Association Between Physical Activity and Insomnia Symptoms in Rural Communities of Southeastern Missouri, Tennessee, and Arkansas

Insomnia is the most common of all sleep complaints and affects millions of people each year. Insomnia is characterized as difficulty in initiating and maintaining sleep and early morning waking with an inability to return to sleep.1 The prevalence of insomnia varies by the population being studied and the specific case definition used. Population-based studies drawn from different countries have indicated that approximately 30% of adults in the general population report one or more insomnia symptoms and 5%-10% have been diagnosed with specific insomnia disorders.2 Risk factors for insomnia include older age, female sex, concurrent depressive symptoms, and comorbid medical or psychiatric disorders.3-5 In addition, individuals who are separated or divorced, of black race, lower socioeconomic status, or who report higher chronic life stress also experience increased risk of insomnia.3,4 Insomnia, particularly chronic forms of insomnia, is a major public health problem because it is associated with significant psychological and physical impairment: insomnia increases psychiatric disturbances, decreases work productivity and quality of life, and may increase mortality.1,3 The economic costs of insomnia associated with increased health care use, workplace absenteeism, accidents, and increased alcohol consumption have been estimated to be between $35 billion and $107 billion a year.6 There are a wide range of pharmacologic and non-pharmacologic therapies available for the management of insomnia. The most common treatments are over-the-counter antihistamines, alcohol, and prescription medications with sedative-hypnotic effects, including benzodiazepine receptor agonists and various sedating antidepressants, antihistamines and antipsychotic medications.3,4 Of note, many drugs commonly prescribed for insomnia do not have a Food and Drug indication for treatment of insomnia, but rather, are used “off-label” for their hypnotic properties. Because the use of these medications has been associated with increased mortality, medication tolerance and dependence, and a number of negative side effects, they are seldom recommended for long-term use.7 Therefore, there is increasing interest in non-pharmacologic treatments such as cognitive and behavioral therapies.3 One behavioral therapy is physical activity, which is thought to promote sleep by increasing slow wave sleep and total sleep time, as well as decreasing sleep latency (the duration between initial attempts to fall asleep and onset of sleep).8 Studies based on self reports indicate that moderate and regular physical activity has sleep promoting benefits.8-11 Regular physical activity has been demonstrated to increase total sleep time, slow wave sleep, and rapid eye movement sleep latency, and reduce REM sleep.8,12,13 But evidence from experimental studies on the beneficial effect of physical activity is not as compelling.8,14,15 Discrepancies in the findings of existing studies may be attributed to small sample size,16 varying definitions and measurement of “physical activity,”9,17-19 and inclusion of mostly good or young sleepers, leaving little room for sleep improvement (ie, a ceiling effect).20 In addition, prior studies of physical activity and insomnia have generally refrained from exploring the relationship between the frequency and intensity (eg, moderate or vigorous) of physical activity and insomnia. Although rural communities have higher rates of chronic illness and disability and poorer overall health status than urban communities,21-25 little is known about sleep patterns in rural populations. Many of the unique demographics and lifestyle characteristics of rural populations have the potential to contribute negatively to health outcomes including insomnia, given existing evidence of rural health disparities in heart disease, physical inactivity, alcohol abuse and tobacco dependence, and psychiatric symptoms.21,24,26 Prior research indicates a link between physical activity and insomnia in the general population. Specifically, regular physical activity may be protective against insomnia.8,14 However, this association is less firmly established among a rural, adult population. Since rural and urban communities vary in their characteristics, the unique rural culture may have bearing on the relationship between physical activity and insomnia.21 Therefore, the objective of our study is to determine the relationship between current regular physical activity and insomnia symptoms in a rural setting. Rural residents fare worse than their urban counterparts in regards to rates of obesity and physical inactivity, and overweight and obesity are associated with short sleep duration and sleep disturbances.27,28 Hence, the present study also evaluated body weight as an effect modifier in the association between current regular physical activity and insomnia symptoms.