170H-progesterone rhythms in congenital adrenal hyperplasia.

Serial blood spot and saliva samples were collected at home by 18 patients being treated for congenital adrenal hyperplasia to determine the circadian rhythm of 170H-progesterone as an index of therapeutic control. There was a strong correlation between the magnitude of the circadian fall and a single morning measurement of the plasma testosterone concentration taken near the time of the 170H-progesterone rhythm samples. Poor control in pubertal girls produced an exaggerated circadian fall in 170H-progesterone concentrations that were raised at all sampling times. Optimal control (plasma testosterone 1.5-2.5 nmol/l) was associated with blood spot and salivary 170H-progesterone concentrations at 0800 hours of between 30-70 nmol/l and 260-1000 pmol/l, respectively, falling thereafter to less than 10 nmol/l and less than 150 pmol/l, respectively. Similar results were obtained in prepubertal patients. Nomograms have been constructed to interpret the daily profiles of blood spot or salivary measurements of 170H-progesterone, or both. The analysis of 170H-progesterone circadian rhythms is useful in monitoring treatment in patients with congenital adrenal hyperplasia, particularly those who may be overtreated.