Myotonic dystrophy type I (DM1) is an autosomal dominant multisystem disorder characterized by myotonia and muscle weakness. Type 2 diabetes (T2D) and cancer have been shown to be part of the DM1 phenotype. Metformin, a well‐established agent for the management of T2D, is thought to have cancer‐preventive effects in the general population. In our study, we aimed to assess the association between T2D, metformin use and the risk of cancer in DM1 patients. We identified a cohort of 913 DM1 patients and an age‐, sex‐ and clinic‐matched cohort of 12,318 DM1‐free controls from the UK Clinical Practice Research Datalink, a large primary care records database. We used Cox regression models to assess cancer risk in T2D patients who were metformin users or nonusers compared to patients without T2D. Separate analyses were conducted for DM1 patients and controls. T2D was more prevalent in DM1 than in controls (8% vs . 3%, p  < 0.0001). DM1 patients with T2D, compared to those without T2D, were more likely to develop cancer (hazard ratio [HR] = 3.60, 95% confidence interval [CI] = 1.18–10.97; p = 0.02), but not if they were treated with metformin (HR = 0.43, 95% CI = 0.06–3.35; p = 0.42). Among controls, we observed no significant associations between T2D and cancer risk in either users or nonusers of Metformin (HR = 1.28, 95% CI = 0.91–1.79; p = 0.16 and HR = 1.13, 95% CI = 0.72–1.79; p = 0.59, respectively). These results show an association between T2D and cancer risk in DM1 patients and may provide new insights into the possible benefits of Metformin use in DM1.

中文翻译：

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I型强直性营养不良的糖尿病、二甲双胍和癌症风险。

强直性肌营养不良 I 型 (DM1) 是一种常染色体显性遗传的多系统疾病，以肌强直和肌肉无力为特征。2 型糖尿病 (T2D) 和癌症已被证明是 DM1 表型的一部分。二甲双胍是一种成熟的治疗 T2D 的药物，被认为对普通人群具有预防癌症的作用。在我们的研究中，我们旨在评估 DM1 患者 T2D、二甲双胍使用与癌症风险之间的关联。我们从大型初级保健记录数据库 UK Clinical Practice Research Datalink 中确定了 913 名 DM1 患者的队列和年龄、性别和临床匹配的 12,318 名无 DM1 对照队列。我们使用 Cox 回归模型来评估使用或不使用二甲双胍的 T2D 患者与没有 T2D 的患者相比的癌症风险。对 DM1 患者和对照进行了单独的分析。T2D 在 DM1 中比对照组更普遍（8%与。3%，p  < 0.0001）。与没有 T2D 的患者相比，患有 T2D 的 DM1 患者更容易患上癌症（风险比 [HR] = 3.60，95% 置信区间 [CI] = 1.18-10.97；p = 0.02），但如果他们接受了二甲双胍（HR = 0.43, 95% CI = 0.06–3.35；p = 0.42）。在对照组中，我们观察到二甲双胍使用者或非使用者的 T2D 与癌症风险之间没有显着关联（HR = 1.28, 95% CI = 0.91–1.79；p = 0.16 和 HR = 1.13, 95% CI = 0.72–1.79；p = 0.59，分别）。这些结果表明 DM1 患者的 T2D 与癌症风险之间存在关联，并可能为二甲双胍在 DM1 中使用的可能益处提供新的见解。