Neurogenic obesity and systemic inflammation following spinal cord injury: A review

Abstract

Content: Spinal Cord Injury (SCI) results in physiological changes that markedly reduces whole-body metabolism, resulting in neurogenic obesity via adipose tissue accumulation. Adipose tissue has been implicated in the release of proinflammatory adipokines that lead to chronic, systemic inflammation, and evidence suggests these adipokines contribute to the pathogeneses of metabolic diseases that often accompany obesity. In this review, we propose the concept of neurogenic obesity through paralysis-induced adiposity as the primary source of systemic inflammation and metabolic dysfunction reported in chronic SCI. We also briefly discuss how exercise in SCI can attenuate the negative consequences of obesity-induced inflammation and its comorbidities.

Methods: A MEDLINE, PubMed, Google Scholar, and ClinicalKey search was performed using the following search terms: obesity, adiposity, adipose tissue, proinflammatory adipokines, proinflammatory cytokines, metabolic dysfunction, exercise, physical activity, and spinal cord injury. All papers identified were full-text, English language papers. The reference list of identified papers was also searched for additional papers.

Results: Research suggests that obesity in SCI results in a state of chronic, systemic inflammation primarily through proinflammatory adipokines secreted from excess adipose tissue. The reduction of adipose tissue through the use of diet and exercise demonstrates promise to combat neurogenic obesity, inflammation, and cardiometabolic dysfunction in SCI.

Conclusion: Proinflammatory adipokines may serve as biomarkers for the development of obesity-related complication in SCI. Mechanistic and interventional studies on neurogenic obesity-induced inflammation in chronic SCI are warranted.

Keywords: Adipokines; Adipose tissue; Inflammation; Neurogenic obesity; Spinal cord injury.

Figure 1.

Proposed mechanism of proinflammatory adipokines in obesity and metabolic dysfunction following spinal cord injury. Color Legend: Blue, anti-inflammatory adipokines; Brown, dyslipidemia; Green, vascular dysfunction and hypertension; Purple, insulin resistance/type 2 diabetes mellitus; Red, proinflammatory adipokines. Legend: AIA, anti-inflammatory adipokines; CRP, high sensitivity-c reactive protein; HDL-C, high density lipoprotein-cholesterol; ICAM-1, intracellular adhesion molecule-1; IL-6, interleukin-6; LDL-C, low density lipoprotein-cholesterol; MCP-1, monocyte chemoattractant protein-1; NEFA, non-esterified fatty acids; PAI-1, plasminogen activator inhibitor-1; SCI, spinal cord injury; TG, triglycerides; TNFα, tumor necrosis factor-α; VCAM-1, vascular cellular adhesion molecule-1; VLDL-C, very low density lipoprotein-cholesterol.