Seasonal variation and sleep patterns in a hot climate Arab Region

Elevated oxidative stress biomarkers in adults with segmented sleep patterns

STUDY OBJECTIVES

We investigated the association between different sleep patterns and inflammatory and oxidative stress biomarkers in adults.

METHODS

A total of 321 consented adults who fulfilled the inclusion criteria were recruited in this cross-sectional study. The inclusion criteria were mainly based on apparently healthy adults aged 18-59 years. To identify sleep patterns, participants were requested to wear the actigraph for 1 week for 24 hours a day. Fasting blood was collected from each participant at day 8. The blood serum was analyzed for inflammatory and oxidative stress biomarkers. Sleep patterns were defined as monophasic (1 episode of night sleep) biphasic (2 episodes of sleep; night and aternoon siesta), and polyphasic sleep pattern (3 or more sleep episodes).

RESULTS

There was no correlation between night sleep duration, total sleep in 24 hours, and napping among inflammatory and oxidative stress biomarkers: high-sensitivity C-reactive protein, malondialdehyde, total glutathione, and basal oxidizability status. Actigraphy reports showed 3 sleep patterns in this cohort, monophasic (24.3%), biphasic-napping (45.2%) and polyphasic (30.5%). Individuals with segmented sleep patterns were significantly associated with oxidative stress biomarkers. A polyphasic sleep pattern was significantly associated with higher basal oxidizability status (P = .023), whereas a biphasic sleep pattern showed higher malondialdehyde (P = .036) as compared to a monophasic sleep pattern. Total glutathione was significantly higher in monophasic sleepers (P = .046). There was no difference in serum high-sensitivity C-reactive protein among all sleep patterns.

CONCLUSIONS

Segmented sleep in polyphasic and biphasic sleep patterns is associated with higher serum malondialdehyde and basal oxidizability status in particular. Further studies are recommended on the cardiometabolic impact of oxidative stress biomarkers in individuals with segmented sleep.

CITATION

Al Lawati I, Zadjali F, Al-Abri MA. Elevated oxidative stress biomarkers in adults with segmented sleep patterns. J Clin Sleep Med. 2024;20(6):959-966.

Individual sleep need is flexible and dynamically related to cognitive function

Given that sleep deprivation studies consistently show that short sleep causes neurocognitive deficits, the effects of insufficient sleep on brain health and cognition are of great interest and concern. Here we argue that experimentally restricted sleep is not a good model for understanding the normal functions of sleep in naturalistic settings. Cross-disciplinary research suggests that human sleep is remarkably dependent on environmental conditions and social norms, thus escaping universally applicable rules. Sleep need varies over time and differs between individuals, showing a complex relationship with neurocognitive function. This aspect of sleep is rarely addressed in experimental work and is not reflected in expert recommendations about sleep duration. We recommend focusing on the role of individual and environmental factors to improve our understanding of the relationship between human sleep and cognition.

Association of elevated glycated hemoglobin and obesity with afternoon napping for more than 1 h in young and middle-aged healthy adults

INTRODUCTION

Sleep has different patterns followed worldwide and can be influenced by social, cultural, and environmental factors. Daytime napping is commonly practiced in different parts of the world with controversial results of its effect on glucose metabolism. The current study aims to examine the association of afternoon napping and night sleep duration with metabolic derangements.

METHODS

This is a cross-sectional study involving young adults and middle-aged subjects. Anthropometric measurements were taken for height and weight and hip and waist ratio. Consented subjects were asked to wear actigraphy for 1 week and run their usual daily activities. Home sleep apnea testing was performed to exclude obstructive sleep apnea. Subjects had been asked to come fasting on day seven for blood collection to test for fasting glucose, glycated hemoglobin, lipid profile, and insulin.

RESULTS

A total of 405 subjects were involved to complete the study (52% male, 48% female). The mean age of participants was 32.8 ± 11.5 years. The study indicated that the duration of afternoon napping was significantly associated with abnormal glycated hemoglobin (HbA1c > 5.7%) (p = 0.01) and body mass index (p = 0.046) independent of age, gender, and nocturnal sleep duration. Nocturnal sleep duration was associated with increased insulin level (p = 0.04).

CONCLUSION

Afternoon napping is associated with an increased level of glycated hemoglobin and obesity and that may predispose to the development of type 2 diabetes mellitus.