Department of Internal Medicine, University of Turin, corso Dogliotti 14, 10126, Turin, Italy.
Diabetologia. 2009 Dec;52(12):2531-5. doi: 10.1007/s00125-009-1538-x. Epub 2009 Oct 11.
AIMS/HYPOTHESIS: A shift towards younger age at onset of diabetes in susceptible people has been suggested as a possible explanation for the increasing temporal trend in incidence of type 1 diabetes. We aimed to test this hypothesis by assessing trends in incidence rates in the period 1984-2004 in children and young adults in Northern Italy.
The study bases were: (1) children resident in the Province of Turin in the period 1984-2004 and in the remaining areas of the Piedmont Region in the period 1990-2004; and (2) young adults (15-29 years) resident in the Province of Turin in the period 1984-2003. Temporal trends in rates were analysed using Poisson regression models.
A total of 1,773 incident cases were identified. Overall incidence rates/100,000 person-years in the age groups 0-14 and 15-29 years were 11.3 (95% CI 10.7-12.0) and 7.1 (95% CI 6.6-7.7), respectively, with sex differences among young adults only (incidence rate ratio [IRR] in males vs females 1.41 [95% CI 1.20-1.64]). Average annual increases in incidence rates were similar in children and young adults at 3.3% (95% CI 2.5-4.1). Compared with the period 1984-89, in 2000-2004 a 60% higher risk was found in both age 0-14 years (IRR 1.60, 95% CI 1.31-1.95) and 15-29 years (IRR 1.57, 95% CI 1.26-1.96) groups. The Poisson modelling showed no interaction between calendar period and age at onset.
CONCLUSIONS/INTERPRETATION: Incidence of type 1 diabetes in Northern Italy is increasing over time in both children and young adults, not supporting the hypothesis of a shift towards younger age as the main explanation for the increasing temporal trend in children.
目的/假设：在易感人群中，糖尿病发病年龄的提前被认为是 1 型糖尿病发病率随时间增加的一个可能原因。我们旨在通过评估意大利北部儿童和年轻人在 1984-2004 年期间的发病率趋势来检验这一假设。
研究基地包括：（1）1984-2004 年居住在都灵省的儿童和 1990-2004 年居住在皮埃蒙特地区其余地区的儿童；（2）1984-2003 年居住在都灵省的年轻人（15-29 岁）。使用泊松回归模型分析各年龄段的发病率趋势。
共发现 1773 例新发病例。0-14 岁和 15-29 岁年龄组的总发病率/100000 人年分别为 11.3（95%CI 10.7-12.0）和 7.1（95%CI 6.6-7.7），仅在年轻人中存在性别差异（男性与女性的发病率比值[IRR]为 1.41[95%CI 1.20-1.64]）。儿童和年轻人的发病率年平均增长率相似，均为 3.3%（95%CI 2.5-4.1）。与 1984-89 年相比，2000-2004 年 0-14 岁（IRR 1.60，95%CI 1.31-1.95）和 15-29 岁（IRR 1.57，95%CI 1.26-1.96）人群的风险均增加 60%。泊松模型分析未显示出日历时间与发病年龄之间存在交互作用。
结论/解释：意大利北部的 1 型糖尿病发病率在儿童和年轻人中随时间推移呈上升趋势，这一结果不支持发病年龄提前是导致儿童发病率随时间增加的主要原因这一假设。
