Stress hyperglycaemia in patients with first myocardial infarction.

OBJECTIVE: To investigate the incidence of stress hyperglycaemia at first acute myocardial infarction (MI) with ST-segment elevation, occurrence of stress hyperglycaemia as a manifestation of previously undiagnosed abnormal glucose tolerance (AGT), and its relation to stress hormone levels. MATERIALS AND METHODS: The population of this prospective cohort study consisted of 243 patients. On admission glucose, adrenaline, noradrenaline and cortisol levels were measured. Patients without previously diagnosed diabetes (n = 204) underwent an oral glucose tolerance test on day 3 of hospitalisation and 3 months after discharge. RESULTS: Abnormal glucose tolerance at day 3 was observed in 92 (45.1%) patients without a previous diagnosis of diabetes mellitus and resolved after 3 months in 46 (50.0%) patients (p < 0.0001). Stress hyperglycaemia, defined as admission glycaemia ≥ 11.1 mmol/l, affected 34 (14.0%) study participants: 28 (54.9%) patients with diabetes vs. 3 (8.8%) subjects with newly detected impaired glucose intolerance (p < 0.00001) and 1 (2.2%) person with AGT at day 3 (p < 0.000001). Multivariable analysis identified elevated glycated haemoglobin (HbA(1c) ; p < 0.0000001), anterior MI (p < 0.05) and high admission cortisol concentration (p < 0.001), but not catecholamines, as independent predictors of stress hyperglycaemia. The receiver operating characteristic curve analysis revealed the optimal cut-off values of 8.2% for HbA(1c) and 47.7 µg/dl for admission cortisol with very good and sufficient diagnostic accuracies respectively. CONCLUSIONS: Newly detected AGT in patients with a first MI is transient in 50% of cases. Stress hyperglycaemia is a common finding in patients with a first MI with ST-segment elevation and diabetes mellitus, but is rarely observed in individuals with impaired glucose tolerance or transient AGT diagnosed during the acute phase of MI. The risk factors of stress hyperglycaemia occurrence include elevated HbA(1c) , anterior MI and high admission cortisol concentration.

A study of sleep in the European blackbird.

Sleep states in the blackbird, Turdus merula, were determined by recording the electroencephalogram (EEG), electrooculogram (EOG), electromyogram (EMG), and heart rate (HR), and from behavioral observations and responses to auditory stimulation by natural calls. The presence of changes in slow wave activity was determined from the power spectra of the EEG. Spectral power density in the 0.5-4.0 Hz band during slow wave sleep (SWS) attained highest values in the first part of the night, then declined. This trend in EEG spectra, which occurred across the night, probably reflects a homeostatic process strikingly similar to that observed in mammals. The reactivity to natural calls during SWS episodes also decreased across the night. Episodes of interhemispheric EEG asymmetry, which typically lasted from 2 to 4 s, occurred when birds displayed the front sleep posture and they constituted 140-200 s of each night. Unihemispheric sleep episodes probably result from unilateral activation of the visual system, and they could be considered as an evolutionary adaptation. HR was highest in wakefulness and lower in sleep but, due to large variability, reliable discrimination between sleep and wakefulness could not be made. Comparison of the blackbird's behavior during 4 different nights revealed a strong effect of the first night on sleeping behavior. A significant reduction in back sleep posture occurred during the baseline night, when lead wires were connected.