Association of caffeine and related analytes with resistance to Parkinson’s disease among LRRK2 mutation carriers: a metabolomic study

Objective: To identify markers of resistance to developing Parkinson’s disease (PD) among LRRK2 mutation (LRRK2+) carriers, we carried out metabolomic profiling in individuals with PD and unaffected controls (UC), with and without the LRRK2 mutation. Methods: Plasma from 368 PD and UC subjects in the LRRK2 Cohort Consortium (LCC), comprising 118 LRRK2+/PD+, 115 LRRK2+/UC, 70 LRRK2-/PD+ and 65 LRRK2-/UC, and CSF available from 68 of them were analyzed by liquid chromatography with mass spectrometry. For 282 analytes quantified in plasma and CSF, we assessed differences among the four groups and interactions between LRRK2 and PD status, using ANCOVA models adjusted by age, study site cohort, and sex, with p-value corrections for multiple comparisons. Results: Plasma caffeine concentration was lower in PD vs. UC subjects (p