Objective: To evaluate how bone mineral density in the calcaneus measured by a dual energy X-ray laser (DXL) correlates with bone mineral density in the spine and hip in Turkish women over 40 years of age and to determine whether calcaneal dual energy X-ray laser variables are associated with clinical risk factors to the same extent as axial bone mineral density measurements obtained using dual energy x-ray absorbtiometry (DXA).
Materials and methods: A total of 2,884 Turkish women, aged 40-90 years, living in Ankara were randomly selected. Calcaneal bone mineral density was evaluated using a dual energy X-ray laser Calscan device. Subjects exhibiting a calcaneal dual energy X-ray laser T- score < or = -2.5 received a referral for DXA of the spine and hip. Besides dual energy X-ray laser measurements, all subjects were questioned about their medical history and the most relevant risk factors for osteoporosis.
Results: Using a T-score threshold of -2.5, which is recommended by the World Health Organization (WHO), dual energy X-ray laser calcaneal measurements showed that 13% of the subjects had osteoporosis, while another 56% had osteopenia. The mean calcaneal dual energy X-ray laser T-score of postmenopausal subjects who were smokers with a positive history of fracture, hormone replacement therapy (HRT), covered dressing style, lower educational level, no regular exercise habits, and low tea consumption was significantly lower than that obtained for the other group (p<0.05). A significant correlation was observed between the calcaneal dual energy X-ray laser T-score and age (r= -0.465, p=0.001), body mass index (BMI) (r=0.223, p=0.001), number of live births (r= -0.229, p=0.001), breast feeding time (r= -0.064, p=0.001), and age at menarche (r= -0.050, p=0.008). The correlations between calcaneal DXL and DXA T-scores (r=0.340, p=0.001) and calcaneal DXL and DXA Z-scores (r=0.360, p=0.001) at the spine, and calcaneal DXL and DXA T- scores (r=0.28, p=0.001) and calcaneal DXL and DXA Z-scores (r=0.33, p=0.001) at the femoral neck were statistically significant.
Conclusion: Bone mineral density measurements in the calcaneus using a dual energy X-ray laser are valuable for screening Turkish women over 40 years of age for the risk of osteoporosis.
Keywords: DXA; DXL; Osteoporosis; Osteoporosis risk factors.