BACKGROUND AND PURPOSE:

• Postprandial hyperglycemia during pregnancy may increase the risk of fetal macrosomia
• Whether physical activity can benefit women with postprandial hyperglycemia is not well understood
• Andersen et al. (AJOG MFM, 2021) assessed the effect of 20 minutes of postprandial interval walking on glycemic control in pregnant women with gestational diabetes (GDM)

METHODS:

• Crossover-controlled trial
• Participants
  • Pregnant women with GDM (75 gram oral glucose load with 2-hour venous plasma glucose ≥ 9.0 mmol/L)
• Interventions
  • 4-day intervention period
    • 20 minutes of postprandial interval walking after breakfast, lunch, and dinner
    • Interval walking comprised alternating three minutes slow and fast intervals
  • 4-day control period
• Study design
  • 3 days in between the intervention period and control period
  • During each study period, participants received a fixed and identical diet
  • Glucose concentrations were determined with a continuous glucose monitor
  • A mixed effects model was used to compare differences between exercise and no exercise
• Primary outcome
  • Measures of glucose control
• Secondary outcome
  • Measures of glycemic variability

RESULTS:

• 14 participants
  • Gestational age 31.8 ± 1.3 weeks
• Postprandial interval walking significantly reduced mean glucose during daytime hours (P<0.05)
  • Intervention period 4-day mean glucose
    • 5.31 (95% CI, 5.04 to 5.59) mmol/L
    • 95.6 (95% CI, 90.7 to 100.6) mg/dl
  • Control period 4-day mean glucose
    • 5.53 (95% CI, 5.25 to 5.81) mmol/L
    • 99.5 (95% CI, 94.5 to 104.6) mg/dl
• On each individual trial day, interval walking significantly reduced mean glucose during daytime hours on
  • Day 1 (P<0.005)
    • Intervention period mean glucose
      • 5.19 (95% CI, 4.92 to 5.47) mmol/L
      • 93.4 (95% CI, 88.6 to 98.5) mg/dl
    • Control period mean glucose
      • 5.55 (95% CI, 5.27 to 5.83) mmol/L
      • 99.9 (95% CI, 94.9 to 104.9) mg/dl
  • Day 2 (P<0.005)
    • Intervention period mean glucose
      • 5.32 (95% CI, 5.05 to 5.60) mmol/L
      • 95.8 (95% CI, 90.9 to 100.8) mg/dl
    • Control period mean glucose
      • 5.57 (95% CI, 5.29 to 5.84) mmol/L
      • 100.3 (95% CI, 95.2 to 105.1) mg/dl
  • Day 3 (P<0.005)
    • Intervention period mean glucose
      • 5.27 (95% CI, 5.00 to 5.54) mmol/L
      • 94.9 (95% CI, 90.0 to 99.7) mg/dl
    • Control period mean glucose
      • 5.46 (95% CI, 5.19 to 5.74) mmol/L
      • 98.3 (95% CI, 93.4 to 103.3) mg/dl
• However, interval walking did not significantly reduce glycemic control on day 4

CONCLUSION:

• Twenty minutes of interval walking after meals effectively controlled glucose concentrations in women with gestational diabetes
• Differences in glucose levels were significant on days 1 to 3, but not day 4
  • This could be due to small sample size or the study diet could have impacted glucose levels  with increasing effect over the course of the trial
• The authors state

The blunting effect of postprandial exercise on blood glucose elevations has been demonstrated in several studies in non-pregnant individuals

The findings could translate into improved and specific recommendations for physical activity during pregnancy, eventually targeting women with GDM

Learn More – Primary Sources:

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

Related ObG Topics:

Cochrane Review 2021: Does Walking Reduce Blood Pressure and Heart Rate?

Does Physical Activity During Pregnancy Reduce Risk for Preterm Birth?

Physical Activity and Time-to-Pregnancy in Women with a History of Pregnancy Loss

Does Exercise in Pregnancy Decrease Risk of Gestational Diabetes?