Plasma variations of biomarkers for muscle damage in male nondisabled and spinal cord injured subjects

Abstract

Deep pressure ulcers represent a major problem for individuals with spinal cord injury (SCI), with the initial damage often hidden underneath intact skin. Accordingly, early detection is difficult and treatment is problematic. In the present study, circulatory levels of biomarkers for muscle damage were investigated to explore their potential in the early detection of deep pressure ulcers. Baseline concentrations of creatine kinase, myoglobin (Mb), heart-type fatty acid binding protein (H-FABP), and C-reactive protein (CRP) were measured in small groups of nondisabled (age 39-66 yr) subjects and subjects with SCI (age 40-68 yr, American Spinal Injury Association grade A-B, level of injury thoracic 11 to lumbar 3) over a period of 5 days. Each subject exhibited a unique concentration profile for all markers, although some correlations were observed; for example, Mb and H-FABP were correlated for both subject groups. No significant differences were found in marker concentrations between the two subject groups, although a trend toward higher CRP levels was observed in the SCI subjects. Furthermore, one SCI subject with a category II pressure ulcer exhibited higher H-FABP and CRP concentrations than all other subjects. Because the variations in each of the marker concentrations were smaller than the predicted increases after pressure ulcers, this combination of plasma markers may prove appropriate for the early detection of deep pressure ulcers.