Walking speed and the risk of type 2 diabetes: a systematic review and meta-analysis.

Objective: To investigate the association between walking speed and the risk of type 2 diabetes.

Design: Systematic review and meta-analysis.

Data Sources: PubMed, Scopus, CENTRAL and Web of Science to 30 May 2023.

Eligibility Criteria For Selecting Studies: We included cohort studies that explored the association between walking speed and the risk of type 2 diabetes in adults. We used random-effects meta-analyses to calculate relative risk (RR) and risk difference (RD). We rated the credibility of subgroup differences and the certainty of evidence using the Instrument to assess the Credibility of Effect Modification ANalyses (ICEMAN) and Grading of Recommendations Assessment, Development and Evaluation (GRADE) tools, respectively.

Results: Ten cohort studies were included. Compared with easy/casual walking (<3.2 km/hour), the RR of type 2 diabetes was 0.85 (95% CI 0.70 to 1.00); RD=0.86 (95% CI 1.72 to 0) fewer cases per 100 patients; n=4, GRADE=low) for average/normal walking (3.2-4.8 km/hour), 0.76 (95% CI 0.65 to 0.87); RD=1.38 (95% CI 2.01 to 0.75) fewer cases per 100 patients; n=10, GRADE=low) for fairly brisk walking (4.8-6.4 km/hour) and 0.61 (95% CI 0.49 to 0.73; RD=2.24 (95% CI 2.93 to 1.55) fewer cases per 100 patients; n=6, GRADE=moderate) for brisk/striding walking (>6.4 km/hour). There was no significant or credible difference across subgroups based on adjustment for the total volume of physical activity and time spent walking per day. Dose-response analysis suggested that the risk of type 2 diabetes decreased significantly at a walking speed of 4 km/h and above.

Conclusions: Low to moderate certainty evidence, mainly from studies with a high risk of bias, suggests that walking at faster speeds is associated with a graded decrease in the risk of type 2 diabetes.

Prospero Registration Number: CRD42023432795.