According to a study recently published in the European Heart Journal – Open, an academic journal of the European Society of Cardiology, individuals who sleep less than five hours per night have a 74% higher chance of developing peripheral artery disease (PAD) in comparison to those who get seven to eight hours of sleep.
“Our study suggests that sleeping for seven to eight hours a night is a good habit for lowering the risk of PAD,” said study author Dr. Shuai Yuan of the Karolinska Institute, Stockholm, Sweden.
Peripheral artery disease (PAD), a condition where leg arteries become blocked, thereby reducing blood flow and elevating the risk of heart attack and stroke, affects over 200 million people worldwide.
Dr. Yuan said: “Insufficient night-time sleep and daytime napping have previously been associated with a raised risk of coronary artery disease which, like PAD, is caused by clogged arteries. In addition, sleeping problems are among the top ranked complaints in PAD patients. There are limited data on the impact of sleep habits on PAD and vice versa, and our study aimed to fill that gap.”
The study included more than 650,000 participants and was conducted in two parts.3 First, the researchers analyzed the associations of sleep duration and daytime napping with the risk of PAD. In the second part, the investigators used genetic data to perform naturally randomized controlled trials – called Mendelian randomization – to examine the causality of the associations.
Dr. Yuan said: “Observational analyses are limited by reverse causality – meaning that if an association between sleep habits and PAD is found, we cannot be certain if sleep habits caused PAD or having PAD caused the sleep habits. Mendelian randomization is a robust method for evaluating causality and provides more certainty about the results.”
Taken together, the strongest evidence was for short sleep, where the relationship with PAD went both ways. In an observational analysis of 53,416 adults, sleeping less than five hours a night was associated with a nearly doubled risk of PAD compared with seven to eight hours (hazard ratio [HR] 1.74; 95% confidence interval [CI] 1.31–2.31). This finding was supported by further analyses in 156,582 and 452,028 individuals. In the causal studies, short sleep was associated with an increased risk of PAD and, in addition, PAD was associated with an increased likelihood of short sleep.
Dr. Yuan said: “The results indicate that brief night-time sleep can raise the chance of developing PAD, and that having PAD increases the risk of getting insufficient sleep.”
Regarding long sleep, in an observational analysis of 53,416 adults, sleeping eight hours or more per night was linked with a 24% higher risk of PAD compared with seven to eight hours (HR 1.24; 95% CI 1.08–1.43). This finding was supported by analyses in two larger populations of 156,582 and 452,028 individuals. However, no causal relationships were found between long sleep and PAD. Similar results were reported for napping, where daytime nappers had a 32% higher risk of PAD compared to those who did not nap (HR 1.32; 95% CI 1.18–1.49) but no causal links were found.
“More studies are needed on the relationships between lengthy night-time sleep, daytime napping, and PAD,” said Dr. Yuan. “Although we found associations in the observational studies, we could not confirm causality.”
He concluded: “More research is needed on how to interrupt the bidirectional link between short sleep and PAD. Lifestyle changes that help people get more sleep, such as being physically active, may lower the risk of developing PAD. For patients with PAD, optimising pain management could enable them to have a good night’s sleep.”
Reference: “Sleep duration, daytime napping, and risk of peripheral artery disease: multinational cohort and Mendelian randomization studies” by Shuai Yuan, Michael G Levin, Olga E Titova, Jie Chen, Yuhao Sun, Veterans Affairs Million Veteran Program, Agneta Åkesson, Xue Li, Scott M Damrauer and Susanna C Larsson, 16 March 2023, European Heart Journal Open.