Background: Obesity and diabetes among adolescents and young adults have gradually increased during the past few decades due to social and biological factors such as home environment, socioeconomic status, and genetics. Sleep deprivation has also become a growing concern within these age groups. Minimal research has explored the correlation between sleep adequacy and body mass index (BMI) for minority adolescents.
Objective: The purpose of this study is to evaluate the relationship between sleep adequacy and BMI in a cohort of minority adolescents and young adults.
Design/Methods: A retrospective cohort study was conducted using data from National Health and Nutrition Examination Survey database (NHANES). Survey cycle data from 2015-2018 were utilized to compare BMI and sleep correlations for different ethnic groups. The number of sleep hours during a regular weekday was categorized into two variables based on the American Academy of Pediatrics average recommendation of sleep for adolescents ≥ 13 years. Adequate sleep was defined as 8 or more hours. BMI cut off values were used to separate participants into non-overweight (including underweight), overweight, and obese groups. The overall data that was collected included age, sex, race/ethnicity, BMI (kg/m^2), and the average sleep hours of weekdays/workdays. Univariate p analyses were used to evaluate the relationship of BMI and sleep adequacy for different demographic variables. The final data results from two survey cycles from 2015-2018 were combined. Sampling weights were added to the final data set to account for certain sampling parameters in the NHANES sample design.
Results: A final pooled sample of 1,358 participants within an age range of 16 to 21 years old was gathered. The average age of participants was 18.0 (SD 0.5) and the average BMI was 26.1 kg/m^2, with a standard deviation of 0.7. The mean age was similar in both adequate and inadequate sleep groups, but BMI was significantly greater for those with inadequate sleep (26.18) compared to those with adequate sleep (26.02), p<0.001. There were also significant differences by race/ethnicity with Non-Hispanic Whites having the largest proportion of adequate sleep and Hispanic youth with the largest proportion of non-adequate sleep, p=0.002 (Table 1). In addition, there were significant associations between sleep adequacy and BMI by race/ethnicity (Table 2).
Conclusion: Significant associations were found in this large nationally representative database between adequate sleep and BMI showing youth with higher BMIs had less sleep. There are many possible reasons for this association such as sleep apnea. Hispanic adolescents had the highest mean BMI associated with inadequate sleep. Overall mean BMI values were higher for inadequate sleep compared to those who received adequate sleep within most ethnic groups.
