This result is supported by additional trends and significant decreases in trabecular number, thickness and connectivity, as well as increases in trabecular spacing and structural model index (SMI) (Figs. 2E,G–J) in cancellous bone within the distal femur of immature HFD-fed mice compared to mature mice. Further, the cortical bone was significantly thinner in HFD than LFD mice (Fig. 2F). The polar moment of inertia and the moment

of inertia about the medial-lateral axis of the femoral mid-shaft, however, were not significantly affected by the diet in either age group. The cancellous BMD of the Stem Cells inhibitor distal femur (Fig. 2C) exhibited a significant interaction between diet and age groups, indicating that the two age groups may have been affected differently, but the diet and age group main effects were not significant. As with the distal femur, HFD decreased vertebral cancellous bone volume relative to LFD controls as demonstrated by 3D renderings of micro-CT images (Figs. 3A,B). Within the L3 vertebral bodies, the trabecular BVF was again significantly lower in the HFD compared to the LFD groups (Fig. 3D), but the decrement was not as drastic as that observed in the femur. Unlike the distal femur, this effect was equivalent across the age groups as the interactive effect was insignificant.

Despite the significantly lower trabecular BVF in the HFD-fed mice, the Conn.D, Tb.N, Tb.Sp, and Tb.Th as well as the cortical shell thickness Omipalisib datasheet (Figs. 3F–J) were not

significantly affected by the HFD. The total cross-sectional (transverse) bone area measurements had similar trends to the BVF, with significant reductions in the HFD-fed mice and trends towards a greater deficit in HFD-fed immature mice (Fig. 3E). Consistent with the lower trabecular BVF and total cross-sectional bone area of the vertebrae, we observed a significantly lower maximum compressive force, yield force, stiffness and energy to maximal loading in the HFD-fed mice (Figs. 4D–G). In accordance with the structural changes, this reduction in compressive strength was similar between the two age groups. After adjusting the compressive force by the cross-sectional bone areas to estimate the apparent much stresses, the HFD did not significantly affect the maximum stress, yield stress, modulus, or toughness (Figs. 4H–K). This suggests that the bone tissue quality may not be significantly affected by the HFD after 12 weeks in either immature or mature mice. After transitioning the HFD-fed mice to a LFD for an additional 12 weeks, the body weight in both age groups returned to that of age-matched LFD:LFD mice (Figs. 5A–B, Table S1). The increased fasting glucose and serum leptin concentrations were also returned to normal levels in both age groups after the diet correction (Figs. 5C–D, Table S1). Interestingly, the fasting glucose levels of the mature LFD:LFD group were significantly higher than the mature HFD:LFD group (Table S1).