Call:
lm(formula = sqrt(newjuul$igf1) ~ newjuul$age)

Residuals:
Min 1Q Median 3Q Max
-4.8642 -1.1661 0.1018 0.9450 4.1136

Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 18.71025 0.49462 37.828 <2e-16 ***
newjuul$age -0.10533 0.01072 -9.829 <2e-16 ***
—
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 1.741 on 120 degrees of freedom
Multiple R-squared: 0.446, Adjusted R-squared: 0.4414
F-statistic: 96.6 on 1 and 120 DF, p-value: < 2.2e-16