Objective Whether varying degrees of glycaemic control impact colonic neoplasm risk in patients with diabetes mellitus (DM) remains uncertain. Design Patients with newly diagnosed DM were retrieved from 2005 to 2013. Optimal glycaemic control at baseline was defined as mean haemoglobin A1c (HbA1c)<7%. Outcomes of interest included colorectal cancer (CRC) and colonic adenoma development. We used propensity score (PS) matching with competing risk models to estimate subdistribution HRs (SHRs). We further analysed the combined effect of baseline and postbaseline glycaemic control based on time-weighted mean HbA1c during follow-up. Results Of 88 468 PS-matched patients with DM (mean (SD) age: 61.5 (±11.7) years; male: 47 127 (53.3%)), 1229 (1.4%) patients developed CRC during a median follow-up of 7.2 (IQR: 5.5–9.4) years. Optimal glycaemic control was associated with lower CRC risk (SHR 0.72; 95% CI 0.65 to 0.81). The beneficial effect was limited to left-sided colon (SHR 0.71; 95% CI 0.59 to 0.85) and rectum (SHR 0.71; 95% CI 0.57 to 0.89), but not right-sided colon (SHR 0.86; 95% CI 0.67 to 1.10). Setting suboptimal glycaemic control at baseline/postbaseline as a reference, a decreased CRC risk was found in optimal control at postbaseline (SHR 0.79), baseline (SHR 0.71) and both time periods (SHR 0.61). Similar associations were demonstrated using glycaemic control as a time-varying covariate (HR 0.75). A stepwise greater risk of CRC was found (Ptrend<0.001) with increasing HbA1c (SHRs 1.34, 1.30, 1.44, 1.58 for HbA1c 7.0% to <7.5%, 7.5% to <8.0%, 8.0% to <8.5% and ≥8.5%, respectively). Optimal glycaemic control was associated with a lower risk of any, non-advanced and advanced colonic adenoma (SHRs 0.73–0.87). Conclusion Glycaemic control in patients with DM was independently associated with the risk of colonic adenoma and CRC development with a biological gradient. Data may be obtained from a third party and are not publicly available.

中文翻译：

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糖尿病患者的最佳血糖控制以及降低结直肠腺瘤和癌症的风险：一项基于人群的队列研究

目的 不同程度的血糖控制是否影响糖尿病 (DM) 患者的结肠肿瘤风险仍不确定。设计 检索 2005 年至 2013 年新诊断 DM 的患者。基线最佳血糖控制定义为平均糖化血红蛋白 (HbA1c)<7%。感兴趣的结果包括结直肠癌（CRC）和结肠腺瘤的发展。我们使用倾向评分 (PS) 与竞争风险模型匹配来估计子分布 HR (SHR)。我们进一步分析了随访期间基于时间加权平均 HbA1c 的基线和基线后血糖控制的综合效果。结果 在 88 468 名 PS 匹配的 DM 患者中（平均 (SD) 年龄：61.5 (±11.7) 岁；男性：47 127 名 (53.3%)），其中 1,229 名 (1.4%) 患者在中位随访时间 7.2 天内发展为 CRC （IQR：5.5–9.4）年。最佳血糖控制与较低的 CRC 风险相关（SHR 0.72；95% CI 0.65 至 0.81）。有益效果仅限于左侧结肠（SHR 0.71；95% CI 0.59 至 0.85）和直肠（SHR 0.71；95% CI 0.57 至 0.89），但不包括右侧结肠（SHR 0.86；95% CI 0.67 至 0.89）。 1.10）。以基线/基线后次优血糖控制为参考，在基线后（SHR 0.79）、基线（SHR 0.71）和两个时间段（SHR 0.61）的最佳控制中发现CRC风险降低。使用血糖控制作为时变协变量（HR 0.75）证明了类似的关联。随着 HbA1c 的增加，CRC 风险逐步增大 (Ptrend<0.001)（HbA1c 的 SHR 为 1.34、1.30、1.44、1.58，HbA1c 7.0% 至 <7.5%、7.5% 至 <8.0%、8.0% 至 <8.5% 和 ≥8.5） ％， 分别）。最佳血糖控制与任何非晚期和晚期结肠腺瘤的较低风险相关（SHR 0.73-0.87）。结论 DM 患者的血糖控制与结肠腺瘤和 CRC 发展风险独立相关，并具有生物梯度。数据可能从第三方获得，并且不公开。