Computerized identification of normal and abnormal diurnal cortisol secretion patterns and levels of testosterone from human saliva samples

Abstract

Normal and abnormal diurnal cortisol secretion patterns are identified from human saliva samples by an in vitro method. First and second saliva samples are taken from one human individual at first and second predetermined times during the same day. A first cortisol concentration is determined in the first saliva sample, and a second cortisol concentration is determined in the second saliva sample. An abnormal secretion pattern is then compared to a normal secretion pattern with the help of a fuzzy logic algorithm. A function of the hypothalamic-pituitary-adrenal (HPA) axis is then determined for the human individual. Optionally, a testosterone level is determined from one of the samples and is used in combination with the cortisol concentrations to provide a redefined determination.

Description

TECHNICAL FIELD [0001] The present invention relates to identification of normal and abnormal diurnal cortisol secretion patterns and levels of testosterone from human saliva samples, so as to determine the function of the hypothalamic-pituitary-adrenal (HPA) axis in individual subjects. BACKGROUND ART [0002] The hypothalamus is a small, central part of the brain with several important regulatory functions, for example as regards physiologic response to external stress, bode weight (especially the metabolically unfavorable abdominal obesity), the sleep-wake cycle and mood fluctuations. As shown in FIG. 1, the hypothalamus 2 is connected to the pituitary 3 as part of the central nervous system 1 and controls the secretion of different hormones from this endocrine gland. One of these hormones is ACTH (adenocorticotropic hormone), the secretion of which is activated through secretion of corticotropin releasing hormone (CRH) from the hypothalamus 2, as indicated by reference numeral 7 i...

AI Technical Summary

Benefits of technology

"The present invention provides a method for accurately identifying abnormal diurnal cortisol secretion patterns in human saliva samples. This is done through a computerized method that requires only two saliva cortisol measurements, making it convenient and easy to determine the function of the HPA axis for individual subjects. The computer program uses a fuzzy logic algorithm to interpret the saliva cortisol values and provide a structured approach for evaluating the HPA axis function. The program also measures testosterone levels simultaneously to further refine the evaluation of the HPA axis. The invention guarantees a high accuracy in identifying abnormal cortisol patterns and provides a detailed analysis of the function of the HPA axis."

Problems solved by technology

Disturbances in this mechanism have been shown to lead to metabolic complications, such as increased insulin resistance and abdominal obesity.

These metabolic abnormalities are associated with increased risk for cardiovascular disease, the major cause of death in industrialized countries.

Abnormal concentrations of cortisol have also been shown to be the biochemical mechanism for the influence of external stress factors on the metabolic system, which lead to increased risk for heart disease, in both humans and experimental animals.

However, the identification of abnormalities has up to now only been possible by means of statistical analysis of groups of subjects.

Due to the large inter- and intra-individual variability, it has hitherto not been possible to classify individual subjects.

However, a high testosterone level also implies negative effects.

However, testosterone levels in the upper quartile in a normal population are associated with increased risk for cardiovascular disease, and this relationship is stronger when cortisol levels are abnormal.

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