Key Points

Life Expectancy

  • Life expectancy for males with SCI is likely lower than the general male population.
  • Persons injured at a younger age will likely have a longer life expectancy than persons injured at an older age.
  • Causes of death post-SCI may be similar to those of the general population.

SCI and Premature Aging

  • SCI may represent a partial model for premature aging.
  • There is strong evidence that the endocrine and musculoskeletal systems are prematurely aging, while there is limited evidence for the respiratory, skin and subcutaneous tissues, genitourinary, and gastrointestinal systems.
  • There is weak and limited evidence that the immune and nervous system are prematurely aging.

Cardiovascular

  • Greater levels of arthersclerotic burden, higher levels of C-reactive protein levels and abnormal lipid profiles compared to the able-bodied population increases the risk for the development of cardiovascular disease in persons with SCI.
  • Men with complete SCI have abnormal heart rate and blood pressure responses to isometric exercise compared to able-bodied controls, which are indicative of altered autonomic control, but this may not represent premature aging.

Endocrine

  • Impaired secretion of both testosterone and human growth hormone in men with SCI may be due to SCI, and not from advancing age per se.
  • Serum IGF-I levels may be impaired compared to the able-bodied population, which may be a sign of premature aging.
  • Glucose tolerance and slower plasma-free cortisol responses may be impaired in persons with SCI, which may lead to an increased risk for premature diabetes mellitus.
  • Persons with SCI are at higher risk for the development of cardiovascular disease and diabetes mellitus than the able-bodied population.

Body Mass

  • Persons with SCI may have higher levels of fat mass than the able-bodied population. Although BMI increases over time in people with SCI, an active lifestyle may help to preserve physical capacity.
  • Age-related declines of lean tissue in males with SCI may occur at a significantly faster rate than the able-bodied population.
  • Body mass index increases over time in persons with SCI.

Hematological / Immunological

  • Age of onset may not influence hematologic abnormalities at the acute phase post-SCI (within first week post-injury).
  • Immune function after SCI at both the acute and chronic phase is compromised compared to able-bodied controls, but age may not play an important role.

Musculoskeletal

  • Premature aging may occur in the femoral and hip regions in persons with SCI. It may be that declines in bone mass occur rapidly following injury, and reach a new steady-state within 3-8 years post-injury, depending on the bone parameter and skeletal site.
  • Older males and females (> 60 years) with SCI may not experience rapid declines in bone mass in certain regions when compared to able-bodied controls.
  • Duration of injury may be more associated with bone loss after SCI than chronological age.
  • Women with complete SCI may be at a greater risk for fracture at the knee compared to males with SCI and the able-bodied population.
  • Premature aging may not occur in the lumbar spine after SCI.
  • Premature aging may not occur in hand grip strength in men with complete paraplegia. Rather, continual wheelchair use may retard the aging process in relation to handgrip strength.
  • Regardless of age or years post-injury, persons with SCI may have increased thoracic kyphosis than the able-bodied population.

Pain

  • Upper limb pain in males with complete paraplegia may be attributed to longer durations of injury and not to the aging process.
  • The incidence of shoulder pain increases over time, and that age of onset may contribute to the development of pain. Adults with SCI (< 10 years post-injury) who were 30 years and older were more likely to report shoulder pain over time than those who were less than 30 years of age.
  • Younger persons (< 30 years) may have less pain interference at one and at two years post-injury than older persons (> 60 years).
  • Previous reports of pain interference after SCI, irrespective of age, may be predictive of later pain interference.

Respiratory

  • Persons with SCI may have reduced lung capacity compared to able-bodied controls, but this reduction is due to SCI and not aging.
  • Sleep disordered breathing may increase or persist with the aging process in persons with SCI.
  • Seated breathing patterns after tetraplegia are compromised early post-injury but recover over time.
  • Adults who are older (50 years +) and ventilator dependent have a higher mortality rate and lower weaning rate than adults who are younger and who are ventilator dependent.

Dermal

  • Males with SCI have higher levels of collagen metabolite, glu-gal Hyl, than the able-bodied population, which may be a sign of premature aging of the skin. Further work is needed to conclusively demonstrate this.
  • Behavioural factors play a stronger role in the development of pressure ulcers in persons with SCI than either age or years post injury.

Genitourinary and Gastrointestinal

  • Various bladder management techniques (indwelling catheterization versus intermittent catheterization) may not impact renal functioning in persons with SCI over time.
  • Repeated episodes of vesicoureteral reflux can cause kidney damage as early as four years post-injury.
  • After SCI, renal plasma flow declines until 10 years post-injury, at which time, a slight reversal occurs.
  • Age of onset may play a role in minimizing renal decline; adults who are under 20 and older than 50 have comparable renal functioning to the able-bodied population, but those between 20 and 50 years of age have impaired functioning.
  • Bowel incontinence increased with age in the able-bodied population but does not change in persons with SCI.
  • Persons with SCI may experience an increase in constipation-related symptoms and decrease in fecal incontinence over time.
  • Level of injury, and not age or years post-injury, plays a primary role in the extent of bowel dysfunction.

Secondary Complications of Multiple Systems

  • Fatigue and the need for physical assistance may increase over time with SCI.
  • The number of secondary health complications increases with more years post injury.
  • The incidence and severity of UTIs decrease over time in persons with SCI but prevalence of pressure sores remains stable.
  • The co-occurrence of pain and depression is common in persons who have lived with SCI for many years.

Functional Independence

  • Functional independence decreases with more years post injury.

Quality of Life and Community Reintegration

  • Selected domains of life satisfaction (i.e., social life and sex life) may decline as one ages with a SCI. Other domains (i.e., employment and finances) may improve as one ages with a SCI. It may be that these changes in satisfaction of certain domains are comparable to changes in the general population.
  • Changes in environmental factors over time (i.e., economics; technology) may influence QoL in persons with SCI rather than the aging process per se.
  • Community participation may decline with age after SCI. However, these changes in community participation may be similar to the aging general population.
  • Individuals with new SCI (i.e. ≤ 5YPI) consistently report improvements to their QoL, whereas, individuals with longer term SCI consistently report high and stable QoL over time.
  • Age of SCI-onset may be an influential factor on life satisfaction.
  • Previous perceptions of life satisfaction may be predictive of later perceptions of life satisfaction.
  • Aging has greater influence on self-rated health in people with SCI than those without a SCI.