Association between dietary and metabolic factors and IgM antibodies to phosphorylcholine and malondialdehyde in patients with systemic lupus erythematosus and population-based matched controls.

OBJECTIVES: Immunoglobulin M (IgM) antibodies against phosphorylcholine (anti-PC) and malondialdehyde (anti-MDA) are implicated in systemic lupus erythematosus (SLE) as markers with potential protective properties. Low IgM anti-PC levels are more common in SLE than in control population. Little is known what influences the levels of these antibodies. We here studied associations between dietary and metabolic factors and levels of IgM anti-PC and anti-MDA. METHODS: This study included 109 SLE patients and 106 controls from SLE Vascular Investigation Cohort (SLEVIC). Data on dietary intake (food frequency questionnaires) and metabolic factors were linked with IgM anti-PC and anti-MDA (determined by enzyme-linked immunosorbent assay). Associations between the dietary, metabolic factors and antibodies were analysed with logistic regression. Antibody levels ≤1st tertile were defined as low level. RESULTS: Low IgM anti-PC and anti-MDA were associated with SLE (odds ratio (OR)=2.5 [95% confidence interval (CI) 1.4-4.4] and OR=1.7 [95% CI 1.0-3.1, respectively). Among SLE patients, overweight/obesity (body mass index >25), elevated high-density lipoprotein (>1.6 mmol/L) and dietary fibre intake (>25.9 g/day) were associated with low IgM anti-PC (OR=2.29 [95% CI 1.06-4.97], OR=2.36 [95% CI 1.01-5.53] and OR=1.24 [95% CI 1.24-6.15], respectively). Further, dietary intake of total fat (>64.0 g/day), specifically saturated fat (>27.1 g/day), was associated with low IgM anti-MDA level (OR=2.55 [95% CI 1.14-5.64] and OR=2.47 [95% CI 1.11-5.51], respectively). Micronutrients were not associated with measured antibodies. CONCLUSIONS: Some dietary and metabolic factors were associated with IgM anti-PC and anti-MDA, though it is not clear whether the associations also represent causation.

Long-Term Dietary Changes after Diagnosis of Rheumatoid Arthritis in Swedish Women: Data from a Population-Based Cohort.

OBJECTIVE: To investigate long-term dietary changes after rheumatoid arthritis (RA) diagnosis in Swedish women, compared to women without RA. METHODS: This study included 21,602 women from the Swedish Mammography Cohort (SMC), who completed dietary questionnaires in 1997 and 2009. Between 1997 and 2009, 191 women were diagnosed with RA. Dietary changes after RA diagnosis were analyzed based on intake of 82 food items. Statistical analysis included linear mixed models. RESULTS: Women with RA, compared to women without RA, had significantly lower intake (mean servings per week) of animal products such as black pudding, egg, kidney, and liver paste (2.94±2.73 versus 2.45±1.82, p=0.010) and dairy products (35.14±20.02 versus 28.42±16.10, p=0.040) in 1997 and of cereals and grains (31.01±15.54 versus 28.00±14.98, p=0.009) in 2009. However, multivariable adjusted changes in dietary intake from 1997 to 2009 did not show any significant difference in intake. Nevertheless, women without RA increased their intake of whole wheat bread, wheat/oat bran, and rice more than women with RA. CONCLUSION: Women who had been diagnosed with RA had similar dietary patterns over time as the general population; these women did not remarkably change their diet over time due to their disease. Dietary recommendations for RA patients are needed.

Dietary Intake of Polyunsaturated Fatty Acids and Pain in Spite of Inflammatory Control Among Methotrexate-Treated Early Rheumatoid Arthritis Patients.

OBJECTIVE: To investigate potential associations between dietary intake of polyunsaturated fatty acids (FAs) and pain patterns in early rheumatoid arthritis (RA) patients after 3 months of methotrexate (MTX) treatment. METHODS: We included 591 early RA patients with MTX monotherapy from a population-based prospective case-control study, the Epidemiological Investigation of Rheumatoid Arthritis. Dietary data on polyunsaturated FAs (food frequency questionnaires) were linked with data on unacceptable pain (visual analog scale [VAS] >40 mm), noninflammatory/refractory pain (VAS >40 mm and C-reactive protein [CRP] level <10 mg/liter), and inflammatory pain (VAS >40 mm and CRP level >10 mg/liter) after 3 months. Statistical analysis included logistic regression. RESULTS: After 3 months of MTX treatment, 125 patients (21.2%) had unacceptable pain, of which 92 patients had refractory pain, and 33 patients had inflammatory pain. Omega-3 FA intake was inversely associated with unacceptable pain and refractory pain (odds ratio [OR] 0.57 [95% confidence interval (95% CI) 0.35-0.95] and OR 0.47 [95% CI 0.26-0.84], respectively). The omega-6:omega-3 FA ratio, but not omega-6 FA alone, was directly associated with unacceptable pain and refractory pain (OR 1.70 [95% CI 1.03-2.82] and OR 2.33 [95% CI 1.28-4.24], respectively). Furthermore, polyunsaturated FAs were not associated with either inflammatory pain or CRP level and erythrocyte sedimentation rate at followup. Omega-3 FA supplementation was not associated with any pain patterns. CONCLUSION: Omega-3 FA was inversely associated with, and the omega-6:omega-3 FA ratio was directly associated with, unacceptable and refractory pain, but not with inflammatory pain or systemic inflammation. The inverse association between omega-3 FA and refractory pain may have a role in pain suppression in RA.

Are dietary vitamin D, omega-3 fatty acids and folate associated with treatment results in patients with early rheumatoid arthritis? Data from a Swedish population-based prospective study.

BACKGROUND: Dietary intake of vitamin D and omega-3 fatty acids (FA) may be associated with superior response to antirheumatic treatments. In addition, dietary folate intake may be associated with worse response to methotrexate (MTX). The aim of this study was to investigate the association between dietary vitamin D, omega-3 FA, folate and treatment results of disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA). METHODS: This prospective study was based on data from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study, and included 727 patients with early RA from 10 hospitals in Sweden. Data on dietary vitamin D, omega-3 FA and folate intake based on food frequency questionnaires were linked with data on European League Against Rheumatism (EULAR) response after 3 months of DMARD treatment. Associations between vitamin D, omega-3 FA, folate and EULAR response were analysed with logistic regression adjusted for potential confounders. RESULTS: The majority of patients (89.9%) were initially treated with MTX monotherapy and more than half (56.9%) with glucocorticoids. Vitamin D and omega-3 FA were associated with good EULAR response (OR 1.80 (95% CI 1.14 to 2.83) and OR 1.60 (95% CI 1.02 to 2.53), respectively). Folate was not significantly associated with EULAR response (OR 1.20 (95% CI 0.75 to 1.91)). Similar results were seen in a subgroup of patients who were initially treated with MTX monotherapy at baseline. CONCLUSIONS: Higher intake of dietary vitamin D and omega-3 FA during the year preceding DMARD initiation may be associated with better treatment results in patients with early RA. Dietary folate intake was not associated with worse or better response to treatment, especially to MTX. Our results suggest that some nutrients may be associated with enhanced treatment results of DMARDs.

Obesity is a strong predictor of worse clinical outcomes and treatment responses in early rheumatoid arthritis: results from the SWEFOT trial.

OBJECTIVES: The aim of this paper was to analyse the impact of obesity, in addition to known predictors, on disease outcome in early rheumatoid arthritis (RA). METHODS: Body mass index (BMI) was available in 260 patients from the Swedish pharmacotherapy trial (SWEFOT). Differences in disease activity (DAS28), functional impairment (HAQ), pain (Visual Analogue Scale, VAS-pain) and radiographic damage were evaluated over 24 months between BMI categories (obese BMI >30, n=43; overweight BMI=25-29.9, n=74; normal BMI <25, n=143) using non-parametric testing. Predictors of European League Against Rheumatism non-remission (DAS28 ≥2.6) at 24 months of follow-up were evaluated using binary univariate and multivariate logistic regression. RESULTS: Obesity at baseline was associated with worse continuous-scale clinical outcomes over 24 months (DAS28, HAQ and VAS-pain at last visit: obese vs normal: p<0.001; obese vs overweight: p<0.05). Furthermore, obese patients compared with non-obese patients had significantly greater odds of non-remission at 24 months (adjusted OR (aOR) 5.2; 95% CI 1.8 to 15.2). Other independent predictors were female sex (aOR 2.6; 95% CI 1.1 to 5.8), current smoking (aOR 2.6; 95% CI 1.1 to 6.3) and HAQ (per-unit increase, aOR 1.9; 95% CI 1.1 to 3.4). The pattern was similar among seropositive and seronegative patients; and in the subgroups of methotrexate responders and patients randomised at 3 months to add-on of sulfasalazine+hydroxychloroquine, although not significant with add-on of infliximab. Obesity had no independent association to radiographic progression. CONCLUSIONS: In this early RA trial reflecting today's standard treatment, obesity, in addition to sex, smoking and functional impairment strongly lowered the chance of attaining good clinical outcomes, including remission, today's treatment goal. This highlights the importance of considering lifestyle modification as one of the cornerstones of RA care. TRIAL REGISTRATION NUMBER: NCT00764725; Post-results. WHO database at the Karolinska University Hospital: CT20080004.

The association between diet and glucocorticoid treatment in patients with SLE.

BACKGROUND: Some studies suggest that the risk for and severity of systemic lupus erythematosus (SLE) can be modified by certain nutrients. The aim of this study was to investigate the association between diet and glucocorticoid (GC) treatment, as a proxy for disease activity, in patients with SLE. METHODS: We included 111 patients with SLE from the SLE Vascular Impact Cohort (SLEVIC). Dietary data were linked with data on GC treatment during a 2-year period. The association between diet and GC treatment was analysed with logistic regression. GC treatment and unchanged/increased doses were considered a proxy for active SLE. RESULTS: During the 2-year period, 54 patients (48.6%) had continued GC treatment. Dietary vitamin D was associated with GC treatment (OR=2.70-2.85 (95% CI 1.00 to 8.11)), whereas alcohol was inversely associated with GC treatment (OR=0.28-0.39 (95% CI 0.10 to 98)). Beta-carotene, fatty acid C18:2 and vitamin B6 were inversely associated with unchanged/increased GC dose (OR=0.29-0.30 (95% CI 0.10 to 0.90)). Finally, total energy intake was associated with GC doses >5.0 mg/day and >7.5 mg/day, explaining a direct association between 35 nutrients and higher GC dose levels (OR=2.98-23.82 (95% CI 1.01 to 203.88)). DISCUSSION: Dietary vitamin D did not protect against lupus activity. Beta-carotene, fatty acid C18:2 and vitamin B6 may protect against increased GC dose. The inverse association between alcohol intake and GC treatment/lupus activity may provide a partial explanation for the link between moderate alcohol intake and reduced risk of SLE. The association between higher dietary intake and higher GC dose levels indicated GC's influence on increasing appetite.