Bruno G, Merletti F, Biggeri A, Cerutti F, Grosso N, De Salvia A, Vitali E, Pagano G
Department of Internal Medicine, University of Turin, Italy.
Diabetologia. 2001 Jan;44(1):22-5. doi: 10.1007/s001250051575.
AIMS/HYPOTHESIS: This study aimed to determine if the incidence of Type I (insulin-dependent) diabetes mellitus increased over time and if the time trend is attributable to linear trend, calendar period or birth cohort effects.
This study was based on a cohort of subjects aged 0-29 years from 1984 to 1996, who resided in the province of Turin, Italy. Poisson regression models were used to estimate the effect of sex, age, calendar time and cohorts on incidence rates.
The mean incidence rate in the age group of 0 to 29 years was 7.78 of 100,000 person-years (95% confidence interval: 7.26-8.32), with a lower risk in women than in men [rate ratio (RR): 0.76 (0.67-0.88)]. We found a trend of incidence increasing over time (annual increase of risk 2.25 % a year, 95 % CI 0.44-4.10). In Poisson regression analysis we found that the best model was the one with sex, age and a linear term attributable to either calendar period or cohort effects. The linear term corresponds to a RR of 1.12 (1.02-1.22,p = 0.015) for each 5-year age span.
CONCLUSION/INTERPRETATION: We found that the time trend in this Mediterranean area was similar in magnitude to that reported in northern European countries. The increase was linear in pattern, each birth cohort and each calendar period showing a higher risk than the preceeding one with some evidence of two steep increases in the incidence of Type I diabetes centered on the years 1964 and 1984. We found that the incidence of diabetes increased in the 0 to 14 age group and also in the older age group of 15 to 29 years and that the age-period models were not statistically significantly better than the age-cohort models.
目的/假设：本研究旨在确定I型（胰岛素依赖型）糖尿病的发病率是否随时间增加，以及这种时间趋势是否归因于线性趋势、日历时间段或出生队列效应。
本研究基于1984年至1996年居住在意大利都灵省的0至29岁的队列研究对象。使用泊松回归模型来估计性别、年龄、日历时间和队列对发病率的影响。
0至29岁年龄组的平均发病率为每10万人年7.78例（95%置信区间：7.26 - 8.32），女性风险低于男性[发病率比（RR）：0.76（0.67 - 0.88）]。我们发现发病率随时间呈上升趋势（每年风险增加2.25%，95%置信区间0.44 - 4.10）。在泊松回归分析中，我们发现最佳模型是包含性别、年龄以及归因于日历时间段或队列效应的线性项的模型。对于每5年年龄跨度，线性项对应的RR为1.12（1.02 - 1.22，p = 0.015）。
结论/解读：我们发现这个地中海地区的时间趋势在幅度上与北欧国家报告的相似。这种增加呈线性模式，每个出生队列和每个日历时间段的风险都高于前一个，有证据表明I型糖尿病发病率在1964年和1984年出现两次急剧上升。我们发现糖尿病发病率在0至14岁年龄组以及15至29岁年龄组均有所增加，并发现年龄 - 时间段模型在统计学上并不比年龄 - 队列模型显著更好。
