Abstract
Objectives
The study aim was to assess bone mineral density (BMD) and bone turnover in pre- and postmenopausal women with severe obesity. Additionally, we explored the association between soft tissue body composition and BMD according to menopausal status.
Methods
This is a cross-sectional study conducted in pre- (n = 37) and postmenopausal (n = 22) morbid obese (BMI >40 kg/cm2) women. Body composition and BMD at different sites (lumbar spine, proximal femur and forearm) were assessed by dual energy X-ray absorptiometry (DXA). Biochemical markers of bone metabolism (serum CTX and osteocalcin) and serum 25(OH)D were also measured. Differences between pre- and postmenopausal women were analyzed by Student´s t-test. Body composition [lean mass, visceral (VAT) and subcutaneous (SAT) adipose tissue] and other potential factors associated with BMD were investigated by multiple regression.
Results
BMD at all sites evaluated was similar in pre- and postmenopausal women (P > 0.05). Also, no differences between groups were observed for bone turnover markers (P > 0.05). In postmenopausal women, years after menopause was inversely associated with BMD at total body (β = −0.010, P < 0.01) and total femur (β = −0.009, P < 0.05). Serum 25(OH)D was also associated with total femur BMD (β = 0.008, P < 0.01) in postmenopausal women. Lean mass was not associated with BMD in both groups. VAT was directly associated with lumbar spine BMD in postmenopausal women (β = 0.135, P < 0.05).
Conclusions
Our results suggest that severe obesity may weaken the impact of menopause on bone mass and turnover. Also, soft tissue body composition appears to poorly influence bone density in these women.
Funding Sources
Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ, Grant number E26/110.764/2013 for FFB).