Songini M, Bernardinelli L, Clayton D, Montomoli C, Pascutto C, Ghislandi M, Fadda D, Bottazzo G F
Department of Internal Medicine, Ospedale S. Michele, Cagliari, Italy.
Diabetologia. 1998 Feb;41(2):221-7. doi: 10.1007/s001250050893.
Analysis of the geographical variation of risk for a disease is a key issue in descriptive epidemiology and may provide useful suggestions for planning further studies to identify the underlying causes. We adopted a Bayesian approach to investigate the geographical distribution of insulin-dependent diabetes mellitus (IDDM) incidence rate across Sardinia. Data on incidence of IDDM in children aged under 15 years (619 IDDM cases) in Sardinia was obtained by the Sardinian Eurodiab ACE register. The overall completeness of ascertainment was: 91.3%. The average yearly standardized incidence rate for the years 1989-1994 was 33.24 per 100000 (95% C.I. 30.60, 35.88), which is the second highest in Europe after Finland. Sex and age-specific risks were higher in males than in females. Considering the variation of IDDM risk according to the age at diagnosis, the risk profile increased up to the 13th year of age for both sexes, being steeper in males. The degree of geographical variation in IDDM risk was small with a slight difference between the highest and the lowest standardized rate across the map. Indeed, even the municipalities at lowest risk in Sardinia showed a risk higher than most European countries. The Sardinian population is genetically atypical, characterized by genetic homogeneity and marked susceptibility to autoimmune diseases. Our finding of a small geographical variation within the island coupled with a marked temporal trend previously observed in data on military conscripts could be interpreted as evidence of a relatively recent environmental aetiological factor that was uniformly distributed across the island and had its effect in a genetically predisposed population.
分析一种疾病风险的地理差异是描述性流行病学中的一个关键问题，并且可能为规划进一步研究以确定潜在病因提供有用的建议。我们采用贝叶斯方法来研究撒丁岛胰岛素依赖型糖尿病（IDDM）发病率的地理分布。撒丁岛15岁以下儿童（619例IDDM病例）的IDDM发病率数据通过撒丁岛欧洲糖尿病ACE登记处获得。确定的总体完整性为：91.3%。1989 - 1994年的年均标准化发病率为每100000人中有33.24例（95%置信区间30.60，35.88），这是欧洲仅次于芬兰的第二高发病率。男性的性别和年龄特异性风险高于女性。考虑到IDDM风险根据诊断年龄的变化，男女的风险概况在13岁之前都有所上升，男性上升得更陡。IDDM风险的地理差异程度较小，地图上最高和最低标准化率之间略有差异。实际上，即使是撒丁岛风险最低的市镇，其风险也高于大多数欧洲国家。撒丁岛人群在基因上是非典型的，其特点是基因同质性以及对自身免疫性疾病有明显易感性。我们在该岛发现的较小地理差异以及先前在应征入伍者数据中观察到的明显时间趋势，可以解释为存在一个相对较新的环境病因因素的证据，该因素在全岛均匀分布，并在具有遗传易感性的人群中发挥作用。
