Bone density at the os calcis: reference values, reproducibility, and effects of fracture history and physical activity.

AIMS: To establish reference values for bone mineral density (BMD) measured at the os calcis (OC) in healthy UK Caucasian children. Secondary objectives were to assess the reproducibility of the measurement and the effects of fracture history and habitual physical activity. METHODS: A total of 403 children aged 5-18 were studied. Main outcome measures were: BMDoc measured by peripheral DXA, total BMD measured by whole body axial scanner, age, anthropometry, pubertal status, self-reported fracture history, and physical activity (PA) expressed as a three point score. RESULTS: Complete data were available on 171 girls and 123 boys free of a history of fracture. BMDoc was related positively to age, body size, and total BMD, and could be predicted using a proportional model based on height alone (R2: 65% girls, 77% boys). Mean BMDoc appears to plateau in girls at 15 years and attain a value that concurs with the mean peak value in adult women. The 95% limits of agreement in repeated measures were -0.029 to 0.029 g/cm2 (n = 53). Compared with sedentary children, those doing regular sports or PA for more than five hours a week had an increased BMDoc (by about 0.03 g/cm2 or about 7% of the overall mean). A history of fracture (n = 81) was associated with a reduced BMDoc in boys but not in girls, though our study may have been underpowered for a subgroup analysis. CONCLUSIONS: BMDoc can be measured easily and quickly in children older than 5 years and provides an objective measure of areal bone density for clinical and research studies using a reference range derived from its relation to height.

An open access bone densitometry service: report of first year's operation.

Medical treatment of symptomatic osteoporosis is unsatisfactory. Treatment of patients with low bone density but without history of fracture includes hormone replacement therapy (HRT) which offers the prospect of reduced fracture risk. Dual energy X-ray absorptiometry (DXA) offers a safe and accurate technique available for the measurement of bone mineral density at a district general hospital level. All open access service providing densitometry measurements for general practitioners and hospital consultants was instigated at South Cleveland Hospital in February 1991. A major purpose of the service was to provide density measurements in order to 'inform' the discussion between the patient and doctor with regard to the use of anti-resorptive and other medical agents. We report our experience of operating such a service. The report analyses the main reasons for referrals. Nine hundred and thirty female subjects and 63 male subjects were scanned. The main reason for female referral were early menopause, consideration for HRT, personal history of fracture and family history of fracture--these account for 54.7% of all referrals. In men, there was a high incidence of fracture, back pain and the use of steroids given as reasons for referral. Sixty-seven per cent of patients were referred by general practitioners. Eighteen per cent of female lumbar spinal BMD values were between 1 and 2 S.D. below the Leeds normative mean and 9.0% below 2 S.D. Figures for the femoral neck were 22.0 and 9.0%.(ABSTRACT TRUNCATED AT 250 WORDS)