Quantitative Ultrasound of the Calcaneus in Brazilian Caucasian Women: Normative Data Are Similar to the Manufacturer’s Normal Range

Quantitative ultrasound (QUS) can be a helpful alternative to identify osteoporotic patients. In this study we establish the QUS Brazilian normal range (BNR) and compare its values (means and standard deviations) with the manufacturer’s normal range (MNR). We measured three QUS parameters (broadband ultrasound attenuation, BUA; speed of sound, SOS; stiffness index, SI) at the right calcaneus in 352 healthy Caucasian Brazilian women, aged 20–84 years. We studied the age-dependent changes in QUS values and correlation with body size and years since menopause (YSM). A comparison of fracture risk classification using the BNR and MNR is also presented. Age was the most significant predictor for all QUS parameters (r=−0.49 for BUA, r=−0.66 for SOS, r=−0.64 for SI). Weight was accepted as the second determinant for BUA (final regression model: BUA = 101.3 − 0.282 × Age + 0.373 × Weight; p<0.001; adjusted R2= 0.33). Body mass index (BMI) was accepted as the second predictor for SI (SI = 94.8 −0.595 × Age + 0.851 × BMI; p<0.001; adjusted R2= 0.44). Height and YSM were accepted as second and third determinants for SOS values (SOS = 1718.7 − 1.147 × Age − 69.863 × Height − 0.521 × YSM; p<0.001; adjusted R2= 0.45).There was a decline in SI of about 41% from the values in young adulthood to those of women in their eighties, about 76.4% of which occurred from age 45–49 years onward. Variation of mean SI with age from the BNR was consistent with the MNR in all but two 5-year age groups. In these two groups (50–54 years, p<0.01; 65–69 years, p<0.05), values derived from the BNR were 5.08% and 5.45% higher than the MNR values, respectively. Comparison of standard deviations in SI with age between the two populations did not show statistically significant differences. Using the fracture risk criteria proposed by the manufacturer, we observed that the MNR was appropriate for skeletal fragility evaluation in Brazilian women.