Diabetes Care：闭环胰岛素给药系统有益于预防T1DM患者夜间低血糖风险

1型糖尿病患者午后运动增加夜间低血糖(NH)风险。来自康涅狄格州耶鲁大学医学院儿科的Sherr博士等人进行了一项研究，研究假设：无论之前有或没有午后运动，在预防NH和维持夜间目标血糖范围内较高比例的血糖水平上，自动反馈控制的闭环(CL)胰岛素给药系统优于开环(OL)给药系统。研究发现，无论午后的活动水平如何，CL胰岛素给药系统是一种有效的降低NH风险的方法，同时增加血糖值在目标范围内的比例。研究结果在线发表于2013年6月11日的美国《糖尿病治疗》(Diabetes Care)杂志上。

受试者按随机顺序完成2项48h的住院研究，研究分别采用普通OL控制给药系统和比例-积分-微分控制技术联合胰岛素反馈系统的CL控制给药系统。每个阶段包括久坐不动日和运动日，下午3点按照标准化方案在跑步机上运动60min，使心率达到最大心率的65-70%。

结果显示，在12名患者(年龄12-26岁，A1C 7.4±0.6%)中，OL控制给药期间，事先运动增加NH发生频率(参考血糖值<60mg/dL)，为6-8次。相反，CL控制给药期间，无论有无事先运动，每个研究阶段夜间仅有一次NH发生(P=0.04 vs. OL控制给药)。整个晚上，采用CL控制给药血糖值在目标范围的比例升高(P<0.0001)。CL控制与OL控制比较，运动后夜间(下午10:00到上午2:00之间)胰岛素给药量下降(P=0.008)。

研究发现，无论午后的活动水平如何，CL胰岛素给药系统是一种有效的降低NH风险的方法，同时增加血糖值在目标范围内的比例。这些数据提示，CL控制系统将有益于1型糖尿病患者，尽管仅限于晚上。

Reduced Hypoglycemia and Increased Time in Target Using Closed-Loop Insulin Delivery During Nights With or Without Antecedent Afternoon Exercise in Type 1 Diabetes.
Abstract
OBJECTIVEAfternoon exercise increases the risk of nocturnal hypoglycemia (NH) in subjects with type 1 diabetes. We hypothesized that automated feedback-controlled closed-loop (CL) insulin delivery would be superior to open-loop (OL) control in preventing NH and maintaining a higher proportion of blood glucose levels within the target blood glucose range on nights with and without antecedent afternoon exercise.RESEARCH DESIGN AND METHODSSubjects completed two 48-h inpatient study periods in random order: usual OL control and CL control using a proportional-integrative-derivative plus insulin feedback algorithm. Each admission included a sedentary day and an exercise day, with a standardized protocol of 60 min of brisk treadmill walking to 65-70% maximum heart rate at 3:00 p.m.RESULTSAmong 12 subjects (age 12-26 years, A1C 7.4 ± 0.6%), antecedent exercise increased the frequency of NH (reference blood glucose <60 mg/dL) during OL control from six to eight events. In contrast, there was only one NH event each on nights with and without antecedent exercise during CL control (P = 0.04 vs. OL nights). Overnight, the percentage of glucose values in target range was increased with CL control (P < 0.0001). Insulin delivery was lower between 10:00 p.m. and 2:00 a.m. on nights after exercise on CL versus OL, P = 0.008.CONCLUSIONSCL insulin delivery provides an effective means to reduce the risk of NH while increasing the percentage of time spent in target range, regardless of activity level in the mid-afternoon. These data suggest that CL control could be of benefit to patients with type 1 diabetes even if it is limited to the overnight period.