Differences between measurements of bone mineral densities by quantitative ultrasound and dual-energy X-ray absorptiometry in type 2 diabetic postmenopausal women.

CONTEXT Quantitative ultrasound (QUS) may be more helpful than dual-energy X-ray absorptiometry (DXA) in detecting bone deficits in patients with type 2 diabetes mellitus (T2DM). OBJECTIVE The objective of the study was to compare differences in bone mass measurement by DXA and QUS in T2DM and nondiabetic postmenopausal women. DESIGN, SETTING, AND PARTICIPANTS This clinical investigation was a cross-sectional study in 76 patients with T2DM and 86 nondiabetic postmenopausal women. MAIN OUTCOME MEASURES The primary outcomes were speed of sound (SOS) at the radius, phalanx, and tibia measured by QUS and bone mineral density (BMD) at the lumbar spine (LS), femoral neck (FN), and total hip (TH) measured by DXA. RESULTS BMDs in T2DM patients were higher (LS, 1.06 +/- 0.12 vs. 0.90 +/- 0.23 g/cm(2); FN, 0.80 +/- 0.13 vs. 0.74 +/- 0.12 g/cm(2); TH, 0.87 +/- 0.14 vs. 0.80 +/- 0.13 g/cm(2), respectively, P < 0.001), whereas SOSs were lower than those in nondiabetics (radius, 4044 +/- 178 vs. 4129 +/- 182 m/sec; phalanx, 3902 +/- 207 vs. 3999 +/- 214 m/sec, respectively, P < 0.001). The positive relationships between SOS and BMD (r = 0.26-0.75, P < 0.05) in nondiabetics were not observed in women with T2DM. T2DM impacted negatively on SOSs (radius, beta= -0.223, P <0.01; phalanx, beta= -0.219, P <0.01) but positively on BMDs (LS, beta = 0.314, P < 0.001; FN, beta = 0.173, P < 0.05; TH, beta = 0.203, P <0.01). CONCLUSIONS Differences in bone mass as measured by DXA and QUS in postmenopausal T2DM and nondiabetic women do not change in parallel. QUS can provide useful information in the skeletal assessment of patients with T2DM.