Sleeping fewer than five hours a night is linked to a 74% higher risk of developing peripheral artery disease (PAD) compared with seven to eight hours, according to a study by Swedish researchers published in European Heart Journal – Open.
“Our study suggests that sleeping for seven to eight hours a night is a good habit for lowering the risk of PAD,” says study author Shuai Yuan, PhD candidate in the Department of Cardiovascular and Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institute, Sweden, in a press release.
More than 200 million people globally have peripheral artery disease, where arteries in the legs are clogged, restricting blood flow and increasing the risk of stroke and heart attack.
“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,” says Yuan in a release.
The study included over 650,000 participants and was conducted in two parts. 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 causality of the associations.
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 fewer 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.
“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,” says Yuan in a release.
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, according to Yuan, who noted that although associations were found in the observational studies, causality couldn’t be confirmed.
“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, optimizing pain management could enable them to have a good night’s sleep,” says Yuan in a release.