In persons with SCI, the usual clinical measures of total body fat, such as weight and body mass index (BMI), underestimate the degree of adiposity (Bauman et al. 1997; Mollinger et al. 1985; Spungen et al. 1993; Spungen et al. 2000; Spungen et al. 2003). The metabolic alterations related to adverse body composition changes, decreased physical activity and other factors in individuals with SCI are considered atherogenic (Maki et al. 1995; National Cholesterol Education Program 2001, 2002). Even a mild decline in glucose tolerance is associated with insulin resistance and hyperinsulinemia, which are also considered atherogenic (Haffner et al. 1990).
Table 4 Lipid Lipoprotein Profiles
|Low-density lipoprotein (LDL)||· Lipid protein complex that transports cholesterol from the liver to other tissues within the body. LDL is often referred to as the “bad” cholesterol. LDL levels above 160 mg/dL (4.1 mmol/L) are considered to be high.|
|High-density lipoprotein (HDL)||· Lipid protein complex that transports cholesterol from the tissues to the liver for excretion and re-utilization. HDL is often referred to as the “good” cholesterol. HDL levels of <40 mg/dL (<1.03 mmol/L) are associated with an increased risk for CVD.|
|Total cholesterol (TC)||· Total amount of all cholesterol in the blood (increased TC related to increased risk for CVD)|
|Triglycerides (TG)||· High energy fatty acids which form much of the fat stored by the body|
Many factors contribute to increased risk of insulin resistance and hyperinsulinemia, glucose intolerance, CVD and obesity in persons with SCI. These factors tend to correlate with the severity and level of the neurological deficit (Javierre et al. 2005). It is hypothesized that the decreased lean muscle mass and increased adipose tissue which follow a SCI lead to impaired glucose uptake and an imbalance in whole body glucose homeostasis (Javierre et al. 2005). Pathogenesis of SCI combined with lifestyle practices impact blood glucose management thereby increasing the risk of morbidity and mortality due to CVDs, a frequent cause of death among persons with SCI (Arrowwood et al. 1987; Javierre et al. 2005; Yekutiel et al. 1989). Abnormalities in lipid metabolism in SCI develop early following injury and tend to progress over time (Brenes et al. 1986; Bauman et al. 1992; Kocina 1997; Szlachcic et al. 2001). Insulin resistance and exaggerated hyperinsulinemia in response to an oral glucose challenge are associated with the development of type II diabetes mellitus, atherosclerosis and ischemic heart disease (Bauman et al. 1992; Defronzo et al. 1991; Duckworth et al. 1983; Mohr et al. 2001). Conventional risk factors for coronary heart disease should be identified and treated aggressively in individuals with SCI according to current standards of care (Bauman & Spungen 2008).