University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
Diabet Med. 2012 Oct;29(10):e361-4. doi: 10.1111/j.1464-5491.2012.03747.x.
There are previous suggestions of increased C-peptide concentration in women with Type 1 diabetes during pregnancy. Our aim was to re-evaluate the hypothesis of a pregnancy-induced increase by measuring plasma C-peptide concentration in women with stable blood glucose control under standardized fasting and meal-stimulated conditions.
Ten women with Type 1 diabetes; median age 31.1 years, median diabetes duration 19 years, median HbA(1c) 52 mmol/mol (6.9%) were admitted to a clinical research facility for two 24-h visits in early (12-16 weeks) and late (28-32 weeks) pregnancy. Women They ate standardized study meals - 80-g carbohydrate dinner, 60-g carbohydrate breakfast, and fasted between meals and overnight. Closed-loop insulin delivery maintained stable and comparable glycaemic conditions. Paired samples for plasma glucose and C-peptide were obtained.
Plasma glucose levels were comparable in early (median 6.5 mmol/l; interquartile range 5.6-8.6) and late pregnancy (median 7.0 mmol/l; interquartile range 6.1-7.8; P = 0.72). There was no change in fasting or meal-stimulated plasma C-peptide concentration from early to late pregnancy; mean difference 4.0 pmol/l (95% CI -6.0 to 7.0; P = 0.9). Four women had detectable C-peptide; peak (range) early vs. late pregnancy 48.5 (10-115) vs. 40.0 pmol/l (80-105); P = 0.5, which was weakly associated with plasma glucose; R(2) = 0.15, P < 0.0001.
We found no gestational changes in plasma C-peptide concentration. Previously reported increases may reflect differences in glucose control and/or exogenous insulin doses. This study highlights the importance and challenges of standardizing experimental conditions for accurate plasma C-peptide measurement during Type 1 diabetes pregnancy.
有研究提示，1 型糖尿病女性在妊娠期间 C 肽浓度增加。本研究旨在通过测量在标准化空腹和餐时刺激条件下血糖控制稳定的女性的血浆 C 肽浓度，重新评估妊娠诱导 C 肽浓度增加的假说。
10 名血糖控制稳定的 1 型糖尿病女性（中位年龄 31.1 岁，中位糖尿病病程 19 年，中位糖化血红蛋白 52mmol/mol[6.9%]）入住临床研究中心，分别在早孕期（12-16 周）和晚孕期（28-32 周）进行两次 24 小时访视。女性进食标准化研究餐-80g 碳水化合物晚餐、60g 碳水化合物早餐，并且两餐之间和夜间禁食。闭环胰岛素输送维持血糖稳定且相似。采集配对的血浆葡萄糖和 C 肽样本。
早孕期（中位数 6.5mmol/L；四分位间距 5.6-8.6）和晚孕期（中位数 7.0mmol/L；四分位间距 6.1-7.8；P=0.72）的血浆葡萄糖水平相似。早孕期到晚孕期空腹和餐时刺激的血浆 C 肽浓度没有变化；平均差值 4.0pmol/L（95%可信区间-6.0 至 7.0；P=0.9）。4 名女性的 C 肽可检测到；早孕期（范围）与晚孕期的峰值（范围）分别为 48.5（10-115）pmol/L 和 40.0（80-105）pmol/L；P=0.5，与血浆葡萄糖呈弱相关；R²=0.15，P＜0.0001。
我们没有发现血浆 C 肽浓度有妊娠相关的变化。之前报道的增加可能反映了血糖控制和/或外源性胰岛素剂量的差异。本研究强调了在 1 型糖尿病妊娠期间准确测量血浆 C 肽时标准化实验条件的重要性和挑战。
