Osteoporosis is associated with an increase in marrow fat.
Fats, particularly polyunsaturated
fats, either in co-cultures or diet, have been shown to significantly influence bone remodeling. Whether the increase in marrow fat seen in
osteoporosis is also associated with a change in
fatty acid composition is not known. This study was undertaken to investigate the
fatty acid composition in subjects of varying bone mineral density (BMD). Samples of marrow fat and subcutaneous fat from 126 subjects (98 females, 34 males, mean age 69.7+/-10.5 years) undergoing
orthopedic surgery were analyzed for
fatty acid composition by gas chromatography. These results were correlated with BMD assessed by DXA. A total of 22
fatty acids were identified in marrow and subcutaneous fat. Significant differences in
fatty acid composition existed between marrow and subcutaneous fat as well as between marrow fat samples obtained from the proximal femur and proximal tibia. Other than cis-7-hexadecenoic
acid [C16:1 (n=9)] and
docosanoic acid [C22:0], no difference in marrow
fatty acid composition was evident between subject groups of varying BMD (normal, low bone mass, and
osteoporosis). In conclusion, there exists a wide range of individual
fatty acids in marrow fat. Marrow
fatty acid composition differs from that of subcutaneous fat and varies between predominantly erythropoetic and fatty marrow sites. Other than cis-7-hexadecenoic
acid [C16:1 (n=9)] and
docosanoic acid [C22:0], no difference in marrow
fatty acid composition was evident between subjects of varying BMD.