Normal cerebrospinal fluid levels of insulin in patients with Parkinson's disease

We compared CSF levels insulin, measured by a Radioimmunoanalysis method, in 24 patients with Parkinson's disease (PD) and 21 matched controls. The CSF insulin levels did not differ significantly between PD patients and controls. CSF insulin levels were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale of the Hoehn and Yahr staging in the PD group. Antiparkinsonian therapy did not influence significantly and CSF levels of insulin. These results suggest that CSF insulin concentrations are not a biological marker of PD and its severity.