SPECTRAL RESOLUTION OF LOW-FREQUENCY, SMALL-AMPLITUDE RHYTHMS IN EXCRETED 17-KETOSTEROIDS; PROBABLE ANDROGEN-INDUCED CIRCASEPTAN DESYNCHRONIZATION

Abstract

ABSTRACT The 17-ketosteroid excretion of a healthy human male is characterized by rhythms with a frequency of one cycle in a) about one week; b) about twenty days (± 3 days); c) about one month, and d) about one year. The terms circaseptan, circavigintan, circatrigintan and circannual are considered as names for these rhythms with a low frequency and a small amplitude. These rhythms, among others, can be resolved as statistically significant components in the frequency domain by so-called least squares spectra, prepared by an electronic computer program. The rhythms then stand out above the general level of the spectrum, as components reproducible during an observation span of over 15 years. Certain displays of the amplitude and phase of a rhythm computed and plotted automatically by the electronic computer also are introduced and illustrated. These techniques quantify objectively the external and internal timing of a rhythm and/or changes of this timing. The crest-time of the seven-day synchronized circaseptan rhythm in 17-ketosteroid excretion and a weekly crest in urine volume are displayed, on the one hand, in a polar amplitude-phase plot. On the other hand, these aspects of physiologic timing are also scrutinized as a function of time in plots on rectangular coordinates involving the fit of a precise frequency, established independently as a characteristic of the series analyzed. For a span covering almost a decade, the circaseptan rhythm in 17-ketosteroid excretion is shown to be clearly synchronized with the seven-day cyclic alternation of professional and other activity of the (one) subject investigated. Moreover, in the face of a continuing precise seven-day routine of living, this circaseptan rhythm can be demonstrated to freerun thereafter during a three year span, presumably as a result of long continued frequent testosterone administration. The computational methods used and, in particular, the displays here introduced are more broadly applicable, inter alia, in endocrinology, to the detection of rhythms and to the objective quantification of their parameters, including the internal and external timing.