Diabetic kidney disease (DKD) is a common diabetic complication, which is mainly characterized by damage in renal microvessels. Early diagnosis and active prevention of DKD are the key to improving the prognosis. The blood inflammatory index may be related to DKD.

To explore the value of systemic immune-inflammation index (SII) for the diagnosis of DKD in elderly type 2 diabetes mellitus (T2DM) patients in the community.

A retrospective study was conducted with 327 elderly patients with T2DM who underwent routine physical examination in Community Medical Department, Beijing Chao-yang Hospital (West Branch), Capital Medical University from January to December 2021. They were divided into non-DKD group (n=112) and DKD group (n=215) by the prevalence of DKD. The general data and laboratory examination data of the two groups were collected and compared. Pearson correlation analysis and Spearman rank correlation analysis were used to assess the correlation of urinary albumin/creatinine ratio (UACR) with other various indicators. Multivariate Logistic regression analysis was used to explore the influencing factors of DKD in the patients. The diagnostic value of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and SII for DKD in these patients was evaluated by using the receiver operating characteristic (ROC) curve, and the area under the curve (AUC) with corresponding 95%CI was calculated.

The course of T2DM in DKD group was longer than that in non-DKD group (P<0.05). Moreover, the proportion of patients with hypertension history, fasting plasma glucose (FPG), low-density lipoprotein (LDL), blood urea nitrogen, serum creatinine (Scr), UACR, neutrophils, platelets, NLR, PLR and SII in DKD group were higher than those in non-DKD group (P<0.05). Correlation analysis showed that course of T2DM, FPG, triacylglycerol, LDL, neutrophils, platelets, NLR, PLR and SII were positively related with UACR (r=0.716, 0.114, 0.113, 0.144, 0.533, 0.226, 0.538, 0.430, 0.494, P<0.05). Multivariate Logistic regression analysis showed that course of T2DM〔OR=1.300, 95%CI (1.173, 1.441), P<0.001〕, LDL〔OR=2.565, 95%CI (1.320, 4.985), P=0.005〕, Scr〔OR=1.093, 95%CI (1.046, 1.143), P<0.001〕, NLR〔OR=2.565, 95%CI (1.320, 4.985), P=0.005〕and SII〔OR=1.011, 95%CI (1.007, 1.015), P<0.001〕were associated with DKD in elderly. In diagnosing DKD in these patients, the AUC of NLR was 0.755〔95%CI (0.696, 0.814) 〕, the optimal cut-off value was 2.49, with a sensitivity of 72.1% and a specificity of 70.5%; the AUC of PLR was 0.689〔95%CI (0.624, 0.754) 〕, the optimal cut-off value was 112.81, with a sensitivity of 90.2%, and a specificity of 43.8%; the AUC of SII was 0.836〔95%CI (0.791, 0.881) 〕, the optimal cut-off value was 492.08, with a sensitivity of 80.5% and a specificity of 73.2%.

The course of T2DM, LDL, Scr, NLR and SII may be the influencing factors of DKD in community-dwelling elderly T2DM patients. Moreover, SII has great clinical diagnostic value for DKD in this population.

糖尿病肾病（DKD）是糖尿病常见并发症，以损伤肾脏微血管为主要特征，其早期诊断、积极防治是改善预后的关键。血液炎性指标可能与DKD存在相关性。

探究系统免疫炎症指数（SII）对社区老年2型糖尿病（T2DM）患者并发DKD的诊断价值。

回顾性分析2021年1—12月于首都医科大学附属北京朝阳医院西区社区医疗部常规体检的老年T2DM患者327例为研究对象。根据是否并发DKD将327例T2DM患者分为非DKD组（n=112）和DKD组（n=215）。收集两组患者的一般资料及实验室检查资料并进行比较。采用Pearson相关分析及Spearman秩相关分析探讨老年T2DM患者尿白蛋白/肌酐比值（UACR）与各指标的相关性；采用多因素Logistic回归分析探讨老年T2DM患者并发DKD的影响因素；采用受试者工作特征曲线（ROC曲线）评估中性粒细胞/淋巴细胞比值（NLR）、血小板/淋巴细胞比值（PLR）、SII对社区老年T2DM患者并发DKD的诊断价值，并计算ROC曲线下面积（AUC）及其95%CI。

DKD组患者的T2DM病程长于非DKD组，高血压病史比例、空腹葡萄糖（FPG）、低密度脂蛋白（LDL）、尿素氮（BUN）、血肌酐（Scr）、UACR、中性粒细胞计数、血小板计数、NLR、PLR、SII水平高于非DKD组（P<0.05）。相关性分析结果显示，老年T2DM患者UACR与T2DM病程、FPG、三酰甘油（TG）、LDL、中性粒细胞、血小板、NLR、PLR、SII呈正相关（r=0.716、0.114、0.113、0.144、0.533、0.226、0.538、0.430、0.494，P<0.05）。多因素Logistic回归分析结果显示，T2DM病程〔OR=1.300，95%CI（1.173，1.441），P<0.001〕、LDL〔OR=2.565，95%CI（1.320，4.985），P=0.005〕、Scr〔OR=1.093，95%CI（1.046，1.143），P<0.001〕、NLR〔OR=2.565，95%CI（1.320，4.985），P=0.005〕和SII〔OR=1.011，95%CI（1.007，1.015），P<0.001〕均是老年T2DM患者并发DKD的影响因素。NLR诊断老年T2DM患者并发DKD的AUC为0.755〔95%CI（0.696，0.814）〕，最佳截断值为2.49，灵敏度和特异度分别为72.1%、70.5%；PLR诊断老年T2DM患者并发DKD的AUC为0.689〔95%CI（0.624，0.754）〕，最佳截断值为112.81，灵敏度和特异度分别为90.2%、43.8%；SII诊断老年T2DM患者并发DKD的AUC为0.836〔95%CI（0.791，0.881）〕，最佳截断值为492.08，灵敏度和特异度分别为80.5%、73.2%。

T2DM病程、LDL、Scr、NLR、SII可能是老年T2DM患者并发DKD的影响因素；SII对社区老年T2DM患者并发DKD具有较高的临床诊断价值。