The prevalence of diabetes is increasing year-on-year. However, current diagnostic methods have many deficiencies in early identification of type 2 diabetes mellitus (T2DM) . Epigenetic factors may be associated with the development and secretory function of pancreatic islet β cells, which reduces the sensitivity of the body to the effects of insulin, ultimately leading to the development of T2DM.

To identify differentially expressed hsa_circ_0005414, hsa_circ_0139634, hsa_circ_0032491 and hsa_circ_0002922 in the peripheral blood of Han Chinese patients with T2DM to assess the clinical significance, and to explore the relationship between candidate circRNAs and T2DM in Han Chinese.

From the Department of Endocrinology and Metabolism, the First Affiliated Hospital of Shihezi University School of Medicine between September 2020 and June 2021, 21 Han Chinese patients with T2DM were selected. 22 healthy examinees were also selected as controls. Glucose metabolism indices and expression levels (2^-ΔΔCT) of the four candidate circRNAs were measured. The relationship between expression levels of candidate circRNAs and glucose metabolism indices was explored using multiple linear regression analysis. Univariate Logistic regression analysis was used to explore the correlation of expression levels of candidate circRNAs with the risk of T2DM. Receiver operating characteristic (ROC) curve analysis was used to assess diagnostic values of these candidate circRNAs for T2DM.

T2DM patients had higher relative expression levels of hsa_circ_0032491 and hsa_circ_0002922, and lower relative expression levels of hsa_circ_0005414 and hsa_circ_0139634 than did the controls (P<0.05) . Multiple linear regression analysis showed that fasting plasma glucose and Log₂-transformed fasting insulin were associated with the expression level of hsa_circ_0032491 in Chinese Han with T2DM (P<0.05) , with an R²=0.503. The areas under the ROC curves of hsa_circ_0005414, hsa_circ_0139634, hsa_circ_0032491, and hsa_circ_0002922 for the diagnosis of T2DM in Chinese Han were 0, 0.199, 0.968, and 0.844, respectively. Univariate Logistic regression analysis showed that elevated relative expression levels of hsa_circ_0139634 may be associated with reduced risk of T2DM 〔OR=0.092, 95%CI (0.016, 0.520) , P=0.007〕, while elevated relative expression levels of hsa_circ_0032491〔OR=3.607, 95%CI (1.625, 8.004) , P=0.002〕 and hsa_circ_0002922〔OR=5.105, 95%CI (1.683, 15.482) , P=0.004〕 may be associated with increased risk of T2DM.

hsa_circ_0032491 and hsa_circ_0002922 could be used as biomarkers for T2DM in Han Chinese. hsa_circ_0139634, hsa_circ_0032491 and hsa_circ_0002922 could be independent predictors of T2DM in Han Chinese population. An increase in the relative expression level of hsa_circ_0139634 decreased the risk of T2DM, while an increase in the relative expression levels of hsa_circ_0032491 and hsa_circ_0002922 increased the risk of T2DM, suggesting that these three candidate circRNAs may play an important role in the development of T2DM.

糖尿病患病率逐年上升，目前的诊断方法对2型糖尿病（T2DM）的早期诊断存在很多不足之处。表观遗传学可影响胰岛β细胞的发育和分泌功能、降低机体对胰岛素的敏感性等，最终导致T2DM的发生。

观察汉族T2DM患者外周血hsa_circ_0005414、hsa_circ_0139634、hsa_circ_0032491、hsa_circ_0002922的差异表达情况及临床意义，探讨候选环状RNA（circRNAs）与汉族T2DM的关系。

选取2020年9月至2021年6月在石河子大学医学院第一附属医院内分泌代谢科就诊的21例汉族T2DM患者（T2DM组），并选取同期体检的汉族健康者22例（健康对照组）。检测各组糖代谢相关指标和4个候选circRNAs的相对表达水平（2^-ΔΔCT）。采用多元线性回归分析探究候选circRNAs与糖代谢相关指标的关系；采用受试者工作特征（ROC）曲线和单因素Logistic回归分析探究候选circRNAs与T2DM患病风险之间的相关性，并评估其对T2DM的诊断价值。

T2DM组hsa_circ_0032491、hsa_circ_0002922相对表达水平均高于健康对照组，hsa_circ_0005414、hsa_circ_0139634均低于健康对照组（P<0.05）。多元线性回归分析结果显示，空腹血糖（FPG）、Log₂空腹胰岛素（FINS）是影响汉族人群hsa_circ_0032491相对表达水平的影响因素（P<0.05），且R²=0.503。hsa_circ_0005414、hsa_circ_0139634、hsa_circ_0032491、hsa_circ_0002922诊断T2DM的ROC曲线下面积分别为0、0.199、0.968、0.844。单因素Logistic回归分析结果显示，hsa_circ_0139634相对表达水平升高可降低T2DM的患病风险〔OR=0.092，95%CI（0.016，0.520），P=0.007〕，hsa_circ_0032491〔OR=3.607，95%CI（1.625，8.004），P=0.002〕、hsa_circ_0002922〔OR=5.105，95%CI（1.683，15.482），P=0.004〕相对表达水平升高可增加T2DM的患病风险。

hsa_circ_0032491、hsa_circ_0002922可作为诊断汉族T2DM的生物学标志物；hsa_circ_0139634、hsa_circ_0032491、hsa_circ_0002922是汉族T2DM患病的独立预测因子，hsa_circ_0139634相对表达水平升高可降低T2DM的患病风险，hsa_circ_0032491、hsa_circ_0002922相对表达水平升高可增加T2DM患病风险，其可能在T2DM发病机制中起重要作用。