Menzies Research Institute, University of Tasmania, Hobart, Australia.
Mult Scler. 2010 Apr;16(4):398-405. doi: 10.1177/1352458509359724. Epub 2010 Feb 18.
Increasing prevalence and variable geographic patterns of occurrence of multiple sclerosis suggest an environmental role in causation. There are few descriptive, population-level, data on whether such variability applies to first demyelinating events (FDEs). We recruited 216 adults (18-59 years), with a FDE between 1 November 2003 and 31 December 2006 in a multi-center incident case-control study in four locations on the south-eastern and eastern seaboard of Australia, spanning latitudes 27 degrees south to 43 degrees south. Population denominators were obtained from the Australian Bureau of Statistics censuses of 2001 and 2006. Age and sex adjusted FDE incidence rates increased by 9.55% (95% confidence interval (CI) 7.37-11.78, p < 0.001) per higher degree of latitude. The incidence rate gradient per higher degree of latitude varied by gender (male: 14.69% (95% CI 9.68-19.94, p < 0.001); female 8.13% (95% CI 5.69-10.62, p < 0.001)); and also by the presenting FDE type: optic neuritis 11.39% (95% CI 7.15-15.80, p < 0.001); brainstem/cerebellar syndrome 9.47% (95% CI 5.18-13.93, p < 0.001); and spinal cord syndrome 5.36% (95% CI 1.78-9.06, p = 0.003). Differences in incidence rate gradients were statistically significant between males and females (p = 0.02) and between optic neuritis and spinal cord syndrome (p = 0.04). The male to female ratio varied from 1 : 6.7 at 27 degrees south to 1 : 2.5 at 43 degrees south. The study establishes a positive latitudinal gradient of FDE incidence in Australia. The latitude-related factor(s) influences FDE incidence variably according to subtype and gender, with the strongest influence on optic neuritis presentations and for males. These descriptive case analyses show intriguing patterns that could be important for understanding the etiology of multiple sclerosis.
多发性硬化症的发病率不断增加且地理分布存在差异，这表明其病因与环境有关。目前，有关这种变异性是否适用于首次脱髓鞘事件（FDE）的描述性、人群水平数据很少。我们在澳大利亚东南部和东部沿海的四个地点进行了一项多中心的病例对照研究，招募了 216 名年龄在 18-59 岁之间的成年人，这些成年人在 2003 年 11 月 1 日至 2006 年 12 月 31 日期间发生了 FDE。人口基数来自澳大利亚统计局 2001 年和 2006 年的人口普查。纬度每增加 1 度，年龄和性别调整后的 FDE 发病率增加 9.55%（95%置信区间为 7.37-11.78，p<0.001）。纬度每增加 1 度，发病率梯度因性别而异（男性：14.69%（95%置信区间为 9.68-19.94，p<0.001）；女性：8.13%（95%置信区间为 5.69-10.62，p<0.001）），也因表现的 FDE 类型而异：视神经炎 11.39%（95%置信区间为 7.15-15.80，p<0.001）；脑干/小脑综合征 9.47%（95%置信区间为 5.18-13.93，p<0.001）；和脊髓综合征 5.36%（95%置信区间为 1.78-9.06，p=0.003）。男性和女性（p=0.02）以及视神经炎和脊髓综合征（p=0.04）之间的发病率梯度差异具有统计学意义。男性与女性的比例从南纬 27 度的 1:6.7 变化到南纬 43 度的 1:2.5。本研究在澳大利亚建立了 FDE 发病率的正纬度梯度。纬度相关因素根据亚型和性别而对 FDE 发病率产生不同的影响，对视神经炎表现和男性的影响最大。这些描述性病例分析显示出有趣的模式，这对于理解多发性硬化症的病因可能很重要。
