Individuals with Acute Spinal Cord Injury Display Impaired Biomarkers of Cardiometabolic Health

Abstract

Individuals with spinal cord injuries (SCI) have a greater incidence of cardiovascular disease (CVD) than the non‐injured. Contributing to the increased CVD is decreased cardiometabolic health including increased insulin resistance, central adiposity, and dyslipidemia. In fact, cross‐sectional analyses of individuals with chronic SCI (up to 50 years post injury) indicates that up to 70% are classified as overweight/obese and 25‐60% have either insulin resistance or dyslipidemia. However, current understanding of cardiometabolic health in SCI derives from those with chronic injury, hence it is unknown if biomarkers are adversely affected in those with more acute injuries. Therefore, we assessed cardiometabolic health in individuals with SCI <3 yrs. Cardiometabolic health was assessed through fasting blood glucose, insulin, triglycerides, low density lipoprotein (LDL), high density lipoprotein (HDL), total cholesterol, C‐reactive protein (CRP), and hemoglobin A1C (HbA1C). In addition, oral glucose tolerance testing (OGTT) was performed, and body composition was estimated via dual energy x‐ray absorptiometry (DXA). Five individuals (1F, 4M) aged 20 to 34 yo with SCI at neurologic level of injury ranging from spinal cord segments C6 to T4 (ASIA A and B) at 9 to 27 months post‐injury participated. All subjects displayed at ≥1 marker of impaired cardiometabolic health, while one displayed five markers. Body fat ranged from 27 to 42%, and one subject was classified as obese, two as overweight, and two as normal weigh based on BMI. Dyslipidemia was prominent in four of five subjects: one had elevated total cholesterol (>200 mg/dL), one had elevated triglycerides (>150 mg/dL), three had low HDL (<40 mg/dL), and two had elevated LDL (>100 mg/dL). Glucose tolerance test data and fasting insulin measurements showed normal fasting glucose (<100 mg/dl), HOMA‐IR (<2.0), and HbA1C (<5.7%) in all individuals, but one subject displayed impaired glucose tolerance during the OGTT (1 hr post >200 mg/dL, 2hr post >180 mg/dL). Three of five subjects had CRP levels >3.0, suggesting an increased inflammatory state. These preliminary results strongly suggest that cardiometabolic health may be impaired within 3 years after SCI. These biomarkers of altered cardiometabolic health, specifically related to lipid dysregulation, may reflect adipose tissue dysfunction, possibly in response to the accumulation of adipose tissue and/or the decreased physical activity, increased sedentary activity, and skeletal muscle atrophy that typically occurs following a spinal injury. More research is needed to determine the mediators of impaired cardiometabolic health in subjects with SCI and determine effective strategies to mitigate the detrimental effects of SCI on cardiometabolic health.