Heart rate variability as a screening tool for Parkinson's disease has age-dependent performance

Objective: To investigate the diagnostic performance of heart rate variability (HRV) as a premotor biomarker for Parkinson’s disease (PD) in an older cohort. Background: Reliably making an early diagnosis of PD is important for researching new treatment and disease modifying strategies. Heart rate variability due to autonomic denervation has been demonstrated early in the course of PD, and may be a potential biomarker. However, this is complicated by the fact that HRV decreases with age independently of medications or comorbidities. While some HRV measures differ between Parkinson’s patients and controls, all of these previous studies have used patient populations of a younger and narrower age range, thus it is unknown if this finding will persist across broader and older age groups. Design/Methods: 164 subjects with PD or controls from the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND) underwent electrocardiogram for HRV assessment using Kubios HRV software. Subjects with any other form of parkinsonism or dementia were excluded. Fifteen variables were analyzed through the Kubios software across time and frequency domains, and each variable was compared between groups for statistical significance after controlling for age. Results: There were 26 Parkinson’s disease (mean age 75.1, SD 8.1, 35% female) and 138 controls (mean age 81.2, SD 6.9, 70% female). None of the variables analyzed were significantly different between the Parkinson’s disease and controls groups after controlling for age. This contrasts with previous studies that demonstrated a significant difference in multiple time- and frequency-domain variables between PD and control groups. The average age of subjects in these previous studies ranged from 54 to 65.6 years. Conclusions: Although increased heart rate variability may be a potential tool for Parkinson’s disease screening in younger patients, this does not appear to differentiate Parkinson’s patients from controls in older age groups as studied in our cohort. Disclosure: Dr. Christiansen has nothing to disclose. Dr. Mehta has nothing to disclose. Dr. Hentz has nothing to disclose. Dr. Beach has received personal compensation for activities with Avid Radiopharmaceuticals. Dr. Beach has received research support from Avid Radiopharmaceuticals and Navidea Biopharmaceuticals. Dr. Serrano has nothing to disclose. Dr. Shill has received research support from Schering-Plough/Merck, Avid Radiopharmaceuticals, UCB Biosciences, and Adamas Pharmaceuticals. Dr. Driver-Dunckley has research support from Allon Therapeutics, Chelsea Therapeutics, EMD Serono, and Ipsen. Dr. Sabbagh has recieved book royalty payments from Tenspeed/RandomHouse. Dr. Davis has received personal compensation for activities with Guidepoint Global, GLG Consulting, Schlesinger Associates, and Lundbeck as a consultant. Dr. Langston has nothing to disclose. Dr. Adler has received personal compensation for activities with Adamas Pharmaceuticals, Cynapsus Lundbeck, and Merz Pharma as a consultant. Dr. Adler has received royalty payments from Springer.