1.8. Influence of low-frequency magnetic fields generated by the power supply on sleep and the concentration of β-amyloid in humans

Project management: Competence Center of Sleep Medicine, Charité – Universitätsmedizin Berlin
Start: 1 January 2022
End: 31 December 2024

Background

A connection between disturbed sleep and neurodegenerative diseases is known from the specialist literature; typical sleep disturbances are among the symptoms of many neurodegenerative diseases. Sleep disorders are also considered a risk factor and one of the possible causes of Alzheimer’s dementia (AD). An important finding in AD is deposits of the peptide β-amyloid. These deposits are influenced by disturbances in the sleep–wake rhythm. After a night of disturbed sleep, the β-amyloid concentration in test subjects increases. The connection between low-frequency magnetic fields and sleep is poorly studied. Only a few experimental studies reported impaired sleep during nocturnal exposure to magnetic fields. Sleep disturbances as a result of exposure to magnetic fields could be a mechanism of action that explains the statistical correlation between magnetic fields and AD.

Objective

The aim is to use the sleep EEG to test whether exposure to magnetic fields can influence the sleep parameters of humans. In addition, the influence of magnetic fields on the concentrations of β-amyloid and the hormone melatonin, which promotes sleep, will be determined, and the subjective quality of sleep will be assessed. Because poor sleep has a negative effect on memory consolidation, it will be tested whether exposure to magnetic fields impairs memory. The results will show whether magnetic fields affect sleep and have physiological effects that could promote AD.

Implementation

20 men and 20 women aged 55 to 75 years will be included in the study. Inclusion criteria: healthy right-handed individuals, non-smokers, post-menopausal women. Exclusion criteria: Use of substances that affect sleep, sleep disorders, implants. Each test person will be subjected to one adaptation night, one sham exposure, and two exposure levels at one-week intervals.

The study participants will be exposed by means of a coil arrangement. This will allow the continuous night-time exposure of lying persons during sleep but will not interfere with getting out of bed. The test persons will be subjected to one exposure with low frequency magnetic fields at 50 Hz and two intensities (high and low; in the range 1–30 microtesla) as well as a sham exposure. The exposure will be blinded (it will not be known when subjects are exposed to the fields).

During sleep, the EEG will be recorded, and the sleep structure (sleep stages, latency to fall asleep, sleep efficiency, sleep duration, and wake-up events) will be analysed. Standardised evening and morning logs will be filled out in order to record special daily events that can influence sleep as well as the state of health in the morning after the study night. Before and after each exposure night, biomarkers for sleep and AD (melatonin, β-amyloid, tau protein) will be determined in the plasma. In order to test whether the magnetic fields had an effect on nocturnal memory consolidation, memory tasks will be used in the evening and in the morning after sleep.