UK Biobank Data Link Weaker Heart-Rate Signals to Later Parkinson's Diagnosis

A prospective study of more than 48,000 UK Biobank participants found that lower heart-rate variability, measured from a brief resting ECG, was associated with a higher chance of developing Parkinson's disease over the next 12 years, with brain structure and inflammation markers offered as possible links.

Researchers analyzing 48,202 UK Biobank participants who had no Parkinson's disease or dementia at enrollment found that those with lower heart-rate variability, a measure of how much the interval between heartbeats fluctuates, were more likely to be diagnosed with Parkinson's disease during an average of 12.24 years of follow-up, according to a study posted to PubMed Central (PMC12780526). Of the cohort, 307 people went on to develop the disease. Using Cox proportional hazards models that adjusted for other factors, the researchers found an L-shaped relationship for one heart-rate variability measure, called RMSSDc: only participants whose readings fell below a specific low threshold had a significantly elevated risk, at 1.63 times that of others (95 percent confidence interval, 1.18 to 2.24).

The study follows earlier, smaller research, including a wearable-monitor study this newspaper reported on that found a distinct heart-rhythm signal in people already diagnosed with Parkinson's. The new work adds scale and a time dimension: a nested case-control analysis within the cohort found that heart-rate variability in people who later developed Parkinson's had already begun diverging from that of unaffected participants roughly 10 years before their diagnosis, the study reported.

To probe why the two might be connected, the researchers ran a mediation analysis, a statistical technique that estimates how much of a link between two factors runs through a proposed middle step. They reported that thalamus-related white matter fiber tracts, a brain structure feature, and several peripheral inflammation markers, including monocyte count and four blood proteins (histamine N-methyltransferase, interleukin-13 receptor subunit alpha-1, secretogranin-2, and BAG family molecular chaperone regulator 3), appeared to carry part of the statistical association between heart-rate variability and Parkinson's risk. The authors describe this as evidence for possible mechanistic pathways, not as proof that any of these factors cause the disease.

The authors frame heart-rate variability as a potential early risk marker worth further study, not as a diagnostic tool; they call for replication in independent cohorts and peer-reviewed publication of the full analysis before any clinical use is considered.