Age-dependent weight gain (A) and blood glucose levels (B) in ob/ob and wild-type mice. A: Ob/ob mice (●) rapidly gain weight from the age of 4 weeks and are significantly heavier than age-matched wild-type mice (□) from
4 weeks of age (*P < 0.001). Compared with 4-week-olds, the body weight of ob/ob mice doubles around 10 weeks of age and triples around 20 weeks of age, at which point it reaches a plateau. Wild-type mice
maintain steady body weight throughout the entire age span (4 to 30 weeks of age) (n = 12–24 ob/ob mice; n = 12–24 wild-type mice). B: Ob/ob mice develop significant hyperglycemia (blood glucose levels >250 mg/dl) from 7 weeks of age and remain hyperglycemic until
23 weeks of age (●). Spontaneous decrease in blood glucose was recorded after the age of 23 weeks. Blood glucose levels in
wild-type matched controls (□) remains steady and within normal limits throughout the entire age span (*P < 0.05 ob/ob vs. wild-type mice). The area within the rectangle indicates ages (8 to 20 weeks old) when ob/ob mice are morbidly obese and significantly hyperglycemic (n = 12–24 ob/ob mice; n = 12–24 wild-type mice). WT, wild type.