Environmental Factors Related to Multiple Sclerosis in Indian Population

BACKGROUND Multiple sclerosis (MS) is less prevalent among Indians when compared to white populations. Genetic susceptibility remaining the same it is possible that environmental associations may have a role in determining disease prevalence. AIMS To determine whether childhood infections, vaccination status, past infection with Helicobacter pylori (H.pylori), diet, socioeconomic and educational status were associated with MS. MATERIAL AND METHODS 139 patients and 278 matched control subjects were selected. A validated environmental exposure questionnaire was administered. Estimation of serum H.pylori IgG antibody was done by ELISA. Patients and controls were genotyped for HLA-DRB1*15:01. RESULTS In our cohort a significant association was seen with measles (p < 0.007), vegetarian diet (p < 0.001, higher educational status (p < 0.0001) and urban living (p < 0.0001). An inverse relationship was seen with H.Pylori infection and MS (p < 0.001). Measles infection (OR 6.479, CI 1.21-34.668, p < 0.029) and high educational status (OR 3.088, CI 1.212-7.872, p < 0.018) were significant risk factors associated with MS. H.pylori infection was inversely related to MS (OR 0. 319, CI 0.144- 0.706, p < 0.005). CONCLUSIONS Environmental influences may be important in determining MS prevalence.