The effect of weight change on DXA scans in a 2-year trial of etidronate therapy.

摘要: Variation in soft tissue composition is a potential cause of error dual X-ray absorptiometry (DXA) measurements bone mineral density (BMD). We investigated the effect patients' change weight on DXA scans 152 women enrolled 2-year trial cyclical etidronate therapy. Scans spine, hip, and total body were performed at baseline, 1 2 years Hologic QDR-2000. The study was completed by 135 subjects (64 etidronate, 71 placebo). Results expressed as percentage BMD (spine, femoral neck, body) or content (BMC) (total only) years. Total analyzed using manufacturer's `standard' `enhanced' algorithms. Analysis multivariate regression with BMC dependent variable, treatment group independent variables. Weight varied between −14.4% +16.7%. All variables showed statistically significant effect. Standard enhanced all dependence (P 25 kg/m2, respectively). For neck root mean square (RMS) residual significantly larger high BMI 5%, respectively) RMS changes large for < 0.05) standard 0.01 P 0.05, With exception algorithm, longitudinal postmenopausal not found to systematic errors results studies but may adversely affect precision.