Multiple resonances among time structures, chronomes, around and in US. Is an about 1.3-year periodicity in solar wind built into the human cardiovascular chronome?

AIMS: Velocity changes in the solar wind, recorded by satellite (IMP8 and Wind) are characterized by a solar cycle dependent approximately 1.3-year component. The presence of any approximately 1.3-year component in human blood pressure (BP) and heart rate (HR) and in mortality from myocardial infarction (MI) is tested and its relative prominence compared to the 1.0-year variation. MATERIALS AND METHODS: Around the clock manual or automatic BP and HR measurements from four subjects recorded over 5 to 35 years and a 29-year record of mortality from MI in Minnesota were analyzed by linear-nonlinear rhythmometry. Point and 95% confidence interval (CI) estimates were obtained for the approximately 1.3-year period and amplitude. The latter is compared with the 1.0-year amplitude for BP and HR records concurrent to the solar data provided by one of us (JDR). RESULTS: An approximately 1.3-year component is resolved nonlinearly for MI, with a period of 1.23 (95% CI: 1.21; 1.26) year. This component was invariably validated with statistical significance for BP and HR by linear rhythmometry. Nonlinearly, the 95% CI for the 1.3-year amplitude did not overlap zero in 11 of the 12 BP and HR series. Given the usually strong synchronizing role of light and temperature, it is surprising that 5 of the 12 cardiovascular series had a numerically larger amplitude of the 1.3-year versus the precise 1.0-year component. The beating of the approximately 1.3-year and 1.0-year components was shown by gliding spectra on actual and simulated data. DISCUSSION AND CONCLUSION: The shortest 5-year record (1998-2003) revealed an approximately 1.3-year component closer to the solar wind speed period characterizing the entire available record (1994-2003) than that for the concurrent 5-year span. Physiological variables may resonate with non-photic environmental cycles that may have entered the genetic code during evolution.

The biological effects of solar activity.

The synchronization of biological circadian and circannual rhythms is broadly viewed as a result of photic solar effects. Evidence for non-photic solar effects on biota is also slowly being recognized. The ultrastructure of cardiomyocytes from rabbits, the time structure of blood pressure and heart rate of neonates, and the heart rate variability of human adults on earth and in space were examined during magnetically disturbed and quiet days, as were morbidity statistics. Alterations in both the about-daily (circadian) and about-weekly (circaseptan) components are observed during disturbed vs. quite days. The about-weekly period of neonatal blood pressure correlates with that of the local geomagnetic disturbance index K. Circaseptans which are seen early in human life and in various other forms of life, including unicells, may provide information about the possible site(s) of life's origins from an integrative as well as adaptive evolutionary perspective.

Near 10-year and longer periods modulate circadians: intersecting anti-aging and chronoastrobiological research.

Biological cycles with relatively long and some unusual periods in the range of the half-week, the half-year, years, or decades are being discovered. Their prior neglect constituted a confounder in aging and much other research, which then"flew blind" concerning the uncertainties associated with these cycles when they are not assessed. The resolution of more about 10-year and other cycles, some reported herein, replaces the admission of complete unpredictability, implied by using the label "secularity." Heretofore unaccounted-for variability becomes predictable insofar as it proves to be rhythmic and is mapped systematically to serve as a battery of useful reference values. About 10-year cycles in urinary 17-ketosteroid excretion and in heart rate and its variability, among others, are aligned with cycles of similar length in mortality from myocardial infarction. Associations accumulate between cycles of natural physical time structures, chronomes such as the 10.5-year (circadecennian) Schwabe and the 21-year (circavigintunennian) Hale cycles of solar activity, and chronomes in biota. There are about 50-year (circasemicentennian) cycles in mortality from stroke in Minnesota and in the Czech Republic and also in human morphology at birth, the latter result reducing the likelihood that these cycles are purely human made. Associations among large populations warrant long-term systematic coordinated sampling of natural physical and biological variables of interest for the design of countermeasures against already documented elevated risks of stroke, myocardial infarction, and other catastrophic diseases, notably in elderly adults. New findings will be introduced against the background of the documented value of mapping rhythms in medicine and gerontology. In both these fields, rhythms promise the seeming paradox of better care for less.

Spin-offs from blood pressure and heart rate studies for health care and space research.

Evidence here cited underlies resolutions at international meetings to initiate a chronobiology project for health improvement. This project demonstrates expeditiously the feasibility and the health benefits of incorporating chronomedical considerations in the diagnosis, treatment, and prevention of one (or a few closely related) vascular (and oncological) diseases, that have high awareness and importance in the public perspective. Thereby, chronomedicine should become a mainstream basic and applied speciality leading to continual improvement in national/international health status. Reference data obtained for health care can also serve to give a better understanding of the relationship between the terrestrial biosphere and cosmoi near and far.

Resonance of about-weekly human heart rate rhythm with solar activity change.

In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.

Effect of autonomic nervous system blockade and acute asphyxia on heart rate variability in the fetal rat.

The effect of parasympathetic (with atropine) and beta-adrenergic (with propranolol) blockade on fetal heart rate variability (HRV) was studied in 162 term fetal Wistar rats. Administration of 1.3 mg of atropine into the jugular vein of the female rat led to an identical decrease of the RR interval in adult rats and in fetuses (about 10%). Administration of 2 mg of propranolol caused a rise in the RR interval by 19% in rats and by 7-9% in fetuses. Overall HRV indices (RMSM, CV) decrease was more pronounced in adult rats than in fetuses. Upon simultaneous administration of both blocking agents the RR interval in adult rats did not differ from the control values; in fetuses it was reduced by 6%. In adult rats HRV indices decreased considerably (by 70%) and their values were within the limits of the estimation error; in fetuses, HRV indices were no higher than upon the administration of any of the blocking agents. Umbilical cord clamping caused a decrease of PO2 in brain tissue from 24.7 +/- 1.7 to 4.7 +/- 0.8 mm Hg within 15 min and led to an immediate increase of the RR interval and the HRV indices if blocking agents were not used. The administration of one or both blocking agents abolished the initial (during the first 7 min of asphyxia) increase of RMSM and CV. Thus, HRV in fetal rats depends to a great extent on the activity of the autonomic nervous system, though it is not fully determined by it. Acute asphyxia causes stimulation of the autonomic nervous system leading to fetal distress.