Posted Feb 22 , 2017 06:56 PM

Advice to walk after meals is more effective for lowering postprandial glycaemia in type 2 diabetes mellitus than advice that does not specify timing: a randomized crossover study

Reynolds AN, et al. Diabetologia 2016 _ Online October 17

What were the findings (excerpted from the Abstract)?

Regular physical activity is a cornerstone of diabetes management and walking is a well-known basic exercise used by many patients. The authors conducted a study to evaluate whether specifying the timing of walking in relation to meals enhances the benefits conferred by current physical activity guidelines. Forty one (41) adults with type 2 diabetes mellitus (mean age 60; mean diabetes duration 10 years) participated in this randomized, crossover study. Randomization was by a computer-generated protocol. For 2 periods of 1 week, advice to walk 30 min each day was compared with advice to walk for 10 min after each main meal starting within 5 min of completing the meal. The 2 study weeks were separated by a 30-day washout period. Both sets of advice met current physical activity guidelines for people with type 2 diabetes. Physical activity was measured by accelerometry over the full intervention, and glycaemia was measured using continuous glucose monitoring (CGM) over 7 days. The primary outcome of postprandial glycemia was assessed during the 3 h after a meal by the incremental area under the blood glucose curve (iAUC). The iAUC was significantly lower when participants walked after meals compared with on a single daily occasion. The improvement was particularly striking after the evening meal when the most carbohydrate was consumed and sedentary behaviors were highest.

Why is this important?

The benefits of physical activity are well recognized, but the benefit of physical activity immediately following meals to help improve postprandial glycemic control have not previously been rigorously studied, but if these benefits are seen in subsequent and larger studies, it may impact future physical activity guidelines for people with type 2 diabetes. A limitation of the study is that the interventions were of insufficient duration to confirm that the improvement in postprandial glycaemia translated into an improvement in overall glycemic control (A1C), however we do know that postprandial glycemia is an important determinant of glycemic control in its own right. The authors suggest that postprandial physical activity may avoid the need for an increased total insulin dose or additional mealtime insulin injections that might otherwise have been prescribed to lower glucose levels after eating. That remains to be tested in a future study, but these results alone are quite intriguing. This study suggests that we should counsel patients that the answer to the question “What’s for dessert?” would best be “a nice long walk.”

Read the Abstract: