Division of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Nobels väg 13, Box 210, SE-171 77, Stockholm, Sweden.
Pediatr Diabetes. 2013 Mar;14(2):138-48. doi: 10.1111/j.1399-5448.2012.00904.x. Epub 2012 Aug 28.
To investigate associations between country of birth, parental country of birth, and education with respect to incidence rate and time trends of type 1 diabetes mellitus (T1DM) among children and young adults.
We followed a nation-wide cohort of 4 469 671 males and 4 231 680 females aged 0-30 years between 1969 and 2008. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) for T1DM were calculated using Poisson regression models. We further calculated age-standardized rates (ASRs) of T1DM, using the world population as standard.
During the study period, the ASR of T1DM increased among children younger than 15 years, but not among young adults (15-30 years). Compared with Swedish-born children, male and female immigrant children had 44 and 42% lower IRR of TIDM, respectively. Among offspring to immigrants, corresponding decreases in IRRs were 27 and 24%, respectively. Compared with children to parents with high education, male children to parents with low education had a 10% decreased IRR of T1DM, while no effect was observed among females. The IRR of T1DM increased with increasing age and calendar time of follow-up in both sexes (p-for trend <0.0001). In young adults, the IRR among immigrants decreased by 32% in males and 22% in females, while corresponding reductions in IRRs were less in offspring to immigrants.
We found a lower IRR of T1DM among offspring to immigrants, but especially among young immigrants compared with Sweden-born individuals. The findings show that environmental factors are important in the etiology of T1DM.
研究出生国、父母出生国和教育程度与 1 型糖尿病（T1DM）在儿童和青年中的发病率和时间趋势的关系。
我们对 1969 年至 2008 年间年龄在 0-30 岁的 4469671 名男性和 4231680 名女性进行了全国性队列研究。采用泊松回归模型计算 T1DM 的发病率比（IRR）及其 95%置信区间（CI）。我们进一步使用世界人口作为标准计算了 T1DM 的年龄标准化率（ASR）。
在研究期间，15 岁以下儿童的 T1DM 发病率呈上升趋势，但 15-30 岁的年轻成年人没有这种趋势。与瑞典出生的儿童相比，移民儿童的男性和女性 TIDM 的 IRR 分别降低了 44%和 42%。在移民子女中，相应的 IRR 下降分别为 27%和 24%。与父母受教育程度较高的子女相比，受教育程度较低的男性子女 T1DM 的 IRR 降低了 10%，而女性则没有观察到这种影响。在两性中，IRR 均随着随访年龄和时间的增加而增加（p 趋势<0.0001）。在年轻成年人中，男性移民的 IRR 下降了 32%，女性下降了 22%，而移民子女的 IRR 下降幅度较小。
我们发现移民子女的 T1DM 发病率较低，尤其是年轻移民，与瑞典出生的个体相比。这些发现表明环境因素在 T1DM 的发病机制中很重要。
