BACKGROUND Alternate methods for characterizing oral glucose tolerance tests (OGTT) have emerged as superior to the 2-hour glucose in identifying individuals at risk for type 2 diabetes. The significance of these methods in cystic fibrosis (CF) is unclear. We compared 3 OGTT classifications in youth with CF: 1. curve shape (biphasic vs. monophasic), 2. time to glucose peak (≤30minutes vs. >30minutes), 3. 1-hour glucose (1hG) <155 mg/dL vs. ≥155 mg/dL to traditional OGTT criteria to determine which best identifies lower oral disposition index (oDI), pulmonary function, and body mass index (BMI). METHODS Youth 10-18 years with CF, not on insulin, underwent 2-hour OGTT. Glucoses were classified by traditional criteria and 3 alternate methods as normal (biphasic curve, glucose peak ≤30minutes, and/or 1hG <155 mg/dL) or abnormal (monophasic curve, glucose peak >30minutes, and/or 1hG ≥155 mg/dL). oDI was calculated [1/fasting insulin*(ΔInsulin0-30 min/ΔGlucose0-30 min)]. Mean oDI, BMI, forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC) were compared by OGTT classification. RESULTS Fifty-two youth with CF participated (mean±SD age 13±4years; 37% male; BMI z-score 0.0±0.8; FEV1 88±16.3%; FVC 97±14.8%). Late time to peak glucose and 1hG ≥155 mg/dL identified individuals with lower oDI (p=0.01); traditional OGTT criteria for prediabetes did not. No OGTT classification identified individuals with worse BMI nor pulmonary function. oDI was not associated with BMI, FEV1, or FVC. CONCLUSIONS Alternate OGTT measures including time to peak glucose and 1hG better identify oDI abnormalities than traditional criteria. Further studies are required to determine whether these alternate methods identify individuals with CF at risk for future clinical decline.

中文翻译：

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口服葡萄糖耐量试验中延迟的葡萄糖峰值和升高的 1 小时葡萄糖可识别患有囊性纤维化且口腔处置指数较低的青年

背景 用于表征口服葡萄糖耐量试验 (OGTT) 的替代方法已经出现，在识别具有 2 型糖尿病风险的个体方面优于 2 小时葡萄糖。这些方法在囊性纤维化 (CF) 中的意义尚不清楚。我们比较了 CF 青年的 3 种 OGTT 分类：1. 曲线形状（双相与单相），2. 达到葡萄糖峰值的时间（≤30 分钟与 >30 分钟），3. 1 小时葡萄糖 (1hG) <155 mg/dL与 ≥155 mg/dL 相比传统 OGTT 标准，以确定哪个最能识别较低的口腔处置指数 (oDI)、肺功能和体重指数 (BMI)。方法 10-18 岁患有 CF 的青少年，未使用胰岛素，接受 2 小时 OGTT。葡萄糖按传统标准和 3 种替代方法分类为正常（双相曲线、葡萄糖峰值 ≤30 分钟和/或 1hG < 155 mg/dL）或异常（单相曲线、葡萄糖峰值 >30 分钟和/或 1hG ≥155 mg/dL）。计算 oDI [1/空腹胰岛素*(ΔInsulin0-30 min/ΔGlucose0-30 min)]。通过OGTT分类比较平均oDI、BMI、1秒用力呼气量（FEV1）和用力肺活量（FVC）。结果 52 名 CF 青年参与（平均±SD 年龄 13±4 岁；37% 男性；BMI z 评分 0.0±0.8；FEV1 88±16.3%；FVC 97±14.8%）。葡萄糖峰值延迟时间和 1hG ≥155 mg/dL 确定了 oDI 较低的个体 (p=0.01)；传统的 OGTT 糖尿病前期标准没有。没有 OGTT 分类识别出 BMI 或肺功能较差的个体。oDI 与 BMI、FEV1 或 FVC 无关。结论 替代 OGTT 测量，包括达到葡萄糖峰值的时间和 1hG 比传统标准更好地识别 oDI 异常。