Guilhem Isabelle, Penet Maxime, Paillard Anaïs, Carpentier Marc, Esvant Annabelle, Lefebvre Marie-Anne, Poirier Jean-Yves
1 CHU de Rennes, Department of Endocrinology, Diabetes and Nutrition, Rennes, France.
2 CHU de Rennes, CIC INSERM 1414, Rennes, France.
J Diabetes Sci Technol. 2017 Sep;11(5):1007-1014. doi: 10.1177/1932296817717503. Epub 2017 Jul 5.
The purpose was to assess the efficacy of a new closed-loop algorithm (Saddle Point Model Predictive Control, SP-MPC) in achieving nocturnal normoglycemia while reducing the risk of hypoglycemia in patients with type 1 diabetes.
In this randomized crossover study, 10 adult patients (mean hemoglobin A1c 7.35 ± 1.04%) were assigned to be treated overnight by open loop using sensor-augmented pump therapy (open-loop SAP) or manual closed-loop delivery. During closed loop, insulin doses were calculated using the SP-MPC algorithm and administered as manual boluses every 15 minutes from 9:00 pm to 8:00 am. Patients consumed a self-selected meal (65-125 g of carbohydrates) at 7:00 pm accompanied by their usual prandial bolus. Blood glucose was measured every 30 minutes. The primary endpoints were the time spent in target (70-145 mg/dl) and time spent below 70 mg/dl from 11:00 pm to 8:00 am.
Time spent in target did not differ between closed-loop and open-loop SAP. The number of hypoglycemic events (<70 mg/dl) was reduced 2.8-fold in closed loop (n = 5, median = 0/patient/hour; interquartile range: 0-0.11) as compared to open-loop SAP (n = 14, median = 0.22/patient/hour, 0.02-0.22) ( P = .02). The area under the curve for sensor glucose values >145 mg/dl was significantly lower during closed-loop than during open-loop SAP ( P = .03) as well as HBGI ( P = .02).
This pilot study suggests that the use of the SP-MPC algorithm may improve mean overnight glucose control and reduce the number of hypoglycemic events as compared to SAP therapy.
目的是评估一种新的闭环算法（鞍点模型预测控制，SP-MPC）在实现1型糖尿病患者夜间血糖正常化的同时降低低血糖风险的疗效。
在这项随机交叉研究中，10名成年患者（平均糖化血红蛋白A1c 7.35±1.04%）被分配接受使用传感器增强泵疗法的开环过夜治疗（开环SAP）或手动闭环给药。在闭环期间，使用SP-MPC算法计算胰岛素剂量，并在晚上9点至早上8点每15分钟作为手动推注给药。患者在晚上7点食用自选餐（65-125克碳水化合物），并伴有常规餐时推注。每30分钟测量一次血糖。主要终点是晚上11点至早上8点处于目标范围（70-145毫克/分升）的时间和低于70毫克/分升的时间。
闭环和开环SAP之间处于目标范围的时间没有差异。与开环SAP相比，闭环中的低血糖事件（<70毫克/分升）数量减少了2.8倍（n = 5，中位数 = 0/患者/小时；四分位间距：0-0.11），而开环SAP为（n = 14，中位数 = 0.22/患者/小时，0.02-0.22）（P = 0.02）。闭环期间传感器葡萄糖值>145毫克/分升的曲线下面积显著低于开环SAP期间（P = 0.03）以及高血糖指数（P = 0.02）。
这项初步研究表明，与SAP疗法相比，使用SP-MPC算法可能改善夜间平均血糖控制并减少低血糖事件的数量。
