Table 1.

Phenotypic comparison of mutant mice with reduced activity of GH/IGF-1 axis with calorie restricted mice^a

Mouse Model	Ames dwarfa (Prop1df)	Snell dwarfa (Pit1dw)	Ghrhb (lit/lit)	GHR−/−c	IGF1R+/−d	p66shc −/−e	Klotho transgenic f	PAPP-A−/−g	IRS-1−/−h	IRS-2+/−i	CRa	GHA transgenic j
Primary Effect	GH, PRL, TSH deficiency	GH, PRL TSH deficiency	GH deficiency	GHR deficiency/ GH resistance	Partial IGF-1 resistance	Stress resistance	Inhibit IGF-1 and insulin signaling	Reduction in IGF-1 bio-availability	Post-IIS receptor signaling	Post-IIS receptor signaling		Reduced GH signaling
% increase in mean lifespan	49% ♂	26% ♂	23% ♂	26–55% ♂	33% ♀	30%	20–31% ♂	41% ♂	32% ♂	↔ or 17%	Varies	Normal
	68% ♀	42% ♀	25% ♀	16–38% ♀			19% ♀	33% ♀
Plasma levels
GH	↓	↓	↓↓	↑	ND	ND	ND	↔	↔	↔	↓	↑
IGF-1	↓↓	↓↓	↓↓	↓↓	↑	ND	ND	↔	↔	↔	↓	↓
Glucose	↓	↓	↓	↓	↔	↔	↔	↔	↔	↓	↓	↔
Insulin	↓	↓	↓	↓↓	↔	↔	↑	↔	↑	↓	↓	↔
Growth
Body size	↓↓	↓↓	↓↓	↓↓	↔	↔	↔	↓↓	↓↓	↔ to ↑	↓	↓
% body fat	↑	↑	↑↑	↑	ND	ND	↓↓	ND	↓	ND	↓	↑
Energy Balance
Food Intake	ND	ND	↔	↑	↔	↔	↔	↔	↔	↔	↓	↑
Metabolic Rate	↓	↓	↔	↑	↔	↔	↔	ND	ND	ND	↓	ND

ND, no available data

↑ refers to elevated; ↔ indicates normal levels and ↓ refers to reduced levels, with large differences indicated by double arrows.

^aAs reviewed [193,194];

^b[43,195–197].

^c[44,52,83,198]

^d[133]

^e[63]

^f[70]

^g[59]

^h[75]

ⁱ[75–77]

^j[78,79,83,198,199]