Comparison of serum IGF-1 concentrations throughout the CFPE cycle. In eight subjects (panel A), mean serum IGF-1 fell by 174.4 ng/ml (95% CI of mean difference = 102.4–246.5, P < 0.001). In 12 subjects (panel B), including those compared in panel A, mean serum IGF-1 increased by 114.7 ng/ml (95% CI of mean difference = 55.6–173.7, P = 0.001). Lines denote mean and SD.