C57BL/6J mice with mutations in leptin (B6-ob, Strain 000632) or its receptor (B6-db, Strain 000697) are hyperglycemic at young ages, but blood glucose levels eventually return to normal due to pancreatic islet cell hypertrophy.  By contrast C57BLKS/J mice with the same mutations (such as BKS-db, Strain 000642) are hyperglycemic throughout life.  Males and females in each strain have similar phenotypes, including weight and glucose (Figure 1, Table 1).  C57BL/6J male mice fed a high fat diet (DIO-B6, Strain 380050) are obese but not overtly diabetic (Table 1).  Detailed phenotypes for each strain are available.

Figure 1 Non-fasted blood glucose measured every other week in BKS-db, B6-db, B6-ob male and female mice.

Table 1 Comparison of four metabolic disease models at 8 and 16 weeks of age.  Blood was collected from the submandibular route and analyzed using a OneTouch Ultra2 or UltraMini glucometer (Blood Glucose) or a Beckman Coulter AU680 chemistry analyzer (Serum Glucose, HbA1c).