Sleep duration and its effect on nutritional status in adolescents of Aligarh, India
Background. The World Health Organization describes obesity as one of today’s most blatantly visible – yet most neglected – public health problems. Sleep duration has been found to have an association with overweight and obesity in many studies, most of which have been conducted outside India. The prevalence of chronic partial sleep deprivation has increased dramatically in the past half century, in parallel with the rising epidemics of overweight and obesity. In addition, sleep per se has a special relevance in obesity.
Objective. This study was part of a larger study based on the Global School Health Survey, and was conducted in the 13 - 15-year-old age group. The study had two objectives: first, it enquired into sleep duration in the aforementioned adolescents and assessed whether this was adequate or inadequate; and second, it sought to evaluate and assess the relationship between sleep duration and the nutritional status of these adolescents, whether overweight or obese.
Methods. A cross-sectional study was conducted in all three schools affiliated to the Aligarh Muslim University Board of Examination. A pretested and prevalidated questionnaire was used to assess sleep duration, and anthropometry was done on all the students of these schools who fulfilled the inclusion criteria. AnthroPlus (World Health Organization, Switzerland) and SPSS (IBM, USA) version 20 were used for z-score and other statistical calculations, respectively.
Results. A total of 1 416 students were studied, of which 23.6% reported inadequate sleep duration. It was found that those with inadequate sleep had significantly higher odds of being overweight or obese, with an odds ratio of 1.56 (confidence interval 1.12 - 2.15). The inadequacy of sleep duration was also associated with a higher body mass index for age z-score (0.77 (standard deviation 0.57)), compared with those with adequate sleep duration (–0.31 (0.08)), which was found to be significant (t=22.59, df=1, p<0.001).
Conclusion. Inadequate sleep is an obesogenic factor, even in developing countries. It is a cause of concern, as the habits developed/ strengthened at this stage may be lifelong.