Late nights, early risings and broken sleep schedules are hallmarks of youth, but those sleepless nights may leave marks deeper than dark circles under the eyes.
Researchers from the University of Oregon and the State University of New York have spotted biological wear and tear in specific body systems among youth with sleep problems. Those biological footprints of stress, known as biomarkers, are found across systems involved in metabolism and inflammation. They may reflect increased risks for disorders such as anxiety, depression and hypertension later in life, the study found.
The findings, published in the journal Psychoneuroendocrinology, shift the scientific conversation from knowing that chronic sleep deprivation can beckon a host of health problems to unveiling some of the potential multisystem mechanisms involved. That's according to co-lead author Melynda Casement, a licensed psychologist and associate professor in the UO's College of Arts and Sciences.
"We have a lot of measures to evaluate sleep health, but what we want to try and do is prevent disease risk," said Casement, who studies the relationship between sleep and youth behavioral health. "Looking at these biomarkers can be a way to identify disease risk early and the systems implicated so that we can intervene and potentially reduce the risk and severity of disorders that are unfortunately so common in adolescents."
Drawn from federal health data that's designed to reflect the experiences of 37 million 16- to 24-year-olds across the U.S., the study is one of the first of its kind to examine and detect biomarker changes associated with poor sleep health in a younger population. It also found that frequent snoring, more than other sleep issues, was commonly reported among teens and young adults with the biomarker changes.
The silver lining is that those early, measurable signs of physiological dysregulation suggest sleep disturbances, notably snoring, as a potential target for intervention before physical and mental disorders develop.
"This is an age group in which many mental illnesses, like depression or risky substance use, really start to become more prevalent," Casement said. "We have some good treatments, but it can be a lot easier to treat sleep disruption than it is to treat depression or anxiety. If we can reduce these health risks by treating sleep, then there is more reason to be attentive to sleep health in adolescents and young adults."
As with any biomarkers, it can be difficult to prove that insufficient sleep is directly causing the changes or whether other kinds of life stressors or factors are at play, Casement cautioned. But identifying the correlation is the first step for more detailed studies that uncover ways to predict problems and protect long-term health during this critical window of development, she said.
Bodily signs of sleepless nights
Casement and her co-lead author, Jason Carbone of the SUNY Upstate Medical University in New York, performed a retrospective analysis of almost 2,700 teens and young adults from the National Health and Nutrition Examination Survey, collected between 2015 and 2020. The survey, run by the U.S. Centers for Disease Control and Prevention, contains data from health exams, laboratory tests and interviews from participants of all ages.
The researchers investigated 13 biological variables, including blood pressure, cholesterol and white blood cell count, as biomarkers to measure cumulative wear and tear in the body.
The sum of dysregulated biomarkers is something researchers call "allostatic load," and a heavy load makes people more susceptible to a variety of physical and mental diseases.
The researchers were curious to find if there were biological features of high allostatic load associated with poor sleep health. The survey database includes reports of participants' sleep habits: regularity, satisfaction, alertness, timing, efficiency, duration and snoring.
Similar studies using the national survey have focused on middle-aged and older populations, but those findings may not easily translate to young people who generally have less cumulative strain, different age-related health risks, and possibly different at-risk biomarker thresholds.
By comparing the biomarker differences between healthy sleepers and poor sleepers, the researchers explored sleep problems as a potential chronic stress that can get "under the skin" of youth, said Carbone, an expert on stress and allostatic load.
The pair found that teens and young adults with biomarkers suggesting a mix of inflammation and changes in cholesterol levels and blood sugar regulation had greater odds of sleep disturbance compared to those with healthier or other types of imbalances. Those odds were almost double that of participants with fewer signs of dysregulation.
Carbone said that theoretically, younger people shouldn't show much impaired biological regulation in their biomarkers because such problems develop over the lifetime. The level of dysregulation associated with poor sleep that researchers found "is somewhat concerning when you think about the potential long-term health impacts. It reinforces the need for earlier prevention and intervention efforts."
Snoring as a standout
Among the disruptive sleep behaviors investigated, snoring largely drove the apparent associations. For instance, female participants with dysregulation in immune and metabolic systems were five times more likely to report snoring than those with little dysregulation.
Casement said she was not surprised by the finding. That's because snoring is a prime symptom of sleep apnea, a condition in which breathing stops while sleeping, triggering continuous wakings. Snoring doesn't always indicate sleep apnea, but the disorder is common, trackable and effectively treatable with the help of a health care professional, she said.
"People joke all the time about how someone they know snores really loudly," Casement said. "It may seem amusing, but snoring is a key indicator of sleep apnea. Seeing a sleep specialist for assessment and treatment could reduce long-term risk for a whole range of diseases."
But what did surprise her was that the other indicators of poor sleep quality, like abnormally short or long sleep and low alertness, were not as clearly associated with biological imbalances. It could be, she said, that those problems don't surface until they become longer-term, chronic conditions.
"Maybe that's the good news here," Casement said. "Adolescents and young adults, in terms of their physiological systems, are resilient to things like not sleeping long enough and going to bed late."
