Effects of Neuromuscular Electrical Stimulation on Insulin Sensitivity and Glycemic Control: A systematic Review and Meta-Analysis

Background: Neuromuscular electrical stimulation (NMES) is an effective method to induce involuntary muscle contraction, particularly for populations that are more prone to physical incapacities and metabolic disease. Purpose: To evaluate existing evidence to determine the effectiveness of NMES on glycemic control and insulin sensitivity. Methods: Electronic search consisted of MEDLINE (PubMed), EMBASE, Cochrane Library, Google Scholar, and Web of science to identify existing original research studies that investigated the effects of NMES on glycemic control and insulin sensitivity in humans. Studies that met inclusion criteria for the systematic review were then considered for meta-analysis if the studies were designed as randomized controlled trials. Risk of bias and quality assessment were performed for all studies. Effect sizes were calculated as the standardized mean difference and meta-analyses were completed using a random-effects model. Results: 31 studies met the inclusion criteria for systematic review and of those, 10 studies qualified for the meta-analysis. The meta-analysis comprised of 189 subjects which reported NMES resulted in an improvement in insulin sensitivity (MD: 0.41; 95% CI, 0.09 to 0.72; p=0.01; I²=11%). Conclusions: Existing evidence suggest that NMES can effectively improve glycemic control (acute) and insulin sensitivity (chronic) predominantly in middle-aged and elderly men and women with type 2 diabetes, obesity, and spinal cord injury. NMES could be considered as an alternate therapeutic strategy to improve insulin sensitivity in populations that are faced with physical incapacities and metabolic disease