To assess the progression of type 1 diabetes using time to peak glucose or C-peptide during oral glucose tolerance tests (OGTTs) in autoantibody-positive relatives of people with type 1 diabetes.

We examined 2-h OGTTs of participants in the Diabetes Prevention Trial Type 1 (DPT-1) and TrialNet Pathway to Prevention (PTP) studies. We included 706 DPT-1 participants (mean ± SD age, 13.84 ± 9.53 years; BMI Z-score, 0.33 ± 1.07; 56.1% male) and 3,720 PTP participants (age, 16.01 ± 12.33 years; BMI Z-score, 0.66 ± 1.3; 49.7% male). Log-rank testing and Cox regression analyses with adjustments (age, sex, race, BMI Z-score, HOMA-insulin resistance, and peak glucose/C-peptide levels, respectively) were performed.

In each of DPT-1 and PTP, higher 5-year diabetes progression risk was seen in those with time to peak glucose >30 min and time to peak C-peptide >60 min (P < 0.001 for all groups), before and after adjustments. In models examining strength of association with diabetes development, associations were greater for time to peak C-peptide versus peak C-peptide value (DPT-1: ² = 25.76 vs. ² = 8.62; PTP: ² = 149.19 vs. ² = 79.98; all P < 0.001). Changes in the percentage of individuals with delayed glucose and/or C-peptide peaks were noted over time.

In two independent at-risk populations, we show that those with delayed OGTT peak times for glucose or C-peptide are at higher risk of diabetes development within 5 years, independent of peak levels. Moreover, time to peak C-peptide appears more predictive than the peak level, suggesting its potential use as a specific biomarker for diabetes progression.

在 1 型糖尿病患者的自身抗体阳性亲属中，在口服葡萄糖耐量试验 (OGTT) 期间使用葡萄糖峰值时间或 C 肽评估 1 型糖尿病的进展。

We examined 2-h OGTTs of participants in the Diabetes Prevention Trial Type 1 (DPT-1) and TrialNet Pathway to Prevention (PTP) studies. We included 706 DPT-1 participants (mean ± SD age, 13.84 ± 9.53 years; BMI Z-score, 0.33 ± 1.07; 56.1% male) and 3,720 PTP participants (age, 16.01 ± 12.33 years; BMI Z-score, 0.66 ± 1.3; 49.7% male). Log-rank testing and Cox regression analyses with adjustments (age, sex, race, BMI Z-score, HOMA-insulin resistance, and peak glucose/C-peptide levels, respectively) were performed.

在 DPT-1 和 PTP 中，葡萄糖峰值时间 > 30 分钟和 C 肽峰值时间 > 60 分钟的患者在前后均有较高的 5 年糖尿病进展风险（所有组 P < 0.001 ）调整。在检查与糖尿病发展关联强度的模型中，C 肽峰值时间与 C 肽峰值之间的关联更大（DPT-1：² = 25.76 对² = 8.62；PTP：² = 149.19 对² = 79.98 ; 所有P < 0.001)。随着时间的推移，注意到具有延迟葡萄糖和/或 C 肽峰值的个体百分比的变化。

在两个独立的高危人群中，我们表明，葡萄糖或 C 肽的 OGTT 峰值时间延迟的人在 5 年内患糖尿病的风险更高，与峰值水平无关。此外，C 肽达到峰值的时间似乎比峰值水平更具预测性，表明它可能用作糖尿病进展的特定生物标志物。