In females, IGF-1 was significantly elevated at both -10 to -5 years (21.04 +/- 5.86, P<0.001) and -5 to 0 years before diagnosis (20.89 +/- 6.38, P<0.05) and 0–5 years after diagnosis (21.87 +/- 6.27, P<0.01) compared to non-PD, (20.13 +/- 5.40, Fig 5B). Here, IGF1 is linked to Parkinson disease.