Gender differences in adolescent sleep neurophysiology: a high-density sleep EEG study

Andjela Markovic,Leila Tarokh,Michael Kaess

doi:10.1038/s41598-020-72802-0

Andjela Markovic, Leila Tarokh + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-72802-0

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Abstract

During adolescence, differences between males and females in physiology, behavior and risk for psychopathology are accentuated. The goal of the current study was to examine gender differences in sleep neurophysiology using high-density sleep EEG in early adolescence. We examined gender differences in sleep EEG power and coherence across frequency bands for both NREM and REM sleep in a sample of 61 adolescents (31 girls and 30 boys; mean age = 12.48; SD = 1.34). In addition, sleep spindles were individually detected and characterized. Compared to boys, girls had significantly greater spindle activity, as reflected in higher NREM sigma power, spindle amplitude, spindle frequency and spindle density over widespread regions. Furthermore, power in higher frequency bands (16.2–44 Hz) was larger in girls than boys in a state independent manner. Oscillatory activity across frequency bands and sleep states was generally more coherent in females as compared to males, suggesting greater connectivity in females. An exception to this finding was the alpha band during NREM and REM sleep, where coherence was higher (NREM) or not different (REM) in boys compared to girls. Sleep spindles are generated through thalamocortical circuits, and thus, the greater spindle activity across regions in females may represent a stronger thalamocortical circuit in adolescent females as compared to males. Moreover, greater global connectivity in females may reflect functional brain differences with implications for cognition and mental health. Given the pronounced gender differences, our study highlights the importance of taking gender into account when designing and interpreting studies of sleep neurophysiology.

Highlights

During adolescence, differences between males and females in physiology, behavior and risk for psychopathology are accentuated
We found no effect of pubertal status for the other frequency bands, REM sleep, or any other spindle features
We found a strong effect of gender for absolute sigma power and sleep spindles during nonrapid eye movement (NREM) sleep, with girls exhibiting greater spindle amplitude, frequency and density across brain regions

Summary

Introduction

Differences between males and females in physiology, behavior and risk for psychopathology are accentuated. Studies investigating developmental periods (e.g., adolescence) with a main focus on gender differences in sleep spindle activity are lacking An exception to this is a large-scale study comprised of a few EEG derivations spanning the ages 4–97 years, which reported greater spindle density in females, but no differences for amplitude, duration or frequency of s pindles[17]. Another recent study examining changes to sleep spindle activity in 134 individuals across the ages 12–21 years found greater frequency of fast spindles in girls as compared to boys, but no differences in amplitude, duration or density[18]. The generalizability of these findings is limited given the broad age range (> years) and the large changes to the sleep EEG that occur during this period coupled with the modest sample size (i.e., in each group) and the focus on SWA

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