Circadian disruption could be a prodromal feature or a risk factor for Parkinson disease, according to new US research.
The substudy of the Osteoportoic Fractures in Men Study comprised almost 3,000 men with a median age of 76 years who were living in the community. Data on rest-activity rhythm (RAR) and sleep variables was available from a wearable actigraph.
During a follow-up of 11 years, 2.7% of men were diagnosed with Parkinson disease (PD).
The study, published in JAMA Neurology found the risk of incident PD increased with decreasing circadian amplitude, mesor or robustness.
“Those in the lowest quartile of amplitude, mesor, or robustness had triple the risk of developing PD compared with those in the highest quartile of amplitude (OR, 3.11; 95% CI, 1.54-6.29), mesor (OR, 3.04; 95% CI, 1.54-6.01), or robustness (OR, 2.65; 95% CI, 1.24-5.66),” the study said.
“Reduced circadian rhythmicity might be an important prodromal feature in incident PD and help with the early detection of the disease.”
“To determine whether circadian rhythm abnormalities precede the development of PD, we excluded all cases with PD at study baseline and in secondary analysis introduced a time lag of 2 years.”
“Although the association was somewhat attenuated in secondary analysis, there remained more than double the risk of incident PD in the lowest compared with the highest quartile of RAR parameters. This indicated that weakened circadian rhythmicity rather than shifts in circadian activity timing might be prodromal features of PD.”
They said their results were consistent with some other studies including one conducted in older women.
There were also experimental studies showing that changes in circadian-related neurons are already present during the asymptomatic stage of PD.
“Future studies are needed to identify more specific biological mechanisms linking circadian disruption and PD. If circadian dysfunction is proven to be a risk factor for PD, then strategies to strengthen circadian output and boost synchronisation of the central and peripheral circadian clocks might provide clues for the prevention and management of PD.”