Comparison of (a) blood glucose levels, (b) wet sawdust, a reflection of polyuria, (c) water bottle volume, an index of polydipsia, and (d) glycosuria in obese db/db mice and age-matched db/db mice in which obesity was prevented by transgenic expression of the leptin receptor on an aP2 promoter (db/db-tg). Clearly the absence of obesity accelerates the appearance of T2DM by about 5 weeks. The transgene on adipocytes prevents adipocyte hypertrophy, which attenuates the usual obesity-associated hyperleptinemia. The limited adipogenesis in these mice was associated with marked increase in ectopic lipid deposition, again absolving obesity as a cause of metabolic syndrome.