Journal of sleep research
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Journal of sleep research · Aug 2015
Multicenter StudyAssociation between obstructive sleep apnea severity and glucose control in patients with untreated versus treated diabetes.
The purpose of this study was to determine whether the association between obstructive sleep apnea severity and glucose control differs between patients with newly diagnosed and untreated type 2 diabetes, and patients with known and treated type 2 diabetes. This multicentre cross-sectional study included 762 patients investigated by sleep recording for suspected obstructive sleep apnea, 497 of whom were previously diagnosed and treated for type 2 diabetes (treated diabetic patients), while 265 had no medical history of diabetes but had fasting blood glucose ≥126 mg dL(-1) and/or glycated haemoglobin (HbA1c ) ≥6.5% consistent with newly diagnosed type 2 diabetes (untreated diabetic patients). Multivariate regression analyses were performed to evaluate the independent association between HbA1c and obstructive sleep apnea severity in treated and untreated patients with diabetes. ⋯ The adjusted mean value of HbA1c increased from 6.68% in the lowest quartile of the apnea-hypopnea index (<17) to 7.20% in the highest quartile of the apnea-hypopnea index (>61; P = 0.033 for linear trend). In treated patients with diabetes, HbA1c was associated with non-sleep variables, including age, metabolic dyslipidaemia and insulin use, but not with obstructive sleep apnea severity. Obstructive sleep apnea may adversely affect glucose control in patients with newly diagnosed and untreated type 2 diabetes, but may have a limited impact in patients with overt type 2 diabetes receiving anti-diabetic medications.
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Journal of sleep research · Aug 2015
The spectrum of the non-rapid eye movement sleep electroencephalogram following total sleep deprivation is trait-like.
The sleep electroencephalogram (EEG) spectrum is unique to an individual and stable across multiple baseline recordings. The aim of this study was to examine whether the sleep EEG spectrum exhibits the same stable characteristics after acute total sleep deprivation. Polysomnography (PSG) was recorded in 20 healthy adults across consecutive sleep periods. ⋯ ICCs were high across all frequencies for baseline and recovery and for baseline and recovery combined. These results show that the spectrum of the NREM sleep EEG is substantially different among individuals, highly stable within individuals and robust to an experimental challenge (i.e. sleep deprivation) known to have considerable impact on the NREM sleep EEG. These findings indicate that the NREM sleep EEG represents a trait.
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Journal of sleep research · Aug 2015
The exploratory power of sleep effort, dysfunctional beliefs and arousal for insomnia severity and polysomnography-determined sleep.
Differences between subjective sleep perception and sleep determined by polysomnography (PSG) are prevalent, particularly in patients with primary insomnia, indicating that the two measures are partially independent. To identify individualized treatment strategies, it is important to understand the potentially different mechanisms influencing subjective and PSG-determined sleep. The aim of this study was to investigate to what extent three major components of insomnia models, i.e., sleep effort, dysfunctional beliefs and attitudes about sleep, and presleep arousal, are associated with subjective insomnia severity and PSG-determined sleep. ⋯ The results showed that subjective insomnia severity was associated positively with sleep effort. PSG-determined total sleep time was associated negatively with somatic presleep arousal and dysfunctional beliefs and attitudes about sleep. This pattern of results provides testable hypotheses for prospective studies on the impact of distinct cognitive and somatic variables on subjective insomnia severity and PSG-determined total sleep time.