Aging is a highly complex phenomenon that can be examined at the genetic, cellular, organ-system, and psychosocial levels (Aldwin & Gilmer 2004). Although there are some conflicting evidence on which systems decline, for the most part, persons aging with SCI exhibit decreases in health status and physical functioning over time, which could serve as markers of premature aging.
In this section, 1 systematic review on physiological aging after SCI is reviewed.
In this systematic review (Hitzig et al. 2011), the hypothesis that SCI represents a model for premature aging is supported by level 5 evidence for the cardiovascular and endocrine systems, level 2, 4 and 5 evidence for the musculoskeletal system, and limited level 5 evidence for the immune system. Only a few level 4 and 5 studies for the respiratory system were found. Evidence on the genitourinary system, gastrointestinal system, and for skin and subcutaneous tissues provide level 4 and 5 evidence that premature aging may not be occurring in these systems.
The following sections review each body system individually, including the cardiovascular and endocrine systems, immune system, musculoskeletal system, respiratory system, nervous system, skin and subcutaneous tissues, and the genitourinary and gastrointestinal systems.