Peripheral levels of angiotensins are associated with depressive symptoms in Parkinson's disease

• Plasma levels of angiotensins are reduced in PD patients.
• Levels of angiotensins are associated with severity of depressive symptoms in PD.
• The renin-angiotensin system is changed in PD.

BackgroundThe pathogenesis of PD remains elusive. The renin-angiotensin-system (RAS) has recently been implicated in the degeneration of dopaminergic neurons. This study aimed to compare plasma levels of components of the RAS of individuals with PD with controls. We also investigated the association between these circulating markers and motor, depressive and cognitive parameters.MethodsThirty PD patients and twenty controls were subjected to clinical evaluation, including cognitive and depressive symptoms assessment. Plasma levels of Angiotensin (Ang) I, Ang II, Ang- (1–7), angiotensin-converting enzyme (ACE) and ACE2 were measured by Enzyme-Linked Immunosorbent Assay (ELISA).ResultsPD patients presented lower plasma levels of Ang I, Ang II and Ang- (1–7) than control individuals. Among PD patients, lower circulating levels of angiotensins were associated with increased severity of depressive symptoms.ConclusionsThis is the first study showing that peripheral levels of RAS components are changed in PD and associated with depressive symptoms.