Micronutrients deficiencies in patients with spondylarthritis: the potential immunometabolic crosstalk in disease phenotype

OBJECTIVE: Micronutrient deficiencies (MNDs) are common among patients with certain chronic inflammatory diseases. They are associated with a pro-inflammatory status and co-morbidities. However, no studies have specifically investigated MNDs in Spondyloarthritis (SpA). This paper aimed at analyzing the occurrence of anemia and deficiencies of ferritin (Fe), vitamin D [25(OH)D], vitamin B12 (B12), and folic acid (FA) in SpA patients. The interplay of MNDs with age, gender, and metabolic abnormalities was also explored. PATIENTS AND METHODS: MNDs were evaluated in 220 SpA outpatients (137 females and 83 age-matched males) with psoriatic arthritis (PsA, n=110) and non-psoriatic SpA (n=110). Metabolic parameters were analyzed. Disease activity was assessed by either Disease Activity in PSoriatic Arthritis (DAPSA) or Ankylosing Spondylitis Disease Activity Score with C-Reactive Protein (ASDAS-CRP) as appropriate, while the functional status was evaluated using Health Assessment Questionnaire modified for SpA (HAQ-S). RESULTS: Anemia o ccurred in 13.6% of subjects of the study cohort and almost wholly in females (p=0.004). Females showed higher Fe deficiency (p=0.04) and lower Fe levels (p=0.0003) than males. Hemoglobin (Hb) resulted inversely related to age and CRP (p=0.01 and p=0.008) in male group. The 25(OH)D deficiency (≤20 ng/ml) was present in 23.2% of the cohort with a higher prevalence in males than females (p=0.02): moreover, 25(OH)D inversely correlated with disease duration (p=0.02) in males. The B12 deficiency (≤200 pmol/l) was rare (13.2%), while FA ≤4 ng/ml was frequent (22%) and associated with B12 deficiency in 31% of cases. SpA patients in moderate/high disease activity had higher Body Mass Index (BMI) (p=0.04) and HAQ-S (p<0.0001), as well as lower Hb (p=0.02), and Fe (p=0.03) than patients in remission/ low disease activity (LDA). In patients with extra-articular manifestations, female sex was prevalent (F:M=2) and B12 levels were lower than in patients without (p=0.005). Interestingly, 25(OH)D was lower (p=0.04) and both BMI and HAQ-S (p=0.036 and p=0.01) were higher in patients without extra-articular involvement than patients with. CONCLUSIONS: Our findings documented a relevant prevalence of MNDs in SpA patients, and its strict interplay with gender and metabolic abnormalities by highlighting the role of MNDs in inflammatory-dependent dysmetabolism in SpA.