Metabolic Responses to Endurance Electrical Stimulation Training in Persons with Spinal Cord Injury

Abstract

Persons with spinal cord injuries are at high risk for metabolic and cardiovascular disease due to reductions in physical activity. Improvements in metabolic health may be possible in this population with the use of electrical stimulation exercise. PURPOSE: Measure metabolic changes in response to 4 months of home-based electrical stimulation endurance training of the quadriceps muscles. METHODS: Oral glucose tolerance test (OGTT), lipid panel, and NIRS-measured mitochondrial capacity assessments were performed before and after electrical stimulation training in 14 persons with motor complete SCI, ranging from C4-T9. RESULTS: Baseline homeostatic model assessment-insulin resistance (HOMA-IR) was 4.3 ± 2.5. On average, glucose and insulin responses to OGTT did not improve after electrical stimulation exercise, p > 0.05. Glucose at 120 min pre: 123.1 ± 34.5 mg/dL vs. post 126.3 ± 36.7 mg/dL and insulin at 120 min pre: 221.1 ± 205 vs. post 195.4 ± 263.3 IU/L. On average, mitochondrial capacity in the vastus lateralis improved by 120% (range: -14 to 387%, p = 0.019). CONCLUSION: Endurance electrical stimulation training of the vastus lateralis muscles was not sufficient to elicit whole-body changes in glucose metabolism, although muscle specific changes in mitochondrial capacity occurred. Future studies should consider training additional muscles, as well as incorporating nutritional interventions. Supported by NIH RO1HD039676.