Sleep Initiation and Maintenance Disorders: Dinges DF

Bonnet MH, Balkin TJ, Dinges DF, Roehrs T, Rogers NL, Wesensten NJ, Anonymous00034. · Dayton Department of Veterans Affairs Medical Center, Wright State University, and Kettering Medical Center, Dayton, OH 45428, USA. · Sleep. · Pubmed #16268386 No free full text.

This publication has no abstract.

Van Dongen HP, Vitellaro KM, Dinges DF. · Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6021, USA. · Sleep. · Pubmed #16171293 No free full text.

Abstract: This paper reviews the literature on interindividual variability in human sleep parameters, sleepiness, responses to sleep deprivation, and manifestations of sleep disorders. Variability among individuals in sleep/wake biology and behavior is pervasive. The magnitude of such individual differences is often considerable and comparable to the effect sizes of many experimental and clinical interventions. Evidence is accumulating that certain aspects of sleep/wake-related variability--such as sleep duration, daytime sleepiness, and vulnerability to the effects of sleep loss--involve trait characteristics in healthy populations and among sleep-disordered patients. Establishing the trait-specific nature of variability in sleep/wake parameters is a prerequisite for elucidating the corresponding neurophysiologic and/or genetic mechanisms. At present, it remains largely unknown what underlies or predicts sleep/wake-related traits, what relationships these traits may have to each other, and what functional significance may be associated with specific traits. Scientific studies addressing these issues are warranted, as understanding the basis of trait variability may yield new insights into sleep/wake regulation and sleep pathology. Understanding individual differences in sleep and wakefulness may also have provocative but important implications for health economics and clinical care, as well as for safety, productivity, and general well-being. This paper gives suggestions for a research agenda focusing on individual differences in sleep research and sleep medicine.

Goel N, Stunkard AJ, Rogers NL, Van Dongen HP, Allison KC, O'Reardon JP, Ahima RS, Cummings DE, Heo M, Dinges DF. · University of Pennsylvania School of Medicine, Philadelphia, PA, USA. · J Biol Rhythms. · Pubmed #19150931 No free full text.

Abstract: Night eating syndrome (NES) is characterized by evening hyperphagia and frequent awakenings accompanied by food intake. Patients with NES display a delayed circadian pattern of food intake but retain a normal sleep-wake cycle. These characteristics initiated the current study, in which the phase and amplitude of behavioral and neuroendocrine circadian rhythms in patients with NES were evaluated. Fifteen women with NES (mean age +/- SD, 40.8 +/- 8.7 y) and 14 control subjects (38.6 +/- 9.5 y) were studied in the laboratory for 3 nights, with food intake measured daily. Blood also was collected for 25 h (every 2 h from 0800 to 2000 h, and then hourly from 2100 to 0900 h) and assayed for glucose and 7 hormones (insulin, ghrelin, leptin, melatonin, cortisol, thyroid-stimulating hormone [TSH] and prolactin). Statistical analyses utilized linear mixed-effects cosinor analysis. Control subjects displayed normal phases and amplitudes for all circadian rhythms. In contrast, patients with NES showed a phase delay in the timing of meals, and delayed circadian rhythms for total caloric, fat, and carbohydrate intake. In addition, phase delays of 1.0 to 2.8 h were found in 2 food-regulatory rhythms-leptin and insulin-and in the circadian melatonin rhythm (with a trend for a delay in the circadian cortisol rhythm). In contrast, circulating levels of ghrelin, the primary hormone that stimulates food intake, were phase advanced by 5.2 h. The glucose rhythm showed an inverted circadian pattern. Patients with NES also showed reduced amplitudes in the circadian rhythms of food intake, cortisol, ghrelin, and insulin, but increased TSH amplitude. Thus, patients with NES demonstrated significant changes in the timing and amplitude of various behavioral and physiological circadian markers involved in appetite and neuroendocrine regulation. As such, NES may result from dissociations between central (suprachiasmatic nucleus) timing mechanisms and putative oscillators elsewhere in the central nervous system or periphery, such as the stomach or liver. Considering these results, chronobiologic treatments for NES such as bright light therapy may be useful. Indeed, bright light therapy has shown efficacy in reducing night eating in case studies and should be evaluated in controlled clinical trials.

Gooneratne NS, Gehrman PR, Nkwuo JE, Bellamy SL, Schutte-Rodin S, Dinges DF, Pack AI. · Division of Geriatric Medicine, Center for Sleep and Respiratory Neurobiology, Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia 19104, USA. · Arch Intern Med. · Pubmed #16983051 links to  free full text

Abstract: BACKGROUND: The prevalence of sleep-related breathing disorder (SRBD) and insomnia symptoms increases considerably with advancing age, but little is known about their cooccurrence and their effects on daytime functioning when present together. METHODS: Older adults with (cases, n = 99) and without (controls, n = 100) symptoms of insomnia underwent 2 nights of in-laboratory polysomnography, daytime nap, and neurobehavioral testing and completed study questionnaires. Predictors of SRBD were identified (apnea-hypopnea index [indicating number of events per hour], > or =15). Participants were divided into 4 groups--with and without insomnia and with and without SRBD--and the groups were compared on measures of daytime functioning. RESULTS: Cases had a lower rate of SRBD (29.3%) than controls (38.0%). Body mass index (calculated as weight in kilograms divided by height in meters squared) of 30 or higher, neck circumference greater than 15.5 inches, and a history of "loud snoring" or "stops breathing, chokes, or struggles for breath" were independently predictive of SRBD in participants with insomnia symptoms. Having both insomnia symptoms and SRBD was associated with significantly lower daytime functioning and longer psychomotor reaction times compared with having neither condition. CONCLUSION: Because insomnia comorbid with SRBD is associated with the greatest functional impairment, and SRBD is commonly found in the elderly population, health care providers should also consider SRBD in elderly patients with insomnia symptoms.

O'Reardon JP, Ringel BL, Dinges DF, Allison KC, Rogers NL, Martino NS, Stunkard AJ. · Weight and Eating Disorder Program, Department of Psychiatry, The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA. · Obes Res. · Pubmed #15601974 No free full text.

Abstract: OBJECTIVE: To compare the eating and sleep-wake patterns of persons with the night eating syndrome (NES) with those of matched control subjects. RESEARCH METHODS AND PROCEDURES: Forty-six overweight/obese NES subjects (mean age 43.3 +/- 9.8 years; 32 women) and 43 similar controls (mean age 39.0 +/- 11.0 years; 28 women) wore wrist actigraphs for 7 days and completed sleep and food diaries at home. RESULTS: There was no difference between the total energy intake of the NES and the control subjects, but the pattern of energy intake differed greatly. Relative to control subjects, the temporal pattern of food intake of night eaters was delayed. Food intake after the evening meal, as a proportion of the 24-hour intake, was more than 3-fold greater in NES subjects than in controls (34.6 +/- 10.1% vs. 10.0 +/- 6.9%, p = 0.001). NES subjects had sleep onset, offset, and total sleep duration times comparable with those of controls. NES subjects reported more nocturnal awakenings than did controls (1.5 +/- 1.0 per night vs. 0.5 +/- 0.5; p < 0.001), and their actigraphically monitored arousals occurred earlier during sleep (at 128 minutes after sleep onset vs. 193 minutes, p = 0.01). NES subjects consumed food on 74% of the awakenings vs. 0% for the controls. DISCUSSION: The pattern of cumulative energy intake of the night eaters suggests a phase delay in energy consumption relative to sleep-wake times. NES may involve a dissociation of the circadian control of eating relative to sleep.

Rogers NL, Dinges DF, Kennaway DJ, Dawson D. · The University of Pennsylvania School of Medicine, Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Philadelphia 19104-6021, USA. · Sleep. · Pubmed #14746391 No free full text.

This publication has no abstract.