Effects of age and genotype on cancellous bone area fraction in distal femur epiphysis (A) and metaphysis (C) and cartilage retention in cancellous bone in distal femur epiphysis (B) and metaphysis (D) and in cortical bone in femur diaphysis (E) in 2-month-old, 4-month-old, and 6-month-old male WT and leptin-deficient ob/ob mice. Data are mean ± SE; n = 10/group for 2-month-old mice, n = 5/group for 4-month-old mice, n = 3 and 5/group for 6-month-old WT and ob/ob mice, respectively.