association was demonstrated for other AHEI-2010 components and SLE risk.

CONCLUSION

We observed no association between long-term adherence to the AHEI-2010, aMed, DASH, or EDIP scores with SLE risk, suggesting a large effect of dietary quality on SLE risk is unlikely. However, potential reduction in overall SLE risk with high nut/legume intake warrants further investigation.

Dietary patterns and risk of developing knee osteoarthritis: data from the osteoarthritis initiative

OBJECTIVE

Some studies have examined the association between dietary factors and risk of knee osteoarthritis (OA). We aimed to examine the prospective association of major dietary patterns with the risk of developing knee OA.

METHOD

We followed 2,842 participants in Osteoarthritis Initiative (OAI) aged 45-79 years and with at least one knee free from radiographic knee OA at baseline for up to 72 months. We defined knee OA incidence as Kellgren and Lawrence grade ≥2 during follow-up visits. Using principal component analysis, Western and prudent dietary patterns were derived. Cox proportional hazards models were used to assess the association between dietary patterns and incident knee OA.

RESULTS

Among study participants, 385 (418 knees) developed knee OA within 72 months. Following a Western dietary pattern was associated with an increased risk of knee OA (HR _{quartile 4 vs 1} = 1.69, 95% CI: 1.13 to 2.52, p trend: 0.03), while adherence to the prudent pattern was associated with a reduced risk of knee OA (HR _{quartile 4 vs 1} = 0.70, 95% CI: 0.50 to 0.98, p trend: 0.05). The observed associations attenuated after additionally adjusting for body mass index (BMI). The observed associations were mediated through BMI by approximately 30%.

CONCLUSION

Following a Western diet was associated with increased risk of knee OA, whereas following a prudent pattern was associated with a reduced risk of knee OA. The associations were partially mediated through BMI.

Diet in Rheumatoid Arthritis versus Systemic Lupus Erythematosus: Any Differences?

In recent years, an increasing interest in the influence of diet in rheumatic and musculoskeletal diseases (RMDs) led to the publication of several articles exploring the role of food/nutrients in both the risk of developing these conditions in normal subjects and the natural history of the disease in patients with established RMDs. Diet may be a possible facilitator of RMDs due to both the direct pro-inflammatory properties of some nutrients and the indirect action on insulin resistance, obesity and associated co-morbidities. A consistent body of research has been conducted in rheumatoid arthritis (RA), while studies in systemic lupus erythematosus (SLE) are scarce and have been conducted mainly on experimental models of the disease. This review article aims to outline similarities and differences between RA and SLE based on the existing literature.