Reciprocal Relations of Subcutaneous and Visceral Fat to Bone Structure and Strength

Abstract

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. The aim of the study was to assess whether the pattern of adipose tissue deposition influences bone structure and strength. 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. 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). 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.