Nocturnal Awakenings

Questions about Epidemiology of Nocturnal Awakenings in the General Population

Nocturnal awakenings are the most prevalent insomnia symptoms in the general population. However, how the severity of this symptom affects the daily functioning has been rarely documented. Little is known about:

  • How to define nocturnal awakenings?
  • When nocturnal awakenings must be considered an insomnia symptom?
  • Admitting that we have a clear definition, how frequent is this symptom in the general population
  • Who is the most affected (age, sex, comorbidity)?
  • What are the associated factors?
  • What are the daytime, social professional and familial consequences?
  • What is the naturalistic way of these individuals to complain and to deal with their general practitioner?
  • What kind of treatment are they taking? For how long? What is the level of satisfaction with their treatment and general practitioner?

Nocturnal Awakenings & Difficulty Returning to Sleep in the U.S. General PopulationPDF icon

Nocturnal awakenings are one of the most prevalent sleep disturbances in the general population.

A multidimensional approach was used to help better define how it could be assessed in general population. A representative sample consisting of 8,937 non-institutionalized individuals aged 18 or over living in Texas, New York and California was interviewed on sleeping habits, health, sleep and mental disorders. Nocturnal awakenings were evaluated according to their frequency per week and per night, as well as their duration.

A total of 35.5% of the sample reported awakening at least 3 nights per week. When the duration was set at 1 month, the prevalence decreased to 34.2%. The addition of daytime impairment dropped the prevalence to 19.5%. More than half of them had Difficulty Resuming Sleep (DRS) once awakened. DRS was associated with greater daytime impairment, greater consultations for sleep disturbances and greater likelihood of receiving a sleep medication.

Nocturnal awakenings significantly disrupt the sleep of about one fifth of the general population. Using DRS identifies individuals with significant daytime impairment who are most likely to seek medical help for their sleep disturbances.

Nocturnal Awakenings in Community-Dwelling Older Adults

Prevalence and frequency of nocturnal awakenings in a sample of 152 community-dwelling, older adults are presented. Specifically, the results of an ongoing investigation of ambulatory polysomnography in the community-dwelling older adults, who do not have any significant medical or psychiatric co-morbidity. Subjects are participants in an ongoing National Institute of Mental Health investigation of the relationship between sleep disturbance in older adults and cognitive and affective symptoms. Participants are on average 70.2 years of age (SD=8.17; range 55-96), with an average of 16.5 years of education (SD=3.76; range 12-20). As part of this ongoing investigation participants undergo a full overnight ambulatory polysomnography, and are administered an extensive battery of cognitive measures of executive function, memory and attention. Additionally, they provide self-report measures of mood, anxiety and function. In addition to the prevalence of nocturnal awakenings in this sample, this presentation describe the sleep disorders which are most strongly associated with these awakenings, and also describe the negative impact of frequent nocturnal awakenings on cognitive function, mood and anxiety symptomatology, health and functional status.

Clinical Concerns and Management of Nocturnal AwakeningsPDF icon

Awakenings from Sleep: Medical Conditions and Other Sources and Potential Consequences on Circadian SystemsPDF icon

Various acute and chronic medical conditions (MC) can negatively impact sleep. The detrimental effects of acute MC on sleep satisfaction are of short duration, while those associated with chronic MC may persist for months, years, decades, or even lifetime. Some MC, e.g., allergic rhinitis and asthma, often commence in childhood. Both exhibit marked circadian rhythmicity, their symptoms being most severe nocturnally. Nearly 75% of asthmatic persons experience nighttime episodes of dyspnea resulting in nocturnal awakenings at least once a week, and 80% or more of allergic rhinitis suffers complain of symptoms indicative of sleep dissatisfaction. Most chronic MC begin to manifest in middle-aged adults and give rise to complaints of sleep dissatisfaction. Common examples include: rheumatoid arthritis, with its characteristic morning peak in symptom intensity prematurely terminating nighttime sleep; osteoarthritis, with its characteristic late afternoon-nighttime peak in symptom intensity delaying sleep onset; GERD (gastroesophageal reflux disorder) and PUD (peptic ulcer disease), with symptoms that tend to be worse in the evening and overnight often disrupting sleep onset or continuity; and nocturia, which may have a different etiology in men versus women, causing frequent sleep awakenings.

Nocturnal awakenings caused by MC typically coincide with one of more artificial light at night (LAN) exposures. Light is the major environmental time cue for the master circadian clock (suprachiasmatic nuclei), serving to synchronize its period and phasing. LAN exposure occurring during the first half of the usual sleep span phase-delays while LAN exposure occurring during the last portion of the usual sleep span phase-advances the circadian clock. Thus, even though a MC may be the primary cause of sleep awakenings and sleep dissatisfaction only one or a few night per week, the secondary effect of the MC-associated LAN exposure(s) on sleep dissatisfaction can extend to subsequent night(s) via either a sleep-onset or sleep-offset insomnia, depending on the exact circadian time of LAN exposure(s). Phase alteration of the sleep-wake circadian rhythm may be further reinforced by daytime napping due to sleep dissatisfaction. Medications (certain beta-blockers and SSRIs) plus lifestyle patterns (late night work and socialization in artificial light) can also alter the circadian sleep-wake rhythm, through sleep onset insomnia, and result in or aggravate complaints of sleep dissatisfaction. Concerns about LAN extend beyond sleep dissatisfaction and include depression, obesity, hypertension, and cancer. Unknown, however, is the threshold and individual differences for LAN effects.

Extensive human LAN exposure -- beyond the low-level natural moon and man-made fire, gas-lamp, and candle light intensities of earlier times - is a recent phenomenon, commencing late in the 19th century. We have much to learn, given that it is only the past 5-6 generations of humans that have experienced LAN of significant intensity to potentially exert biological effects.