Chronopharmacologic issues in space

Geographic and extraterrestrial aspects of morbidity and/or mortality patterns from myocardial infarction and stroke

Two authors (M.K. and M.M.) provided insight into a manuscript submitted by them elsewhere for publication and kindly offered for meta-analysis data on the monthly incidence from January 1989 up to December 2004, of 6094 cerebral infarctions, 414 intracerebral and 277 subarachnoid hemorrhages, cases admitted at the Neurological Clinic in Nové Zamky, Slovakia. Spectral components with a period exceeding (beyond = trans) the length of the calendar year--transyears--reported originally by M.K. and M.M. are here also documented linearly on original data without and after detrending by the fit of first- or second-order polynomials. For intracerebral and subarachnoidal hemorrhage, the zero-amplitude (no-rhythm) assumption is rejected (P < 0.05, not corrected for multiple testing) for the transyear but not for a precise 1.0-year trial period. As reported earlier by M.K. and M.M., the transyear's amplitude is larger than the calendar year's amplitude for all three series of stroke incidence in Slovakia. The putative importance of the new findings stems from earlier and new analyses revealing other spectral components that are presumed signatures of magnetoperiodisms, e.g. about 50- and 7-year components in about five decades of diagnostically unqualified, pooled data on stroke in Minnesota. There is, however, the danger of relatively small numbers providing artifacts for loosely defined transyears. The original cosinor approach by M.K. and M.M., testing anticipated periods, had its strength. The observation of a quindecadal component in mortality from strokes in Minnesota supports the presence of signatures of effects from extraterrestrial space in acute human pathology such as strokes, myocardial infarctions and sudden cardiac death. Magnetoperiodic mechanisms remain to be investigated further as added strokes accumulate in Nové Zamky and greater Slovakia as well as for sudden cardiac death where transyears have been documented in the Czech Republic, in Arkansas and particularly in Minnesota, but not elsewhere (as yet?). This study is also a plea for worldwide access to morbidity, mortality and natality data that constitute a largely unexploited treasure, brought to the fore mainly for relatively short-term comparisons of the effect of interventions against the fiction of imaginary baselines.

Chronobiologically explored effects of Telmisartan

Effects of Micardis (Telmisartan), alone or with low-dose aspirin, on blood pressure and other cardiovascular endpoints are examined in 20 patients with MESOR-hypertension in a crossover, double-blind, randomized study consisting of three stages, each lasting 7 days: I-placebo, II-Micardis, and III-Micardis with low-dose aspirin. Treatment was administered each day at a different circadian stage, upon awakening, and 3, 6, 9, 12, 15 and 18 hr after awakening. During each stage, the following variables were measured at 3-hr intervals during waking: systolic and diastolic blood pressure, heart rate, ejection fraction, intrarenal resistive index, acceleration time, and serum creatinine. Each data series was analyzed by single cosinor. Results were summarized by population-mean least squares spectra. At matched treatment times, the MESOR and circadian amplitude of each variable were compared among the three treatments by paired t-tests. A prominent circadian rhythm characterizes all variables. Micardis was associated not only with a lowering of blood pressure, but also with a reduction of the circadian blood pressure amplitude. The ejection fraction was increased, and the resistive index and acceleration time were decreased, the effect being more pronounced when low-dose aspirin was added to Micardis. Any circadian-stage dependent effect of Micardis, with or without low-dose aspirin, will require monitoring over spans longer than a single day for a given treatment administration time.

Individual assessment of antihypertensive response by self-starting cumulative sums

A self-interpreted control chart, on an individualized basis, assesses the effect of a switch from beta-blockers to an angiotensin-converting enzyme (ACE)-inhibitor in a patient with occasional blood pressure (BP) excess. In dense and long data series, the BP and heart rate (HR) of this patient respond to the change in treatment by the test criterion of a self-starting Cumulative Sum (cusum), which reaches values outside a decision interval with a lowering of BP and an increase in HR and vice versa, at least for BP, after treatment cessation. Thereafter, minimal sampling requirements are sought in the same data by applying the same control chart approach to decimated data. Skeleton sampling schemes in a system of chronobiologic self-analysis and interpretation of manually recorded data obtained at strategically placed times (established on the basis of data decimations) could complement control charts that are used on a home computer or preferably would be built into the output of ambulatory monitors used at the outset as a minimum and routinely as an optimum.

Excessive circadian amplitude of blood pressure increases risk of ischaemic stroke and nephropathy

After 48-h ambulatory blood pressure monitoring, the incidence of ischaemic stroke, nephropathy, coronary heart disease and retinopathy was prospectively assessed for 6 years in 297 subjects, including 176 treated patients with an elevated blood pressure mean (MESOR-hypertensives). The relative risk associated with an excessive circadian blood pressure amplitude is 8.2 (95% confidence interval 3.1 to 21.7; p < 0.001) for ischaemic stroke and 6.9 (2.9 to 16.3; p < 0.001) for nephropathy. In MESOR-hypertensives, the relative risk for ischaemic stroke and nephropathy is 6.3 (p < 0.005) and 4.0 (p < 0.05), respectively. In MESOR-normotensives as well, an excessive circadian blood pressure amplitude is associated with a large increase in risk for ischaemic stroke and nephropathy (p < 0.05). An excessive circadian blood pressure amplitude is an entity in its own right that increases the risk of adverse vascular events irrespective of the blood pressure MESOR, age and the presence of other known risk factors. The diagnosis of this condition requires around-the-clock monitoring of blood pressure. The treatment of patients with this condition should aim not only at lowering the blood pressure mean but also at reducing blood pressure variability within 24 h.

Chronobiometric assessment of autogenic training effects upon blood pressure and heart rate

Autogenic training, a method of self-hypnosis, lowers the extent of within-day variation of systolic blood pressure assessed by the circadian double amplitude. The blood pressure and heart rate of ten patients, conventionally diagnosed as having hypertension or white-coat hypertension, were automatically monitored at 30-min intervals for 7 days before autogenic training and again for 7 days, at 1 or 2 months after the start of autogenic training (practiced three times daily). The circadian double amplitude of systolic blood pressure of the patients investigated was 3 to 17 mm Hg lower on autogenic training. In 5 patients, reductions by 7 to 17 mm Hg were statistically significant. These results are regarded as provisional statistics, the utility of which depends on replication. By contrast, the over-all group reduction of the circadian double amplitude of systolic blood pressure by 8 mm Hg on the average can be taken at face value. Autogenic training also lowered the circadian double amplitude of diastolic blood pressure, but the effect was small as was the effect of autogenic training upon the MESOR (a rhythm adjusted mean) and acrophase (a measure of the timing of over-all high values recurring each day). The effect of autogenic training upon the circadian double amplitude of systolic blood pressure suggests its trial as first-line treatment of patients with an excessive circadian blood pressure amplitude, a condition which, even in the absence of an elevated 24-hr, average of blood pressure, is associated with a large increase in the risk of developing ischemic stroke or nephropathy.