Occasional napping may promote cardiovascular health
Napping one to two times per week appears to be protective against the risk of developing cardiovascular disease (CVD) events, according to a recent study. No such association is observed for any napping duration.
The study included 3,462 individuals with no previous history of CVD. Of these, 2,014 individuals (58 percent) reported that they did not nap during the previous week, 667 (19 percent) took 1–2 naps, 411 (12 percent) took 3–5 naps and 370 (11 percent) took 6–7 naps.
Compared with non-nappers, frequent nappers (3–7 times weekly) were older, more likely to be men, to have a lower educational status, to frequently smoke, and had a higher body mass index and longer nocturnal sleep duration. Additionally, those who napped frequently experienced excessive daytime sleepiness and presented with more severe obstructive sleep apnoea.
A total of 155 fatal and nonfatal CVD events occurred over a mean follow-up of 5.3 years. Unadjusted Cox proportional hazard analysis revealed that the risk of incident CVD was significantly lower in individuals who napped 1–2 times weekly (hazard ratio [HR], 0.39, 95 percent CI, 0.21–0.72) and elevated in those taking 6-7 naps weekly (HR, 1.67, 1.10–2.55) compared with non-nappers.
In multivariate models, the protective association between occasional napping and CVD incidence risk remained significant (HR, 0.52, 0.28–0.95), whereas the risk increase associated with frequent napping disappeared (HR, 0.89, 0.58–1.38).
Neither obstructive sleep apnoea nor excessive daytime sleepiness modified the protective benefit of occasional napping. Furthermore, nap duration showed no association with CVD events.
The discrepant findings regarding the association between napping and CVD events may be explained by nap frequency, according to researchers.