Title: Lack of adult-type salivary cortisol circadian rhythm in hospitalized preterm infants. Author: Kidd S, Midgley P, Nicol M, Smith J, McIntosh N. Journal: Horm Res; 2005; 64(1):20-7. PubMed ID: 16088204. Abstract: BACKGROUND/AIMS: Knowledge of the presence or absence of cortisol (F) circadian rhythm in preterm infants is important for the interpretation of F measurements made in samples taken for both clinical and research purposes. Little is known about its emergence in very preterm infants. This study examines circadian rhythm in F secretion in hospitalized infants born before 30 weeks' gestation. DESIGN: Prospective longitudinal observational study. SUBJECTS: 11 infants admitted consecutively and born before 30 completed weeks of gestation. MEASUREMENTS: F was measured by highly specific radioimmunoassay on morning and evening saliva samples gathered at weekly intervals until discharged home. Circadian rhythm was defined as > or =40% reduction from morning to evening level. RESULTS: For all data, the median salivary F was 10.3 nmol/l (range <0.5-372.8). F levels were highest in the first 3 weeks of life. No infants displayed classical circadian rhythm for 4 weeks or more prior to being discharged from hospital. The other infants showed randomly distributed morning and evening F values with a trend in 4 infants towards periods of consistently higher evening than morning values. CONCLUSION: Adult-type F circadian rhythm is rarely evident in hospitalized preterm infants born before 30 weeks' gestation.[Abstract] [Full Text] [Related] [New Search]
