Systemic lupus erythematosus is associated with an increased risk for orthorexia nervosa: a cross-sectional study.

Orthorexia nervosa (ON) is an atypical eating disorder marked by persistent preoccupation with consuming only ‘pure’ or healthy foods, coupled with harmful compulsive behaviors. Rheumatic and musculoskeletal diseases (RMDs) are a broad group of conditions, characterized by pain and inflammation, affecting the joints and other connective tissues. Nutritional factors have been shown to exert a substantial influence on the development of these pathologies; however, orthorexic tendencies have not yet been studied among RMDs. This cross-sectional study recruited 367 patients from the Department of Rheumatology and Clinical Immunology at the University General Hospital, situated in Larissa. Patients were interviewed during their regular appointments in order to assess orthorexic tendencies. ON was evaluated using the Düsseldorf Orthorexia Scale (DOS), and linear regression analyses were performed. Although the presence of ON was relatively uncommon among patients with RMDs (2.2%), women (β = 2.41, 95% CI: 1.16, 3.65, p = 0.0002) and patients with systemic lupus erythematosus (β = 2.01, 95% CI: 0.39, 3.64, p = 0.02) or fibromyalgia syndrome (β = 8.17, 95% CI: 2.61, 13.73, p = 0.004) were at a greater risk for ON. On the other hand, patients with idiopathic inflammatory myopathies demonstrated a reduced propensity for orthorexic tendencies (β=-2.39, 95% CI: -4.70, -0.09, p = 0.04). Although ON demonstrates a low prevalence among patients with RMDs, certain diagnoses are associated with a higher propensity for orthorexia. Identifying ON is important for improved disease outcomes, metabolic function, and patients’ quality of life.