Sodium intake not linked to multiple sclerosis progression

(HealthDay)—There is no association between average 24-hour urine sodium levels and conversion from clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (MS), according to a study published online May 26 in the Annals of Neurology.

Kathryn C. Fitzgerald, Sc.D., from the Johns Hopkins School of Medicine in Baltimore, and colleagues examined whether a high-salt diet is associated with faster conversion from CIS to MS. A total of 465 patients with CIS provided a median of 14 spot urine samples during five-year follow-up of the BENEFIT trial.

The researchers observed no correlation between average 24-hour urine sodium levels and conversion to clinically definite MS over the five-year follow-up (hazard ratio, 0.91 95 percent confidence interval, 0.67 to 1.24 per 1 g increase in estimated daily sodium intake). There were also no associations with clinical or magnetic resonance imaging (MRI) outcomes (new active lesions after six months: hazard ratio, 1.05 [95 percent confidence interval, 0.97 to 1.13]; relative change in T2 lesion volume: −0.11 [95 percent confidence interval, −0.25 to 0.04]; change in Expanded Disability Status Scale: −0.01 [95 percent confidence interval: −0.09 to 0.08]; relapse rate: hazard ratio, 0.78 [95 percent confidence interval, 0.56-1.07]). In categorical analyses using quintiles, the results were similar.

"Our results, based on multiple assessments of urine sodium excretion over five years and standardized clinical and MRI follow-up, suggest that salt intake does not influence MS disease course or activity," the authors write.

One author is an employee of Bayer AG.