Sleepless for a \'sweet sleep\'

A good sleep is always needed for a healthy and productive life. Sleep is believed to be the fuel for the brain, and brain is the wheel of all actions and reactions. Many of our stomachic, cognitive, and psychological processes are dependent on sleep; insufficient sleep can therefore pose a threat to our well-being.  Several studies have shown that 7-8 hours of sleep are sufficient for adults with the elderly requiring less sleep. However, sleep duration in a given population is variable and depends on individual characteristics. While some of us tend to pass sleepless nights in search of a 'sweet sleep', no research has yet been done on duration of sleep by Bangladeshis and the ramifications thereof. A group of researchers, however, attempts to fill the void by presenting interesting research findings. The group of researchers include Fakir Md. Yunus, Mohammad Safayet Khan, Tahera Akter, FatemaTuz Jhohura, Saifur Reja, Md Akramul Islam and Mahfuzar Rahman.
To start with, a review has indicated that both the employment characteristics and technology penetration might be responsible for both increasing and decreasing average duration of sleep. Although there is a working definition of acute sleep deprivation (sleeping 25-50 per cent of a normal eight-hour night's sleep), there is no cut-off for 'too much sleep'. However, research has shown that inadequate sleeping time (both shorter and/or longer) could have been associated with adverse health effects. Some studies have shown a U-shaped association between short and long sleep duration and the risks of morbidity and mortality. Moreover, daytime sleep and fatigue have substantial societal cost implications. Despite the odds with sleep, relatively little attention has been paid to sleep-related problems, and it remains an unrecognised public health issue in many developing countries. Too little sleep affects memory, immunity, and risks the overall safety of the individual, and chronic lack of sleep (6 hours) has been associated with an increased risk of obesity, diabetes, mental health disorders, hypertension, and other cardiovascular diseases.
Acute sleep deprivation contributes to inflammation and disturbs immunological responses. On the other hand, longer sleep duration has been associated with obesity, hypertension, other cardiovascular diseases, and a 20-30 per cent greater risk of mortality; these associations can sometimes be stronger than those observed with short sleep duration Other previous studies have indicated that excessive sleeps are associated with mortality and work disability. Nevertheless, the duration of sleep of Bangladeshi people according to age, gender and socio-economic characteristics is still largely unknown. To the best of knowledge, this is the first study to explore sleep duration in the Bangladeshi population.
Using a multi-stage random sampling technique, the researchers observed that the majority of the population in different age groups tends to sleep less than their consecutive recommended sleeping hours. "Perhaps worryingly, over half of school-age children were at risk of sleeping less than their recommended sleeping hours. Other age groups such as teenagers, young adults and adults and older adults also tended to sleep less. This may have implications for the health of a population since some studies have demonstrated that lack of sleep is associated with increased risk of being overweight or obese. In contrast, a relatively smaller proportion of the population slept longer than recommended except a relatively high proportion of older adults (almost one-third of older adults). This is also of public health concern, since the incidence and risk of adverse health behaviour is higher in the elderly in the long sleep duration group. Other studies have shown that adults who have over 8 hours of sleep per night have a higher incidence of stroke and mortality.
The majority of the Bangladeshi children sleep less and, conversely, a large proportion of older adults sleep longer than the National Sleep Foundation (NSF) recommended sleep hour's guidelines. In addition, urban residents sleep more than rural residents. This inadequate sleep duration may increase risk for various chronic health conditions among the Bangladeshi population and resulting in altered quality of life.
These data could be interpreted in two ways. First, a high proportion of the population of all ages slept much less or, alternatively, a small proportion of the population slept for longer. However, either way, populations are at risk of reduced quality of life, since previous studies have reported either shorter and/or longer sleep could be a risk factor for chronic disease. In contrast, together, these two factors increase the population's vulnerability to ill health. The researchers show that urban populations sleep significantly longer than rural populations. Individuals living in rural areas had over 3-times greater chance of sleeping less than recommended than individuals living in urban areas.
A similar trend was also found in people involved in the agriculture sector, mostly living in rural Bangladesh. Individuals involved in agriculture are more likely to sleep less compared to other professions. It is not clear why there is such geographical variation in sleep patterns. Bangladesh has experienced rapid urbanisation over the last few decades, and people living in urban areas lead a sedentary lifestyle that raises the concern that the chronic disease burden may be even greater in urban populations. Longer sleeping time may further exacerbate their risk by making them more vulnerable to developing chronic diseases. A similar trend was also observed when Bangladesh was categorised into seven operational districts from the capital city to peripheral areas. All the people residing in districts other than the Dhaka division (except Chittagong, a port city in the southeast) slept significantly less than recommended, and the participants, particularly in Rangpur, Khulna, and Barisal, which are the most distant parts of Bangladesh, had over 7, 4 , and 2 times (respectively) greater chance of sleeping for less than those in the Dhaka division. This might be due to the fact that residents in Dhaka (which is the capital of Bangladesh) are more likely to be sedentary than residents in the peripheral parts of the country.
A similar observation has previously been made in the rural population in a study that established an association between short sleep duration and BMI. In our study, we considered Dhaka, Rajshahi, and Rangpur divisions as dry regions and Khulna, Barisal, and Chittagong divisions as wet regions based on temperature and average annual precipitation. The research reveals that populations in the dry regions slept significantly more than those in the wet regions. It is often said that people sleep more in the hot season, which might be due to excess heat, sweating, and consequent tiredness. One study has also reported that human sleep quality is sensitive to changes in air temperature, as the skin temperature increased with air temperature and fluctuated during sleeping. We hope, after reading the article, the readers would have a good sleep and would not pass a sleepless night for a sweet sleep.
The writer is Professor of Economics
at Jahangirnagar University.
[email protected]