AUTHOR=Gorgey Ashraf S., Khalil Refka E., Carter William , Ballance Boyd , Gill Ranjodh , Khan Rehan , Goetz Lance , Lavis Timothy , Sima Adam P., Adler Robert A.

TITLE=Effects of two different paradigms of electrical stimulation exercise on cardio-metabolic risk factors after spinal cord injury. A randomized clinical trial

JOURNAL=Frontiers in Neurology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1254760

DOI=10.3389/fneur.2023.1254760

ISSN=1664-2295

ABSTRACT=<sec id="sec1"><title>Objective</title><p>To examine the combined effects of neuromuscular electrical stimulation-resistance training (NMES-RT) and functional electrical stimulation-lower extremity cycling (FES-LEC) compared to passive movement training (PMT) and FES-LEC in adults with SCI on (1) oxygen uptake (VO<sub>2</sub>), insulin sensitivity and glucose disposal in adults with SCI; (2) Metabolic and inflammatory biomarkers; (3) skeletal muscle, intramuscular fat (IMF) and visceral adipose tissue (VAT) cross-sectional areas (CSAs).</p></sec><sec id="sec2"><title>Materials and methods</title><p>Thirty-three participants with chronic SCI (AIS A-C) were randomized to 24 weeks of NMES-RT + FES or PMT + FES. The NMES-RT + FES group underwent 12 weeks of evoked surface NMES-RT using ankle weights followed by an additional 12 weeks of progressive FES-LEC. The control group, PMT + FES performed 12 weeks of passive leg extension movements followed by an additional 12 weeks of FES-LEC. Measurements were performed at baseline (BL; week 0), post-intervention 1 (P1; week 13) and post-intervention 2 (P2; week 25) and included FES-VO<sub>2</sub> measurements, insulin sensitivity and glucose effectiveness using the intravenous glucose tolerance test; anthropometrics and whole and regional body composition assessment using dual energy x-ray absorptiometry (DXA) and magnetic resonance imaging to measure muscle, IMF and VAT CSAs.</p></sec><sec id="sec3"><title>Results</title><p>Twenty-seven participants completed both phases of the study. NMES-RT + FES group showed a trend of a greater VO<sub>2</sub> peak in P1 [<italic>p</italic> = 0.08; but not in P2 (<italic>p</italic> = 0.25)] compared to PMT + FES. There was a time effect of both groups in leg VO<sub>2</sub> peak. Neither intervention elicited significant changes in insulin, glucose, or inflammatory biomarkers. There were modest changes in leg lean mass following PMT + FES group. Robust hypertrophy of whole thigh muscle CSA, absolute thigh muscle CSA and knee extensor CSA were noted in the NMES-RT + FES group compared to PMT + FES at P1. PMT + FES resulted in muscle hypertrophy at P2. NMES-RT + FES resulted in a decrease in total VAT CSA at P1.</p></sec><sec id="sec4"><title>Conclusion</title><p>NMES-RT yielded a greater peak leg VO<sub>2</sub> and decrease in total VAT compared to PMT. The addition of 12 weeks of FES-LEC in both groups modestly impacted leg VO<sub>2</sub> peak. The addition of FES-LEC to NMES-RT did not yield additional increases in muscle CSA, suggesting a ceiling effect on signaling pathways following NMES-RT.</p></sec><sec id="sec143"><title>Clinical trial registration</title><p>identifier NCT02660073.</p></sec>