Miriam Antoinette Bredella MD, Presenter: Nothing to Disclose

Eleanor Lin, Abstract Co-Author: Nothing to Disclose

Anu V. Gerweck, Abstract Co-Author: Nothing to Disclose

Bijoy J. Thomas MD, Abstract Co-Author: Nothing to Disclose

Martin Torriani MD, Abstract Co-Author: Nothing to Disclose

Mary L. Bouxsein PhD, Abstract Co-Author: Nothing to Disclose

Karen K. Miller MD, Abstract Co-Author: Nothing to Disclose

Recent studies have suggested that obesity may exert damaging effects on the skeleton. The purpose of our study was to investigate determinants of bone mechanical properties by micro-finite element analysis (FEA) of HR-pQCT scans of the distal radius in obese men.

We studied 35 obese men with a mean age of 33.8±6.4 years and a mean BMI of 36.5±5.8 kg/m2, who underwent 3D HR- pQCT with an isotropic voxel size of 82 μm (Xtreme CT, Scanco Medical, Basserdorf, Switzerland) of the distal radius. FE models were generated from the segmented HR-pQCT images and estimated failure load (N) and stiffness (kN/mm) were determined. QCT of the abdomen and thigh was performed to quantify abdominal subcutaneous (SAT), visceral (VAT) and total abdominal (TAT) adipose tissue, thigh muscle and thigh SAT (cm2). Linear regression analysis was performed to determine predictors of bone mechanical properties. Subjects were divided into high VAT and low VAT groups based on the VAT median.

Men with high VAT had lower failure load and stiffness compared to men with low VAT (p<0.05), despite comparable BMIs. VAT and TAT were inversely associated with estimated failure load (r=−0.42, p 0.01 and r= -0.39, p= 0.03, respectively) and stiffness (r= -0.45, p=0.008 and r= -0.42, p=0.02, respectively). Thigh muscle area correlated positively with failure load and stiffness (r=0.39, p=0.02 and r=0.34, p=0.05, respectively). There was no association between age, BMI, abdominal or thigh SAT and mechanical properties.

Our study shows that VAT and TAT are negative, and muscle mass positive, predictors of bone mechanical properties in obese men. Our results support the notion that visceral fat exerts detrimental effects on bone strength.

Men with visceral obesity have impaired bone mechanical properties. Muscle mass is a positive predictor of bone strength in obese men.  

Bredella, M, Lin, E, Gerweck, A, Thomas, B, Torriani, M, Bouxsein, M, Miller, K, Determinants of Bone Mechanical Properties in Obese Men.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12021708.html