Optimal Dose and Type of Physical Activity to Improve Glycemic Control in People Diagnosed With Type 2 Diabetes: 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 include consideration of baseline HbA1c for activity prescription. PURPOSE:To examine the dose-response relationship between physical activity and HbA1c (%) in individuals with type 2 diabetes. DATA SOURCES:A systematic search was performed in Embase, MEDLINE, Scopus, CINAHL, SPORTDiscus, and Web of Science. STUDY SELECTION:We included trials that involved participants diagnosed with type 2 diabetes that included any type of physical activity as intervention. DATA EXTRACTION:Pre- and postintervention 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 (6,718 participants). The optimal physical activity dose was 1,100 MET min/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. LIMITATIONS:The time required to achieve these HbA1c reductions could not be estimated due to the heterogeneity between interventions' duration and protocols and the interpersonal variability of this outcome. CONCLUSIONS:The result of this meta-analysis provide key information about the optimal weekly dose of physical activity for people with diabetes with consideration of 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.