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.
