Sleep is essential for optimal health. The American Academy of Sleep Medicine (AASM) and Sleep Research Society (SRS) developed a consensus recommendation for the amount of sleep needed to promote optimal health in adults, using a modified RAND Appropriateness Method process. The recommendation is summarized here. A manuscript detailing the conference proceedings and evidence supporting the final recommendation statement will be published in SLEEP and the Journal of Clinical Sleep Medicine.

This validation quantifies strengths and weaknesses of actigraphy as a tool measuring sleep in clinical and population studies. Overall, the participant-specific accuracy is relatively high, and for most participants, above 80%. We validate this finding across multiple nights and a variety of adults across much of the young to midlife years, in both men and women, in those with and without insomnia, and in 77 participants. We conclude that actigraphy is overall a useful and valid means for estimating total sleep time and wakefulness after sleep onset in field and workplace studies, with some limitations in specificity.

Epidemiological studies link short sleep and circadian disruption with risk of metabolic syndrome and diabetes. We tested the hypotheses that prolonged sleep restriction with concurrent circadian disruption, as can occur with shift work, impairs glucose regulation and metabolism. Healthy adults spent >5 weeks in controlled laboratory conditions including: sleep extension (baseline), 3-week sleep restriction (5.6 h sleep/24 h) combined with circadian disruption (recurring 28-h ‘days’), and 9-day recovery sleep with circadian re-entrainment. Prolonged sleep restriction with concurrent circadian disruption significantly decreased resting metabolic rate, and increased postprandial plasma via inadequate pancreatic beta cell responsivity; these normalized with 9 days of recovery sleep and stable circadian reentrainment. Thus, in humans, prolonged sleep restriction with concurrent circadian disruption alters metabolism and could increase risk of obesity and diabetes.

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OBJECTIVEShort sleep duration is associated with impaired glucose tolerance and an increased risk of diabetes. The effects of sleep restriction on insulin sensitivity have not been established. This study tests the hypothesis that decreasing nighttime sleep duration reduces insulin sensitivity and assesses the effects of a drug, modafinil, that increases alertness during wakefulness.RESEARCH DESIGN AND METHODSThis 12-day inpatient General Clinical Research Center study included 20 healthy men (age 20–35 years and BMI 20–30 kg/m2). Subjects spent 10 h/night in bed for ≥8 nights including three inpatient nights (sleep-replete condition), followed by 5 h/night in bed for 7 nights (sleep-restricted condition). Subjects received 300 mg/day modafinil or placebo during sleep restriction. Diet and activity were controlled. On the last 2 days of each condition, we assessed glucose metabolism by intravenous glucose tolerance test (IVGTT) and euglycemic-hyperinsulinemic clamp. Salivary cortisol, 24-h urinary catecholamines, and neurobehavioral performance were measured.RESULTSIVGTT-derived insulin sensitivity was reduced by (means ± SD) 20 ± 24% after sleep restriction (P = 0.001), without significant alterations in the insulin secretory response. Similarly, insulin sensitivity assessed by clamp was reduced by 11 ± 5.5% (P < 0.04) after sleep restriction. Glucose tolerance and the disposition index were reduced by sleep restriction. These outcomes were not affected by modafinil treatment. Changes in insulin sensitivity did not correlate with changes in salivary cortisol (increase of 51 ± 8% with sleep restriction, P < 0.02), urinary catecholamines, or slow wave sleep.CONCLUSIONSSleep restriction (5 h/night) for 1 week significantly reduces insulin sensitivity, raising concerns about effects of chronic insufficient sleep on disease processes associated with insulin resistance.

Glucose tolerance is lower in the evening and at night than in the morning. However, the relative contribution of the circadian system vs. the behavioral cycle (including the sleep/wake and fasting/ feeding cycles) is unclear. Furthermore, although shift work is a diabetes risk factor, the separate impact on glucose tolerance of the behavioral cycle, circadian phase, and circadian disruption (i.e., misalignment between the central circadian pacemaker and the behavioral cycle) has not been systematically studied. Here we show-by using two 8-d laboratory protocols-in healthy adults that the circadian system and circadian misalignment have distinct influences on glucose tolerance, both separate from the behavioral cycle. First, postprandial glucose was 17% higher (i.e., lower glucose tolerance) in the biological evening (8:00 PM) than morning (8:00 AM; i.e., a circadian phase effect), independent of the behavioral cycle effect. Second, circadian misalignment itself (12-h behavioral cycle inversion) increased postprandial glucose by 6%. Third, these variations in glucose tolerance appeared to be explained, at least in part, by different mechanisms: during the biological evening by decreased pancreatic β-cell function (27% lower earlyphase insulin) and during circadian misalignment presumably by decreased insulin sensitivity (elevated postprandial glucose despite 14% higher late-phase insulin) without change in early-phase insulin. We explored possible contributing factors, including changes in polysomnographic sleep and 24-h hormonal profiles. We demonstrate that the circadian system importantly contributes to the reduced glucose tolerance observed in the evening compared with the morning. Separately, circadian misalignment reduces glucose tolerance, providing a mechanism to help explain the increased diabetes risk in shift workers.circadian disruption | shift work | night work | glucose metabolism | diabetes I n healthy humans, there is a strong time-of-day variation in glucose tolerance, with a peak in the morning and a trough in the evening and night (1-6). Understanding the underlying mechanisms of the day/night variation in glucose tolerance is important for diurnally active individuals as well as shift workers, who are at increased risk for developing type 2 diabetes (7-9). The endogenous circadian system and circadian misalignment (i.e., misalignment between the endogenous circadian system and 24-h environmental/behavioral cycles) have been shown to affect glucose metabolism (4,(10)(11)(12)(13)(14). However, the relative and separate importance of the endogenous circadian system and circadian misalignment-after accounting for behavioral cycle effects (including the sleep/wake, fasting/feeding, and physical inactivity/activity cycles, etc.)-on 24-h variation in glucose tolerance is not well understood.Most species have evolved an endogenous circadian timing system that optimally times physiological variations and behaviors relative to the 24-h environmental cycle (15-17). The mammalian circadian system is comp...

Sleep is essential for optimal health. The American Academy of Sleep Medicine (AASM) and Sleep Research Society (SRS) developed a consensus recommendation for the amount of sleep needed to promote optimal health in adults, using a modified RAND Appropriateness Method process. The recommendation is summarized here. A manuscript detailing the conference proceedings and evidence supporting the final recommendation statement will be published in SLEEP and the Journal of Clinical Sleep Medicine.

The American Academy of Sleep Medicine and Sleep Research Society recently released a Consensus Statement regarding the recommended amount of sleep to promote optimal health in adults. This paper describes the methodology, background literature, voting process, and voting results for the consensus statement. In addition, we address important assumptions and challenges encountered during the consensus process. Finally, we outline future directions that will advance our understanding of sleep need and place sleep duration in the broader context of sleep health.