Postprandial interval walking-effect on blood glucose in pregnant women with gestational diabetes

BACKGROUND: During pregnancy, postprandial hyperglycemia may increase the risk of complications such as fetal macrosomia. However, evidence on beneficial effects of physical activity on postprandial hyperglycemia is sparse. OBJECTIVE: This study aimed to investigate the effect of 20 minutes of postprandial interval walking on glycemic control and glycemic variability in pregnant women diagnosed as having gestational diabetes mellitus. STUDY DESIGN: A crossover controlled trial including 14 pregnant women (gestational age 31.8 +/- 1.3 weeks) diagnosed as having gestational diabetes mellitus (75 g oral glucose load with 2-hour venous plasma glucose of >= 9.0 mmol/L) was conducted. Participants completed a 4-day intervention period and a 4-day control period with 3 days in between. In each study period, participants received a fixed and identical diet. In the intervention period, participants engaged in 20 minutes of postprandial interval walking after breakfast, lunch, and dinner. Interval walking comprised alternating 3 minutes of slow and fast intervals. Interstitial glucose concentrations were determined during both study periods with a continuous glucose monitor. The mixed effects model was used to compare differences between exercise and no exercise. RESULTS: Of note, 20 minutes of postprandial interval walking significantly reduced glycemic control during daytime hours relative to the control period (4-day mean glucose, 5.31 [5.04-5.59] vs 5.53 [5.25-5.81] mmol/L [95.6 (90.7-100.6) vs 99.5 (94.5-104.6) mg/dL]; P<.05). On each individual trial day, interval walking significantly reduced glycemic control during daytime hours on day 1 (mean glucose, 5.19 [4.92-5.47] vs 5.55 [5.27-5.83] mmol/L [93.4 (88.6-98.5) vs 99.9 (94.9-104.9) mg/dL]; P=.00), day 2 (mean glucose, 5.32 [5.05-5.60] vs 5.57 [5.29-5.84] mmol/L [95.8 (90.9-100.8) vs 100.3 (95.2-105.1) mg/dL]; P=.00), and day 3 (mean glucose, 5.27 [5.00- 5.54] vs 5.46 [5.19-5.74] mmol/L [94.9 (90.0-99.7) vs 98.3 (93.4-103.3) mg/dL]; P=.00), but not on day 4. CONCLUSION: A total of 20 minutes of postprandial interval walking seems to be an effective way to control postprandial glucose excursions in women with gestational diabetes mellitus.