Exercise and WBV increase serum osteocalcin levels in db/db mice. (a) TE and WBV increase serum osteocalcin in db/db mice relative to SED db/db mice. (b) Micrographs show representative montages of tetracycline labeling in tibial cross-sections from the indicated groups. Scale bar = 200 µm. Insets show labeled surfaces visualized after two injections of tetracycline, with 10 days between injections. (c) Analysis of endocortical mineral apposition rates (Ec.MARs) in tibial cross-sections revealed no significant effect of genotype or intervention. (d) db/db mice exhibit reductions in cortical bone area (Ct.Ar) as determined by microCT analysis in the femur. (e) Leptin receptor deficiency reduces the periosteal area (Ps.Ar) in femur samples, as determined by microCT. For graphs, bars represent the average of (n = 6 to 8) mice in the indicated conditions, and hashtags denote the effect of genotype following 2 × 3 ANOVA with statistical significance at P < 0.05. Asterisks indicate significant differences relative to matched-genotype SED mice following one-way ANOVA with Bonferroni-corrected post hoc comparisons.