Kurtzke J F, Beebe G W, Norman J E
Neurology. 1985 May;35(5):672-8. doi: 10.1212/wnl.35.5.672.
World War II or Korean Conflict veterans with MS (5,305 in number) and pre-illness-matched controls were compared for residence at birth and entry on active duty (EAD) within three north-south tiers of states in the United States. A strong north-south gradient of MS risk was present. Migrants were defined as those whose birth and EAD tier differed. For white men of World War II, all white men, and all whites, there were highly significant reductions in risk for moves southward from either the north or middle tier, and increases in risk for moves northward from the middle tier. Increases similar in magnitude of middle to north did not attain statistical significance in the few southern-born migrants. For the small groups of black men and white men of Korean service, trends were similar but did not attain significance, whereas for white women, they were of borderline significance. Findings imply an environmental cause for MS, with acquisition years before symptom-onset.
对患有多发性硬化症的二战或朝鲜战争退伍军人（共5305人）以及疾病前匹配的对照组，就其出生时的居住地以及在美国南北三个层级州内的现役入伍地进行了比较。多发性硬化症风险存在明显的南北梯度。移民被定义为出生层级和现役入伍层级不同的人。对于二战白人男性、所有白人男性以及所有白人而言，从北部或中部层级向南迁移的风险显著降低，而从中部层级向北迁移的风险增加。少数南方出生的移民中，从中部到北部类似幅度的增加未达到统计学显著性。对于少数朝鲜战争服役的黑人男性和白人男性群体，趋势相似但未达到显著性，而对于白人女性，处于临界显著性。研究结果表明多发性硬化症存在环境病因，在症状出现前数年就已患病。
