Endocrine Abstracts

Background: Adrenal insufficiency has been well established in patients with pulmonary tuberculosis in Nigeria. It has however not been well documented in patients with extra pulmonary TB. This study compared the adrenal function in patients with pulmonary TB vs those with extra pulmonary TB.

Methods: We randomized 100 cases of pulmonary TB and 50 cases of diagnosed extra pulmonary TB, with the aim of assessing the adreno-cortical functions using both serum and salivary cortisol assay. Serum and salivary cortisol were measured after the administration of a low dose ACTH stimulation test using 1μg synacthen (synthetic ACTH analogue). The morning fasting basal serum and salivary cortisol levels were assayed, followed by the post-stimulation serum cortisol levels. Basal serum cortisol levels<220 nmol/l or post-stimulation test serum cortisol level increment<200 nmol/l or post-stimulation serum cortisol levels <500 nmol/l were suggestive of adrenal insufficiency.

Result: Of the 100 cases of pulmonary TB, 13 had drug resistance. The mean age (yrs) of the study population was 34.3 PTB cases vs 32.6 in EPTB cases. There was no statistically significant difference in the basal serum cortisol or salivary cortisol of the PTB cases compared with the EPTB cases (243.21 vs 239.63 nmol/l, P=0.713) and (0.68 vs 0.65 nmol/l, P=0.116). The thirty-minute response to ACTH stimulation and increment was significantly lower in ETB than PTB in both serum and salivary cortisol. Adrenal insufficiency was reported in 36% of PTB cases and 21% of ETB cases respectively. The most consistent symptom of adrenal insufficiency were vomiting, salt craving and hyperpigmentation (73.2%, 66.8% and 63.7% respectively). The presence of HIV was a positive predictor for adrenal insufficiency.

Conclusions: This study showed that the prevalence of adrenal insufficiency in EPTB is similar to the prevalence in PTB. Salivary cortisol can be used to screen for AI in patients with TB (EPTB and PTB).