Lower osteocalcin and osteopontin contents of the femoral head in hip fracture patients than osteoarthritis patients

Summary In patients with femoral neck fracture, clinical factors, bone metabolism markers (in serum, urine, and bone), bone mineral density, radiographic parameters, and bone histomorphometric parameters were investigated to detect determinants of fragility fracture. The osteocalcin/ deoxypyridinoline ratio and osteopontin/calcium ratio of cortical bone were selected as significant predictors. Introduction Measurement of bone mineral density is widely used to assess bone strength, but this also depends on other bone components and on bone structure. The objective of this study was to investigate risk factors for fracture related to bone quality, the patient’s history, and the patient’s lifestyle. Methods Twenty-one patients with femoral neck fracture and 18 patients with osteoarthritis were enrolled. Blood and urine samples were collected on admission to hospital, and bone samples were obtained from femoral necks resected during surgery. Multivariate logistic regression analysis was performed using osteoarthritis and femoral neck fracture as combined variables to assess the influence of alcohol or coffee intake, eating natto (fermented soybeans), osteocalcin and calcium concentrations, the osteocalcin/deoxypyridinoline ratio and osteopontin/calcium ratios of cortical bone and cancellous bone, various bone histomorphometric parameters, the bone mineral density of the lumbar spine and the intact contralateral femoral neck, and various radiographic parameters of the spine Results By forward stepwise multivariate analysis, the osteocalcin/deoxypyridinoline and osteopontin/calcium ratios of cortical bone were selected as significant factors for fracture (the odds ratios were 0.493 and <0.001, respectively; both P<0.001). Conclusions A decrease of osteopontin and osteocalcin in bone is important for promoting vulnerability to hip fracture.