Effect of sex and rs2229765 A-allele on IGF-1 circulating level. (A) The sample was divided into two groups, older and younger than 85 years of age, then each group was divided according to sex. The distribution of IGF-1 concentrations in each group was stratified according to the rs2229765 genotype. The vertical bars represent the mean ± standard deviation (SD); *: p < 0.05, Tukey's post-hoc test vs. M 85+ G/G group; M: men, F: women (B) Scatter plot showing male rs2229765 genotype-specific linear regressions according to age. All males have been included. Regression slopes are reported next to each regression line.