GHR and Insulin resistance: Consistent with previously published data on heightened glucose-stimulated insulin secretion (GSIS) in GHR-KO;RIP::IGF-1 mice (Guo et al., 2005), and with the increased levels of circulating insulin in GHR-KO mice carrying the RIP::IGF-1 transgene (Fig.2A), comparisons of HOMA-IR and HOMA-β scores suggested increased insulin resistance without β-cell dysfunction, respectively, in female GHR-KO;RIP::IGF-1 mice relative to control GHR-KO mice (data not shown).