Testosterone and Long-Pulse-Width Stimulation (TLPS) on Denervated Muscles and Cardio-Metabolic Risk Factors After...

Area of Science:

• Neurology
• Muscle Physiology
• Metabolic Health

Background:

• Long pulse width stimulation (LPWS) offers potential for denervated muscle stimulation in spinal cord injury (SCI).
• Investigating testosterone treatment (TT) combined with LPWS to enhance skeletal muscle size, leg lean mass, and metabolic health in SCI individuals with denervation.

Purpose of the Study:

• To evaluate the efficacy of one year of combined TT + LPWS in downregulating muscle atrophy gene expression and upregulating muscle hypertrophy and mitochondrial health in SCI individuals with lower motor neuron (LMN) injury.

Main Methods:

• Ten SCI participants with chronic LMN injury were randomized into two groups for 12 months: TT + LPWS (n=5) or TT + standard neuromuscular electrical stimulation (NMES) (n=5).
• Measurements included body composition (MRI, DXA), metabolic rate, carbohydrate/lipid profiles, and muscle biopsy for gene expression and mitochondrial function.

Main Results:

• A 25% increase in rectus femoris (RF) muscle cross-sectional area (CSA) was observed in the TT + LPWS group after 6 months.
• Trends indicated decreased intramuscular and visceral adipose tissue (VAT) with TT + LPWS.
• TT + LPWS showed a trending decline in muscle atrophy genes (MURF1, FOXO3).

Conclusions:

• Pilot data confirm the safety of LPWS in SCI individuals.
• Six months of TT + LPWS led to modest increases in RF muscle CSA.
• Signaling pathway analysis suggests LPWS downregulates muscle atrophy pathways, warranting further investigation with home-based, more frequent applications.