RESUMEN
CONTEXT: Dual-energy x-ray absorptiometry (DXA) limits osteoporosis screening because of machine size, technical requirements for operation, and exposure to ionizing radiation. OBJECTIVE: To establish data ranges from calcaneus ultrasonography (US) that correspond to bone mineral density (BMD) stratification identified by DXA and to determine whether vitamin D concentration adds to US bone health assessment. METHODS: Patients scheduled for DXA at the Robert C. Byrd Clinic, a rural primary care facility in Lewisburg, West Virginia, were recruited from June 2015 to June 2016. Ultrasonography was used to scan the left and right calcaneus of the patients, and blood was collected from a finger prick for vitamin D analysis. Information was collected regarding Fracture Risk Assessment tool parameters, menstrual history, and drug and supplement use. The correlations within and between DXA and US measurements were calculated, as well as the correlations between DXA and US measurements and vitamin D levels. Predictive performance of US readings on bone health determined by DXA scan was assessed with area under the curve analysis using receiver operator characteristic curves. RESULTS: Ninety-nine participants were included. Ultrasonography readings of either the left or right foot were predictive of good vs poor bone quality. No differences were found between US scans of the left foot vs the right foot. Area under the curve values for US BMD T scores for the left and right foot were 0.69 and 0.68, respectively. There was no correlation between DXA- and US-assessed BMD and vitamin D concentrations. Negative correlations were observed between the DXA BMD T scores and vitamin D concentration of the spine and right hip; negative correlations were also observed in the Z score from the spine in the subset of participants who reported not taking vitamin D supplements. CONCLUSION: Ultrasonography of the calcaneus offers a low-cost, efficient means to screen bone health. The affordability and mobility of a US machine enables its use as a screening method that may be applicable to large numbers of people. This study established a T score greater than -1.05 as an indicator of good bone quality and a T score less than -1.05 as an indicator of poor bone quality when using US for BMD screening.