Fig. 1.

Igfals gene inactivation leads to decreased serum IGF-1 levels and affects body size and body composition through aging. a Plasma IGF-1 levels at 52, 80, and 104 weeks of age (n = 10–16). b Body weight (n = 10–48). c Plasma GH levels (n = 8–15). d Relative fat mass, assessed by MRI (n = 10–48). e Relative lean mass, assessed by MRI. Data presented as mean + SD (n = 10–48). Asterisk, significant difference between WT and ALSKO mice at the indicated age; section sign, significant difference from all other groups; number sign, significant difference from 21 weeks of age