高齢者の腰痛症におけるサルコペニア

抄録

The neologisms sarcopenia, meaning “loss of flesh,” was first described in 1989 to refer to the age–related involuntary loss of skeletal muscle mass and function. Since this time the concept of sarcopenia has been now widely accepted and used in the field of gerontology identifying physical, metabolic,and functional impairment in elderly persons. The primary purpose of this study was to examine differences in appearance of sarcopenia as age–related systemic change in older adults with low back pain, and evaluate the relationships between the age–associated loss of skeletal muscle mass and chronic pain. Impact of iatrogenic muscle atrophy in the lumbar multifidus and sarco penic aging atrophy on postoperative low back pain in patients with posterior lumbar surgery were evaluated in 233 elderly cases. Both muscle volumes in the lumbar multifidus and four extremities were significantly reduced one year after surgery, however, surgical results was associated with sarcopenic atrophy rather than iatrogenic back muscle atrophy. A series of 93 patients with chronic low back pain, aged 65 years or older with moderate to severe low back pain persisting for a minimum of 3 months were evaluated regarding sarcopenic state, compared with 305 subjects without chronic low back pain. Patients who meet Sanada’s criteria were greater in chronic low back pain patients (35.5%), and skeletal muscle mass index (kg/m²) was significantly lower in chronic low back pain patients. Fat mass volume in the lower extremities and body fat percentage were significantly higher in chronic low back pain patients. The muscle mass decrease due to aging may be associated with the development of chronic pain. Mechanism of “sarcopenic pain” remains uncertain, however, aging process including inflammatory cytokines and/or hypovitaminosis D seems to be related to chronic low back pain.