Kerstin M. Oltmanns

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Obstructive sleep apnea (OSA) syndrome is a disorder characterized by repetitive episodes of upper airway obstruction that occur during sleep. Associated features include loud snoring, fragmented sleep, repetitive hypoxemia/hypercapnia, daytime sleepiness, and cardiovascular complications. The prevalence of OSA is 2-3% and 4-5% in middle-aged women and men,(More)
BACKGROUND Controlled transcranial stimulation of the brain is part of clinical treatment strategies in neuropsychiatric diseases such as depression, stroke, or Parkinson's disease. Manipulating brain activity by transcranial stimulation, however, inevitably influences other control centers of various neuronal and neurohormonal feedback loops and therefore(More)
OBJECTIVE Early nocturnal sleep enhances the consolidation of declarative memories acquired during prior wakefulness. Patients with type 1 diabetes frequently experience hypoglycemic episodes during sleep. We investigated whether short-lasting hypoglycemia during early nocturnal sleep affects the sleep-associated consolidation of declarative memories. (More)
Disturbances in hormonal counterregulation may be the main reason why many type 1 diabetic patients are asymptomatic during nighttime hypoglycemia. While it is known that sleep attenuates counterregulatory responses to hypoglycemia, the influence of the time of day on hormonal counterregulation regulation remains obscure. We induced hypoglycemia at 2(More)
OBJECTIVE To assess the whole-body glucose disposal in patients with both typical and atypical depression and to characterize the neuroendocrine responses during a hyper-, eu-, hypoglycemic stepwise clamp experiment in patients with both subtypes of major depression. Depressive disorders and alterations in glucose metabolism are closely associated. The(More)
Sexual dimorphisms in hypoglycemic counterregulation are well documented in young healthy and type 1 diabetic subjects. Here, we questioned whether sex differences in counterregulation are present also in type 2 diabetic patients who are in a postmenopausal state. In an attempt to answer this question, we examined hormonal responses to a single-step(More)
The plasma glucose concentration is a major short-term regulator of hunger and food intake. In patients with diabetes, therapies lowering plasma glucose are frequently associated with body weight gain, suggesting that lowered plasma glucose leads to increased feelings of hunger and food intake. However, as many physiological and symptomatic responses to low(More)
Patients with obstructive sleep apnea syndrome (OSAS) show recurrent episodes of nightly hypoxic stress. The purpose of this study is the detection of alterations of the hypothalamic-pituitary-adrenal stress axis in OSAS patients before and after continuous positive airway pressure (CPAP) therapy. An activation of the hypothalamic-pituitary-adrenal axis was(More)
Hypoxic respiratory diseases are frequently accompanied by glucose intolerance. We examined whether hypoxia is a cause of glucose intolerance in healthy subjects. In a double-blind within-subject crossover design, hypoxic versus normoxic conditions were induced in 14 healthy men for 30 minutes by decreasing oxygen saturation to 75% (versus 96% in control(More)
In animals, blocking of glutamate signaling at the N-methyl-D-aspartate (NMDA) receptor reduces the neuroendocrine counterregulation to hypoglycemia. Hence, it has been proposed that increased excitatory glutamatergic input to the hypothalamus signals enforced central nervous energy demand under conditions of reduced supply. We examined the effect of the(More)