Endocrine Abstracts

JOINT3828

Introduction. : Traditionally, obesity was thought to be a protective factor against osteoporosis. This assumption has influenced clinical practice, as Body Mass Index (BMI) is incorporated into the Fracture Risk Assessment Tool (FRAX), where a higher BMI is associated with a lower fracture risk. However, recent studies have challenged this perspective, indicating that excess adiposity may be linked to osteopenia and osteoporosis. Other finding suggest that this relationship is more complex and site dependent. This study aims to assess the correlation between bone mineral density (BMD) and body composition parameters.

Methods: Inclusion of obese individuals followed in an Obesity Endocrinology appointment who underwent dual-energy X-ray absorptiometry (DEXA) scans to evaluate BMD at the spine, femur (neck and proximal regions), and forearm. Additionally, body composition was also assessed using DEXA. The relationship between BMD and body composition variables was examined.

Results: A total of 101 patients were included, of whom 81. 2% were female and 18. 8% were male. The mean age was 44. 4±12. 1 years (between 18 and 67), with 62. 4% being under 50 years. Mean BMI was 41. 09±5. 68kg/m². Mean total BMD was 1. 097±0. 11g/cm². BMD was significantly higher in males (P < 0. 001) and in individuals younger than 50 years (P = 0. 019). After adjusting for age and sex, no significant correlation was found between BMI and total BMD (P = 0. 859), spine BMD (P = 0. 199) and forearm BMD (P = 0. 131). A weak positive correlation was observed for femoral neck (r = 0. 220; P = 0. 031) and proximal femur (r = 0. 282; P = 0. 005). A weak negative correlation was identified between fat mass percentage and total BMD (r = -0. 274; P = 0. 013), though no significant correlation was found at other sites. This correlation was stronger in males (r = -0. 581; P = 0. 032) compared to females (r = -0. 274; P = 0. 013) A weak positive correlation was observed between lean mass and total BMD (r = 0. 215; P = 0. 032), as well as at all analyzed skeletal sites. No correlation was found between BMD and visceral tissue adiposity index.

Conclusion: In this study, BMI did not demonstrate a protective effective on overall BMD, with only a weak positive correlation found for femoral neck and proximal femur. Additionally, fat mass percentage showed a weak negative correlation with total BMD, particularly in males. In contrast, lean mass exhibited a weak positive correlation with BMD across all analyzed segments, reinforcing its protective role in bone health. No significant relationship was identified between BMD and visceral tissue adiposity index. These findings highlight the complex interplay between body composition and bone health in obese individuals.