Oral baclofen administration in persons with chronic spinal cord injury does not prevent the protective effects of spasticity on body composition and glucose homeostasis

Abstract

Study design: Correlation study. Objectives: To determine the effects of oral baclofen on body composition (fat mass (FM), fat-free mass (FFM)), extra-and intracellular fluid compartments and glucose homeostasis (plasma glucose and plasma insulin concentrations) in individuals with spinal cord injury (SCI) after controlling for spasticity. Settings: Laboratory settings at the University of Michigan, MI, USA. Methods: Fifteen individuals with chronic motor complete SCI (32 ± 8 years old, 25 ± 5 kg/m 2 , C6-T11, American Spinal Injury Association A and B) underwent multifrequency bioelectrical impedance analysis to measure body composition and body fluid compartments. Spasticity of the hip, knee and ankle flexors and extensors was measured using a modified Ashworth Scale and the dose of daily oral baclofen was recorded. After overnight fasting, plasma glucose and insulin sensitivity were measured in response to an oral glucose tolerance test. Results: Oral baclofen dose was positively related to body mass index, but not to extensor or flexor spasticity. The dose of baclofen seemed to be correlated to extensor spasticity after considering spasticity per FFM. The increased dose of oral baclofen was positively associated with increased FFM, extra-and intracellular fluid compartments and total body water, but not with FM. Oral baclofen dose was negatively associated with the homeostatic model assessment index. Conclusion: Administration of oral baclofen did not attenuate the protective effects of spasticity on body composition and metabolic profile after SCI. The possibility that oral baclofen could exert an independent protective effect needs to be further investigated.

Effects of spinal cord injury on body composition and metabolic profile – Part I

“…29 This led the same investigators to hypothesize that the inhibitory effects of oral baclofen on spasticity may obliterate the aforementioned effect. 46 Contrary to the hypothesis, oral baclofen administration did not attenuate the protective effects of spasticity on body composition and metabolic profile after SCI and was negatively associated with the homeostatic model assessment index. 46 The positive relationship between spasticity and muscle size as well as lean mass has recently been explained by the effect of spasticity on the circulating plasma IGF-1.…”

“…46 Contrary to the hypothesis, oral baclofen administration did not attenuate the protective effects of spasticity on body composition and metabolic profile after SCI and was negatively associated with the homeostatic model assessment index. 46 The positive relationship between spasticity and muscle size as well as lean mass has recently been explained by the effect of spasticity on the circulating plasma IGF-1. 47 Those with MAS greater than 2 have 44% higher plasma IGF-1 than those with lower MAS.…”

“…44 Spasticity of paralyzed skeletal muscle may defend against skeletal muscle atrophy. 29,35,45,46 Those with a spastic knee extensor (modified Ashworth Score (MAS) > 2) have 22% greater knee extensor CSA and less infiltration of IMF compared to non-spastic individuals with SCI. 35 In a follow-up study, there was a negative association between spasticity and total body and regional FM, and positive associations with between spasticity and percentage FFM, and between FFM and BMR 29 suggesting that spasticity may play a role in several obesity-associated disorders following SCI.…”

Secondary complications and subjective well-being in individuals with chronic spinal cord injury: associations with self-reported adiposity

“…31 It also has been suggested that spasticity may promote a favorable body composition and muscle mass. 32 Accordingly, it may be that our findings are indicative of the inability of BMI to differentiate between fat-and fat-free mass.…”

Retrospective Analysis of Goal Assessment for Conservative Treatment and Surgical Intervention for Spasticity of Upper and Lower Limbs in an Interdisciplinary Neuro-Orthopedic Spasticity Clinic

“…Its incidence after a stroke is 17% to 38% [2,3]. Moreover, the severity of spasticity increases over time [4] and induces significant pain, contractures, joint subluxations or dislocations, peripheral neuropathy and pressure ulcers [5].…”