Fava D, Gardner S, Pyke D, Leslie R D
Department of Diabetes and Metabolism, University of Bristol, U.K.
Diabetes Care. 1998 Jun;21(6):925-9. doi: 10.2337/diacare.21.6.925.
The aim of this study was to determine the impact of genetic or environmental factors on the age or time of onset of IDDM by studying pairs of twins and siblings concordant for the disease.
From 404 twin pairs referred to a diabetic twin study, we selected pairs concordant for IDDM: 1) 116 identical pairs with an index twin diagnosed diabetic under age 60 years and 2) 12 identical and 12 nonidentical matched twin pairs. From 972 families referred to a population-based diabetic family study, we selected sibling pairs with IDDM: 33 pairs with an index case diagnosed diabetic under age 21 years. Twin and sibling pairs were analyzed for intraclass correlations for age and time of diagnosis.
Of twins concordant for IDDM, the age at diagnosis correlated 1) in 116 identical pairs (R = 0.94; P < 0.000001) and 2) more closely in 12 identical twins (R = 0.96, P < 0.000001) than 12 nonidentical twins (R = 0.59, P = 0.046). Of 33 sibling pairs with IDDM, the age, but not the time, of diagnosis was correlated (R = 0.53, P = 0.0016).
Correlations within pairs of twins and siblings for age, not time, at diagnosis suggest that much of the variability of the age at diagnosis of IDDM is genetically determined.
本研究的目的是通过研究患该疾病的双胞胎和兄弟姐妹对，来确定遗传或环境因素对胰岛素依赖型糖尿病（IDDM）发病年龄或发病时间的影响。
在404对参与糖尿病双胞胎研究的双胞胎中，我们选择了患IDDM的双胞胎对：1）116对同卵双胞胎，其中索引双胞胎在60岁以下被诊断为糖尿病；2）12对同卵双胞胎和12对匹配的异卵双胞胎。在972个参与基于人群的糖尿病家族研究的家庭中，我们选择了患IDDM的兄弟姐妹对：33对，其中索引病例在21岁以下被诊断为糖尿病。对双胞胎和兄弟姐妹对的诊断年龄和诊断时间进行组内相关性分析。
在患IDDM的双胞胎中，诊断年龄的相关性为：1）在116对同卵双胞胎中（R = 0.94；P < 0.000001）；2）在12对同卵双胞胎中相关性更强（R = 0.96，P < 0.000001），高于12对异卵双胞胎（R = 0.59，P = 0.0[46]）。在33对患IDDM的兄弟姐妹对中，诊断年龄存在相关性（R = 0.53，P = 0.0016），但诊断时间不存在相关性。
双胞胎和兄弟姐妹对中诊断年龄而非诊断时间的相关性表明，IDDM诊断年龄的大部分变异性是由基因决定的。
