People with excessive daytime sleepiness were more likely to have high blood pressure than those without daytime sleepiness.
The highest risk was seen in people who were both excessively sleepy during the day and took at least 30 minutes to fall asleep at night.
Researchers say evaluating both daytime sleepiness and nighttime sleep difficulties may help identify people at greater cardiovascular risk.
Most people expect to feel a little sluggish after a poor night's sleep. But new research suggests that daytime drowsiness — especially when it's paired with difficulty falling asleep at night — may also be linked to a greater likelihood of high blood pressure.
Researchers from Penn State College of Medicine found that adults who reported excessive daytime sleepiness had higher odds of both existing hypertension and developing hypertension over time. The connection became even stronger among people who also took at least 30 minutes to fall asleep during an overnight sleep study.
“Adults with excessive daytime sleepiness and prolonged sleep-onset latency appeared to represent a distinct subgroup with significantly greater cardiovascular risk,” lead author Dr. Alexandros Vgontzas said in a news release.
“Neither excessive daytime sleepiness on its own, nor prolonged sleep latency on its own, showed the same increased risk of hypertension.”
How the study was conducted
The researchers analyzed data from 1,741 adults enrolled in the Penn State Adult Cohort. Every participant completed an eight-hour overnight sleep study, known as polysomnography, which objectively measured their sleep.
Excessive daytime sleepiness was identified through self-reports of moderate to severe daytime sleepiness or irresistible sleep attacks. Researchers also measured how long it took participants to fall asleep, defining prolonged sleep-onset latency as taking 30 minutes or longer to drift off.
To examine the development of high blood pressure over time, the team followed 786 participants who did not have hypertension at the beginning of the study for an average of 7.5 years.
The analyses accounted for numerous factors that could influence blood pressure, including age, sex, body mass index, race and ethnicity, smoking, caffeine and alcohol use, diabetes, depression, sleep apnea severity, total sleep time, and time spent awake after initially falling asleep.
What the findings mean
Compared with people who did not report excessive daytime sleepiness, those who did had 52% higher odds of already having hypertension and 74% higher odds of developing it during follow-up.
However, the greatest differences appeared when daytime sleepiness occurred alongside prolonged sleep-onset latency. In that group, the odds of existing hypertension were more than twice as high, while the odds of developing hypertension over time were more than three times higher.
According to the researchers, excessive daytime sleepiness combined with difficulty falling asleep may represent a distinct pattern that deserves closer attention during sleep evaluations.
They suggest that looking beyond sleep apnea alone and considering both daytime symptoms and nighttime sleep difficulties could help identify people who may have elevated cardiovascular risk and guide more targeted treatment approaches.
“These findings suggest that evaluating excessive daytime sleepiness should extend beyond screening for sleep apnea alone,” Dr. Vgontzas said. “Assessing nighttime sleep difficulties and objective sleep measures such as prolonged sleep-onset latency may help identify patients with elevated cardiovascular risk and support more targeted treatment approaches.”