Correlation of the dynamics of minute-scale heart rate oscillations and biochemical parameters of the blood in healthy subjects to Pc5–6 geomagnetic pulsations

Abstract

Long-term synchronous monitoring of heart rate and biochemical parameters of the blood was performed at the minute scale in four healthy female volunteers. Each experiment involved continuous ECG recording during 90 minutes and blood sampling once in every 2 minutes. The concentrations of triiodothyronine, cortisol, glucose, and stable metabolites of nitrogen oxides (NOx) in venous blood were measured. Synchronous oscillations of blood levels of cortisol and free triiodothyronine were detected in all four volunteers; the spectra of both oscillations exhibited 7–8 and 15–17-minute periodicities. The spectra of the oscillations of NOx levels exhibited 7, 13, and 25–30 minute periodicities. Fluctuations of blood NOx levels were shown to play a major role in the regulation of heart rate variation; the periods in the wavelet spectra of these physiological parameters were similar to the periods in the spectra of synchronous variations of the geomagnetic field vector in the 0.5–3.0 mHz frequency range. The results of the study point to nitrogen oxide and its metabolites in the blood as the biochemical factor that is probably involved in the “fine tuning” of the body to geomagnetic field variations and synchronization of heart rate to geomagnetic fluctuations in the absence of geomagnetic storms.