Effects of Lifestyle Interventions to Promote Physical Activity on Physical Activity and Glycated Hemoglobin in Patients with Type 2 Diabetes: a Systematic Review and Meta-Analysis

BACKGROUND: Numerous studies have explored the impact of controlled exercise interventions in type 2 diabetes, as physical activity can positively influence its progression. However, our understanding of how broader lifestyle interventions can effectively promote physical activity in practical real-world scenarios remains limited. OBJECTIVE: This systematic review and meta-analysis aimed to investigate the potential of lifestyle interventions targeting the promotion of physical activity on physical activity outcomes and glycated hemoglobin (HbA1c), providing a comprehensive understanding of both behavioral and clinical impacts. METHODS: We performed a systematic review and meta-analysis, searching three databases and examined the study design, structure, and content of the lifestyle interventions. We assessed physical activity and HbA1c as endpoints and performed a multivariate meta-regression to explore physical activity's impact on HbA1c. RESULTS: This review incorporated 13 studies (n = 5301 patients), with heterogeneity in intervention designs, components, and durations. Lifestyle interventions showed a slight increase in physical activity, equivalent to an average of 9.0 min more total physical activity per day (95% confidence interval 5.8, 12.2) and 1.7 min more moderate-to-vigorous physical activity per day (95% confidence interval 1.1, 2.3), irrespective of objective (e.g., accelerometers) or subjective measurement (e.g., questionnaires) method. However, HbA1c reduction through these interventions was minimal 0.09% (95% confidence interval - 0.20, 0.03). The effect of physical activity was - 0.04 (standard error = 0.05, 95% confidence interval - 0.15, 0.06), suggesting that physical activity does not act as a moderator for changes in HbA1c. CONCLUSIONS: Lifestyle interventions effectively increase physical activity but have limited impact on HbA1c compared to controls. The role of physical activity as a moderator for changes in HbA1c remains uncertain. Further research is needed to enhance the efficacy of these interventions in reducing HbA1c in individuals with type 2 diabetes.