Departments of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing 100044, China.
J Diabetes Res. 2019 Aug 7;2019:1747684. doi: 10.1155/2019/1747684. eCollection 2019.
Urinary C-peptide creatinine ratio (UCPCR) is used as a marker of endogenous insulin secretion. This study aims to assess the effectiveness of UCPCR for distinguishing between type 1 diabetes (T1DM) and non-T1DM (monogenic diabetes and T2DM) and predicting therapeutic choices in type 2 diabetes (T2DM) patients.
Twenty-three patients with genetically confirmed monogenic diabetes (median age 35.0 years (interquartile range 30.0-47.0), 13 (56.5%) men), 56 patients with T1DM (median age 46.0 years (interquartile range 26.5-59.5), 28 (50.0%) men), 136 patients with T2DM (median age 53.0 years (interquartile range 42.0-60.0), 87 (64.0%) men), and 59 healthy subjects (median age 36.0 years (30.0-42.0), 26 (44.1%) men) were included. UCPCR was collected in the morning. Receiver operating characteristic (ROC) curves were used to identify optimal UCPCR cut-off values to differentiate T1DM from non-T1DM. This UCPCR cut-off was used to divide T2DM patients into two groups, and the two groups were compared.
The UCPCR was lower in patients with T1DM compared with T2DM, monogenic diabetes, and healthy subjects, while the UCPCR was similar in T2DM and monogenic diabetes. A UCPCR cut-off of ≥0.21 nmol/mmol distinguished between monogenic diabetes and T1DM (area under the curve [AUC], 0.949) with 87% sensitivity and 93% specificity. UCPCR ≥ 0.20 nmol/mmol had 82% sensitivity and 93% specificity for distinguishing between T2DM and T1DM, with an AUC of 0.932. UCPCR was not reliable for distinguishing between monogenic diabetes and T2DM (AUC, 0.605). Twenty-five of 136 (18.4%) T2DM patients had UCPCR ≤ 0.20 nmol/mmol. Compared with T2DM patients with a UCPCR > 0.20 nmol/mmol, T2DM patients with UCPCR ≤ 0.20 nmol/mmol had a lower serum C-peptide (fasting C-peptide, 0.39 nmol/L vs. 0.66 nmol/L, < 0.001; postprandial C-peptide, 0.93 nmol/L vs. 1.55 nmol/L, < 0.001), lower BMI (22.8 kg/m vs. 25.2 kg/m, = 0.006), and higher percentage of insulin or secretagogue therapy (92.0% vs. 59.5%, = 0.002).
UCPCR is a practical and noninvasive marker that can distinguish between TIDM and T2DM or monogenic diabetes. UCPCR ≤ 0.20 nmol/mmol reflects severe impaired beta cell function and the need for insulin or secretagogue therapy in T2DM patients.
尿 C-肽肌酐比 (UCPCR) 被用作内源性胰岛素分泌的标志物。本研究旨在评估 UCPCR 区分 1 型糖尿病 (T1DM) 和非 T1DM（单基因糖尿病和 T2DM）以及预测 2 型糖尿病 (T2DM) 患者治疗选择的有效性。
23 名经基因证实的单基因糖尿病患者（中位年龄 35.0 岁（四分位距 30.0-47.0），13 名男性（56.5%））、56 名 T1DM 患者（中位年龄 46.0 岁（四分位距 26.5-59.5），28 名男性（50.0%））、136 名 T2DM 患者（中位年龄 53.0 岁（四分位距 42.0-60.0），87 名男性（64.0%））和 59 名健康受试者（中位年龄 36.0 岁（30.0-42.0），26 名男性（44.1%））纳入研究。清晨采集 UCPCR。使用受试者工作特征 (ROC) 曲线确定区分 T1DM 与非 T1DM 的最佳 UCPCR 截断值。使用该 UCPCR 截断值将 T2DM 患者分为两组，并对两组进行比较。
与 T2DM、单基因糖尿病和健康受试者相比，T1DM 患者的 UCPCR 较低，而 T2DM 和单基因糖尿病患者的 UCPCR 相似。UCPCR 截断值≥0.21nmol/mmol 可区分单基因糖尿病和 T1DM（曲线下面积 [AUC]，0.949），灵敏度为 87%，特异性为 93%。UCPCR≥0.20nmol/mmol 用于区分 T2DM 和 T1DM 的灵敏度为 82%，特异性为 93%，AUC 为 0.932。UCPCR 无法可靠地区分单基因糖尿病和 T2DM（AUC，0.605）。136 名 T2DM 患者中有 25 名（18.4%）的 UCPCR≤0.20nmol/mmol。与 UCPCR＞0.20nmol/mmol 的 T2DM 患者相比，UCPCR≤0.20nmol/mmol 的 T2DM 患者的血清 C 肽较低（空腹 C 肽，0.39nmol/L 比 0.66nmol/L，＜0.001；餐后 C 肽，0.93nmol/L 比 1.55nmol/L，＜0.001），BMI 较低（22.8kg/m 比 25.2kg/m，=0.006），胰岛素或促分泌素治疗的比例较高（92.0%比 59.5%，=0.002）。
UCPCR 是一种实用且非侵入性的标志物，可区分 TIDM 和 T2DM 或单基因糖尿病。UCPCR≤0.20nmol/mmol 反映了 2 型糖尿病患者严重受损的β细胞功能，需要胰岛素或促分泌素治疗。
