ADRENAL-FUNCTION DURING TUBERCULOUS INFECTION AND EFFECTS OF ANTITUBERCULOSIS TREATMENT ON ENDOGENOUS AND EXOGENOUS STEROIDS

SETTING: To date, few studies have been published on the frequency of adrenal disorder during active tuberculosis and whether rifampicin tre atment has an adverse effect on adrenal function. OBJECTIVE: We evalua ted endogenous and exogenous steroid metabolism in patients with activ e tuberculosis before and during treatment to observe whether the func tions were affected by tuberculosis and rifampicin. DESIGN: Basal horm one levels and Synacthen stimulation test were obtained in 22 patients with active tuberculosis before and 20-30 days after antituberculosis treatment including rifampicin. Exogenous steroid metabolism was asse ssed by 1 mg overnight dexamethasone suppression test before and durin g antituberculosis treatment. RESULTS AND CONCLUSION: No significant d ifferences were found on basal plasma cortisol or adrenocorticotropic hormone levels, but significant decrements were found on basal dehydro epiandrosterone sulfate (P < 0.05) and urinary free cortisol levels (P < 0.01) before and after commencing antituberculosis treatment. After Synacthen stimulation, only one patient had insufficient increment in plasma cortisol levels. This patient was diagnosed as a case of Addis on's disease. Although nine patients (42%) showed sufficient suppressi on of cortisol secretion on the dexamethasone test before treatment, n one had sufficient suppression with dexamethasone after antituberculos is treatment. We found less mean maximum adrenal cortisol responsivene ss to Synacthen stimulation during the course of antituberculosis trea tment (P < 0.01). Although impairment of adrenal function is a rare co ndition in active tuberculosis, rifampicin may have a significant effe ct on steroid metabolism.