concept

moderate sleep duration

Also known as: MSD

Facts (31)

Sources

Improvement in sleep duration was associated with higher cognitive ... aging-us.com Aging Oct 20, 2020 31 facts

measurementIn a 2020 study by Q. Zhu involving 5,419 Chinese participants aged 70-90 from the Chinese Longitudinal Healthy Longevity Survey, a change to moderate sleep duration (MSD) was associated with a higher risk of mild cognitive impairment (MCI) with an odds ratio (OR) of 1.02 to 2.09.

measurementA history of stroke was reported by 2.7% of the less than 6 hours sleep group, 1.7% of the 6-8 hours group, and 2.2% of the greater than 8 hours group, with an overall prevalence of 2.1%.

procedureFor subjects with Short Sleep Duration (SSD) in Wave 1, the study classifies change patterns as: 'Excessive' (if there was one wave with Long Sleep Duration), 'No change' (maintained SSD in two waves), 'Benefit 1' (maintained SSD in one wave and had Moderate Sleep Duration in another), and 'Benefit 2' (Moderate Sleep Duration in two waves).

claimAmong participants who were moderate sleepers (6-8 hours) at baseline (Wave 1), increasing or decreasing sleep duration by 2 or more hours by Wave 2 was associated with lower global cognition scores compared to participants who did not change their sleep duration.

measurementThe mean Body Mass Index (BMI) of all participants was 23.4 (standard deviation 3.7), with the less than 6 hours sleep group at 23.0, the 6-8 hours group at 23.6, and the greater than 8 hours group at 23.2.

referenceA meta-analysis revealed an inverted-U-shaped association between sleep duration and the risk of Alzheimer’s disease, where both short sleep duration (SSD) and long sleep duration (LSD) are associated with a higher risk compared to moderate sleep duration (MSD).

claimExcessive change and deviation from moderate sleep duration (MSD) correlates with the disruption of the circadian rhythm, which is associated with worse cognitive function.

measurementThe mean age of all participants in the study was 59.1 years (standard deviation 9.8), with the less than 6 hours sleep group having a mean age of 61.0 years, the 6-8 hours group having a mean age of 58.1 years, and the greater than 8 hours group having a mean age of 59.7 years.

claimFor short sleepers, a consistent change to moderate sleep duration is correlated with better cognition, while for long sleepers, there is no need to reduce sleep duration; however, excessive changes or deviation from a moderate sleep duration is associated with lower cognition.

procedureFor subjects with Long Sleep Duration (LSD) in Wave 1, the study classifies change patterns as: 'Excessive' (if there was one wave with Short Sleep Duration), 'No change' (maintained LSD in the two waves), 'Benefit 1' (maintained LSD in one wave and had Moderate Sleep Duration in another), and 'Benefit 2' (Moderate Sleep Duration in two waves).

claimThe Chinese Longitudinal Healthy Longevity Survey reported that a change from long sleep duration (LSD) to moderate sleep duration (MSD) could decrease the risk of dementia.

referenceThe study defines sleep duration categories as Short Sleep Duration (SSD), Moderate Sleep Duration (MSD), and Long Sleep Duration (LSD).

claimFor short sleepers, a consistent change to moderate sleep duration (MSD) was associated with high global cognition scores, equivalent to 4-10 years of cognitive ageing, with improvements in figure drawing and TICS domains.

measurementShort sleepers in Wave 1 demonstrated lower scores in the specific cognitive domains of episodic memory, figure drawing, and the Telephone Interview of Cognitive Status (TICS) compared to moderate sleepers.

claimHua et al. conclude that for short sleepers, improvement in sleep duration correlates with better cognition, while for long sleepers, there is no need to reduce sleep duration, and excessive changes or deviation from moderate sleep duration is associated with lower cognition.

measurementA change from short sleep duration to moderate sleep duration is associated with better global cognition scores (β=0.54, P <0.01) in individuals aged 45 and older.

claimA change from low sleep duration (LSD) to moderate sleep duration (MSD) may restore the circadian rhythm and lead to improved cognitive function in study participants.

measurementLong sleepers, defined as those sleeping more than 8 hours per night in Wave 1, had lower global cognition scores compared to moderate sleepers (6-8 hours) in the study.

measurementThe prevalence of hypertension was 26.7% in the less than 6 hours sleep group, 22.9% in the 6-8 hours group, and 25.5% in the greater than 8 hours group, with an overall prevalence of 24.2%.

measurementThe effect of short sleep duration on global cognition scores was equivalent to being 5 to 9 years older compared to the moderate sleep-duration group.

measurementParticipants who slept 6-8 hours per night in Wave 1 exhibited the highest global cognition scores in the study.

measurementThe effect of long sleep duration on global cognition scores was equivalent to being 6 to 11 years older compared to the moderate sleep-duration group.

measurementThe study categorized 15,216 participants into three sleep duration groups in Wave 1: less than 6 hours (n=4,453), 6 to 8 hours (n=9,508), and greater than 8 hours (n=1,255).

measurementThe use of tranquilizers was reported by 0.6% of the less than 6 hours sleep group, 0.2% of the 6-8 hours group, and 0.0% of the greater than 8 hours group, with an overall prevalence of 0.3%.

measurementFor individuals with moderate sleep duration, a 2-hour or greater increase in sleep duration is associated with lower global cognition scores (β=-0.89, P <0.001).

measurementShort sleepers, defined as those sleeping less than 6 hours per night in Wave 1, had lower global cognition scores compared to moderate sleepers (6-8 hours) in the study.

measurementA history of heart disease was reported by 15.3% of the less than 6 hours sleep group, 11.1% of the 6-8 hours group, and 9.4% of the greater than 8 hours group, with an overall prevalence of 12.1%.

measurementCurrent smoking prevalence was 37.2% in the less than 6 hours sleep group, 40.0% in the 6-8 hours group, and 37.2% in the greater than 8 hours group, with an overall prevalence of 39.0%.

measurementThe prevalence of depression among participants was 6.8% for the less than 6 hours sleep group, 6.9% for the 6-8 hours group, and 9.5% for the greater than 8 hours group, with an overall prevalence of 7.1%.

claimFor moderate sleepers, a change in sleep duration of 2 hours or more was significantly associated with lower global cognition and lower scores on episodic memory, figure drawing, and TICS tests.

measurementFor individuals with moderate sleep duration, a 2-hour or greater decrease in sleep duration is associated with lower global cognition scores (β=-0.70, P <0.001).