Background: Regional average crude or sex-adjusted mortality rates (CMR, S-AMR) and female-to-male ratio (FTMR) in multiple sclerosis (MS) may correlate to the past long-term meteorological factors (MF) in Poland. Objective: To analyse association between regional MR or FTMR in MS and the past long-term MF. Method: The study was based on death certificates of 2172 MS patients (M – 878, F – 1294) who died in Poland in the years 2004-2008. Demographic data were derived from the General Registry Office and meteorological data (1931-1970) from the Meteorological Institute. Correlational investigation was carried out using Spearman’s rank test. Results: Higher CMR in northeastern Poland was 1.45/100 000 individuals and accompanied by minimal solar insolation (SI) in December (16 h) and the lowest air temperature (AT) in January (-5.6°C). CMR was inversely correlated to mean minimal SI in December (r=-0.518; p=0.04), mean annual or January AT (r=-0.539; p=0.03; r=-0.611; p=0.01). CMR was not correlated to annual SI, degree of cloudiness, the annual number of frosty days or sum of precipitation. S-AMR in M and in F were not associated with MF. Higher FTMR (2.72) occurred in northwestern Poland with warmest AT in January (-1.4°C) and the low number of frosty days (65). Mean FTMR (1.55) correlated to annual or January AT (r=+0.638; p=0.01; r=+0.726; p=0.004). Conclusions: CMR in MS was inversely correlated in Poland to the past SI and annual or minimal AT in January. The past SI and AT might influence vitamin D3 level, immunosuppressive cytokines, immune dysregulation and higher mortality especially in northeastern Poland. Greater FTMR in MS correlated to annual or January AT and the annual number of frosty days. AT might facilitate particularly in women more frequent respiratory tract infections.

multiple sclerosis, mortality rates, female-to-male ratio, meteorological factors, Poland, provinces of Poland