In a recent study published within the journal BMJ Open, researchers evaluated the associations between energy drink (ED) intake and sleep characteristics amongst Norwegian students attending colleges and universities. In addition they examined whether there have been sex-based differences.
Energy drinks are non-alcoholic caffeine-containing beverages, often consumed for mental health and physical performance. Consumption is common amongst students.
Nonetheless, scientific data on energy drinks and sleep parameters in young adults are scarce and contradictory. Furthermore, most studies have used crude measures to evaluate sleep. More comprehensive sleep quality evaluations, similar to diagnostic guidelines for insomnia, could add to the body of literature.
The authors of the current study previously reported higher insomnia rates amongst young female students than their male counterparts; nevertheless, there have been no significant sex-based differences in sleep durations.
In regards to the study
In the current cross-sectional study, researchers evaluated ED consumption frequency amongst Norwegian students and associated sleep characteristics. Further, the study assessed whether these associations differed based on sex.
The Students’ Health and Well-Being SHOT2022 study, conducted by student well-being organizations between February 8 and April 19, 2022, surveyed 53,266 individuals aged 18 to 35 years receiving higher education in Norway. The researchers collected data on participants’ sex, age, educational level, and relationship status from their National Identity Numbers.
The team assessed energy intake through food and beverage questionnaires, specializing in ED consumption frequency. They reported participants’ bedtime and wake-rise times individually for weekends and weekdays.
Time in bed (TIB) was calculated based on differences between bedtimes and bed-rise times. They defined late bedtime as retiring to bed post-midnight. In addition they assessed wake after sleep onset (WASO) and sleep onset latency (SOL). The researchers calculated sleep efficiency by dividing sleep duration by TIB values and multiplying by 100, and sleep duration by subtracting WASO and SOL from TIB.
All participants reported difficulties experienced in early morning awakenings (EMA), difficulty in initiating sleep (DIS), difficulty maintaining sleep (DMS), daytime tiredness and sleepiness, and the duration of sleep difficulties. The team operationalized insomnia using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) guidelines: EMA, DMS, or DIS presence for 3 or more nights every week, daytime tiredness and sleepiness for 3 or more days every week, and the duration of sleep difficulties for 3 or more months.
The first study outcomes were insomnia and sleep duration. The team performed general linear modeling (GLM) and used least significant differences (LSD) for post-hoc comparisons to judge the associations between ED intake and continuous variables. They performed log-linked binomial regressions to calculate age-adjusted estimated marginal means (EMM) and the effect magnitudes for age-adjusted dichotomous variables.
Amongst 53,226 participants, the mean age was 24, and 66% were women. ED consumption frequency was inversely related to sleep duration and efficiency. ED intake frequency was directly related to sleep patterns similar to SOL and WASO across the sexes.
Higher ED consumption was related to an increasing risk of sleep problems across all sleep parameters, with the strongest association observed between day by day ED intake and short sleep duration, with men and ladies having risk ratios (RR) of two.1 and 1.9, respectively.
There have been significant sex-based differences in ED consumption, with 50% of ladies and 40% of men reporting rare to no consumption. Women consumed ED lower than men.
Ladies and men who consumed energy drinks day-after-day slept half-hour lower than those that consumed ED rarely or never. The team found similar associations between SOL and WASO; increasing ED intake frequency was related to increased nocturnal wake times and time to go to sleep.
Insomnia was prevalent amongst 51% of female day by day ED consumers, in comparison with 33% amongst females who never or rarely drank energy drinks, with similar graded patterns in males (37% versus 22%, respectively).
Men showed stronger associations with ED intake for the sleep parameters. In comparison with rare or never ED consumers, regular male consumers had a >2.0-fold higher risk of lower than six hours of sleep (risk ratio, 2.1), with similar patterns in females (risk ratio, 1.9).
Infrequent ED use (one to 3 times a month) was significantly related to the next likelihood of poor-quality sleep for many sleep characteristics, other than late bedtimes and temporary sleep for men and women.
The study findings showed that excessive ED consumption significantly impacts sleep outcomes, with even small amounts related to poorer sleep. The study highlights the necessity for more attention to ED intake consequences amongst students.
ED consumption frequency had dose-response associations with sleep difficulties, sleep durations, and insomnia. Regular ED intake increases the likelihood of sleep difficulties for men and ladies.