Healthy sleep involves more than just the number of hours you spend in bed. It also includes how quickly you fall asleep, how often your sleep is interrupted, how rested you feel during the day, and how satisfied you are with your sleep overall. Addressing these different aspects may help reduce cardiometabolic risk, according to a new American Heart Association (AHA) scientific statement published in Circulation: Cardiovascular Quality and Outcomes.
The statement, titled Multidimensional Sleep Health: Definitions and Implications for Cardiometabolic Health, outlines key components of sleep health and reviews evidence linking sleep patterns to cardiometabolic factors such as body fat, blood sugar, cholesterol, and blood pressure. The authors also emphasize that healthy sleep supports both physical health and mental well-being.
“Most adults need 7 to 9 hours of sleep each night, and suboptimal sleep raises the risk for cardiovascular disease, along with risk of cognitive decline, depression, obesity, and high blood pressure, blood sugar, and cholesterol levels,” said Marie-Pierre St-Onge, Ph.D., chair of the scientific statement writing group and a sleep and circadian researcher at Columbia University Irving Medical Center. She added that growing evidence shows sleep health involves more than sleep duration alone.
Why sleep affects cardiometabolic health
The AHA notes that no single sleep measure fully reflects a person’s sleep experience or how their body responds. Several less-discussed sleep dimensions may meaningfully affect overall health. The statement highlights these components:
Sleep duration is the number of hours a person sleeps per night (or within 24 hours). It can be estimated through questionnaires and sleep diaries, or measured using devices such as actigraphy trackers or laboratory-based polysomnography. Research shows that sleeping fewer than 7 hours per night is associated with a higher risk of atrial fibrillation, cardiometabolic syndrome, and abnormal overnight blood pressure patterns (blood pressure should typically drop during sleep). On the other end, regularly sleeping more than 9 hours per night has also been linked to higher risks, including cardiometabolic syndrome, stiffer arteries, stroke, and death from heart disease or stroke.
Sleep continuity describes how consistently a person stays asleep once sleep begins. It is influenced by how long it takes to fall asleep, nighttime awakenings, time spent awake after falling asleep, early morning awakenings, and conditions such as obstructive sleep apnea. Poor sleep continuity has been associated with increased risk of atrial fibrillation, heart attack, high blood pressure, and insulin resistance.
Sleep timing refers to when someone typically goes to sleep over a 24-hour day. Although high-quality research in this area is still limited, available data suggest that late or misaligned sleep timing may increase cardiovascular risk factors. For example, a typical bedtime of midnight or later has been associated with a higher risk of overweight or obesity, insulin resistance, and elevated blood pressure compared with earlier bedtimes.
Sleep satisfaction is a person’s perception of how good or restorative their sleep feels. Analyses of multiple studies suggest that lower sleep satisfaction is linked with higher blood pressure, stiffer arteries, coronary heart disease, and reduced nighttime blood pressure dipping.
Sleep regularity describes how stable sleep timing and duration are from day to day. Large differences between workdays and weekends—often called “social jetlag”—have been associated with higher risks of overweight and obesity. Variability in sleep timing has also been linked with cardiovascular disease, high blood pressure, inflammation, obesity, and abnormal nighttime blood pressure patterns. In large studies, more consistent sleep-wake schedules have been associated with a 22% to 57% lower risk of cardiovascular death. A large UK Biobank analysis also found that irregular sleep timing was tied to higher type 2 diabetes risk even among people who slept enough hours, with the greatest risk in those who combined short sleep with very irregular schedules.
Sleep-related daytime functioning reflects how well a person can stay alert and awake during the day, including feelings of sleepiness or fatigue. It can be estimated through self-reported likelihood of dozing in common situations or through tests of cognitive alertness such as reaction time. Excessive daytime sleepiness has been associated with cardiovascular disease, coronary heart disease, stroke, and increased risk of death from cardiovascular and all causes. Factors linked with greater daytime sleepiness include obesity, type 2 diabetes, depression, smoking, and obstructive sleep apnea, while weight loss appears to reduce excessive daytime sleepiness in some people.
Sleep architecture refers to the stages of sleep the body cycles through, measured using brain-wave monitoring (EEG). Sleep includes non-rapid eye movement (NREM) stages—ranging from light to deep sleep—and rapid eye movement (REM) sleep. Disruptions to sleep continuity can alter these stages. One combined analysis found that interrupting deep NREM (slow-wave) sleep increased insulin resistance compared with uninterrupted sleep.
Unequal sleep health across communities
The statement also discusses how adverse social drivers of health can affect sleep. A review of more than 300 studies found consistent links between lower socioeconomic status and poorer sleep health. Environmental and neighborhood conditions—such as light exposure, air and noise pollution, and safety—may also contribute to differences in one or more sleep components.
Compared with non-Hispanic white populations, people in historically underrepresented racial and ethnic groups tend to sleep less and are more likely to experience poorer sleep continuity, lower sleep satisfaction, later bedtimes, more irregular sleep, greater daytime sleepiness, and higher rates of sleep disorders. These gaps are seen throughout the lifespan and persist over time, with Black adults experiencing the worst overall sleep health in many studies.
“It’s important to know that every individual has different sleep experiences, and these differences may contribute to other health inequities,” St-Onge said. She noted that discussing multiple sleep dimensions with patients can give clinicians a clearer picture and help improve care.
What clinicians can ask—and why it matters
The authors suggest that simple, targeted questions can help patients describe their sleep issues more accurately. Examples include how long it usually takes to fall asleep, how often they wake during the night, and how frequently they feel exhausted during the day.
Recording these details in medical notes can help the broader care team understand sleep health concerns and may prompt additional screening or evaluation. This information can also guide discussions about whether health conditions or medications might be interfering with sleep and whether treatment plans need adjustment.
St-Onge emphasized that while some sleep changes can occur naturally with age, people should not treat worsening sleep as inevitable. New problems falling asleep, staying asleep, or persistent daytime sleepiness should be discussed with a doctor for evaluation and potential treatment.
More research is needed
Although awareness of sleep’s importance is increasing, the AHA notes that more research is needed to define and measure the full range of sleep health dimensions in ways that clinicians can confidently use. Consumer wearables can estimate sleep duration, but better tools and validated methods are still needed to assess other components reliably. Combining self-reported information with objective measures may provide more complete and dependable guidance.
Sleep is included in the AHA’s Life’s Essential 8 cardiovascular health measures. However, within that framework the sleep metric currently focuses only on duration, because research has not yet established validated approaches for routinely scoring other sleep dimensions.
Some studies suggest that poor sleep health—such as short sleep and irregular schedules—contributes to worse cardiovascular outcomes. The statement stresses the need for clinical trials to confirm whether improving sleep health leads to better cardiometabolic results and to identify which interventions most effectively improve different sleep components.
The authors also call for multidisciplinary research involving specialties such as sleep medicine, cardiology, endocrinology, gastroenterology, nephrology, pulmonology, and neurology. They emphasize that studies should include participants from underrepresented racial and ethnic groups to better reflect real-world diversity and capture sleep health patterns across communities.
The scientific statement was prepared by a volunteer writing group on behalf of multiple AHA councils focused on lifestyle and cardiometabolic health, cardiovascular and stroke nursing, clinical cardiology, and quality of care and outcomes research. AHA scientific statements summarize what is currently known about a topic and identify research gaps; they are intended to inform health care decision-making but do not provide direct treatment recommendations.
