Age-associated changes in quantitative ultrasonometry (QUS) of the os calcis in Lebanese women-assessment of a Lebanese reference population.

OBJECTIVE This study was aimed to assess age changes in quantitative ultrasonometry (QUS) in a large sample of Lebanese women to determine a Lebanese reference population. DESIGN Cross-sectional study. SUBJECTS AND METHODS Broadband ultrasound attenuation (BUA) and speed of sound (SOS) and the stiffness index (SI) of the os calcaneus was measured in 4,320 women with a mean age of 52.5 years (age range 20 to 79 years) using three identical Achilles Express (GE/Lunar) and one Achilles Plus (GE/Lunar) ultrasonometry devices. Women were randomly selected and asked to participate in a nationwide screening program using the media, conferences, telephone calls etc. Measurements were performed at Red Cross centers located all over the country. No inclusion or exclusion criteria were used. RESULTS There was an overall decline of 19.2% for BUA, 3.1% for SOS and 30.3% for SI between late adolescence and old age. In premenopausal women, BUA decreased only slightly by 3%, while postmenopausal women showed a significant decline of 16.2%. In contrast, SOS continuously decreased from the age of 42; there was a decline of 0.8% from adolescence to the menopause; postmenopausal women showed a larger decline of 2.4%. The SI of premenopausal women decreased by 6%, while postmenopausal women showed a significantly larger decline of 24.3%. SI value for the female Lebanese young adult reference is 8% lower than that of the American and European women (92 SI units compared to 100). At the age of 42, SI value for the Lebanese women is 10.4% lower than the American women and 7.5% lower than the European women (86 SI units compared to 96 and 93, respectively). At the age of 75, SI values for the Lebanese women is 4.4% lower than the American women and the European women (65 SI units compared to 68). The decline in stiffness index for the Lebanese women between age 20 and 75 years is about 30.3% compared to 32% for the American or European reference curves. The rate of decrease for the Lebanese women was 0.2 SI units per year for the premenopausal period, and 0.7 SI units per year for the postmenopausal period. CONCLUSION The age-related female, Lebanese reference curve was significantly different from the American and the European reference curves used by the manufacturer. Therefore, the use of our standardized reference data instead of the proposed US or European database reduces the risk of overestimating osteoporosis in the Lebanese population. The impact of our results on the prevalence of osteoporotic fracture in Lebanon has to be evaluated later on.