Osteoporosis is a major public health problem through its association with age-related fractures. Bone mineral density (BMD) is an important determinant of fracture risk, with an approximate doubling of fracture risk for every 1 SD reduction in BMD. Low bone mineral density is also associated with an increased risk of cardiovascular mortality in postmenopausal women, and several drugs, the statins, hormone replacement therapy and bisphosphonates alter bone density and lipid synthesis.
Furthermore osteoblasts and adipocytes share a common progenitor from stromal cells in bone marrow. This has led investigators to study the relationship between cholesterol concentration and bone mass, and to suggest a relationship between hyperlipidaemia and BMD as a link between atherosclerosis and osteoporosis.
E.M. Dennison et al in their paper Lipid profile, obesity and bone mineral density: the Hertfordshire Cohort Study, Q.J.Med 2007, 100, 297-303 have looked at this possible association in a population of 1000 men and women living in Hertfordshire. This population has already provided a wealth of information thanks to detailed information at birth allowing studies on birth weight and health events in later life.
The new study showed was that people with high triglyceride concentrations had better bones, and at least part of the explanation for this was that people with higher triglyceride concentrations tended to be ‘fatter’, which is apparently good for bones for many reasons. By contrast, people with high concentrations of HDL cholesterol, tended to have thinner bones. The reason for this is not clear, but it would appear that in in this group, people with high concentrations of HDL cholesterol tended to be slimmer, so this may be important.
- Martin Eastwood