Glycemic Management Around Postprandial Exercise in People With Type 1 Diabetes: Challenge Accepted.
Study Goal
The researchers aimed to examine the acute, subacute, and late effects of postprandial walking on blood glucose levels in adults with type 1 diabetes.
Results Summary
Walking reduced postprandial glucose excursion compared to rest, with a consistent blood glucose decline (-45 ± 24 mg/dL). However, hyperglycemia occurred in more than half of participants after exercise, necessitating insulin correction, and nocturnal hypoglycemia was more frequent post-exercise.
Population
Adults with type 1 diabetes (n = 8, aged 44 ± 13 years, BMI 24 ± 2.1).
Effective Dosage
30 minutes of walking performed 60 minutes after a standardized meal.
Duration
Acute effects during exercise, subacute (≤2 h after), and late effects (≤24 h after).
Interactions
Prandial insulin reductions were noted as necessary precautions.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
postprandial exercise | decrease | postprandial glucose excursion | adults with type 1 diabetes | - | reduced | #1 |
walking exercise | decrease | blood glucose | adults with type 1 diabetes | -45 ± 24 mg/dL | reduced | #2 |
moderate-intensity exercise | decrease | blood glucose | adults with type 1 diabetes | -71 ± 39 mg/dL | reduced | #3 |
intermittent high-intensity exercise | decrease | blood glucose | adults with type 1 diabetes | -35 ± 21 mg/dL | reduced | #4 |
postprandial exercise | increase | blood glucose | adults with type 1 diabetes | - | increased | #5 |
postprandial exercise | increase | hyperglycemia after exercise | more than half of participants | - | caused | #6 |
postprandial exercise | increase | nocturnal hypoglycemic events | adults with type 1 diabetes | - | caused | #7 |
postprandial exercise | no change | hypoglycemia during exercise | adults with type 1 diabetes | - | did not cause | #8 |
postprandial exercise | no change | hypoglycemia shortly after exercise | adults with type 1 diabetes | - | did not cause | #9 |
CONTEXT: The precise glycemic impact and clinical relevance of postprandial exercise in type 1 diabetes (T1D) has not been clarified yet. OBJECTIVE: This work aimed to examine acute, subacute, and late effects of postprandial exercise on blood glucose (BG). METHODS: A randomized, controlled trial comprised 4 laboratory visits, with 24-hour follow-up at home. Participants included adults with T1D (n = 8), aged 44 ± 13 years, with body mass index of 24 ± 2.1. Intervention included 30 minutes of rest (CONTROL), walking (WALK), moderate-intensity (MOD), or intermittent high-intensity (IHE) exercise performed 60 minutes after a standardized meal. Main outcome measures included BG change during exercise/control (acute), and secondary outcomes included the subacute (≤2 h after) and late glycemic effects (≤24 h after). RESULTS: Exercise reduced postprandial glucose (PPG) excursion compared to CONTROL, with a consistent BG decline in all patients for all modalities (mean declines -45 ± 24, -71 ± 39, and -35 ± 21 mg/dL, during WALK, MOD, and IHE, respectively (P < .001). For this decline, clinical superiority was demonstrated separately for each exercise modality vs CONTROL. Noninferiority of WALK vs MOD was not demonstrated, noninferiority of WALK vs IHE was demonstrated, and equivalence of IHE vs MOD was not demonstrated. Hypoglycemia did not occur during exercise. BG increased in the hour after exercise (more than after CONTROL; P < .001). More than half of participants showed hyperglycemia after exercise necessitating insulin correction. There were more nocturnal hypoglycemic events after exercise vs CONTROL (P < .05). CONCLUSION: Postprandial exercise of all modalities is effective, safe, and feasible if necessary precautions are taken (ie, prandial insulin reductions), as exercise lowered maximal PPG excursion and caused a consistent and clinically relevant BG decline during exercise while there was no hypoglycemia during or shortly after exercise. However, there seem to be 2 remaining challenges: subacute postexercise hyperglycemia and nocturnal hypoglycemia.