Relationships between blood biochemistry and cortical porosity (a-d) or cortical cross-sectional thickness (e-h) as tested by Spearman correlation for NL and CKD animals. Data include all longitudinal time points collected for each measure. BUN ( a,e), Phosphorus (b,f), and PTH (d,h) were significantly associated with cortical porosity (+) and cross-sectional thickness (-) in CKD animals. Calcium (c,g) was not associated with either bone measure in CKD animals. No significant relationships were identified between the blood and bone measures for NL animals. N= 6–36 for the various correlations, see methods for more details.