Major arteries stiffen with age: that is a fact of human biology and time.
50%+Nearly half of Americans will have cardiovascular disease by the year 2035 (American Heart Association estimate)
Stiffer arteries, in turn, contribute to cardiovascular diseases like high blood pressure, heart failure, chronic kidney disease, and stroke because blood flows faster along stiffer, thinner, more constricted arteries and bombards organs in a rush of pressure. A large body of evidence also suggests that arterial stiffness predicts cognitive impairment.
What’s less clear, though, is whether higher quality sleep might alleviate these problems. No previous study has ever examined the interrelationships among arterial stiffness, sleep disturbance (insomnia), and cognitive impairment simultaneously—precisely why a new pilot study by associate professor Jeongok Logan that aims to suss out these connections is stirring such interest.
“We spend almost one-third of our lives sleeping,” explained Logan, who earned a 4-VA Collaborative Research Grant earlier this year, “and a growing body of evidence suggests connection points between sleep and an elevated risk of cardiovascular disease and cognitive decline. By improving our sleep, we have potential to mitigate the burden these conditions impose on society.”
Logan’s research comes at a critical moment in the United States, given upticks in citizens’ already-high rates of cardiovascular disease. According to estimates from the American Heart Association, nearly half of Americans are expected to have some form of cardiovascular disease by 2035. The country’s leading killer for decades running, cardiovascular disease currently costs $555 billion in medical costs and lost productivity annually but has the potential to top $1.1 trillion a year by the year 2035.
JEONGOK LOGAN, PhD, RN
$30,900 4-VA Collaborative Grant
Does sleep moderate the association between arterial stiffness and cognitive impairment?
With colleagues from James Madison University School of Nursing, Logan will measure the interplay between these three factors—sleep disturbance, cognitive impairment, and arterial stiffness—in a study of 50 adults ages 60 and older. One-third of those studied will have normal cognitive function while another third will have mild cognitive impairment, and the remaining third will have moderate to severe cognitive impairment. All will be experiencing some degree of insomnia.
All 50 participants will be assessed for arterial stiffness, using a pulse wave velocity machine, the gold standard for assessing stiffness in major arteries, which measures travel time of a pulse waveform along the arterial system; for cognition, using a 10-minute assessment tool; and for sleep quality and duration across two consecutive 24-hour periods during which they wear a wristwatch-like ActiGraph on their non-dominant hand.
$1.1 trillionAmount that cardiovascular disease is expected to cost the country by 2035 (American Heart Association estimate)
With those measures in hand, Logan will analyze how sleep variables are associated with arterial stiffness and cognitive impairment and whether participants who slept more soundly had less serious cognitive decline, compared with those who had the same level of arterial stiffness but experienced poorer sleep.
In her previous studies, Logan found that gentle trunk stretching measurably decreased arterial stiffness and that stress measurably increased it, evidence that supports introduction of lifestyle changes and physical activity which may naturally ease the condition without resorting to drugs or surgery. With this latest pilot, Logan hopes to do a larger scale study to establish evidence of the role of sleep and an increased risk of cognitive impairment, identify behavioral risk factors to prevent cognitive impairment, and minimize future costs of treating this expensive, often devastating condition.
Logan’s study results will be ready in spring 2024.