PD patient groups with low (<122 ng/mL) and high (≥122 ng/mL) IGF-1 baseline levels differed neither in annual changes of motor symptom severity (UPDRS-III), levodopa equivalent dose medication (LED), depressive symptoms (BDI), nor global cognition (MMSE), p > .1; see Fig 3. This evidence concerns the gene IGF1 and Parkinson disease.