Lack of Optimum Sleep Onset/Duration Adversely Affects Cardiometabolic Outcomes

Adverse cardiometabolic outcomes are possible for adults with late sleep onset and insufficient or excessive sleep duration, according to study findings published in the Journal of the American Heart Association.

At least 7 hours of sleep per night is recommended by the American Academy of Sleep Medicine and Sleep Research Society to maintain optimal health, although recommendations are lacking relating to sleep characteristics like optimum sleep onset time. Loss of sleep, social jet lag, early morning start, and delayed bedtime while common in modern society may result in circadian rhythm misalignment. Disentangling the independent effects on heart-health of sleep onset time and sleep duration is problematic. Investigators, therefore, sought to explore independent and joint associations of sleep onset time and sleep duration with cardiometabolic health outcomes.

The investigators conducted a cross-sectional study using data from NHANES (National Health and Nutrition Examination Study) 2015 to 2018 that included 6696 adults aged 20 to 80 years (50.8% women). Participants were stratified according to cross-tabulation of sleep onset time (before 10 pm [early]; 10 pm-11:59 pm [optimal]; midnight or later [late]) and sleep duration (<7 hours [insufficient]; 7-8 hours [sufficient]; at least 9 hours [excessive]) using optimal sleep onset time and sufficient duration as the reference. Participants with history of cardiovascular disease or cancer were excluded. Sleep onset time and sleep duration were evaluated by participant self-report questionnaire.

Overall, about 19.8% of participants reported early sleep onset time and 25.7% reported late onset time. Approximately 24.1% reported insufficient sleep duration and 20.7% reported excessive sleep duration. Compared with optimal sleep onset time, early and late sleepers had a higher prevalence of hypertension (odds ratio [OR], 1.17) and hypertriglyceridemia (OR, 1.28). Compared with sufficient sleep duration, individuals with excessive duration had higher prevalence of hypertriglyceridemia (OR, 1.34).

The investigators found inappropriate sleep onset time and sleep duration was associated with metabolic syndrome, hypertriglyceridemia, and hypertension especially among participants 40 to 59 years of age. Men reporting optimal onset but with excessive duration compared with men reporting optimal onset and sufficient duration had higher odds of metabolic syndrome (odds ratio [OR], 2.01; 95% CI, 1.12-3.58), as did men reporting late onset with insufficient duration (OR, 1.74; 95% CI, 1.13-2.68).

Women reporting optimal onset and insufficient duration compared with women reporting optimal onset and sufficient duration had higher odds of hypertension (OR, 1.61; 95% CI, 1.11-2.32), as did women reporting early onset and excessive duration (OR, 2.16; 95% CI, 1.30-3.57). Highest odds of hypertriglyceridemia were reported by women with late onset and excessive duration (OR, 5.64; 95% CI, 1.28-6.77).

Study limitations include unmeasured covariates (insomnia, obstructive sleep apnea, shift work), the cross-sectional design precludes the determination of causality, and possible recall bias.

“Late sleep onset as well as insufficient or excessive sleep duration are associated with increased odds of cardiometabolic health outcomes,” the investigators concluded. “These associations were more pronounced among adults aged 40 to 59 years.” The study authors wrote, “Both optimal sleep onset time and sufficient sleep duration are important for improving cardiometabolic health.”

This article originally appeared on The Cardiology Advisor