Pattern of adrenal morphology and function in pulmonary tuberculosis: response to treatment with antitubercular therapy

Abstract

Although previous studies have shown enlargement of adrenal glands in patients with tuberculosis, only few have studied its natural history. Similarly, there have been variable reports of adrenal function in these patients. Some but not all the studies revealed a high prevalence of adrenal insufficiency. The aim of this study was to prospectively study the adrenal cortical function and morphology before and after treatment of pulmonary tuberculosis. In a prospective case-control study, 45 patients with acute pulmonary tuberculosis and 45 healthy age- and gender-matched controls were studied. Adrenal function was tested using a short Synacthen test at the baseline and after 6 months of antitubercular treatment. Size of both adrenal glands was studied using 64 slice MDCT (Somatom Sensation, Siemens) before and after 6 months of antitubercular treatment. The findings were compared with a group of healthy controls. The mean age of cases was 42·4 ± 20·4 years and that of controls was 41·1 ± 17·7 years. The various clinical and biochemical parameters were comparable between cases and controls. The mean cortisol both basal and one-hour postintravenous Synacthen was significantly lower in cases as compared to controls (mean ± SD basal cortisol of 413·57 ± 108·42 nmol/l in cases vs 615·26 ± 108·15 nmol/l in controls and post Synacthen cortisol of 685·61 ± 83·87 nmol/l in cases vs 1497·30 ± 734·44 nmol/l in controls). Both the adrenal length and thickness of the right and left adrenal gland were greater in patients with active tuberculosis compared with controls and reversed to baseline after completion of antitubercular treatment. Adrenal enlargement demonstrated by CT is common in active tuberculosis and is reversible. Basal and stimulated cortisol is less in patients with pulmonary tuberculosis as compared with healthy controls and increases after antitubercular treatment, although unlike previous studies, none of the patients had adrenal insufficiency.