Biorhythm Theory Does Not Predict Admission for Acute Myocardial Infarction

Introduction

P revious articles suggest a marked temporal variation in the vulnerability of acute myocardial infarction (AMI). The existence of a circadian pattern is now well established through large-scale population studies, with the highest incidence in the early morning hours. ^1,2 Similarly, weekly variations were shown with the first few days of the week, carrying a significantly higher risk of AMI. ^3,4 The existence of seasonal variation in the occurrence of AMI has also been suggested by various studies, ^3,5 with a peak incidence in the winter months and lower rates during the summer season.

Current biorhythm theory, as popularized by George Thommen ⁶ and Bernard Gittleson, ⁷ proposes the existence of three endogenous independent infradian cycles that start at the moment of birth and proceed throughout life with absolute regularity. The intraperiod variations are usually expressed as a sinusoidal function and are said to influence human capacity. The cycles were labeled as a 23-day Physical cycle affecting resistance to disease, strength, coordination, aggressiveness, and endurance; a 28-day Emotional cycle, which is considered to influence constructive interpersonal sensitivity; and a 33-day Intellectual cycle that is supposed to regulate retention, comprehension, and creativity. ⁷ Hence, performance is said to be better when the biorhythm curves are above the midpoint and worst when the curves are below. The theory further postulates that during the transitions in phase of the cycle from positive to negative state, or vice versa, individuals are more vulnerable to external stress and environmental pressures. These are named critical days. If two or more cycles reach transition simultaneously, the possibility of critical incident and instability increases. Triple critical days are greatly dreaded in biorhythm lore.

Whether the biorhythm theory does predict the biologic timing of events remains the subject of debate. ⁸ Nevertheless, if biorhythm cycles were to influence human life, it seems relevant to test the theory on serious medical problems. To our knowledge, the relationship between AMI incidence and biorhythm has only been assessed in two small published reports ^9,10 with conflicting conclusions. Therefore, in this study, the objective was to determine whether specific days in the biorhythm cycle are related to incidence of admission for AMI. For that purpose, patients' data were analyzed from the hospital database warehouse of the Sherbrooke University Hospital Center.

Materials and Methods

The data of all patients admitted for AMI to the Centre Hospitalier Universitaire de Sherbrooke from April 1993 to March 2008 were analyzed, collected in the hospital database warehouse. Myocardial infarction was defined according to the codes of the International Classification of Diseases. Whenever the same patient occurred more than once in the database, he was considered as a new case each time. Owing to the nature of AMI symptoms, hospital admission is normally very close to the occurrence of AMI. Therefore, the date of hospital admission was considered as the onset of AMI. For all patients, the date of birth and the date of hospital admission were gathered.

Biorhythm cycles of each patient were calculated from their date of birth and their date of admission using the following equations as published by Englund and Naith ¹¹ :

Physical cycle = sin (2 × PI × DBA/23)

where DBA represents the number of days from birth to admission.

Several methods for identifying days of vulnerability to an unfortunate event have been used in previous studies. The present study used the same definitions as those of D'Andrea et al., ¹² which represent in the present authors' opinion the most complete classification.

Admissions for AMI were therefore grouped as follows. Critical days of patients admitted for AMI were defined as the days when their performance curves cross the zero. When such event occurred after the beginning of the day, the following day was also considered as a critical day. Maximal and minimal performance days were defined when the curve was either maximal or minimal. For the same reason as for critical days, the day preceding or following day were also included.

Chance expected frequencies of admission for AMI were initially calculated on a full 21,252-day cycle, which represents the total amount of time for physical, emotional, and intellectual cycles to return to their initial status. Owing to the small number of events occurring in patients younger than 40 years of this population, expected frequencies were then recalculated from ages 40 to 85. The cohort was also restricted to patients 40–85 years old. However, no significant variations of the probabilities were noted. A χ² analysis was used to compare the frequencies expected from the random model with the actual numbers of AMI on prespecified day. A p value < 0.05 was considered statistically significant.

Results

There were 12,953 admissions for AMI over the time period of 15 years. Of these, 1558 were excluded on the basis of age criteria: 265 patients were younger than 40 and 1293 older than 85 years old. The mean age of the remaining patients was 66 years, with a standard deviation of 12 years.

The observed frequency for AMI admissions of any particular combination of critical and noncritical days during the three cycles did not differ significantly from the chance expected frequency, as shown in Table 1. Table 2 shows the number of admissions for AMI at each phase of the various cycles. The analysis revealed that it was as likely for a patient to be admitted at any combination of maximum or minimum performance of all three cycles.

The differences presented in Table 1 and Table 2 remained statistically nonsignificant when analyses were made with the initial cohort of 12,953 admissions for AMI.

Discussion

Our results demonstrate that the biorhythm theory does not predict admission for AMI. Most publications in support for the biorhythm theory consisted mainly of success stories and retrospective anecdotes regarding isolated incidents in accordance with the theory. ^{6 –8} Claims of all kinds have been made regarding its application to different events: accidents, ¹¹ cognitive performance, ¹³ sports injuries or performance, ^14,15 crimes, and many medical-related topics including postoperative analgesia and infections, ¹⁶ psychiatric hospital admission, ^17,18 nursing errors in medication, urinary glucose levels, suicide, ¹² and even death. ¹⁹ However, after an extensive review of experimental research literature, Hines ⁸ concluded that empirical investigations reveal a preponderance of evidence supporting random distribution, lending very little support to the biorhythm theory.

Two (2) articles previously published in Spanish ^9,10 claimed to demonstrate a possible relation between AMI and biorhythms in small numbers of patients. However, using the data provided in the tables of these articles, Hines ⁸ later recalculated χ² values to validate their claims and concluded that neither article performed relevant statistical analysis of their data. Maspons et al. ⁹ reviewed 40 admissions for AMI. According to Hines' calculations, ⁸ no more admissions for AMI than those expected by chance occurred on critical days or on the physical negative phase. However, these calculations noted significantly more infarctions on negative phases of both emotional (31 of 40; χ₁ ² = 12.1, p < 0.01) and intellectual (29 of 40: χ₂ ² = 8.1, p < 0.01) cycles. Oramas and Velazquez ¹⁰ studied the possible influence of biorhythms on the date of death with 58 patients who died of MI. Again, after χ² analysis by Hines, ⁸ death did not occur more often than what was expected, although first symptoms were more likely to occur on critical days of the physical cycle (χ₂ ² = 7.72, p < 0.05). Furthermore, in an unpublished dissertation mentioned in Hines' review, Kauth observed no evidence of relationship between AMI and biorhythm cycles after reviewing 3079 patients with AMI from the University of Utah's database system. Also in support of our findings, Bradshaw ¹⁹ failed to establish any validity for biorhythm effect on date of death after retrospective review of 2214 persons selected from Webster's American Biographies.

A distinction must be made between biorhythm and biologic rhythms resulting from empirical investigation. As stated in the introduction section, the existence of rhythmic cycles in humans is well established, giving rise to more or less predictable temporal variation in the vulnerability to AMI. ^{1 –5} Among reasons for such variation, psychologic and physical stress factors such as increase of the sympathetic activity, vasoconstrictive hormones, alterations of hemostasis, and platelet agreeability may be mentioned. ²⁰

On the other hand, biologic plausibility of the fundamental principles underlying biorhythm theory has been challenged. For example, the relentless sinusoidal pattern without regard for life events such as sleep habit or diet changes, disease, and other disturbing influences is at odds with much of our current knowledge of the biologic cycle. ⁸ In addition, not all rhythmic behaviors identified by chronobiologists are pure sine waves. The term “birthdates-based biorhythm” has been proposed to identify these theoretical cycles. ¹¹

Conclusions

In conclusion, the present results do not lend support to the biorhythm theory regarding the time of admission for AMI. Hence, we found no evidence of a possible relationship between the date of AMI and critical days maximum and minimum performance days of an individual's physical, emotional, or intellectual biorhythm cycles.