Blood lead levels and multiple sclerosis: A case-control study.

BACKGROUND:Multiple sclerosis (MS) is a debilitating disease of the central nervous system, with disseminating demyelination of nerve fibers and spinal cord. Exposure to heavy metals seems to be associated with a higher incidence of MS. Few studies have assessed the correlation of the incidence of MS with heavy metal concentrations. The present study aimed to assess the relationship between blood lead levels and MS. METHODS:This case-control study was conducted on 29 MS patients and 29 healthy control persons. The controls were age, gender and occupation matched at the time of blood sampling. Blood lead levels were measured using the atomic absorption spectrometry method. Data were analyzed using Student t-test, Mann-Whitney U, and multiple logistic regression, using a significance level of p ˂ 0.05. RESULTS:According to the result of this study, the mean blood lead level (BLL) was 75.6 ± 9.35and33.8 ± 28.8 µg/L in patients with MS and control group, respectively. Median blood lead levels were significantly higher in MS patients (38 µg/L, range: 27-67), compared to the controls (30 µg/L, range: 11-49) (p = 0.03). The risk of MS increased 1.17 times per one µg/L increment of blood lead level, using the multiple logistic regression analysis on the present results. CONCLUSION:In conclusion, based on our results, BLL was higher in MS patients, compared with healthy individuals. The risk of MS increased 1.17 times per one µg/L increment of blood lead level.