Effect of Physical Exercise on Insulin Sensitivity and the Modifiable Cardiovascular Risk Factors of Patients with T2DM: A Systematic Review

Introduction: Diabetes mellitus is one of the chronic diseases that have increased in prevalence in Indonesia and the world. Optimal glycemic control is important to prevent the complications of diabetes mellitus. Several recommendations that are used in diabetes treatment involve regular exercise training. This study was undertaken to verify effect of regular exercise training on insulin sensitivity and the modifiable cardiovascular risk factors, and to determine if there was any effect from the different regular exercises. Methods: A database search using PRISMA examined articles from Scopus, ScienceDirect and ProQuest. The inclusion criteria were that the article used a randomized controlled trial within the last 10 years, that the respondents were people with type 2 diabetes mellitus and that only physical exercise was the intervention involved. In total, 1,303 articles were screened and 16 articles were included that fit the criteria of inclusion in this systematic review. Results: Based on the review of the 15 articles, the findings show that regular exercise training has some benefits related to glycemic control. It can reduce insulin resistance, plasma insulin, fasting blood glucose, postpandrial blood glucose and hbA1c. It also can increase insulin sensitivity and the disposition index of insulin as well. Furthermore, regular exercise training has benefits concerning some of the cardiovascular risk factors. It can reduce the systolic and diastolic blood pressure, waist circumference, fat mass, visceral fat, total cholesterol, and improve the lipid profile and endothelial function by decreasing the carotid intima media thickness and left ventricle wall mass. Conclusion: Regular exercise training has benefits for people with type 2 diabetes mellitus and it can allow them to achieve of optimal glycemic control by improving insulin resistance and decreasing the cardiovascular risk factors. Physical exercise such as combined exercises (aerobic and resistance exercise) or a single exercise such as aerobic exercise can be recommended to improve insulin sensitivity and the modifiable cardiovascular risk factors in patients with T2DM.