In the JournalsPerspective

Timing of daily walks improves glycemic profile in type 2 diabetes

Adults with type 2 diabetes saw lower postprandial blood glucose when they took three daily 10-minute walks after meals vs. when they took daily 30-minute walks at unspecified times, according to recent findings.

“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,” Andrew N. Reynolds, PhD, of the Edgar Diabetes and Obesity Research Center at the University of Otago, New Zealand, told Endocrine Today. “An increase in insulin dose might, in turn, be associated with weight gain in patients with type 2 diabetes, many of whom are already overweight or obese.”

Andrew Reynolds
Andrew N. Reynolds

In a randomized, crossover study, Reynolds and colleagues analyzed data from 41 adults with type 2 diabetes assigned to two interventions separated by a 30-day washout period (mean age, 60 years; mean diabetes duration, 10 years). For the first intervention, participants were asked to take a single 30-minute walk at any time of day for 2 weeks. In the second intervention, participants were asked to take a 10-minute walk after each of the three main meals, started within 5 minutes of completing the meal. Researchers asked participants not to change their diet or lifestyle habits during the study period beyond complying with the walking regimens.

On day 1 of each intervention, participants provided a fasting blood sample and received accelerometers. On day 7, participants received continuous glucose monitors, blood glucose meters and 7-day food diaries. Participants provided a second fasting blood sample on day 14 of each intervention. Primary outcome of postprandial glycemia was assessed during the 3 hours after the meal by incremental area under the curve.

Researchers found that participants had improved postprandial blood glucose when performing the after-meal walks vs. when performing the unspecified 30-minute daily walks (ratio of geometric means, 0.88; 95% CI, 0.78-0.99). Researchers noted that the improvement was “particularly striking” after the evening meal walk (ratio of geometric means, 0.78; 95% CI, 0.67-0.91), when the most carbohydrates were consumed and sedentary behaviors were highest.

Reynolds said it is important to identify means of achieving adherence to increase physical activity or to support dietary change.

“We need to enable the healthy choice by making it the easy choice,” he said. – by Regina Schaffer

For more information:

Andrew N. Reynolds, PhD, can be reached at the Edgar Diabetes and Obesity Research Center at the University of Otago, PO Box 56, Dunedin 9054, New Zealand; email: Andrew.reynolds@otago.ac.nz.

Disclosure: The researchers report no relevant financial disclosures.

Adults with type 2 diabetes saw lower postprandial blood glucose when they took three daily 10-minute walks after meals vs. when they took daily 30-minute walks at unspecified times, according to recent findings.

“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,” Andrew N. Reynolds, PhD, of the Edgar Diabetes and Obesity Research Center at the University of Otago, New Zealand, told Endocrine Today. “An increase in insulin dose might, in turn, be associated with weight gain in patients with type 2 diabetes, many of whom are already overweight or obese.”

Andrew Reynolds
Andrew N. Reynolds

In a randomized, crossover study, Reynolds and colleagues analyzed data from 41 adults with type 2 diabetes assigned to two interventions separated by a 30-day washout period (mean age, 60 years; mean diabetes duration, 10 years). For the first intervention, participants were asked to take a single 30-minute walk at any time of day for 2 weeks. In the second intervention, participants were asked to take a 10-minute walk after each of the three main meals, started within 5 minutes of completing the meal. Researchers asked participants not to change their diet or lifestyle habits during the study period beyond complying with the walking regimens.

On day 1 of each intervention, participants provided a fasting blood sample and received accelerometers. On day 7, participants received continuous glucose monitors, blood glucose meters and 7-day food diaries. Participants provided a second fasting blood sample on day 14 of each intervention. Primary outcome of postprandial glycemia was assessed during the 3 hours after the meal by incremental area under the curve.

Researchers found that participants had improved postprandial blood glucose when performing the after-meal walks vs. when performing the unspecified 30-minute daily walks (ratio of geometric means, 0.88; 95% CI, 0.78-0.99). Researchers noted that the improvement was “particularly striking” after the evening meal walk (ratio of geometric means, 0.78; 95% CI, 0.67-0.91), when the most carbohydrates were consumed and sedentary behaviors were highest.

Reynolds said it is important to identify means of achieving adherence to increase physical activity or to support dietary change.

“We need to enable the healthy choice by making it the easy choice,” he said. – by Regina Schaffer

For more information:

Andrew N. Reynolds, PhD, can be reached at the Edgar Diabetes and Obesity Research Center at the University of Otago, PO Box 56, Dunedin 9054, New Zealand; email: Andrew.reynolds@otago.ac.nz.

Disclosure: The researchers report no relevant financial disclosures.

    Perspective

    PERSPECTIVE
    Sheri Colberg

    Sheri R. Colberg

    A recent study by Reynolds and colleagues investigated the impact of walking done at a self-selected pace under free-living conditions in adults with type 2 diabetes. This intervention study is important for several reasons. For starters, all participants were engaging in the recommended amounts of daily physical activity (30 minutes of daily walking) during the randomized, crossover study; this allowed investigators to compare the glycemic management benefits of walking either all at once at a self-selected time of day or spread out during the day as 10-minute walks taken after each meal. Past studies have shown a definite glycemic benefit of exercising after meals compared with before, but have not specifically tested this specific protocol (walking done after each meal, free-living conditions, and lasting more than 2 days).
    In addition, these participants were studied using accelerometers and continuous glucose monitors over a full week (for each protocol, separated with a 30-day washout period) under free-living conditions in which they chose their own meals and exercise times, which makes positive results more meaningful and applicable to real-world settings. In this case, the results demonstrated that postprandial glycemia was 12% lower during the post-meal walking period when participants followed the prescription to walk after meals compared with when they simply followed more conventional physical activity advice of walking 30 minutes daily. These results were largely due to much lower values following the evening meal; this was also the meal when the most carbohydrate was consumed and when participants tended to be more sedentary.
    Finally, given all of the issues related to getting patients to follow prescribed exercise regimens, this study is also important in demonstrating that exercise advice can be tailored to and complied with during free-living conditions when given as a prescription that can do the most benefit in terms of glycemic management. Doing some light to moderate physical activity after all meals is a practice that would likely benefit everyone, not just adults with type 2 diabetes!


    Sheri R. Colberg, PhD, FACSM
    Professor Emerita of Exercise Science, Old Dominion University

    Disclosure: Colberg reports no relevant financial disclosures.