The reference value of trabecular bone score (TBS) in the Iranian population

Abstract

Background Trabecular bone score (TBS), as a tool for measurement of bone microarchitecture, represents fracture risk independently of bone density. The aim of this study was to estimate the reference values of TBS in both genders among the Iranian population to evaluate osteoporotic fractures in the future. Methods The study was performed on healthy Iranian subjects who live in urban areas of Bushehr city, the capital of Bushehr province in southwestern Iran. The participants in this study were selected through a multistage, age and sex stratified, cluster random sampling. The TBS of L1-L4 was assessed by spine DXA images using TBS iNsight software (Discovery WI, Hologic Inc, USA). Age-related models of TBS were constructed using piecewise linear regression analysis. Results In total, 691 participants aged ≥ 18 years (381 men and 310 women) were selected for the study. The mean and standard deviation (SD) of TBS value for men was 1.420 ± 0.094 and the age at the peak TBS was 30.0 years. Among women, the corresponding value for the mean of TBS was 1.428 ± 0.070 and the age at the peak TBS was 24.5 years. Two SDs below the mean of TBS were 1.326 in men and 1.357 in women. Therefore, the following normal range for TBS values has been proposed: Among men, TBS ≥ 1.326 is considered to be normal; TBS between 1.231 and 1.326 is considered to be partially degraded microarchitecture; and TBS ≤ 1.231defined degraded microarchitecture. Among women, TBS categories are defined as normal ≥ 1.357, partially degraded between 1.287 and 1.357 and degraded ≤ 1.287. Conclusions This was the first study to propose evaluation of the normal range for TBS values in both genders in the Middle-East and Iran. According to our results: TBS ≤ 1.231 in men and TBS ≤ 1.287 in women is considered to be degraded microarchitecture among the Iranian population.

Age-Specific Normative Values of Lumbar Spine Trabecular Bone Score (TBS) in Taiwanese Men and Women

“…Our finding in women was in-between the 1.32 reported in a study of 537 healthy Chinese women with ages from 20–89 years [ 15 ] and the 1.362 reported in population-based study of 3985 Japanese women aged 15–79 years [ 27 ]. For men, our value was higher than the 1.326 reported in a study of 381 Iranian men [ 17 ] and the 1.226 found in a study of 894 Australian men aged 24 to 98 years [ 14 ]. To put the value of TBS into perspective, based on a meta-analysis of individual-level data of TBS for fracture risk prediction on 17,809 individuals from 14 prospective cohorts in different countries or regions, a TBS > 1.31 could be considered as normal, 1.23 ≤ TBS ≤ 1.31 as partially degraded microarchitecture, and TBS < 1.23 as degraded microarchitecture in both men and women [ 12 ].…”

“…Several studies have reported normative values of TBS in women of different countries, including China [ 15 ], France [ 16 ], Japan [ 27 ], Sri Lanka [ 22 ] and the United States [ 21 ], and in both men and women of Australia [ 14 ], Iran [ 17 ], Italy [ 18 ], Mexico [ 20 ] and Thailand [ 23 ]. There is a need for establishing reference values for different populations because ethnicity is reported to be an important factor in bone quality [ 28 ] and fracture risk [ 29 ].…”

“…For clinical use, reference standards for TBS values for different populations worldwide are required. At present, TBS normative data are available for several populations, including Australians [ 14 ], Chinese women [ 15 ], French women [ 16 ], Iranians [ 17 ], Italians [ 18 ], Japanese women [ 19 ], Mexicans [ 20 ], non-Hispanic American white women [ 21 ], Sri Lankan women [ 22 ], and Thais [ 23 ]. Nevertheless, to the best of our knowledge, TBS normative data are not available for Taiwanese adults.…”

Review of the Clinical Applications of Trabecular Bone Score

“…TBS is captured from the gray-level variation of pixels on DXA images as a higher number, and the homogeneity of these pixels indicates a better microarchitecture and bone quality [5] (Figure 1). Although the TBS range for normal and abnormal values is still an open research question, there is greater consensus on the following [ Nevertheless, a recent study on an Iranian population has suggested microarchitecture degradation cut-offs of ≤ 1.23 and ≤ 1.29 in men and women, respectively [6].…”

“…Future research will provide more precise evidence for the TBS application in daily routine practice and will identify the population who will take the most benefit from this tool. Moreover, TBS measurement shows technical variations, and with the newly published study of Shafiee et al on the reference value of TBS in an Iranian population, further research is needed [6].…”