Reciprocal Relations of Subcutaneous and Visceral Fat to Bone Structure and Strength
CONTEXT: Increased body fat is a risk factor for cardiovascular and metabolic disease, yet it is uncertain whether obesity protects against osteoporosis or adiposity is harmful to bone. OBJECTIVE: The aim of the study was to assess whether the pattern of adipose tissue deposition influences bone structure and strength. DESIGN: The relations between sc and visceral adiposity and the cross-sectional dimensions and polar and principal moments of the femur in 100 healthy women ages 15 to 25 years were obtained using computed tomography. RESULTS: Multiple linear regression analyses indicated that, after adjusting for leg length and thigh musculature, both sc and visceral fat had strong and independent associations with femoral cross-sectional area, cortical bone area, principal moment maximum, principal moment minimum, and polar moment (all P values < 0.03). However, whereas sc fat had a positive predictive value with all femoral bone phenotypes, a similar but negative effect was observed between visceral fat and these measures (all P values < 0.01). CONCLUSIONS: We found that visceral and sc fat have opposite effects on the appendicular skeleton; whereas sc fat is beneficial to bone structure and strength, visceral fat serves as an unique pathogenic fat depot.