Ultrasound measurement of proximal phalanges in a normal Polish female population

In this cross-sectional study 954 Polish healthy women aged 30-80 years were evaluated (mean age 50.8 +/- 8.9 years). Among them were 460 premenopausal (mean age 44.4 +/- 5.5 years) and 494 postmenopausal women (mean age 56.8 +/- 7.2 years). Women suffering from diseases known to affect bone metabolism and/or treated with drugs that affect bone tissue were excluded. All women were volunteers from six towns in the south of Poland, who underwent bone measurements for screening purposes. Bone status was assessed using an ultrasound device (DBM Sonic 1200, Igea, Italy) that measures amplitude-dependent speed of sound (AD-SoS) in metres per second. Phalanges (II-V) of the non-dominant hand were measured and an average value was computed. In vivo short-term precision was 0.49% for intraobserver, and 0.42% for interobserver measurements. Mean AD-SoS values were: in the whole group, 1974.6 +/- 90.7 m/s; in premenopausal women, 2032.1 +/- 50.0 m/s; and in postmenopausal women, 1921.0 +/- 87.3 m/s (p < 0.0001). The mean decrease in AD-SoS value in the studied population was 6.1 m/s per year. Simple linear regression analysis showed significant, negative correlations between age and AD-SoS: in the whole group r = -0.70 (p < 0.0001); in pre- and postmenopausal women, r = -0.29 (p < 0.0001) and r = -0.58 (p < 0.0001), respectively. Years since menopause (YSM) showed a significant influence on AD-SoS: linear correlation in the whole group resulted in a value of r = -0.59 (p < 0.0001) and in the group of postmenopausal women in a value of r = -0.57 (p < 0.0001). AD-SoS decreased in the first 8 YSM by 5.1% (0.63%/year) and in the next 15 YSM by 5.44% (0.36%/year). In postmenopausal women mean AD-SoS was regressed simultaneously on age and YSM, resulting in AD-SoS = 2181.0 - 4.031 x Age - 3.911 x YSM. In conclusion, ultrasound measurements of proximal phalanges were found to enable detection of age- and YSM-related skeletal changes in a Polish healthy female population. Results obtained in this study showed a premenopausal decrease in the ultrasound parameter (not observed by other authors) and an AD-SoS value lower than those in French, Italian and Spanish populations. The premenopausal decline in AD-SoS, the most important observation, requires further longitudinal investigations to determine factors affecting the skeleton before menopause.