SFEBES2022 Oral Poster Presentations Adrenal and Cardiovascular (4 abstracts)
1Oxford Centre for Diabetes, Endocrinology and Metabolism and NIHR Oxford Biomedical Research Centre, Churchill Hospital, University of Oxford, Oxford, United Kingdom; 2Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy; 3Department of Clinical Chemistry and Immunology, Heartlands Hospital, Birmingham, United Kingdom; 4Department of Clinical Biochemistry, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
Background: There is currently no agreed consensus for the optimization and titration of mineralocorticoid (MC) therapy in patients with primary adrenal insufficiency (PAI).
Objective: To explore the relationship between serum (sFC) and urine (uFC) fludrocortisone levels and biochemically and clinically important variables, and to assess their utility in guiding and titrating MC replacement.
Methods: Multi-centre, observational, cross-sectional study on 40 patients (mean age 43±19 years) with PAI on MC replacement therapy (median dose 125 mg/d, range 50-400). sFC and uFC levels (measured by LC-MS/MS), plasma renin concentration (PRC), electrolytes (Na+, K+), systolic (SBP) and diastolic (DBP) blood pressure, total daily Glucocorticoid dose (dGC, hydrocortisone equivalents) and anthropometric parameters were incorporated into statistical models to determine their relative importance in guiding MC dose.
Results: We observed a close relationship between sFC and uFC (r=0.434, P=0.005) as well as between sFC and the time from the last FC dose (r=-0.355, P=0.023). Total daily MC dose was related to dGC dose (r=0.556, P<0.001), K+ (r=-0.388, P=0.013) as well as sFC (r=0.356, P=0.022) and uFC (r=0.531, P<0.001) levels. PRC was related to Na+ levels (r=0.517, P<0.001) and SBP (r=-0.485, P=0.002), but not to MC dose, sFC or uFC. Principal component analysis and multiple linear regression analyses confirmed Na+, K+ and SBP as important variable to guide MC total daily dose titration, but did not support a role for sFC, uFC or PRC measurements.
Conclusions: Our data suggest that sFC and uFC levels are not helpful in MC dose titration in PAI. Clinicians should continue to rely on clinical and biochemical important variables including electrolytes, blood pressures and symptoms to guide their decisions on MC dose adjustment.