SALIVARY CORTISOL-LEVELS THROUGHOUT CHILDHOOD AND ADOLESCENCE - RELATION WITH AGE, PUBERTAL STAGE, AND WEIGHT

The measurement of cortisol in saliva has become a reliable tool for b oth the scientist and the clinician for studying adrenal cortical func tion in the adult. We have measured salivary cortisol in samples from 138 healthy infants, children, and adolescents, and from 14 adults. Sa liva samples were obtained at home using a cotton swab and a saliva-co llecting tube at 800, 1300, and 1800 h before meals. Cortisol was meas ured using a time-resolved fluorescent immunoassay. Cortisol levels in saliva ranged from less than 2 nmol/L up to more than 100 nmol/L. Cor tisol levels were age-dependent. Interestingly, after the age of 6 y, cortisol levels correlated significantly with pubertal stages (analysi s of variance). No sex difference was found. In addition, cortisol mor ning levels and daily cortisol levels (area under the curve from three measurements) increased with body weight and body mass index. The hig hest cortisol levels were measured in saliva of children younger than 1 y. No circadian variation was evident before the age of 9 mo. After 1 y of age, salivary cortisol levels varied in a circadian fashion. Th e measurement of salivary cortisol levels is an attractive way of test ing adrenal function in infants and children, It provides a reliable t ool for the determination of the physiology and developmental characte ristics of cortisol metabolism.