OBJECTIVE: The aim of this study was to investigate the role of dietary micronutrient intake in systemic lupus erythematosus (SLE).
METHODS: This study included 111 SLE patients and 118 age and gender-matched controls. Data on diet (food frequency questionnaires) were linked with data on Systemic Lupus Activity Measure, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and carotid atherosclerotic/echolucent plaque (B-mode ultrasound). Dietary micronutrient intake were compared between SLE patients and controls and in relation to lupus activity and atherosclerosis in SLE. Associations between micronutrient intake and plaque were analyzed through logistic regression, adjusted for potential confounders.
RESULTS: Micronutrient intake did not differ between patients and controls, and between lower and higher lupus activity, apart from the fact that phosphorus was associated with SLEDAI > 6. In SLE patients, some micronutrients were associated with atherosclerotic plaque, left side. Lower intake of riboflavin and phosphorus was associated with atherosclerotic plaque, left side (odds ratio (OR) 3.06, 95% confidence interval (CI) 1.12-8.40 and OR 4.36, 95% CI 1.53-12.39, respectively). Higher intake of selenium and thiamin was inversely associated with atherosclerotic plaque, left side (OR 0.28, 95% CI 0.09-0.89 and OR 0.26, 95% CI 0.08-0.80, respectively). In addition, higher intake of thiamin was inversely associated with echolucent plaque, left side (OR 0.22, 95% CI 0.06-0.84). Lower intake of folate was inversely associated with bilateral echolucent plaque (OR 0.36, 95% CI 0.13-0.99).
CONCLUSIONS: SLE patients did not have different dietary micronutrient intake compared to controls. Phosphorus was associated with lupus activity. Riboflavin, phosphorus, selenium and thiamin were inversely associated with atherosclerotic plaque, left side in SLE patients, but not in controls. Dietary micronutrients may play a role in atherosclerosis in SLE.