El Brahimi Sanae, Smith Matthew Lee, Pinheiro Paulo S
Department of Epidemiology and Biostatistics, School of Public Health, University of Nevada, Las Vegas, 4505 S Maryland Pkwy, Box 453036, Las Vegas, NV, 89154, USA.
Center for Population Health and Aging, Texas A&M University, 212 Adriance Lab Rd., 1266 TAMU, Suite 360, College Station, TX, 77843-1266, USA.
Int J Colorectal Dis. 2019 Aug;34(8):1467-1475. doi: 10.1007/s00384-019-03345-8. Epub 2019 Jul 9.
Type 2 diabetes mellitus (diabetes) is a common comorbid condition among older adult colorectal cancer (CRC) patients, yet its effects on CRC mortality have not been adequately examined. This study aims to investigate the association between pre-existing diabetes, with and without complications, and CRC mortality.
Medicare beneficiaries 67 years and older diagnosed with CRC between 2002 and 2011 were studied using the Surveillance, Epidemiology, and End Results (SEER)-Medicare datasets. Pre-existing diabetes was ascertained using validated algorithms. Cox proportional hazards models were used to compare all-cause and CRC-cause-specific death risk differences in relation to prior diabetes diagnosis and diabetes severity (with and without complications) with adjustment for relevant patient demographics and disease characteristics.
Analyses included 93,710 CRC patients. Among the study population, 22,155 (24%) had diabetes prior to CRC diagnosis and 4% had diabetes-related complications (neuropathy, nephropathy, retinopathy, or peripheral circulatory disorders). All-cause CRC mortality was significantly higher among diabetic patients compared with non-diabetic patients (hazard ratio (HR) = 1.20; 95% confidence interval (CI) = 1.17-1.23). The results were more pronounced for diabetes with complications (HR = 1.47; 95% CI = 1.34-1.54). Diabetic patients with complications were 16% more likely to die of colorectal cancer compared with patients without diabetes (HR = 1.16; 95% CI = 1.08-1.25).
Pre-existing diabetes contributes to poorer all-cause mortality among CRC patients and increased mortality from CRC among those with diabetes and complications. Opportunities exist to incorporate diabetes prevention and management interventions during CRC treatment phases among older adults.
2型糖尿病是老年结直肠癌（CRC）患者中常见的合并症，但其对CRC死亡率的影响尚未得到充分研究。本研究旨在探讨既往患糖尿病（有无并发症）与CRC死亡率之间的关联。
利用监测、流行病学和最终结果（SEER）-医疗保险数据集，对2002年至2011年间诊断为CRC的67岁及以上医疗保险受益人进行研究。使用经过验证的算法确定既往患糖尿病情况。采用Cox比例风险模型，比较与既往糖尿病诊断及糖尿病严重程度（有无并发症）相关的全因死亡和CRC特异性死亡风险差异，并对相关患者人口统计学和疾病特征进行调整。
分析纳入93,710例CRC患者。在研究人群中，22,155例（24%）在CRC诊断前患有糖尿病，4%有糖尿病相关并发症（神经病变、肾病、视网膜病变或外周循环障碍）。糖尿病患者的全因CRC死亡率显著高于非糖尿病患者（风险比（HR）=1.20；95%置信区间（CI）=1.17-1.23）。有并发症的糖尿病患者结果更明显（HR=1.47；95%CI=1.34-1.54）。与无糖尿病患者相比，有并发症的糖尿病患者死于结直肠癌的可能性高16%（HR=1.16；95%CI=1.08-1.25）。
既往患糖尿病导致CRC患者全因死亡率更差，且糖尿病合并并发症患者的CRC死亡率增加。在老年患者的CRC治疗阶段，存在纳入糖尿病预防和管理干预措施的机会。
