Exercise lowers postprandial glucose but not fasting glucose in type 2 diabetes: a meta‐analysis of studies using continuous glucose monitoring

Abstract

Exercise has repeatedly been shown to improve glycemic control as assessed by glycated hemoglobin. However, changes in glycated hemoglobin do not provide information regarding which aspects of glycemic control have been altered. The purpose of this systematic review was to examine the effect of exercise as assessed by continuous glucose monitoring systems (CGMS) in type 2 diabetes. Databases (PubMed, Medline, EMBASE) were searched up to February 2013. Eligible studies had participants with type 2 diabetes complete standardized exercise protocols and used CGMS to measure changes in glycemic control. Randomized controlled trials, crossover trials and studies with pre-post designs were included. Average glucose concentration, daily time spent in hyperglycemia or hypoglycemia, and fasting glucose concentration were compared between exercise and control conditions. Eleven studies met the inclusion criteria and were included in the review. Eight studies had short-term (≤2 weeks) exercise interventions, whereas three studies had a longer-term intervention (all >2 months). The types of exercises utilized included aerobic, resistance and a combination of the two. The eight short-term studies were included in quantitative analysis. Exercise significantly decreased average glucose concentrations (-0.8 mmol/L, p < 0.01) and daily time spent in hyperglycemia (-129 minutes, p < 0.01), but did not significantly affect daily time spent in hypoglycemia (-3 minutes, p = 0.47) or fasting glucose (-0.3 mmol/L, p = 0.13). The four randomized crossover trials had similar findings compared to studies with pre-post designs. Exercise consistently reduced average glucose concentrations and time spent in hyperglycemia despite not significantly affecting outcomes such as fasting glucose and hypoglycemia.

Postprandial dysmetabolism: Too early or too late?

“…111 A meta-analysis of 11 studies, including aerobic exercise, resistance exercise or a combination of these, concluded that exercise decreased significantly average glucose concentrations (-0.8 mmol/L, p <0.01) and daily time spent in hyperglycemia (-129 minutes, p <0.01) but did not have an impact on fasting glucose in patients with type 2 diabetes. 136 This finding strengthens the beneficial impact of exercise on postprandial glucose metabolism. As far as postprandial lipid metabolism is concerned, it seems that exercise improves postprandial triglyceride levels in overweight young women and men with metabolic syndrome and in type 2 diabetic patients.…”

The Effect of Regular Exercise on Insulin Sensitivity in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

“…As reported by Umpierre et al [3], individuals who exercised ≥150 minutes per week showed a significant reduction in HbA1c (–0.89%) compared with those who participated in less than 150 minutes. Another systematic review and meta-analysis which investigated the effect of short-term exercise training (≤2 weeks) on glycaemic control, as measured with continuous glucose monitoring in T2DM, showed that exercise significantly reduced the daily time spent in hyperglycaemia (>10.0 mmol/L), but did not significantly change fasting blood glucose levels [34]. Statistical analysis of longer-term interventions could not be undertaken in this study due to the heterogeneity in the timing of the continuous glucose monitoring measures.…”

Glycemic Variability and Oxidative Stress: A Link between Diabetes and Cardiovascular Disease?

“…In this case, glinides are recommended as a substitute for SUs. In addition to general lifestyle modification, selection of food with lower glycemic index, increasing dietary fiber and implementing a brisk walk after meals are recommended to reduce postprandial glycemic excursion [122,123]. …”