title: Sodium intake is associated with increased disease activity in multiple sclerosis.
abstract: BACKGROUND
  Recently, salt has been shown to modulate the differentiation of human and mouse Th17 cells and mice that were fed a high-sodium diet were described to develop more aggressive courses of experimental autoimmune encephalomyelitis. However, the role of sodium intake in multiple sclerosis (MS) has not been addressed. We aimed to investigate the relationship between salt consumption and clinical and radiological disease activity in MS.
  
  
  METHODS
  We conducted an observational study in which sodium intake was estimated from sodium excretion in urine samples from a cohort of 70 relapsing-remitting patients with MS who were followed for 2 years. The effect of sodium intake in MS disease activity was estimated using regression analysis. We then replicated our findings in a separate group of 52 patients with MS.
  
  
  RESULTS
  We found a positive correlation between exacerbation rates and sodium intake in a multivariate model adjusted for age, gender, disease duration, smoking status, vitamin D levels, body mass index and treatment. We found an exacerbation rate that was 2.75-fold (95% CI 1.3 to 5.8) or 3.95-fold (95% CI 1.4 to 11.2) higher in patients with medium or high sodium intakes compared with the low-intake group. Additionally, individuals with high-sodium intake had a 3.4-fold greater chance of developing a new lesion on the MRI and on average had eight more T2 lesions on MRI. A similar relationship was found in the independent replication group.
  
  
  CONCLUSIONS
  Our results suggest that a higher sodium intake is associated with increased clinical and radiological disease activity in patients with MS.
authors.affiliation: Department of Neurology, Raúl Carrea Institute for Neurological Research (FLENI), Buenos Aires, Argentina.
authors.forename: Mauricio F
authors.initials: MF
authors.lastname: Farez
authors.affiliation: Department of Neurology, Raúl Carrea Institute for Neurological Research (FLENI), Buenos Aires, Argentina.
authors.forename: Marcela P
authors.initials: MP
authors.lastname: Fiol
authors.affiliation: Department of Neurology, Raúl Carrea Institute for Neurological Research (FLENI), Buenos Aires, Argentina.
authors.forename: María I
authors.initials: MI
authors.lastname: Gaitán
authors.affiliation: Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Quintana
authors.affiliation: Department of Neurology, Raúl Carrea Institute for Neurological Research (FLENI), Buenos Aires, Argentina.
authors.forename: Jorge
authors.initials: J
authors.lastname: Correale
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis* / Q000473:pathology / Q000652:urine; D059906:Neuroimaging; D012008:Recurrence; D012964:Sodium / Q000009:adverse effects* / Q000097:blood / Q000652:urine; D014807:Vitamin D / Q000097:blood; D055815:Young Adult
chemical_list: D014807:Vitamin D; D012964:Sodium
keywords: Multiple Sclerosis