Short night-time sleep doubles risk of clogged leg arteries: Research

According to research published in the European Heart Journal – Open, an ESC journal, sleeping less than five hours per night is associated with a 74% increased risk of developing the peripheral arterial disease (PAD) compared to sleeping seven to eight hours.

“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. More than 200 million people globally have peripheral artery disease (PAD),2 where arteries in the legs are clogged, restricting blood flow and increasing the risk of stroke and heart attack. 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 had over 650,000 participants and was divided into two parts. 3 First, the researchers looked at the links between sleep duration and daytime napping, and the risk of PAD. In the second part, the researchers used genetic data to conduct naturally randomised controlled trials, also known as Mendelian randomisation, to investigate 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 randomisation is a robust method for evaluating causality and provides more certainty about the results.”

Taken together, the strongest evidence was for insufficient sleep, where the relationship with PAD was bidirectional. In a study of 53,416 adults, sleeping less than five hours per night was linked to a nearly doubled risk of PAD compared to sleeping seven to eight hours (hazard ratio [HR] 1.74; 95 percent confidence interval [CI] 1.31-2.31). This finding was supported by additional analyses of 156,582 and 452,028 people, respectively. Short sleep was linked to an increased risk of PAD in the causal studies, and PAD was linked to 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.”

In an observational study of 53,416 adults, sleeping eight hours or more per night was associated with a 24% increased risk of PAD compared to seven to eight hours (HR 1.24; 95 percent CI 1.08-1.43). Analyses in two larger populations of 156,582 and 452,028 people supported this finding. However, no causal relationships between long sleep and PAD were discovered. Similar findings were reported for napping, with daytime nappers having a 32% higher risk of PAD than 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.”