Objective: To compare the effectiveness of moderate exercise for 30 min at 30 min and 60 min after dinner on glycemic control in patients with type 2 diabetes.
Methods: This randomized, crossover, self-controlled pilot study was conducted in 15 inactive patients with type 2 diabetes without serious complications or use of exogenous insulin. The participants completed two randomly ordered exercise protocols (brisk walking for 30 min at 30 min or 60 min after dinner on the exercise day) spaced 1 week apart. All the exercise was performed while maintaining a heart rate reserve of 40%. The interstitial glucose level was monitored using a continuous glucose monitor (CGM) for all the participants, who maintained a standardized diet with routine medications. The 2-h postprandial mean glucose, peak glucose, and glucose area under the curve (AUC) were measured. The mean amplitude of glycemic excursions (MAGE) and other plasma glucose fluctuation parameters in 12 h after dinner, including the mean blood glucose (MBG) and the coefficient variation (CV) of glucose, were also calculated. The incidence of nocturnal hypoglycemia was recorded in all the participants.
Results: The participants had a mean age of 46±11 years with a mean BMI of 25.8±3.1 kg/m2 and a mean HbA1c of 7.7%. No significant differences were found between postprandial 30 min exercise group and postprandial 60 min exercise group in terms of 2-h postprandial mean glucose, peak glucose, glucose AUC, or in MBG, CV and MAGE during the 12-h period after dinner. No nocturnal hypoglycemia occurred in the participants after exercise at 30 or 60 min after dinner. However, significant reductions in the 2-h postprandial glucose levels were detected after exercise at 60 min after dinner as compared to exercise at 30 min.
Conclusions: The timing (30 min vs 60 min after dinner) of moderate exercises for 30 min does not produce significant difference in the improvement of postprandial hyperglycemia in type 2 diabetic patients, and both exercise protocols are safe without a potential risk of hypoglycemia. Nevertheless, exercise at 60 min after dinner can be more effective to lower 2-h postprandial glucose, while exercise at 30 min after dinner might be safer for patients with a high risk of hypoglycemia.
目的: 使用动态血糖监测(CGM)观察晚餐后0.5 h与晚餐后1 h短时中强度运动分别对2型糖尿病(T2DM)患者血糖谱的影响。
方法: 纳入15例平时缺乏运动的无严重并发症T2DM患者(9名男性，6名女性)，且均未使用胰岛素。将受试者随机分配到晚餐后0.5 h运动组和晚餐后1 h运动组，进行0.5 h中强度运动，1周后交叉。运动强度设定为40%储备心律(HRR)。在饮食标准化和药物治疗不变的条件下，通过CGM监测血糖。观察受试者晚餐后2 h平均血糖、高峰血糖及血糖曲线下面积(AUC)等，同时观察餐后12 h平均血糖、血糖变异系数(CV)、平均血糖波动幅度(MAGE)。观察受试者是否出现夜间低血糖。
结果: 晚餐后0.5 h运动组与晚餐后1 h运动组，在餐后2 h平均血糖、高峰血糖及血糖AUC方面均无统计学差异。但晚餐后1 h运动组餐后2 h即时血糖明显低于晚餐后0.5 h运动组(P=0.04)。同样，两组间餐后12 h平均血糖、CV及MAGE均无统计学差异，且均无夜间低血糖发生。
结论: 晚餐后0.5 h与晚餐后1 h进行短时中等强度运动对T2DM患者血糖谱影响无明显差异，均安全有效。晚餐后1 h运动可能对降低餐后2 h血糖更有利，但对于易出现低血糖的患者餐后0.5 h运动可能更安全。
Keywords: diabetes mellitus, type 2; exercise; hyperglycemia; postprandial period.