Department of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden.
Diabetologia. 2013 May;56(5):1031-5. doi: 10.1007/s00125-013-2859-3. Epub 2013 Feb 13.
AIMS/HYPOTHESIS: The aim of this study was to examine the long-term associations of BMI and physical activity with type 2 diabetes, and to estimate shared genetic components of these traits.
We used data from the Swedish Twin Registry on 23,539 twins born 1886-1958 who answered questionnaires between 1967 and 1972 and were followed up until 1998. The risk of type 2 diabetes in relation to BMI and physical activity was assessed by Cox regression. Structural equation models were used to estimate genetic and environmental variance components and genetic correlations.
The risk of type 2 diabetes increased with BMI (HR 1.32 [95% CI 1.29, 1.35] per kg/m²) and decreased with physical activity (HR 0.56 [95% CI 0.39, 0.80] for high vs low). Heritability was estimated to be 77% (95% CI 54%, 83%) for type 2 diabetes, 65% (95% CI 58%, 73%) for BMI, and 57% (95% CI 47%, 67%) for physical activity. The genetic correlation with type 2 diabetes was 0.43 (95% CI 0.31, 0.58) for BMI and -0.23 (95% CI -0.46, 0.02) for physical activity, implying that 18% (95% CI 9%, 34%) of the genetic influence on type 2 diabetes is shared with BMI and 5% (95% CI 0%, 20%) with physical activity.
CONCLUSIONS/INTERPRETATION: Indications of shared genetic effects are found for BMI and type 2 diabetes, which suggests that these traits are partly influenced by the same genetic factors. In contrast, our findings suggest that the genes related to physical activity are essentially different from those associated with type 2 diabetes.
目的/假设：本研究旨在探讨 BMI 和身体活动与 2 型糖尿病之间的长期关联，并估计这些特征的共同遗传成分。
我们使用了瑞典双胞胎登记处的数据，该登记处包含了 1886 年至 1958 年出生的 23539 对双胞胎，他们在 1967 年至 1972 年之间回答了问卷，并在 1998 年之前进行了随访。通过 Cox 回归评估 BMI 和身体活动与 2 型糖尿病风险的关系。结构方程模型用于估计遗传和环境方差分量以及遗传相关性。
2 型糖尿病的风险随着 BMI（每公斤体重增加 1.32 [95%置信区间 1.29，1.35]）而增加，随着身体活动（高 vs 低的 HR 为 0.56 [95%置信区间 0.39，0.80]）而降低。2 型糖尿病的遗传率估计为 77%（95%置信区间 54%，83%），BMI 为 65%（95%置信区间 58%，73%），身体活动为 57%（95%置信区间 47%，67%）。2 型糖尿病与 BMI 的遗传相关性为 0.43（95%置信区间 0.31，0.58），与身体活动的遗传相关性为-0.23（95%置信区间-0.46，0.02），这意味着 2 型糖尿病遗传影响的 18%（95%置信区间 9%，34%）与 BMI 共享，5%（95%置信区间 0%，20%）与身体活动共享。
结论/解释：BMI 和 2 型糖尿病存在共同遗传效应的迹象，这表明这些特征部分受相同遗传因素的影响。相比之下，我们的研究结果表明，与身体活动相关的基因与 2 型糖尿病相关的基因本质上不同。
