Using an app to encourage more physical activity

The goal of this clinical trial is two-fold. First to investigate the feasibility of whether a remotely administered smartphone app can increase the volume and intensity of physical activity in daily life in individuals with a LRRK2 G2019S or GBA1 N370S genetic mutation over a long period of time (24 months). Second, to explore the preliminary efficacy of exercise on markers for prodromal Parkinson's disease progression in individuals with a LRRK2 G2019S or GBA1 N370S genetic mutation. Participants will be tasked to achieve an incremental increase of daily steps (volume) and amount of minutes exercised at a certain heart rate (intensity) with respect to their own baseline level. Motivation with regards to physical activity will entirely be communicated through the study specific Slow Speed smartphone app. A joint primary objective consists of two components. First to determine the longitudinal effect of an exercise intervention in LRRK2 G2019S or GBA1 N370S variant carriers on a prodromal load score, comprised of digital biomarkers of prodromal symptoms. The secondary component of the primary outcome is to determine the feasibility of a remote intervention study. The secondary objective is the effect of a physical activity intervention on digital markers of physical fitness. Exploratory outcomes entail retention rate, completeness of remote digital biomarker assessments, digital prodromal motor and non-motor features of PD. Using these biomarkers, the investigators aim to develop a composite score (prodromal load score) to estimate the total prodromal load. An international exercise study with fellow researchers in the United Kingdom are currently in preparation (Slow-SPEED-UK) and active in the Netherlands (Slow-SPEED-NL). Our intention is to analyse overlapping outcomes combined where possible through a meta-analysis plan, to obtain insight on (determinants of) heterogeneity in compliance and possible efficacy across subgroups

Rationale: Parkinson's Disease (PD) is the fastest growing neurodegenerative disease. Exercise beneficially effects motor symptoms and neuroplasticity in people with PD. However, disease-slowing interventions have been ineffective in clinically manifest PD, when pathology is already advanced, but could succeed in prodromal PD, when pathology is limited. People with a LRRK2 G2019S or GBA1 N370S genetic mutation have an increased risk to develop clinically manifest PD. Therefore, this group is likely to develop prodromal PD. This study will take an important step forward by studying the feasibility and preliminary efficacy of long-term physical activity on prodromal symptoms and disease progression in people with prodromal PD using a newly developed, fully remote smartphone-based app. The app is inspired by the app used in the STEPWISE trial (NCT04848077) and currently used in Slow-SPEED-NL (NCT06193252). Objective: The joint primary objective has two components. First, to evaluate the long-term (36-month) impact of an exercise intervention on a prodromal load score in individuals carrying the LRRK2 G2019S or GBA1 N370S variants. This score will be derived from digital biomarkers capturing both motor and non-motor prodromal symptoms. Using these biomarkers, the investigators aim to develop a composite prodromal load score to estimate the overall burden of prodromal features. The secondary component of the primary outcome is to determine the feasibility of a long-term (36 months) remote intervention study expressed as longitudinal change in digital measures of physical activity (step count) measured using a Fitbit smartwatch. Our secondary objective is the potential group effect on physical fitness. Thirdly, the investigators investigate whether the intervention, prodromal motor- and non-motor symptoms can be assessed remotely in a digital, decentralized fashion. Currently blood- and imaging biomarkers are not incorporated as outcome measures. The investigators intend to add these biomarkers pending appropriate funding. Study design: Double-blind randomized controlled trial Study population: A total of 600 English speaking individuals living in the United States of America with a LRRK2 G2019S or GBA1 N370S genetic mutation aged 50 years and older, who are in possession of a suitable smartphone without mobility hampering conditions and absence of cognitive impairment which impedes usage of a smartphone will be recruited. Participant recruitment will primarily target individuals from the 23andMe customer base. Enrollment and onboarding of study participants will be supported by research staff at the University of Rochester. Intervention: Participants will be randomized to a group (1:1 ratio) and will be motivated to increase the volume and intensity of physical activity based on their own baseline level. Baseline physical activity levels will be determined during a 4-week period. The two groups differ in the amount of physical activity that they are tasked to achieve.