Lipoprotein heterogeneity in persons with Spinal Cord Injury: a model of prolonged sitting and restricted physical activity

Abstract

BackgroundPersons with spinal cord injury (SCI) often have low levels of physical activity, which predispose to increased adiposity and decreased high density lipoprotein cholesterol (HDL-C) concentrations, and, generally, normal low density lipoprotein cholesterol (LDL-C) concentrations. In spite of the mixed lipoprotein profile, the SCI population has been reported to have an elevated risk of cardiovascular-related morbidity and mortality. Nuclear magnetic resonance spectroscopy may permit a more precise quantification of lipoprotein particle (P) species, enabling a more accurate inference of risk for cardiovascular disease (CVD) in the SCI population.MethodsFasting blood samples were obtained on 83 persons with chronic SCI and 62 able-bodied (AB) subjects. Fasting plasma insulin (FPI), triglycerides (TG), and P number and size of VLDL (very low density lipoprotein), LDL, and HDL subclasses were determined. AB and SCI subjects were stratified based on HDL-C (i.e., Low <40 and Normal ≥40 mg/dl): AB-Normal (n = 48), AB-Low (n = 14), SCI-Normal (n = 49), and SCI-Low (n = 34). Factorial analyses of variance were performed to identify group differences in lipoprotein measurements. Pearson correlations were performed between the number of P by lipoprotein subclass, size, FPI, and TG.ResultsThe SCI-Normal group was not significantly different from the AB-Normal group for body composition, FPI, TG or LP-IR and had negligible differences in the lipoprotein P profile, except for fewer number and smaller size of HDL-P. The SCI-Low group had a similar lipoprotein profile to that of the AB-Low group, but with a lipid P composition associated with a heightened atherogenic risk and greater tendency toward insulin resistance by the Lipoprotein-Insulin Resistance (LP-IR) score. In the SCI-Low group, the decreased number and reduced size of lipoprotein P were more prevalent and may be associated with increased waist circumference (i.e., abdominal adiposity), relatively elevated TG values (compared to the other subgroups), and an underlying subclinical state of insulin resistance.ConclusionsProlonged sitting and restricted physical activity in individuals with SCI had the most profound effect on the HDL-C and its lipoprotein P subclasses, but not on LDL-C, however its P subclasses were also unfavorably affected but not to the same degree. The quantification of lipoprotein P characteristics may be a potent tool for the determination of risk for CVD in persons with SCI.

Establishing a threshold to predict risk of cardiovascular disease from the serum triglyceride and high-density lipoprotein concentrations in persons with spinal cord injury

“…The challenge in applying the NCEP (4), ACC/AHA guidelines (37), or that of cardiometabolic risk (38) to individuals with SCI is that the characteristic lipid profile includes an extremely depressed serum HDL-C concentration, with values <~40 mg/dl observed in about half, <35 mg/dl occurring in about one-third, and <30 mg/dl in about one-fifth of the population (15, 39). The serum TG concentrations have been reported to be mildly elevated or normal by conventional standards (TG ≥150 mg/dl), and LDL-C are often within the normal range and present with a similar distribution to that of the general population (15, 17, 40, 41). As such, initiating therapy with a statin is not recommended by the current guidelines for most individuals with SCI.…”

Wearable Robotic Exoskeletons for Overground Walking in Rehabilitation: Specific Contexts of Use and Improvement Opportunities

“…In fact, whether the WRE is used as a dynamic walking orthosis or as a neurorehabilitation intervention, prolonged walking with the WRE remains highly demanding from musculoskeletal, cardiorespiratory, and cognitive perspectives. Consequently, possible positive adaptations to these systems with increased demands of walking may overcome the deleterious effects of prolonged non-active sitting time [24] and the reduction or cessation of physical activity that typically contribute to the development or exacerbation of complex and chronic secondary health problems in individuals with sensorimotor impairments and limited or no walking ability. Furthermore, these health problems are often coupled with increased risk of nociceptive or neuropathic pain, or psychological morbidity (e.g., increased depressive symptoms).…”

Effects of an Overground Walking Program With a Robotic Exoskeleton on Long-Term Manual Wheelchair Users With a Chronic Spinal Cord Injury: Protocol for a Self-Controlled Interventional Study

“…Hence, they will generally use a powered or manually propelled wheelchair as their main mode of mobility. The prolonged, nonactive sitting time [ 5 ] and the reduction or cessation of physical activity [ 6 , 7 ] typically linked to this mode of mobility contribute to the development or exacerbation over time of complex and chronic secondary health problems. These health problems often effect the cardiorespiratory [ 8 - 12 ], musculoskeletal [ 13 - 17 ], and endocrine-metabolic [ 18 - 23 ] systems.…”