Improved Urinary Cortisol Metabolome in Addison's disease: a Prospective Trial of Dual-Release Hydrocortisone.

CONTEXT Oral once-daily dual-release hydrocortisone (DR-HC) replacement therapy has demonstrated an improved metabolic profile compared to conventional 3-times-daily (TID-HC) therapy among patients with primary adrenal insufficiency. This effect might be related to a more physiological cortisol profile, but also to a modified pattern of cortisol metabolism. OBJECTIVE To study cortisol metabolism during DR-HC and TID-HC. DESIGN Randomized, 12-week, crossover study. INTERVENTION AND PARTICIPANTS DC-HC and same daily dose of TID-HC in patients with primary adrenal insufficiency (n=50) versus healthy subjects (n=124) as control. MAIN OUTCOME MEASURES Urinary corticosteroid metabolites measured by gas chromatography/mass spectrometry on 24-hour urinary collections. RESULTS Total cortisol metabolites decreased during DR-HC compared to TID-HC (P < 0.001) and reached control values (P = 0.089). During DR-HC, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity measured by tetrahydrocortisol+5α-tetrahydrocortisol/tetrahydrocortisone ratio was reduced compared to TID-HC (P < 0.05), but remained increased versus controls (P < 0.001). 11β-HSD2 activity measured by urinary free cortisone/free cortisol ratio was decreased with TID-HC versus controls (P < 0.01) but normalized with DR-HC (P = 0.358). 5α- and 5β-reduced metabolites were decreased with DR-HC compared to TID-HC. Tetrahydrocortisol/5α-tetrahydrocortisol ratio was increased during both treatments, suggesting increased 5β-reductase activity. CONCLUSIONS The urinary cortisol metabolome shows striking abnormalities in patients receiving conventional TID-HC replacement therapy with increased 11β-HSD1 activity that may account for the unfavorable metabolic phenotype in primary adrenal insufficiency. Its change towards normalization with DR-HC may mediate beneficial metabolic effects. The urinary cortisol metabolome may serve as a tool to assess optimal cortisol replacement therapy.