A groundbreaking study recently published in the journal Nature Medicine reveals a significant correlation between insufficient, irregular, and poor-quality sleep and the prevalence of numerous chronic conditions, such as obesity, atrial fibrillation, hypertension, major depressive disorder, and generalized anxiety disorder. The study was led by Dr. Evan Brittain, MD, MSCI, a professor of Medicine, and marks a departure from traditional sleep research methodologies.
Unlike previous studies that relied on cross-sectional and self-reported survey data or polysomnograms, this research utilized objectively measured, longitudinal sleep data from commercial wearable devices. These devices were linked to electronic health record data from the National Institutes of Health’s All of Us Research Program, making it the largest study of its kind to date.
“It’s a departure from most of the literature,” Brittain stated. “We had a really unique opportunity to understand sleep hygiene and health over a very long period of time in a large population.”
The study underscores the importance of sufficient sleep and consistent sleep patterns in reducing the incidence of chronic diseases. The findings could potentially inform clinical guidelines aimed at promoting better sleep hygiene for overall health improvement.
The study analyzed data from 6,875 individuals who wore Fitbit devices, collecting sleep data for a minimum of six months, and linked this information to their electronic health records. Due to data limitations, the median age of participants was 50 years old, with 71% being female, 84% identifying as white, and 71% holding a college degree. The participants tracked their sleep with wearable devices for a median period of nearly 4 ½ years.
The extensive dataset from the All of Us Research Program allowed researchers to explore the relationship between sleep and a wide range of conditions, not just a select few.
The study revealed that reduced amounts of rapid eye movement (REM) and deep sleep were associated with an increased likelihood of developing atrial fibrillation. Additionally, irregular sleep patterns were linked to higher odds of obesity, hyperlipidemia, hypertension, major depressive disorder, and generalized anxiety disorder.
“Every aspect of sleep is important,” Brittain emphasized. “The major takeaway of the study for me was the more regular your sleep pattern is, the healthier you’re likely to be.”
One of the surprising findings of the study was the suggested amount of sleep needed for good health outcomes. Contrary to the traditional recommendation of eight hours of sleep per night, the study indicated that seven hours was the median amount required for optimal health.
“It probably matters less whether you’re getting eight hours of sleep than the consistency of what time you go to bed and when you wake up,” Brittain explained. “That seems to be the most important aspect of this. That is practical advice I can offer my patients.”
This study provides a new perspective on the critical role of sleep quality and consistency in maintaining overall health and preventing chronic conditions. As research continues to evolve, these findings may lead to more refined and practical sleep guidelines for both healthcare providers and patients.