Lack of association between B 12 and Body Mass Index among Saudi multiple sclerosis patients

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system. It is an autoimmune disease of multifactorial etiology, linked to a variety of genetic and well-defined environmental factors. It typically affects more women than men and more frequently affects adults aged 20-45 years. Besides, vitamin B12 deficiency and obesity are associated with exacerbating central nervous system inflammation and a higher clinical disability.

The study aims to determine the association of the vitamin B12 serum concentration with the Body Mass Index BMI, thyroid-stimulating hormone serum levels and MS clinical features in Saudi MS patients.

This is a retrospective cohort study, and data were collected from the MS database at the King Fahad Medical City Multiple Sclerosis Clinic, from December 2015 to December 2019. Data were entered and analyzed using the Statistical Package for Social Sciences (SPSS ver. 20, Chicago, IL, USA). Cobalamin, also known as vitamin B12, has a reference concentration that ranges from 138 to 652 Pmol/L in adults. The patient's BMI was calculated by dividing the weight (in kilograms) by the square of the height (in square meters), expressed in kg/m².Data for 169 MS subjects were collected. A total 83 of them, with a mean age of 36.2 ± 9.57 years, had vitamin B12 results. Of all patients, 16.6% had vitamin B12 deficiency (<138 pmol/L) and 9.52% of them were overweight, BMI kg/m² = (25-29.9). The mean vitamin B12 level in all MS subjects was 240 ± 117 pmol/L. Moreover, 58.33% of the MS patients had high BMIs (BMI >25). However, no significant correlation was found between vitamin B12 deficiency neither with the BMI nor TSH concentration in MS cases (r = 0.03, p = 0.64), (r = 0.00, P = 0.9) respectively.

These findings revealed no association between serum vitamin B12 concentration and TSH, BMI in MS clinical parameters, however, further studies are required to validate these results.