Objective: To assess the value of neutrophil?to?lymphocyte ratio (NLR) for predicting type 2 diabetes mellitus (T2DM) in patients with chronic obstructive pulmonary disease (COPD).
Methods: A cohort of 404 non?diabetic patients diagnosed with stable COPD between January, 2010 and December, 2012 at Zhujiang Hospital were enrolled and followed up for 3 years, during which fast blood glucose (FBG) was monitored every 6 months. The primary endpoint was the occurrence of T2DM, and the cumulative incidence of T2DM in this cohort was calculated. The patients who developed T2DM and those without T2DM at the end of the follow?up were compared for clinical parameters to identify the potential predictors for T2DM in patients with stable COPD.
Results: After follow?up for a mean of 2.1 years, 41 (10.1%) patients with COPD developed T2DM, who showed significantly higher baseline NLR levels than those without T2DM (P<0.001). The receiver?operating characteristic (ROC) analysis revealed that the optimum cut?off value for NLR was 5.626. Spearman rank correlation analysis suggested that the incidence of T2DM in the patients was positively correlated with the number of hospital admissions for acute exacerbation of COPD in the past year (r=0.136, P=0.006), hypertension (r=0.151, P=0.002) and NLR (r=0.340, P<0.001). Logistic regression analysis identified triglyceride (TG) (P=0.047) and NLR (P<0.001) as the independent risk factors for T2DM in patients with COPD.
Conclusion: The occurrence of T2DM in COPD patients is closely related to NLR level, which may serve as an early predictor for T2DM in these patients.
目的: 探讨中性粒细胞/淋巴细胞比率（NLR）在慢性阻塞性肺疾病（COPD）患者合并2型糖尿病（T2DM）的预测价值。
方法: 采用前瞻性研究方法收集2010年1月~2012年12月南方医科大学珠江医院确诊为稳定期且未合并T2DM的404例COPD患者。入组后每半年随访1次，随访重点监测空腹血糖，诊断T2DM即结束随访，最长随访时间为3年。分析COPD患者中T2DM的累积发病率。根据随访期间是否发生T2DM，将受试者分为COPD合并T2DM组和COPD未合并T2DM组（对照组），比较两组中各项指标，探索COPD患者发生T2DM的早期预测指标。
结果: 所有患者平均门诊随访2.1年，其中41名患者发生T2DM，COPD合并T2DM 3年累计发病率为10.1%。本研究发现发生T2DM的COPD患者的NLR值在合并T2DM前与对照组差异存在统计学意义（P < 0.001）。ROC曲线显示NLR的最佳阈值为5.626。Spearman秩相关性分析显示T2DM的发生与既往1年COPD急性加重住院次数（r=0.136，P=0.006）、高血压（r=0.151，P=0.002）和NLR（r=0.340，P < 0.001）呈正相关。多因素Logistic回归分析显示三酰甘油（TG）（P=0.047）和NLR（P < 0.001）是COPD患者合并T2DM的独立危险因素。
结论: COPD合并T2DM与NLR水平密切相关，NLR可能是COPD患者合并T2DM的早期预测指标。