Age-related differences in bone structural parameters using 3D-DXA and TBS in men and women: The Bunkyo Health Study

Recent advancements in imaging technology, including trabecular bone score (TBS) and 3D-DXA, enable comprehensive bone structure assessment beyond traditional bone mineral density (BMD) measurements in osteoporosis. However, age-related differences in bone structure remain unclear.

Using data from the Bunkyo Health Study, we analyzed bone structural parameters in 1372 participants (662 men, 710 women) for the proximal femur and 1053 participants (500 men, 553 women) for the lumbar spine, aged 65-84 years. Parameters included TBS of the lumbar spine and proximal femur measurements (3D-Shaper), including volumetric BMD of trabecular, cortical, and integral, cortical thickness, and surface BMD in each bone region. Age group comparisons (65-69, 70-74, 75-79, and 80-84 years) were performed using Kruskal-Wallis test with Bonferroni correction.

In men, only cortical thickness significantly decreased in the proximal femur regions, particularly in the 80-84 age group compared to the 65-69 and 70-74 age groups (-2.3 %, P < 0.05). In women, all parameters significantly decreased (P < 0.001), especially in the 80-84 age group-cortical thickness (-3.9 %), cortical surface BMD (-9.6 %), cortical volumetric BMD (-4.0 %), and trabecular volumetric BMD (-8.4 %)-compared to the 65-69 age group. TBS was significantly lower in women aged 70-74 and 80-84 years compared to those aged 65-69 years (P < 0.001); however, no significant changes were observed in men.

Women showed widespread changes across all parameters, whereas men exhibited primarily cortical thickness changes, suggesting the need for sex-specific approaches for osteoporosis assessment and fracture risk prediction.