Exercise improves glycaemic control in women diagnosed with gestational diabetes mellitus: a systematic review

Question: Does exercise improve postprandial glycaemic control in women diagnosed with gestational diabetes mellitus? Design: A systematic review of randomised trials. Participants: Pregnant women diagnosed with gestational diabetes mellitus. Intervention: Exercise, performed more than once a week, sufficient to achieve an aerobic effect or changes in muscle metabolism. Outcome measures: Postprandial blood glucose, fasting blood glucose, glycated haemoglobin, requirement for insulin, adverse events and adherence. Results: This systematic review identified eight randomised, controlled trials involving 588 participants; seven trials (544 participants) had data that were suitable for meta-analysis. Five trials scored ≥ 6 on the PEDro scale, indicating a relatively low risk of bias. Meta-analysis showed that exercise, as an adjunct to standard care, significantly improved postprandial glycaemic control (MD –0.33 mmol/L, 95% CI –0.49 to –0.17) and lowered fasting blood glucose (MD –0.31 mmol/L, 95% CI –0.56 to –0.05) when compared with standard care alone, with no increase in adverse events. Effects of similar magnitude were found for aerobic and resistance exercise programs, if performed at a moderate intensity or greater, for 20 to 30 minutes, three to four times per week. Meta-analysis did not show that exercise significantly reduced the requirement for insulin. All studies reported that complications or other adverse events were either similar or reduced with exercise. Conclusion: Aerobic or resistance exercise, performed at a moderate intensity at least three times per week, safely helps to control postprandial blood glucose levels and other measures of glycaemic control in women diagnosed with gestational diabetes mellitus.