Adrenal morphology and function in patients of extra pulmonary tuberculosis- response to treatment with anti tubercular therapy.

Abstract

Background: Work on adrenal function and morphology in patients with extra pulmonary tuberculosis(EPTB) is limited. While some authors have also included few patients of EPTB in their cohort, and studied their adrenal reserve, none have evaluated adrenal gland size and its natural course after treatment of tuberculosis.

Objective(s): The present study was designed to evaluate the morphology and cortical function of adrenal glands in patients with EPTB before and after treatment of tuberculosis.

Study design: A prospective longitudinal study.

Participants: Thirty-seven patients of extra pulmonary tuberculosis aged 12 to 84 years, of either sex were recruited to study adrenocortical function.

Methods: Adrenocortical function and adrenal gland size were studied before and after completion of ATT. Adrenal reserve was studied by ACTH stimulation test. And adrenal size was tested with CT scan. Twenty-five units of ACTH (Acton prolongatum) was injected intramuscularly and venous blood sample was collected after 60 minutes for estimation of cortisol. Serum cortisol one-hour post ACTH cortisol less than 18µg/dl was diagnosed as adrenal insufficiency Multi-detector computed tomography scanner taking 3-mm thin sections was used for measurement of adrenal size.

Results: Before start of ATT mean basal cortisol (14.39±5.34 µg/dl) was significantly lower in cases compared with cortisol levels after completion of ATT (19.2±3.64 µg/dl).  Also cortisol level post ACTH stimulation test at 60 minutes was significantly lower (27.2±6.4 µg/dl) at start of ATT as compared at completion of treatment (36.8±4.34 µg/dl); p<0.05. Taking a post stimulation cut off <18 µg/dl as per protocol, none of the persons either before ATT or after ATT had adrenal insufficiency. The adrenal stem length and thickness of right and left limbs were significantly higher in tuberculosis patients and repeat CT after completion of ATT revealed a significant decrease in the size of adrenal gland dimensions.

Conclusions: Plasma cortisol is low in patients with extra pulmonary tuberculosis which increases after treatment though none of patients have adrenal insufficiency. Adrenal gland size in increased in these patients which normalizes after ATT treatment.