Kinoshita Masako, Obata Kaoru, Tanaka Masami
Department of Neurology, Utano National Hospital, National Hospital Organization, 8 Ondoyama-Cho, Narutaki, Ukyoku, Kyoto, 616-8255, Japan,
Neurol Sci. 2015 Jul;36(7):1147-51. doi: 10.1007/s10072-015-2150-0. Epub 2015 Mar 10.
Higher latitude is known to be associated with higher prevalence of multiple sclerosis (MS). We investigated the degree of impact of latitude, ultraviolet (UV) radiation, and sunshine on the prevalence of MS in Japan, which has 47 prefectures with a variety of climates. MS prevalence in each prefecture was collected from database of the Ministry of Health, Labour, and Welfare of Japan. Latitude of each prefecture was represented by that of the capital city. Data of UV radiation level and annual actual sunshine duration were obtained from databases of Japan Meteorological Agency. We performed linear correlation analyses of MS prevalence against latitude, UV radiation, and annual actual sunshine duration. MS prevalence significantly correlated to latitude (Pearson's correlation, r = 0.69, p < 0.001) and UV radiation level (r = -0.65, p < 0.001) but not to annual actual sunshine duration (r = -0.37, p = 0.011). Stepwise multiple linear regression analyses revealed significant correlation between MS prevalence and only latitude (p < 0.001). While our result shows that both latitude and the UV intensity have significant relationship to MS prevalence, the stronger relevance of the former suggests an existence of risk factors other than UV radiation.
已知纬度越高，多发性硬化症（MS）的患病率越高。我们调查了纬度、紫外线（UV）辐射和日照对日本MS患病率的影响程度，日本有47个气候各异的县。各县的MS患病率数据来自日本厚生劳动省的数据库。各县的纬度用其首府城市的纬度表示。紫外线辐射水平和年实际日照时长的数据来自日本气象厅的数据库。我们对MS患病率与纬度、紫外线辐射和年实际日照时长进行了线性相关分析。MS患病率与纬度（皮尔逊相关系数，r = 0.69，p < 0.001）和紫外线辐射水平（r = -0.65，p < 0.001）显著相关，但与年实际日照时长（r = -0.37，p = 0.011）无关。逐步多元线性回归分析显示，MS患病率仅与纬度显著相关（p < 0.001）。虽然我们的结果表明纬度和紫外线强度均与MS患病率有显著关系，但前者的相关性更强，这表明除紫外线辐射外还存在其他风险因素。
