By Paul Ian Cross, PhD — Fact checked by Hannah Flynn
A new study, published in the European Heart Journal, has discovered a significant link between inadequate sleep and an increased likelihood of developing peripheral artery disease (PAD).
The research revealed that those who sleep less than 5 hours per night have a 74% higher chance of developing PAD, compared to those who maintain a healthy sleep routine of 7 to 8 hours per night.
Both insufficient nighttime sleep and excessive daytime napping have been previously linked to an increased risk of coronary artery disease, which, like PAD, results from obstructed arteries.
This study aimed to address the knowledge gap surrounding the impact of sleep habits on PAD and vice versa, providing valuable insights into the relationship between the two. It involved over 650,000 participants and was carried out in two stages.
First, the researchers looked at how the amount of sleep people got at night and daytime napping were related to their risk of developing PAD.
Next, they used genetic information to conduct a Mendelian randomization analysis, helping to identify if these associations were actually causing the increased risk of PAD.
Mendelian randomization is a research method that uses genetic information to see if there is a cause-and-effect relationship between certain factors and a particular outcome. In simple terms, it is like a natural experiment that takes advantage of the random way our genes are inherited.
This method helps researchers separate true cause-and-effect relationships from mere associations, providing stronger evidence for potential causal links.
The limitations of observational studies include the possibility of reverse causality, which means that when a connection between sleep habits and PAD is identified, it is unclear whether sleep habits led to PAD or if having PAD influenced sleep habits.
Mendelian randomization is a reliable technique for assessing causality, offering greater confidence in the findings.
In an observational study involving 53,416 adults, sleeping less than 5 hours a night nearly doubled the risk of PAD compared to sleeping 7 to 8 hours. Additional analyses with 156,582 and 452,028 individuals supported this finding.
In the causal studies, not only was short sleep linked to an increased risk of PAD, but having PAD also increased the likelihood of not getting enough sleep.
These results suggest that insufficient nighttime sleep can heighten the risk of developing PAD, and having PAD, in turn, can lead to inadequate sleep.
In the case of long sleep, an observational study of 53,416 adults found that sleeping 8 or more hours per night was associated with a 24% increased risk of PAD compared to sleeping 7 to 8 hours.
This observation was backed by analyses in two larger groups of 156,582 and 452,028 individuals.
However, no cause-and-effect relationship was discovered between long sleep and PAD.
The researchers reported similar findings for daytime napping, where those who napped had a 32% higher risk of PAD than non-nappers, but no causal connections were established.
Dr. Rigved Tadwalkar, a board-certified cardiologist at Pacific Heart Institute in Santa Monica, CA, not involved in this research, told Medical News Today that “this is a well-put-together study that better evaluates the relationship of sleep duration with PAD.”
“The study is of high value because prior studies exploring this association have been limited, due to less robust study design and lower statistical power,” Dr. Tadwalker explained.
“The strongest finding is that when applying Mendelian randomization analysis, there appears to be a linear inverse association between sleep duration and PAD. In other words, less sleep duration is associated with a higher risk of PAD. While other studies with [a] similar design have determined that lower sleep duration is associated with coronary artery disease (CAD), it is noteworthy to see that the relationship extends to other forms of vascular disease.”
– Dr. Rigved Tadwalkar
Dr. Tadwalkar noted that the implications for patients and the public are significant, telling MNT that last year, the American Heart Association published a document called “Life’s Essential 8“.
The document is an update to “Life’s Simple 7,” and it aims to improve public health by providing guidelines for lifestyle changes that can reduce cardiovascular disease risk. The new update adds an eighth component, focusing on sleep duration.
“In ‘Life’s Essential 8,’ it is clarified that 7–9 hours of sleep is optimal from a cardiovascular perspective, on the basis of other research,” said Dr. Tadwalkar.
“The main analyses from this study support this recommendation as well, as those who slept in the 7-8 hour range seemed to fare the best when it comes to PAD. Ultimately, this underscores the importance of a good night’s rest in cardiovascular health,” he added.
Dr. Tadwalkar also stressed that “[g]reater awareness is needed on the importance of high-quality sleep for individuals to maximize their health outcomes.”
Dr. Devin W. Kehl, a cardiologist at Providence Saint John’s Health Center in Santa Monica, CA, not involved in the current research, agreed, saying that “this study adds to the growing body of data demonstrating strong and consistent links between sleep quality and risk of developing cardiovascular disease.”
“Most people are aware of the importance of a healthy diet and regular exercise in lowering one’s risk of heart disease. Now, with studies like this and others, it is becoming increasingly clear that we also need to think of adequate sleep duration and sleep quality in that same category as an essential lifestyle habit.”
– Dr. Devin Kehl
Dr. Collin Johnston, a board-certified physician with specialty training in vascular procedures, also not involved in the research, said: “[I]n my years practicing medicine, I have always believed that the western medical model must try and focus more on the prevention of disease rather than just the treatment of disease.”
“Unfortunately, during my medical school and residency training, a relatively small proportion of time was spent learning the importance of basic health principles such as well-balanced nutrition, consistent and frequent physical activity, and the integral role that quality ‘sleep hygiene’ practices can play in helping prevent the onset of chronic health conditions,” Dr. Johnston added.
According to him, “[a] stronger focus on studies which scientifically prove the benefits of relatively simple lifestyle changes can have a strong positive effect for both patients and practitioners alike.”
“This can help practitioners educate their patients with more confidence when teaching them important principles of being proactive instead of reactive with their health,” said Dr. Johnston.
This article originally appeared here and was republished with permission.