Age-related variations of fat tissue fraction in normal human bone marrow depend both on size and number of adipocytes: a stereological study.
Studies dealing with the number or size of individual adipose cells in human bone marrow are lacking. To ascertain whether the age-related variations in fat tissue fraction depend on the size of individual adipocytes or their number or both, a stereological study of 20 normal human bone marrow specimens was performed. A total number of 17,039 adipose cell profiles was measured and two stereological parameters were obtained in each specimen: mean diameter and number of cells per mm3 of bone marrow. With increasing age, an increasing fat tissue fraction was observed (r = 0.61; p = 0.004). The fat tissue fraction correlated positively with the size (r = 0.81; p less than 0.001) and the number/volume (r = 0.59; p = 0.006) of adipocytes. The significance of both adipocyte size and adipocyte number/volume was confirmed by stepwise multiple regression, in which the size alone explained 66.2% of fat tissue fraction and both size and number/volume explained 97.2% of fat tissue fraction. These results are discussed from a pathophysiological point of view.
Rozman
C
C
Postgraduate School of Haematology Farreras Valenti, Hospital Clínic, University of Barcelona, Spain.
Feliu
E
E
Berga
L
L
Reverter
J C
JC
Climent
C
C
Ferrán
M J
MJ
D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology*; D001856:Bone Marrow Examination / Q000379:methods*; D006801:Humans; D008223:Lymphoma / Q000473:pathology; D008875:Middle Aged