Table 1.

Correlation coefficients between standardized properties in bone from (a), (c) Chow and (b), (d) HFD groups. Coefficients from correlation analysis applied between standardized mechanical properties and standardized bone and physiological properties of (a) Chow group and (b) HFD group. In cases where measurements were related and highly positively correlated, a composite score was used in the analysis. Bone size is the largest predictor of mechanical properties, more so than bone-mineral measures or body composition. Interestingly, size-independent measures of bone quality are most affected by the size of the bone, which implies a reduced quality with increasing quantity. Correlation coefficients between body mass measures and bone size measures show that LBM is positively correlated with bone size in both groups (c) & (d), and that FBM is very weakly negatively correlated with bone size. HFD (d) was almost significant for LBM-bone size correlation (P=0.053).

	a. Chow (n=15)				b. HFD (n=14†)
	Size – independent measures		Size – dependent measures		Size – independent measures		Size – dependent measures
Predictors	(σy, σu, E)	Kc	P y	P u	(σy, σu, E)	Kc	P y	P u
vBMD	0.12	0.55*	0.08	−0.42	−0.24	−0.07	0.24	−0.01
(M.A.A,Ro)	−0.44	−0.43	0.23	0.19	−0.86***	−0.59*	0.57	−0.04
LBM	−0.37	−0.18	0.25	−0.07	−0.67*	−0.16	0.50	0.02
FBM	−0.30	0.16	−0.11	−0.53*	0.41	0.10	−0.54	−0.02
	c. Bone size in Chow- (M.A.,A,Ro)				d. Bone size in HFD - (M.A.A,Ro)
LBM	0.514*				0.548
FBM	−0.215				−0.315

^†One mouse was found to be diabetic and was excluded from all analyses.

^*P<0.05

** P<0.01

^***P<0.001.

vBMD = volumetric bone-mineral density; M.A.= second moment of area; A = Ct. cross-sectional area; R_o = outer Ct. Rd; LBM = lean body mass; FBM = fat body mass; σ_y = yield strength; σ_u = maximum strength; E = bending modulus; K_c = fracture toughness; P_y = yield load; P_u = maximum load. (M.A., A, R_o ) = composite bone size score, (σ_y, σ_u, E) = composite strength and modulus score.