Optimal dose and type of physical activity to improve glycemic control in people diagnosed with type II diabetes mellitus: A systematic review and meta-analysis

BACKGROUND The optimal dose or type of physical activity to control glycosylated hemoglobin (HbA1c) in people with diabetes remains unknown. Current guidelines do not consider the baseline HbA1c for activity prescription.

PURPOSE To examine the dose-response relationship between physical activity and HbA1c (%) in individuals with type II diabetes.

DATA SOURCES A systematic search was performed in EMBASE, MEDLINE, Scopus, CINAHL, SportDiscus, and WOS.

STUDY SELECTION We included trials that involved participants diagnosed with type II diabetes that used any type of physical activity as intervention.

DATA EXTRACTION Pre-post HbA1c data, population and interventions characteristics, and descriptive statistics were collected to calculate change scores for each study arm.

DATA SYNTHESIS We used Bayesian random-effects meta-analyses to summarize high-quality evidence from 126 studies (6718 participants). The optimal physical activity dose was 1100 METs-min/week (Metabolic Equivalent of Task per week), resulting in HbA1c reductions ranging from –1.02% to –0.66% in severe uncontrolled diabetes, from –0.64% to –0.49% in uncontrolled diabetes, from –0.47% to –0.40% in controlled diabetes, and from –0.38% to –0.24% in prediabetes.

LIMITATION The time required to achieve these HbA1c reductions could not be estimated due to the heterogeneity between interventions’ duration and protocols, and the inter-personal variability of this outcome.

CONCLUSION This meta-analysis provides key information about the optimal weekly dose of physical activity for people with diabetes considering their baseline HbA1c level, and the effectiveness of different types of active interventions. These results enable clinicians to prescribe tailored physical activity programs for this population.