If you’re chronically fidgeting, kicking and tossing and turning in your sleep, Canadian doctors have new research you should pay attention to: they say they’ve uncovered a link between sleep-related leg movements and an increased risk of stroke and heart disease.
Scientists out of Toronto’s Sunnybrook Health Sciences Centre are warning those who grapple with periodic limb movements – when people involuntarily move their hips, ankles, knees or toes during their sleep – could be more likely to suffer from silent strokes.
Their findings are in the preliminary stages, they caution. They haven’t yet pieced together what the overall increased risk is either.
“This is pretty novel. It’s just emerging evidence that’s coming out. If you have enough periodic limb movements, then your sleep can be quite disruptive and that might be associated with a higher blood pressure. The prospective evidence suggests that it might be linked with heart attacks, strokes and the risk of dying is higher as well,” Dr. Mark Boulos, the study’s lead author, told Global News.
“No matter how I ran the statistics, the relationship kept coming out,” he said.
Boulos is a neurologist at Sunnybrook and a University of Toronto professor. He specializes in studying sleep and stroke risk.
Sleep disorders, such as sleep apnea, have already been tied to increased risk of high blood pressure, diabetes and heart attacks.
Boulos wanted to know if this extended into restless legs syndrome (RLS) and periodic limb movements. With RLS, the disorder is marked by an overwhelming urge to move your legs. It’s most severe in the evening and during nighttime hours.
With periodic limb movements (PLM), patients flick their feet, extend their hips, and bend ankles and toes back and forth repeatedly.
“It’s almost like you’re watching your foot flicker all night long. I have patients doing that 100 times per hour – that’s a movement every minute and you can imagine how much disruption that is to sleep,” Boulos said.
In Boulos’ two part-study, he looked at patients who had a stroke or mini-stroke (called a transient ischemic attack or TIA) within two weeks of the incident. Turns out, when he studied their overnight sleep patterns, those with more periodic limb movements in sleep had a greater amount of white matter lesions in their brains, which are key predictors of increased risk of future stroke, dementia and death.
After that, Boulos’ team pored over literature from 1947 to 2016 on PLM and RLS and how they tampered with risk of heart disease and stroke. In that case, there was no “real relationship” between restless legs syndrome and cardiovascular health but leg kicking escalated risk.
“We think these periodic limb movements cause a fluctuating in blood pressure and heart rate at night. If you have a lot of them, your blood pressure will move up and down and that’ll have cardiovascular implications. It might also be associated with inflammation, plaque development or rupturing of plaque – all early warning signs,” Boulous said.
Because the findings are in their infancy, Boulos said it’s too early to apply them to a clinical setting. But ultimately, they could help sleep specialists detect who may be at a greater risk of suffering a stroke or heart disease.
People grappling with limb movements in their sleep that disrupt their rest or their partner’s rest should seek help. Meanwhile, doctors need to pay close attention to heart health risk factors, Boulos said.
“Evolving – albeit early – work suggests that periodic limb movements are an ominous sign because they may be either a potential marker for or a risk factor for heart disease and stroke,” he warned.
His next steps are to look at whether treating patients with PLM improves their heart health outcomes and decreases risk of having a stroke in the future.
Boulos’ full findings were published Tuesday morning in the journal SLEEP.