Effectiveness of Resistance Training and Associated Program Characteristics in Patients at Risk for Type 2 Diabetes: a Systematic Review and Meta-analysis

BACKGROUND: Resistance training (RT) is an effective intervention for glycemic control and cardiometabolic health in individuals with type 2 diabetes (T2D). However, the use of RT in individuals at risk for T2D to prevent or delay the onset of T2D, and RT program characteristics that are most effective are still unknown. The purpose of this review is to determine the effects of RT on cardiometabolic risk factors in those at risk for T2D and to examine RT program characteristics associated with intervention effectiveness. METHODS: PubMed, Cochrane, Web of Science, and Embase databases were systematically searched for published controlled trials that compared cardiometabolic outcomes in adults with cardiometabolic risk for those that underwent an RT intervention with those that did not. A systematic review and meta-analysis was conducted to determine the effect of RT on glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG), body fat percentage (BF%), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides (TG). Additional analyses examined effects of intervention duration and dietary intervention on FPG and TG. RESULTS: Fourteen trials with 668 participants were included. For RT compared to controls, the standardized mean difference (SMD) was −1.064 for HbA1c (95% confidence interval [CI] −1.802 to −0.327; p=0.005), −0.99 for FPG (95% CI −1.798 to −0.183; p=0.016), −0.933 for TC (95% CI −1.66 to −0.206; p=0.012), −0.840 for BF% (95% CI −1.429 to −0.251; p=0.005), −0.693 for HDL (95% CI −1.230 to −0.156; p=0.011), −1.03 for LDL (95% CI −2.03 to −0.050; p=0.039), and −0.705 for TG (95% CI −1.132 to −0.279; p=0.001). CONCLUSIONS: RT is beneficial for improving glycemic control, BF%, and blood lipids in those at risk for diabetes. The addition of a dietary component did not result in larger reductions in FPG and TG than RT alone. PROSPERO REGISTRATION ID: CRD42019122217 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40798-021-00321-x.