Exercise and Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Exercise Duration and Intensity and Their Effects on HbA1c and BMI

Abstract

Specific Aims: To assess the impact that exercise-type has on diabetes control through improvement in monitoring parameters such as hemoglobin A1c and fasting blood glucose. Methods: Studies were selected using a study inclusion tool and then data was extracted using the data extraction tool. The primary outcomes assessed were BMI and HbA1c. The standardized mean difference (SMD) was the main summary measure and the I2 statistic ¬¬¬¬¬¬was used to assess variability among the studies. Main Results: Ten studies met inclusion criteria (Total N = 1,787). The age range of patients was 40-66 years old with equal amounts of male and female participants. Aerobic and resistance exercise were effective (p < 0.01) in reducing A1c; Tai Chi was not (p = 0.50). Aerobic exercise did not have a significant effect on BMI (p = 0.07), however Tai Chi and Resistance exercise did (p<0.04). Conclusion: Aerobic and resistance exercise produced a significant reduction in HbA1c, whereas Tai Chi did not. The non-significant impact aerobic exercise had on BMI was probably due to large variation between the studies. No significant differences were found between the different forms of exercise and their overall impact on diabetes control. Based upon the data incorporated in this meta-analysis, it is reasonable for patients with diabetes mellitus type 2 to use aerobic or resistance exercise to improve their HbA1C. However, it remains to be seen whether recommending specific exercise types over others will provide increased benefit.