Sleep is essential for the optimum functioning of many physiological processes inside the human body. In reality, we spend approximately one-third of our lifetimes asleep.
However, there are also working adults suffering from inadequate sleep. A local survey reported that more than half of Malaysian working adults has less than seven hours of sleep daily.
Having insufficient sleep is unhealthy. Such modifiable behaviour is a potential risk factor for the development of non-communicable diseases.
For instance, the risk of acquiring cardiovascular disease is likely to increase following deviation from the recommended sleep duration. Even a single hour of chronic sleep deficit may result in higher chance to develop mental health disorders like depression or anxiety.
Sleep-deprived individuals may also be more susceptible to acute infections. Insufficient sleep affects our immune system by causing a decreased production of protective infection-fighting antibodies.
Thus, longer recovery time may be needed after a simple viral infection. During the Covid-19 pandemic, certain Covid patients may get insomnia following an acute SARS-CoV-2 infection as a manifestation of long Covid. This may further reduce their quality of life.
In general, working adults should aim to sleep for seven to nine hours per night. Shorter sleep duration (less than seven hours) is related to a higher release of the appetite’s regulatory hormone (ghrelin), which may lead to obesity.
Compared to seven hours of sleep duration, extreme sleep deprivation (less than five hours) may cause calcification on the coronary artery (blood vessel which supplies oxygen-rich blood to the heart muscle), which increases the risk of a heart attack.
On the other hand, a longer sleep duration is not recommended for healthy working adults. In fact, longer sleep duration (more than nine hours) may raise blood vessel stiffness, leading to high blood pressure, especially among Asians.
Sleep timing may also be altered following a longer sleep duration. This may cause dysfunctional circadian rhythm (akin to jet lag disorder in the temporary form), leading to increased risks of insomnia.
Sleep quality, which measures how well we sleep, is equally important. If we spend more than 30 minutes trying to fall asleep, have waking-up episodes at least twice in a night, or spend more than 20 minutes to fall back asleep after awakening, the sleep quality is considered as subpar.
Obstructive sleep apnoea, which causes poor sleep quality, may increase cardiometabolic risks in the long term.
In summary, neither too short nor too long sleep durations are desired, as both conditions are associated with a myriad of adverse health outcomes.
In line with National Sleep Comfort Month, every working adult should adhere to the recommended sleep duration (seven to nine hours per night) and aim to have good sleep quality by practising healthy sleep hygiene (be physically active, avoid consuming alcohol or caffeine before bedtime, or dim the lights upon sleeping).
Dr Yap Jun Fai, Prof Dr Moy Foong Ming and Dr Lim Yin Cheng are affiliated with the Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya and the Department of Public Health, University of Malaya Medical Centre.
- This is the personal opinion of the writer or publication and does not necessarily represent the views of CodeBlue.
