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

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.