Bone mechanical competence in hypercholesterolemic rats fed MUFAn9 rich diets.

Abstract

Reduced bone mass in growing rats fed MUFAn9‐rich diets was observed. But bone stiffness has not been defined yet. To study the mechanical bone competence in hypercholesterolemic (HC) rats fed MUFA diets, weanling male Wistar rats (n=48) were assigned to one of 7 diet groups for 8 weeks (T8). Three control groups fed a commercial diet (C), C+olive oil (COO) or C+high‐oleic sunflower oil (CHOSO) and 4 groups, an atherogenic diet for 3 weeks; then either one of OO, HOSO, HOSO+sterols or HOSO+fish oil diet. At T8, serum lipid‐lipoprotein profile and femur mechanical properties were assessed: Load‐bearing capacity, yielding load and deformation, stiffness, Cross‐sectional bone area, Cortical Area, moment of inertia, yield stress, elastic modulus. Body weight was lower in HOSO (p<0.0001). HOSO had the highest T‐chol & nHDL & the lowest HDL. HOSO+fish oil, the lowest T‐chol & nHDL. HOSO+sterols oil improved HDL, nHDL & T‐chol vs. HOSO (p<0.01). Structural & geometric properties were negatively affected but material bone quality properties remained unchanged in HC. The impaired mechanical bone competence in HC could be due to an altered bone mass and architectural distribution rather than to intrinsic bone quality with detrimental effects on femoral stiffness and strength. UBACyT 0613 and 0070 and Ped Sunshine Acad USA grants. Champin G technical support.