Disease relapses in multiple sclerosis can be influenced by air pollution and climate seasonal conditions.
Vojnosanit Pregl. 2015 Jan ;72(1):44-9. PMID: 26043590
BACKGROUND/AIM: Environmental factors may influence the disease activity in patients with relapsing-remitting multiple sclerosis (MS). The aim of this study was to evaluate the in- fluence of air pollution and seasonal climate factors of any on number of relapses in MS patients during a consecutive 5 years of observation.
METHODS: We retrospectively analyzed data of MS patients from the town of Niš, hospitalized at the Clinic of Neurology, Clinical Center Niš, Serbia, from 2005 to 2009. Climate data: mean daily sun shining; mean monthly sun shining, mean whole daily cloudiness, daily cloudiness at 7 a.m, 2 p.m. and 9 p.m. and air pollution expressed by NSR (New Source Review) were obtainedfrom the Meteorology Observatory Niš.
RESULTS: During a 5-year of observation there were 260 relapses in 101 MS patients. The number of relapses showed a significantly negative correlation with the number of days with NSR<2 (p = -0.31; p<0.01) and a positive correlation with the mean whole daily cloudiness (p<0.05), mean daily cloudiness at 7 a.m. (p<0.05) and 2 p.m. (p<0.01). We found a significantlly positive correlation (p<0.05) between the reduced number of relapses during the period of high vitamin D season, i.e. July-October. There was a statistically significant increase (p<0.01) of the number of relapses during spring (x = 6.53; SD = 3.98) compared to the other three seasons. The joint presence of lower number of days with NSR<2 during low vitamin D season (January- April) correlated with a statistically significant increase of the number of relapses in MS patients (F = 5.06, p<0.01). CON- CLUSION: The obtained results confirmed the influence of air pollution and climate seasonal conditions on disease relapses in MS patients based on a long-term observation. Lower numbers of days with low air pollution during the periods with low vitamin D (January-April), especially with increased cloudiness at 2 p.m, induce a higher risk of MS relapses in southern continental parts of Europe.