Franz Halberg, Associate Fellow

Assessment of Physiologic Chronomes From Womb to Tomb

The global index of geomagnetic disturbance Kp is analyzed for the span from 1932 to 1990. Analyses are carried out over consecutive years to obtain estimates of the yearly mean value (MESOR) and standard deviation (SD) and of the amplitude, period, and power within given spectral ranges, around the month (solar rotation period), half-month, week, and half-week, as well as around 36 hours, as a control in a spectral region devoid of signals. The vertical band corresponds to the average duration of the sunspot cycle ±3 SDs for the same 59-year span. The horizontal bars correspond for each endpoint considered to the nonlinear estimate of the about 11-year cycle with the corresponding 95% confidence limits. Most point estimates fall within ±3 SDs of the average duration of the sunspot cycle. Of interest is the statistically significant modulation by the solar activity cycle of the circaseptan amplitude of Kp (P = 0.031), showing that this component is more prominent during years of descending than during years of ascending solar activity.

Strokes and other adverse vascular events are major cripplers at an estimated yearly cost of over $30 billion. These researchers are developing a system for the chronobiologic analysis of cardiovascular records, with focus on disease prevention, but also addressing the question of the optimal scheduling of treatment when needed. Ambulatory devices are now used in different geographic locations that automatically monitor blood pressure and the electrocardiogram (ECG) for seven days at the outset. Chronobiologic analyses of such records serve first and foremost to assess how environmental factors affect human physiology, notably heart rate and blood pressure.

These researchers are using supercomputing resources to:

• Analyze beat-to-beat records for resolving chronobiologic and chaotic endpoints. A typical record consists of about 2,400,000 data points resampled at 0.25-second intervals over seven days.
• Automatically update reference standards as added data accumulate.
• Detect the earliest risk by means of chronome alterations.
• Follow up at-risk individuals longitudinally by means of control charts.

The researchers also recently found associations between endpoints of nonlinear dynamics computed on respiratory movement and electroencephalographic signals, which help the understanding of mechanisms underlying the coordination among physiological functions.

Towards this goal, the researchers are organizing existing records into databases. Reference values derived from these databases help detect any abnormality. A library of programs for such chronobiologic applications is being organized and integrated with the incorporation of graphic displays of the results.

The researchers have found that the vascular disease risks associated with reduced heart rate variability and with an elevated circadian amplitude of blood pressure, documented in a number of trials, are mostly independent and additive. Also, the choice of treatment and its scheduling play important roles in normalizing altered dynamics of blood pressure and heart rate. Circadian hyper-amplitude-tension (CHAT), a condition defined by an excessive circadian amplitude of blood pressure (above the 95% prediction limit of healthy peers), occurs more frequently among patients with glucose intolerance. An odd timing of the circadian blood pressure rhythm in patients with non-insulin-dependent diabetes mellitus is associated with a reduced heart rate variability indicative of an impaired autonomic nervous system.

Analyses of magnetometer data over twenty-five months assessed time structures usually found in human physiology. In particular, the researchers assessed and quantified about-weekly components, which demonstrated the prominence of a natural component with a period shorter than seven days over the precise seven-day rhythm. This was also detected at Station A80 in Antarctica, about 600 km away from any civilization. The relative prominence of the man-made and natural components was used as an index to examine any change in human pollution in analyses of the global geomagnetic index. Maps of about 10.5-, 21-, and 50-year cycles in physical and physiological records are being prepared and interpreted in the light of two putative mechanisms underlying the influence of geomagnetic disturbances, acting via the heart and heart rate variability on the one hand, and via the pineal and melatonin on the other.