Endocrine Abstracts

Background: The diagnosis of hypocortisolism is challenging in hemodialysis (HD) patients due to shared clinical features between renal failure and cortisol deficiency. We hypothesize that in a significant percentage of HD patients we miss cortisol deficiency.

Methods: A prospective cohort of 56 end stage kidney disease patients on maintenance HD treatment (mean age 65.3±13.1, females 80 %) was studied. Low dose (1 mg) adrenocorticotropic hormone (ACTH) test was performed on all patients and blood tests for cortisol, ACTH, insulin like growth factor 1 (IGF-1), triiodothyronine (TSH), free thyroxine (FT4), renin and aldosterone, were obtained before hemodialysis session. Adrenal insufficiency was defined as a peak serum cortisol level of <500 nmol/l at 30 or 60 min after stimulation.

Results: 14 patients (25%) out of the study population had an abnormal low dose ACTH test. Mean systolic blood pressure in the group with abnormal ACTH test was 135.2±22.0 mm Hg with no difference in blood pressure in multivariable models between the groups of HD patients with abnormal and normal ACTH test. Neither differences were observed in electrolyte levels, nor in renin/aldosterone levels between these groups. Baseline ACTH level predicted an abnormal ACTH test in the study population in both, univariate and multivariate analyses. For each pg/ml increase in baseline ACTH concentration the odds for abnormal ACTH test was 1.15 (95% CI: 1.03 to 1.29). In addition, IGF-SDS (standard deviation score) higher than -0.04 significantly decreased odds for hypocortisolism (OR 0.14, 95% CI: 0.02 to 0.81) in multivariable logistic regression models.

Conclusions: We offer routine testing of hypophyseal-adrenal axis function to detect adrenal insufficiency in HD patients even in the absence of markers characteristic of hypocortisolism.