Excessive daytime sleepiness, primarily among individuals who sleep longer than 9 hours a night, increases the risk for myocardial infarction (MI), according to study findings published in the Journal of the American Heart Association.
The relationship between individuals with short or long sleep duration who experience excessive daytime sleepiness (EDS) and subsequent cardiovascular disease (CVD) and death is ill-defined. Therefore, investigators aimed to clarify the relationship between EDS (self-reported) sleep duration subtypes (short, normal, long) with cardiovascular outcomes.
The investigators conducted a prospective incident event study using the medical records of 355,901 individuals in the UK Biobank database to compare sleep duration subtypes of excessive daytime sleepiness (short [<6 hours], normal [6-9 hours], long [>9 hours]) with individuals with a non-sleepy daytime, normal nighttime-sleep duration reference group, to analyze associations with incident MI and stroke.
Briefly, the UK Biobank is a prospective study including more than half a million community-dwelling individuals (>90% European ancestry) aged 40 to 69 years across Scotland, Wales, and England between 2006 and 2010 (baseline), and includes clinical and demographic data.
In the current study, individuals taking psychiatric medications, having CVD or stroke at baseline, or missing sleep measures were excluded, as were self-reported shift workers. Baseline daytime sleepiness was assessed with a single question (How likely are you to doze off or fall asleep during the daytime when you don’t mean to?). Self-reported answer options included never/rarely, sometimes, often, all of the time, do not know, prefer not to answer. Individuals reporting often or all of the time were categorized as having EDS. Those reporting never/rarely were categorized as non-EDS. All others were excluded from analysis.
Participants were stratified into 6 subgroups for analysis (short-, normal-, long-EDS, and short-, normal-, long-non-EDS). The non-EDS focus was on the normal-sleep group, used as the comparative reference. The investigators used ICD-10 codes to identify baseline and incident CVD cases.
During an 8.2-year median follow-up (as late as March 2017), the investigators found that individuals with long-sleep EDS vs healthy sleep had an 83% increase in the rate of MI (hazard ratio, 1.83; 95% CI, 1.21-2.77) adjusting for sociodemographic and multiple health factors. The investigators performed a 2-sample Mendelian randomization, analysis which supported the causal role for a genetic long-sleep EDS subtype in MI (inverse-variance weighted β=1.995, P =.001).
No evidence was noted to indicate that other EDS subtypes were associated with incident MI, and no evidence was found to suggest any associations with stroke (all P >.05).
Study limitations include lack of evidence that EDS and sleep duration are independent risk factors, the heterogeneity of EDS subtypes, and limited generalizability.
“Excessive daytime sleepiness increases the risk of myocardial infarction, mostly driven by its long-sleep subtype,” the investigators wrote. “Our study suggests the previous evidence linking EDS with increased cardiovascular disease risk may be primarily driven by the effect of its long-sleep subtype on higher risk of MI.”
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
This article originally appeared on The Cardiology Advisor
References:
Goodman MO, Dashti HS, Lane JM, et al. Causal association between subtypes of excessive daytime sleepiness and risk of cardiovascular diseases. J Am Heart Assoc. Published online December 12, 2023. doi:10.1161/JAHA.122.030568