Time-course response in serum markers of bone turnover to a single-bout of electrical stimulation in patients with recent spinal cord injury

Abstract

The objective of the present repeat-measures study was to determine whether plasma serum levels of testosterone, cortisol, osteocalcin or type I collagen C-telopeptide (CT) are acutely affected following an electro-myostimulation (EMS) bout, and their relation to bone mineral density and muscle mass. Ten men with recent (8 weeks) thoracic spinal cord injury (SCI) (ASIA A) and 10 age-matched able-bodied (AB) men performed one EMS bout on the quadriceps femoris muscle. Blood samples were drawn at basal condition, immediately after EMS, and 15 min, 30 min, 24 h and 48 h post-EMS. Muscle cross-sectional area was measured by magnetic resonance imaging. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry. In the SCI group, a significant decrease in testosterone, cortisol and CT together with a significant increase in testosterone/cortisol ratio and osteocalcin/CT ratio was observed after EMS. For the AB subjects, only testosterone and CT decreased significantly following EMS. Muscle size was only related to testosterone/cortisol ratio in the SCI sample (R = 0.659, p < 0.05), whereas BMD did not show any relation to any biomarker. Acute EMS in recent spinal cord injured men seems to induce positive effects on bone turnover biomarkers, and anabolic and catabolic hormones.

Effects of electromyostimulation on muscle and bone in men with acute traumatic spinal cord injury: A randomized clinical trial

“…13,14 The intensity of the evoked contraction proved to be an important factor in an electrical stimulation training program in SCI, 27 which is true for patients with either recent 13 or chronic SCI. 28 The present protocol was proved to acutely induce positive alterations in serum markers of bone turnover in persons with recent SCI 24 ; therefore, the selected evoked contraction intensity was thought to be sufficient to elicit positive changes in bone metabolism longitudinally.…”

“…The selection of this protocol was based on the positive acute adaptation, which was proved to induce on bone biomarkers in recent spinal cord injured persons. 24 The EMS training program was performed 5 days a week for 14 weeks by the same physiotherapist for a given subject. Sessions took place in the morning or in the afternoon depending on participant's availability.…”

“…24 Briefly, 18 T1 2D axial scans of the thigh were obtained perpendicularly to the femur diaphysis. Each scan was separated 1/18 of the distance between greater trochanter and the lateral condyle of femur on a coronal plane using a 500-mm localizer.…”

“…20 The present protocol used stimulation patterns that acutely decrease the serum concentration of osteoclastic markers in men with recent SCI (i.e. CTx), 24 suggesting a positive effect on bone metabolism. However, the training effects of our study could have been either insufficient to attenuate bone loss longitudinal or encumbered by as-yet-unexplained factors affecting the osteogenic response to mechanical strain.…”

Spinal Cord Injury-Induced Osteoporosis: Pathogenesis and Emerging Therapies

“…Several animal and human studies have shown new bone formation in response to electrical stimulation [73–75]. In a small study of 8 men with acute thoracic motor complete SCI, a single session of electrical stimulation reduced c-telopeptide levels indicating reduced bone resorption 48 hours after treatment [76]. Electrical stimulation of the quadriceps muscle in upright stance reduced bone loss and preserved trabecular bone micro-architecture at the distal femur in seven subjects with SCI compared to 5 subjects who stood without stimulation and 15 subjects with SCI who received no standing or stimulation [77].…”