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Biomedical subjects

C Aström

Publications and source records attributed to C Aström.

7 recordsLinked to original sources
PubMed1992

Relationship of age to power spectrum analysis of EEG during sleep.

We describe a method of power spectrum analysis of all-night sleep EEGs in 20 normal subjects aged 18-43 years. The analysis calculates the energy of the whole sleep period, the various frequency bands, and selected sleep stages automatically. The numerical value of the energies was directly comparable between subjects, presented in numbers (microV2s) and displayed as a color density spectral array with fixed power values for each color. A significant relationship between age and power spectra was found, in that total energy/minute was higher in younger subjects than in older. The energy in delta sleep/minute also showed an inverse relationship with age.

Adolescent↗
PubMed1992

Effect of growth hormone on human sleep energy.

OBJECTIVE: We wished, by means of power spectrum EEG analysis, to examine REM and delta sleep energy in adults with high and normal plasma growth hormone (GH) concentration. DESIGN: After a 3-day regular sleep/wake schedule, all-night polysomnographic recordings were performed on two consecutive nights before as well as one year after treatment for acromegaly by adenomectomy. The sleep energy was calculated by power spectrum analysis. PATIENTS: We studied nine patients aged 24-45 years with untreated active acromegaly. The same patients were reexamined one year after adenomectomy when plasma GH concentrations were normal. MEASUREMENTS: The acromegaly was verified biochemically by measuring basal plasma GH concentration and plasma GH during hyperglycaemia as well as insulin-like growth factor. Cerebral computer tomography (CT) and magnetic resonance (MR) scans revealed an intrasellar adenoma in all patients. The resulting sleep records obtained before and after adenomectomy were subjected to power spectrum analysis and a manually blinded sleep scoring. RESULTS: The power spectrum analysis showed that when circulating GH was elevated the energy in the REM sleep per minute was significantly higher compared to the REM energy/min after surgery when GH concentration had normalized. A similar relation was found for delta sleep (stage 3 + 4, deep sleep) where the energy per minute was higher before treatment than after. CONCLUSIONS: The study demonstrates that plasma GH concentration was correlated to sleep energy. During high GH concentration the REM and delta sleep energy were high and normalization of plasma GH was followed by normalization of REM and delta sleep energy per time unit.

Acromegaly↗
PubMed1991

Sleep in acromegaly before and after treatment with adenomectomy.

Daytime somnolence and fatigue are frequently ignored symptoms in acromegaly. To examine whether sleep apnea or other abnormalities in the sleep structure is the underlying cause, 9 young patients with active untreated acromegaly for 2-7 years were studied with all night polysomnography. It revealed a decrease in REM sleep time in all the acromegalics compared to age- and sex-matched normal subjects (p less than 0.001) and also a reduction in delta sleep (p less than 0.05). None had obstructive sleep apnea. At reexamination 12-15 months posttreatment the daytime sleepiness had disappeared in all patients. REM sleep time increased in all patients (p less than 0.001) to normal level; delta sleep time increased moderately (p less than 0.05). Thus sleepiness in patients with high fasting level of growth hormone (GH) is not related to sleep apnea but more likely to a reduced amount of REM sleep time. By normalizing the GH concentration, REM sleep time became normal and the daytime sleepiness disappeared in all patients.

Acromegaly↗
PubMed1990

The influence of growth hormone on sleep in adults with growth hormone deficiency.

Eight patients with isolated growth hormone deficiency (IGHD), 20-30 years old were studied with polysomnography before and after 6 months of treatment with growth hormone (GH). During GH treatment total sleep time decreased and REM sleep time increased significantly. Delta sleep time (stage 3 + 4) did not change significantly. All patients reported improved well-being and none wished to discontinue the treatment with growth hormone. These findings suggest that GH has an effect on sleep. The effect of increased REM sleep in humans is incompletely understood, but sleep recordings may be one way of directly monitoring the effect of GH on the central nervous system.

Adult↗
PubMed1990

Growth hormone-deficient young adults have decreased deep sleep.

The sleep in young adults with severe isolated growth hormone deficiency (IGHD) was examined by polysomnography. There was a significant decrease in delta sleep time (= stages 3 + 4, slow wave sleep, 'deep sleep'), especially in stage 4. The total sleep time was significantly increased compared to age- and sex-matched normal subjects. The increase in total sleep time was related to an increase in stage 1 and stage 2 sleep. There was no significant difference in total rapid eye movement (REM) sleep time, but when correcting for the very long sleep time in the IGHD subjects, the cumulated REM time within the first 390 min of sleep was significantly less than in the normal subjects.

Adolescent↗
PubMed1989

Decrease in delta sleep in growth hormone deficiency assessed by a new power spectrum analysis.

Seven pituitary dwarfs between 18 and 28 years old with congenital absence of growth hormone, i.e., isolated growth hormone deficiency (IGHD), were examined with polysomnography. Power spectrum analyses of the delta band showed a significant decrease in power in the delta sleep in the IGHD patients compared with the controls. Power spectrum analyses add a new dimension to the description of sleep, as it evaluates, not only frequency of the electroencephalogram (EEG) in time but also the amplitude of the EEG signal. This means that sleep of same quantity can have different powers; for example, 15 min of stage 4 in one person can have another quality than 15 min of stage 4 in another person. An additional observation was that the power in the delta band in the normal young controls showed a correlation to age, with significant decrease within a 10-year period.

Adolescent↗