Quantitative ultrasound (QUS) of bone is a valuable tool in the assessment of postmenopausal osteoporosis. QUS and new markers of bone turnover have been poorly assessed in Cushing's syndrome, however. Twenty-five patients with Cushing's syndrome (20 women, 3 men; mean age +/- SEM: 38+/-2 years) were studied and compared with 35 age- and sex-matched control patients (mean age +/- SEM: 38+/-2 years). The following variables were measured in both groups: QUS parameters at the heel (BUA; SOS; Stiffness Index, SI); bone mineral density (BMD) at both the lumbar spine (LS) and femoral neck (FN) by dual-energy X-ray absorptiometry; and serum markers of bone turnover (osteocalcin, procollagen type I N- and C-terminal propeptides (PINP and PICP), bone alkaline phosphatase (BAP), procollagen type I C-terminal telopeptide (ICTP) and urinary type I collagen C-telopepetide breakdown products (CTX)). Both BUA and SI were decreased in patients with Cushing's syndrome (p<0.01) but not SOS (p=0.08). BMD was also strongly decreased in Cushing's syndrome, at both the LS and FN (p<0.005). The two markers of bone turnover statistically significantly different between the two groups were osteocalcin (mean + SEM: 3.5 + 0.7 ng/ml (Cushing's syndrome) vs 6.4+/-0.5 ng/ml (controls, p<0.01)) and CTX (mean +/- SEM: 148.7+/-17.1 microg/mmol Cr (Cushing's syndrome) vs 220.8+/-22.9 microg/mmol Cr (controls), p<0.05). The areas under the receiver operating characteristic curve (AUC) were 0.72 (BUA), 0.73 (SI), 0.90 (BMD(LS)), 0.81 (BMD(FN)), 0.83 (osteocalcin) and 0.64 (CTX) respectively. AUC was significantly higher for BMD(LS) than for both BUA and SI (p<0.05). Conversely AUC was not statistically significantly different for BMDFN as compared with either BUA or SI. AUC was also higher for osteocalcin than for other markers of bone turnover. In conclusion, QUS of bone seems to be a relevant tool for assessing bone involvement in Cushing's syndrome. QUS does have a lower sensitivity compared with DXA, however, and the relevance of QUS cannot be ascertained until some longitudinal data are forthcoming. Except for CTX, the other new markers of bone turnover assessed in this study (PINP, PICP, BAP and ICTP) do not seem of interest in Cushing's syndrome.

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Quantitative ultrasound (US) measurements have been shown to be a new technique assessing bone status. This study aimed to assess a new US instrument, the DBM Sonic 1200(R) (IGEA) which permits the measurement of the speed of sound in the proximal phalanges (SOSp) of the hand. The results obtained were compared with DXA (SOPHOS) and US measurements at the calcaneus (Achilles(R) LUNAR). The in vivo precision expressed by coefficient of variation was 0.91%. Ultrasound measurements of phalanges were significantly correlated with BMD in the entire group of 90 subjects: osteoporotic patients (n = 47) and controls (n = 43) (r = 0.44, femoral neck and 0.45, lumbar spine, P < 0.01). A significant correlation was also found in the control group (r = 0.33, lumbar spine and 0.38, femoral neck, P < 0.05) but not in the osteoporotic group (r = 0.3, lumbar spine and 0.17, femoral neck, P > 0.05). Mean values for 31 postmenopausal, osteoporotic women and age-matched controls showed a significant decrease in US measurements at the phalanges (P < 0.05) and the calcaneus (P < 0.01) as well as bone mineral density (BMD) at the spine and femoral neck (P < 0.01) in the osteoporotic group. A decision threshold for a sensitivity of 80% for osteoporotic fractures resulted in a specificity value of only 37% for SOSp, between 53 to 65% for calcaneus US measurements and 45 to 56% for BMD. The Z score, the odds ratio, the ROC curves, and areas under the curves plotted for the subgroup of 31 fractures and their healthy controls showed poorer values for SOSp than BMD and calcaneus US measurements. In conclusion, US measurements of phalanges seem to be less efficient than calcaneus US and BMD measurements to distinguish osteoporotic from healthy women. Other studies and also prospective studies are required to assess the interest in fracture risk assessment.

Quantitative ultrasound (QUS) of bone and new markers of bone remodeling have been poorly investigated in mild primary hyperparathyroidism (PHPT). In this study 26 patients (20 females and 6 males) were evaluated. BUA and SOS were measured by QUS at the heel. Markers of bone remodeling assessed were bone alkaline phosphatase (BAP), osteocalcin (OC), procollagen type I N- and C-terminal propeptides (PINP et PICP), and procollagen type I C-terminal telopeptide in blood and urine (ICTP and CTX). Bone mineral density (BMD) was measured at the lumbar spine (LS), femoral neck (FN), and Ward's triangle (WT). The control group comprised 35 sex- and age-matched subjects. The statistically significant variables between the two groups were (P < 0.05) BUA, BMD(LS), BMD(FN), BMD(WT), BAP, and OC. Corresponding z-scores were -0.55 +/- 0.75, -0.66 +/- 0.77, -0.66 +/- 0.71, -0.67 +/- 0.52, 1.87 +/- 3.87, and 1.93 +/- 3.53, respectively. Although PICP and PINP levels were higher in PHPT patients as compared with controls, the difference was not significant. Several markers of bone turnover were moderately correlated with both QUS (r = -0.39 to -0.55) and BMD (r = -0.48 to 0.63). In conclusion QUS seems to be a relevant tool in the assessment of bone status for patients with mild PHPT.

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