Although poor sleep is associated with increased risk for obesity, there is no proven cause-effect relationship.20 Nutrition and physical activity have been identified as 2 critical factors in childhood obesity, but sleep health also needs to be investigated. Shorter sleep duration is strongly associated with the development of obesity.Furthermore, children with obesity are more likely to have shorter sleep duration.21 A short sleep duration alters plasma levels of insulin, low-density lipoprotein, and high-sensitivity C-reactive protein. It is associated with lower diet quality, an increased intake of nutrient-poor foods, and a lower intake of vegetables and fruits.22 Recent studies have shown that interventions to promote earlier bedtimes can improve sleep duration in children.
Older adults have many sleeping issues, including insomnia, circadian rhythm sleep-wake disorders, sleep-related movement disorders, and sleep-breathing disorders. Additionally, the older population has increased sleep latency, decreased sleep efficiency and total sleep time, decreased REM sleep, more frequent nighttime awakenings, and more daytime napping.23 The increased sleep disturbance with age is mainly related to higher risk factors for sleep disorders than the aging process itself. Sleeping 5 or fewer hours is associated with an increased risk for obesity and central abdominal fat compared with those who sleep 7 to 8 hours per night.24 Similar to children and youth, older adults also show a strong correlation between inadequate sleep and obesity.24
The consequence: A vicious cycle
Obesity in turn leads to shorter sleep duration and more disruptions. This negatively affects the orexigenic system, and the resulting hormonal derangement promotes worsening obesity. It is a cycle of poor sleep causing obesity and obesity causing poor sleep. Insomnia, in combination with shorter (and longer) sleep times, also has been linked with obesity.25 These patients experience more daytime sleepiness, fatigue, and nighttime sleep disturbances, all correlated with decreased quality of life and higher prevalence of medical comorbidities.8,26 Additional comorbidities secondary to obesity, including gastroesophageal reflux, depression, and asthma, also have been linked to sleep disturbances.8
OSA is a common sleep complication associated with obesity. With the increasing prevalence of obesity, the prevalence of OSA is rising.8,27Factors that heighten the risk for OSA are male sex, age 40 to 70 years, postmenopausal status, elevated BMI, and craniofacial and upper airway abnormality.28However, the US Preventive Services Task Force found insufficient evidence to screen for or treat OSA in asymptomatic adults.28 Signs and symptoms of OSA include nighttime awakenings with choking, loud snoring, and feeling unrefreshed after sleep.29
Approximately half of primary care clinicians do not screen at-risk patients for OSA, and 90% do not use validated OSA screening tools.
OSA is caused by the intermittent narrowing and obstruction of the pharyngeal airway due to anatomical and structural irregularities or neuromuscular impairments. Untreated OSA is associated with cardiovascular disease and cardiac arrhythmias such as atrial fibrillation. Even with this correlation between obesity and sleep, it is estimated that 80% of OSA remains undiagnosed.30 Approximately half of primary care clinicians do not screen at-risk patients for OSA, and 90% do not use validated OSA screening tools.31Screening tools that have been validated are the STOP, STOP-BANG, Epworth Sleepiness Scale, and 4-Variable Screening Tool. However, the US Department of Veterans Affairs and the US Department of Defense have a more recent guideline recommending STOP as an easier-to-administer screen for OSA.32 A positive result with a screening tool should be confirmed with polysomnography.32
