Comparison of low dose and standard dose adrenocorticotropin stimulation tests in healthy Nigerians

Hypothalamo-pituitary-adrenal (HPA) axis dysfunction is a potentially life-threatening condition. It is of paramount importance that safe; reliable diagnostic tests be available to identify patients at risk for adrenal insufficiency. The 250?g Adrenocorticotropic hormone (ACTH) stimulation test is commonly used to assess adrenocortical function. The 250?g dose is supraphysiological; therefore several investigators; over the years; have used 1?g ACTH stimulation test to assess adrenocortical function.The aim of the study was to compare the response of healthy adult Nigerian subjects to the 250?g and 1?g ACTH tests.Ten healthy subjects; five males and five females; aged between 20-60 years; (mean; 38.7 years) participated in this study. They all had normal medical histories and physical examinations; were nonsmokers; and had never received any type of glucocorticoid therapy. Serum chemistries; full blood counts; erythrocyte sedimentation rate; were all within normal limits. Both low dose ACTH test and standard dose ACTH test were performed on the 10 subjects in a randomized order on different days.There was no statistically significant difference in mean serum cortisol levels between the two test doses at 30 minutes (928.4 vs 929.8nmol/L). There was a strong correlation between 30-minute cortisol responses to 1?g and 250?g ACTH stimulation tests; r=0.999; p0.001.In agreement with other published data; our study confirms that 1?g ACTH stimulates adrenocortical secretion in normal subjects in the period 30 minutes post injection comparable to 250?g ACTH testing

Adrenocortical function in Nigerian patients with pulmonary tuberculosis (PTB)

Addison's disease was frequently consequent upon affectation of the glands by tuberculosis. Pulmonary Tuberculosis (PTB) is still very common in Nigeria but no report on the functional status of the adrenal cortex in patients with PTB in Nigeria exists. It is very important to note that subclinical adrenocortical failure in tuberculosis is an entity that should be considered as cortisol deficiency could be responsible for unexpected sudden death in this category of patients. This study sets out to determine the prevalence of subclinical adrenocortical failure in persons with PTB by determining the response to low-dose (1 ìg) ACTH stimulation. Forty four persons with newly diagnosed sputum-positive PTB and treatment naive, (23 males and 21 females, mean age 34.4 +/- 11.3 years, and mean body mass index (BMI) of 18.9 +/- 2.9 kg/m2) completed the study. Of the one hundred healthy volunteers recruited as control subjects, 70 persons (35 males and 35 females, mean age 38.1 +/- 12.5 years, BMI 24.1 +/- 3.7 kg/m2) completed the exercise. There was no statistically significant difference in the basal cortisol of healthy subjects and persons with PTB (239.9 vs. 229.1 nmol/L, p = 0.661). The thirty minute response to ACTH stimulation test and increment were significantly lower in persons with PTB than in healthy subjects. Adrenocortical insufficiency, mostly at the subclinical level, is common in persons with PTB infection, occurring in about 23% of patients. We therefore recommend that basal cortisol levels should not be used to detect adrenocortical insufficiency; rather stimulation tests should be used to exclude or confirm suspected adrenocortical insufficiency in patients with PTB