Fig. 1.

Both male and female db/db (db) mice in a C57BL6J background exhibit severe obesity, increased adiposity, and overt diabetes. A–C: body weight (BW) was markedly higher in db/db mice compared with age-matched wild-type (WT) control mice. Compared with age-matched WT mice, female db/db mice had a more impressive increase in body weight than male mice (female db/db mice: 2.38-fold higher body weight than age-matched WT mice at 6 mo of age and 2.37-fold higher at 12 mo vs. male db/db mice: 1.88-fold at 6 mo and 1.74-fold at 12 mo of age). D–F: magnetic resonance imaging showed a marked increase in body fat weight in both male and female db/db mice at 2 and 6 mo of age. G–I: in contrast, lean mass was comparable between age- and sex-matched WT and db/db mice. J and K: dual-energy X-ray absorptiometry performed at 4 mo of age also showed that db/db mice had a marked increase in total (G) and abdominal (H) fat content. L–N: although there was significant variability, both male (M) and female (N) db/db animals exhibited a marked increase in fasting plasma glucose levels at 2 and 6 mo of age. **P < 0.01, ***P < 0.001, ****P < 0.0001, and ^P < 0.05 vs. corresponding 2-mo-old mice; ^^^P < 0.001 vs. corresponding 2-mo-old mice. Body weight sample size: WT mice: 1 mo n = 37, 2 mo n = 63, 4 mo n = 58, 6 mo n = 91, 12 mo n = 22; db/db mice: 1 mo n = 11, 2 mo n = 35, 4 mo n = 45, 6 mo n = 68, 12 mo n = 24. Male mice: WT 1 mo n = 16, 2 mo n = 23, 4 mo n = 32, 6 mo n = 53, 12 mo n = 11; db/db: 1 mo n = 7, 2 mo n = 22, 4 mo n = 29, 6 mo n = 38, 12 mo n = 10. Female mice: WT 1 mo n = 21, 2 mo n = 40, 4 mo n = 31, 6 mo n = 38, 12 mo n = 11; db/db: 1 mo n = 4, 2 mo n = 13, 4 mo n = 16, 6 mo n = 30, 12 mo n = 14. Magnetic resonance imaging fat content: n = 12–16 mice/group, n = 5–9 male mice/group, n = 4–8 female mice/group. Dual-energy X-ray absorptiometry: n = 7–16/group. Fasting plasma glucose: n = 18–49 mice/group, n = 9–27 male mice/group, and n = 9–22 female mice/group.