title: Fatty marrow in the vertebrae. A parameter for hematopoietic activity in the aged.
abstract: Fatty alteration of bone marrow was analyzed in upper lumbar vertebrae obtained from 94 autopsies. Of these, 85 were from individuals over 60 years of age. Fatty marrows were classified grossly into three groups: Group I, a massive type, Group II, a moderate or less significant type; Group III, a nonfatty type. Fatty marrows of Groups I and II were found most frequently in the older subjects. They were not observed (0/9) below 60 years of age, but were present in 42% (5/12) in the 6th decade, 61% (23/38) in the 7th decade, 76% (25/33) in the 8th decade, and 100% (2/2) in the 9th decade. This may relate to a decreasing volume of a reservoir stem cell compartment for blood cell generation. Since the vertebral marrow is the last reserve site for hematopoietic activity, the volume of fatty marrow in the vertebrae may be used as a parameter for the estimation of hematopoietic activity in the entire skeletal system in the aged.
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000503:physiopathology; D000368:Aged; D000375:Aging; D001853:Bone Marrow / Q000033:anatomy & histology* / Q000503:physiopathology; D005260:Female; D006410:Hematopoiesis; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged