Supports Chapter 22: The dangers of low cholesterol
A new study shows that low levels of cholesterol, LDL and triglycerides are associated with fractures of the vertebrae in postmenopausal women.
“Many factors other than low bone mineral density (BMD) have been suggested as predictors of risk for osteoporosis-related fractures,” comment Ebru Alemdaroglu and colleagues from Ankara Numune Training and Research Hospital, Turkey.
They add that growing evidence suggests bone and fat metabolism are related, but data are limited and contradictory.
To investigate the effect of the serum lipid levels on BMD and vertebral fractures, Alemdaroglu and team examined lumbar spine, hip and radius bone mineral density (BMD) measurements, lateral dorsal and lumbar spine radiographs, and serum lipid levels in 107 postmenopausal women aged 45–79 years.
The researchers were able to score 89 radiographs with good technical properties using the Kleerekoper method. Vertebrae fractures were observed in 71% of the women.
Analysis showed that patients with vertebrae fractures had significantly lower levels of total cholesterol, triglycerides and LDL cholesterol than the patients without vertebrae fractures.
Total cholesterol level was most strongly associated with vertebral fracture. An increase of 1 mg/dl (0.03 mmol/l) total cholesterol was associated with a 2.2% decreased risk for vertebrae fracture.
The researchers reason that estrogen is synthesized by cholesterol and esterified forms of estrogen are stored and transported by lipoproteins. Thus, decreased LDL levels would be associated with decreased stored estrogen and may explain the relationship between vertebrate fracture and reduced serum lipids.
According to the T-scores obtained by BMD measurement, 36 (33.6%) of the 107 women examined were suffering from osteoporosis. Alemdaroglu and co-researchers report that the lipid profiles of women with osteoporosis did not differ significantly from those without osteoporosis.
There was no correlation between serum lipid levels and BMD at the lumbar spine, right hip and radius in any of the study participants. Only total cholesterol and LDL cholesterol were weakly associated with BMD at the forearm after the adjustment for possible confounders.
Sivas F, et al. Serum lipid profile: its relationship with osteoporotic vertebrae fractures and bone mineral density in Turkish postmenopausal women. Rheumatol Int 2008. [Online publication ahead of print]
The bottom line is: This is yet another indication that low cholesterol levels are not desirable.