Better Sleep, Better Function: New Study Links Sleep Quality to Clinical Outcomes in Huntington’s Disease

Sleep problems are nearly universal in Huntington’s disease (HD) with up to 90% of people with HD reporting sleep-related issues. But new research from a Spanish team suggests these nighttime struggles might be more than just an inconvenience. A year-long study tracking people with HD using wearable devices has uncovered some surprising connections between sleep quality and aspects of living with HD that range from daily function to muscle health. The findings point toward practical interventions that might help improve quality of life for people with HD.

Catching Zzz’s Is Critical

We’ve known for years that sleep-related issues are incredibly common in people with HD. But a new study from researchers in Spain suggests that sleep quality isn’t just about feeling tired. It may be directly connected to how well people function day-to-day, how severe their symptoms are, and their overall quality of life.

Published in Sleep Medicine, the study followed 28 people with HD for one year, using wearable Fitbit devices to objectively measure their sleep patterns. Unlike questionnaires that rely on people remembering how they slept, these devices tracked sleep continuously and provided a clearer picture of what’s really happening night-after-night.

The HD-Sleep Connection

Perhaps unsurprising to anyone who has suffered a poor night’s sleep, there was a link between better sleep and increased ability to function. The researchers found that people who slept better at the one-year follow-up had better functional capacity (measured by the Total Functional Capacity scale), fewer behavioral problems, better mental and physical quality of life, and less mental fatigue.

One surprising finding was that at the start of the study, younger people and those with more CAG repeats tended to sleep better. Initially, this might seem counterintuitive. Wouldn’t more CAG repeats mean more severe disease and worse sleep? The researchers say, not necessarily. Everyone with HD has a unique journey, and folks could have entered the study at different disease stages. Essentially, the research suggests that sleep is more aligned with clinical status than the length of one’s CAG repeat.

Muscle Strength and Sleep: A Two-Way Street?

One of the most interesting findings was the connection between muscle strength and sleep. People with lower handgrip strength, which is a key measure of sarcopenia (muscle loss), had significantly worse sleep quality. The researchers measured muscle mass and strength, and the pattern was clear: weaker muscles = worse sleep.

Why might this be? Sleep disturbances can disrupt hormones that are critical for muscle health, like growth hormone, cortisol, and insulin-like growth factor. When sleep is disrupted, these hormones get thrown off balance, potentially accelerating muscle loss. But it may work the other way too, since losing muscle strength might somehow worsen sleep quality, creating a vicious cycle. However sleep is impacted by numerous things, so the interplay between strength and sleep may be more complex, with these symptoms arising together, but not in a directly causative role. 

Does Walking More Mean Better Sleep?

In this 1 year study with a small group of people, the researchers also found that people with worse sleep walked about 600 fewer steps per day on average. But surprisingly, just walking more didn’t seem to improve sleep quality for these folks. This seems to contradict what we know from the general population, where aerobic exercise typically improves sleep.

Why might HD be different? The researchers suggest that HD damages the brain regions that control sleep and circadian rhythms, particularly the hypothalamus and suprachiasmatic nucleus. This damage might limit how much exercise can help sleep, at least when it comes to just walking more steps.

However, the study did suggest that strength training, not just walking, might be key. Since people with better muscle strength slept better, resistance exercises that build strength could potentially help more than just increasing step counts.

Wearables vs. Questionnaires

When it comes to tracking sleep, wearables seem to give more accurate data than self-reported questionnaires. The Fitbit data didn’t match up well with traditional sleep questionnaires, especially early in the study (though agreement improved by one year). This suggests that wearable devices might catch sleep problems that people don’t notice or remember, making them potentially valuable screening tools.

The devices showed 67% sensitivity and 80% specificity, which means they’re pretty good at identifying when someone has a sleep problem. If a Fitbit flags an issue, it might be worth discussing sleep interventions or, if needed, more detailed sleep testing.

What This Means for HD Families

This small study adds to growing evidence that sleep health matters tremendously in HD, possibly even more than in the general population. Good sleep appears to be associated with maintaining independence, managing psychiatric symptoms, and preserving quality of life.

The findings also point toward actionable strategies, like strength training exercises that might help with sleep quality (and have many other benefits). Additionally, wearable devices, like a Fitbit, could help identify sleep problems before they become severe.

The Bigger Picture

It’s important to note this was a relatively small study (28 participants) conducted over one year. The researchers couldn’t determine cause and effect: does poor sleep cause worse function, or does worse function lead to poor sleep? Honestly, it’s probably both, in a complex cycle.

The study also couldn’t account for all the factors that affect sleep, like medications, stress, or other health conditions. And we don’t know yet whether interventions that improve sleep, like strength training, sleep hygiene, or medications, would actually improve the clinical outcomes the researchers measured.

But the message is clear that sleep isn’t just about feeling rested. In HD, it appears to be intimately connected with muscle health, daily function, mood, and quality of life. Taking sleep seriously, and working with healthcare providers to address sleep problems, might be an important step people with HD can take for their overall health.

Summary

• Spanish researchers tracked 28 people with HD for one year using Fitbit wearables to measure sleep objectively
• People with better sleep had better functional capacity, fewer behavioral problems, less fatigue, and better quality of life
• Lower muscle strength was associated with worse sleep quality
• Those with poor sleep walked ~600 fewer steps per day on average
• Wearable devices may be useful screening tools for sleep problems in HD
• Findings suggest strength training, not just increasing step count, might help improve sleep in HD