Cortisol marker rhythmometry in pediatrics and clinical pharmacology

Curve fitting to sparse data yields first-order statistics as endpoints interpreted in the light of a previously established reference standard, such as a 90% prediction region. 22 blood cortisol profiles, sampled from 8 healthy female Minnesotan adolescents across all seasons every 20 mintues for 24h served for computing a paradesm - a 90% prediction region for the circadian amplitude-acrophase pair, with the amplitude expressed as percentage of mesor Cortisol data from Japanese and Bavarian children, sampled across all seasons every 4-6 hours, were analyzed by the single-cosinor method. Circadian parameters were interpreted by reference to the Minnesotan paradesm. The population-mean cosinor demonstrated a prominent circadian rhythm in healthy children older than 1 month of age, when the amplitude was expressed as percentage of mesor. Despite differences in age, sex, ethnicity, climate, diet, and sampling conditions between the Minnesotan adolescents and the Japanese and Bavarian children, individual estimates of the circadian amplitude and acrophase of children 6 years of age and older were mostly inside the Minnesotan paradesm. Cortisol marker rhythmometry based on relatively few blood samples (covering 24 hours, preferably at intervals shorter than 4 hours) constitutes a practical approach for the estimation of parameters of the adrenal cortisol cycle. This procedure yields personalized characteristics for the timing of therapy with corticoid, oncostatic and other drugs and for gauging effects upon the adrenal cortex.