Background: Osteoporosis and fracture risk are polygenic conditions which result from an interplay of genetic, biochemical and environmental factors. A number of biochemical markers including serum calcium, total alkaline phosphatase (ALP) and albumin, were analysed in relation to bone mineral density (BMD) and different types of low-trauma fractures in Maltese postmenopausal women. Levels were also correlated with a number of clinical risk factors including physical activity and years since menopause (YSM).
Methods: An age-matched case-control study of 1045 women was performed. Women who suffered low-trauma fractures were classified as cases whereas those without a fracture history were included as controls subdivided into normal, osteopenic or osteoporotic according to their BMD status. Blood specimens were collected following good standard practice and within 18 hours of fracture in the case of fresh-trauma fractures. Biochemical testing was performed using spectrophotometric analysis.
Results: Serum calcium, and to a lower extent ALP levels, were correlated with BMD levels at the femoral neck, FN (calcium rho: 0.111, P<0.01, ALP rho: 0.089, P<0.05). Fracture cases had the lowest levels of serum calcium, ALP and albumin relative to all other control groups (P<0.05), which significantly decreased with increasing age (P<0.05), possibly contributing to an increased fracture risk due to reduced intestinal absorption, malnutrition and depleted protein levels, as well as a lower overall well-being. Levels were lowest in women who sustained a hip fracture and in those who sustained more than one fracture (P<0.05). YSM was correlated with lower calcium levels in fracture cases (rho: -0.229, P<0.01). Low physical activity was associated with low BMD at the lumbar spine (LS) and FN (P<0.00), and with lower concentrations of serum calcium, ALP and albumin (P<0.05).
Conclusion: Results suggest that measurements of serum calcium, ALP and albumin levels could be indicative of frailty and low BMD.
Disclosure: The authors declared no competing interests.