Introduction This study aimed to assess the association between fasting serum C-peptide levels and the presence of impaired awareness of hypoglycemia (IAH) in people with type 1 diabetes. Research design and methods We performed a cross-sectional study among 509 individuals with type 1 diabetes (diabetes duration 5–65 years). Extensive clinical data and fasting serum C-peptide concentrations were collected and related to the presence or absence of IAH, which was evaluated using the validated Dutch version of the Clarke questionnaire. A multivariable logistic regression model was constructed to investigate the association of C-peptide and other clinical variables with IAH. Results In 129 (25%) individuals, residual C-peptide secretion was detected, while 75 (15%) individuals reported IAH. The median (IQR) C-peptide concentration among all participants was 0.0 (0.0–3.9) pmol/L. The prevalence of severe hypoglycemia was lower in people with demonstrable C-peptide versus those with absent C-peptide (30% vs 41%, p=0.025). Individuals with IAH were older, had longer diabetes duration, more frequently had macrovascular and microvascular complications, and more often used antihypertensive drugs, antiplatelet agents and cholesterol-lowering medication. There was a strong association between IAH and having a severe hypoglycemia in the preceding year. In multivariable regression analysis, residual C-peptide, either continuously or dichotomous, was associated with lower prevalence of IAH (p=0.040–0.042), while age at diabetes onset (p=0.001), presence of microvascular complications (p=0.003) and body mass index (BMI) (p=0.003) were also independently associated with the presence of IAH. Conclusions Higher BMI, the presence of microvascular complications and higher age at diabetes onset were independent risk factors for IAH in people with type 1 diabetes, while residual C-peptide secretion was associated with lower risk of this complication. Data are available upon reasonable request.

中文翻译：

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1 型糖尿病患者的残余 C 肽分泌和低血糖意识

简介 本研究旨在评估 1 型糖尿病患者空腹血清 C 肽水平与低血糖 (IAH) 意识受损之间的关联。研究设计和方法 我们对 509 名 1 型糖尿病患者（糖尿病病程 5-65 年）进行了横断面研究。收集了广泛的临床数据和空腹血清 C 肽浓度，并与 IAH 的存在或不存在相关，并使用经过验证的荷兰版克拉克问卷进行评估。构建多变量逻辑回归模型以研究 C 肽和其他临床变量与 IAH 的关联。结果 129 (25%) 人检测到残留的 C 肽分泌，而 75 (15%) 人报告 IAH。所有参与者的中位 (IQR) C 肽浓度为 0.0 (0.0–3.9) pmol/L。与没有 C 肽的人相比，具有明显 C 肽的人的严重低血糖发生率较低（30% 对 41%，p=0.025）。IAH 患者年龄较大，糖尿病病程较长，出现大血管和微血管并发症的频率更高，使用抗高血压药物、抗血小板药物和降胆固醇药物的频率更高。IAH 与前一年的严重低血糖症之间存在很强的关联。在多变量回归分析中，残留的 C 肽，无论是连续的还是二分的，与 IAH 的较低患病率相关（p=0.040-0.042），而糖尿病发病年龄（p=0.001）、微血管并发症的存在（p=0.003）和体重指数 (BMI) (p=0. 003) 也与 IAH 的存在独立相关。结论 较高的 BMI、存在微血管并发症和较高的糖尿病发病年龄是 1 型糖尿病患者 IAH 的独立危险因素，而残留的 C 肽分泌与较低的这种并发症的风险相关。可根据合理要求提供数据。