Adrenocortical function and involvement in high risk cases of pulmonary tuberculosis

A regional hospital in Hong Kong.

To evaluate adrenocortical function in older patients admitted to hospital with active pulmonary tuberculosis (TB) and to determine whether adrenal insufficiency contributes to mortality in this high risk group.

Adrenocortical function was assessed in 39 consecutive patients aged over 50 admitted to hospital with active pulmonary TB. Short Synacthen stimulation tests were performed before treatment and repeated at 2 months. In patients who died during treatment, a post-mortem examination was performed. Particular attention was paid to TB involvement of the adrenal glands.

None of the patients had a subnormal basal cortisol concentration before treatment. 7 (18%) had raised basal cortisol concentrations and 16 (41%) had suboptimal cortisol responses to Synacthen stimulation. 14 patients (36%) died during treatment. The basal cortisol concentrations were significantly higher in the non-survivors compared to the survivors (743.7 +/- 288.5 vs 460.5 +/- 123.2 nmol/L, P < 0.0001). Autopsies were performed in 9 patients who died during treatment. Tuberculous involvement of the adrenal glands was found in only 1 patient who had a high basal cortisol concentration. After 2 months of treatment, all patients had normal cortisol concentrations and only 4 had borderline suboptimal Synacthen responses. The basal cortisol concentrations were significantly higher at presentation compared to those at 2 months after treatment (570.4 +/- 243.8 vs 386.3 +/- 108.3 nmol/L, P = 0.0014).

Adrenal insufficiency is uncommon in patients with pulmonary TB. Suboptimal cortisol responses to Synacthen usually reflect a hyperstimulated basal state secondary to stress. Treatment with anti-TB drugs causes reduction in basal cortisol with associated improvement in the Synacthen response.