The effect of a pre-meal snack and/or postprandial exercise on breakfast glycemic excursion in adults with cystic fibrosis: A pilot study

Background & aims

Cystic fibrosis (CF)-related diabetes (CFRD), a common comorbidity in CF, is often preceded and characterized with elevated postprandial glycemic (PPG) excursions. In the general population, the consumption of a pre-meal protein snack and/or physical activity (PA) hinder the elevation of PPG levels. Our objective is to evaluate the effect of a pre-meal snack and/or post-meal PA on PPG excursions in CF.

Methods

This is a double-blinded randomized controlled crossover interventional study in 14 adults with CF, with 4 interventions: placebo pre-meal snack + no PA (control: CTL), pre-meal soy snack + no PA (SK), placebo pre-meal snack + PA (PA), and pre-meal soy snack + PA (SK + PA). The pre-meal soy snack or placebo beverage (vanilla flavoured water) is served at 8 AM, followed by a standardized breakfast at 9 AM and, postprandially, 5 repeated bouts of 3-min walk every 30 min or sedentary activity. Blood glucose and insulin were measured every 15–30 min during the interventions.

Results

Plasma glucose (PG) was higher 30 min after snack consumption compared to placebo beverage. One-hour post-breakfast, PG levels were lower during both PA interventions than with sedentary behavior. However, the overall 3 h post-breakfast glucose area under the curve (AUC) was similar between interventions. Post-breakfast 3 h insulin AUC was significantly lower during the SK + PA intervention compared to the sedentary behavior interventions.

Conclusion

Repeated short bouts of post-meal physical activity may positively impact PPG control in adults with CF, with or without the addition of a pre-meal soy snack. A pre-meal snack alone does not improve PPG.