Context: Cardiovascular risk is increased in patients with secondary adrenal insufficiency, which may be ascribed to an unfavorable metabolic profile consequent to a relatively high hydrocortisone replacement dose.
Objective: We determined the effects of a higher versus a lower glucocorticoid replacement dose on blood pressure (BP), the renin-angiotensin-aldosterone system, 11β-hydroxysteroid dehydrogenase enzyme activity and circulating (nor)metanephrines.
Design, setting, and patients: Forty-seven patients with secondary adrenal insufficiency from the University Medical Center Groningen participated in this randomized double-blind crossover study.
Interventions: Patients randomly received 0.2-0.3 mg hydrocortisone/kg body weight followed by 0.4-0.6 mg hydrocortisone/kg body weight, or vice versa, each during 10 weeks.
Main outcome measure(s): BP and regulating hormones were measured.
Results: The higher hydrocortisone dose resulted in an increase in systolic BP of 5 (12) mm Hg (P = .011), diastolic BP of 2 (9) mm Hg (P = .050), and a median [interquartile range] drop in plasma potassium of -0.1 [-0.3; 0.1] nmol/liter (P = .048). The higher hydrocortisone dose led to decreases in serum aldosterone of -28 [-101; 9] pmol/liter (P = .020) and plasma renin of -1.3 [-4.5; 1.2 ] pg/mL (P = .051), and increased the ratio of plasma and urinary cortisol to cortisone (including their metabolites) (P < .001 for all). Furthermore, on the higher dose, plasma and urinary normetanephrine decreased by -0.101 [-0.242; 0.029] nmol/liter (P < .001) and -1.48 [-4.06; 0.29] μmol/mol creatinine (P < .001) respectively.
Conclusions: A higher dose of hydrocortisone increased systolic and diastolic BP and was accompanied by changes in the renin-angiotensin-aldosterone system, 11β-hydroxysteroid dehydrogenase enzyme activity, and circulating normetanephrine. This demonstrates that hydrocortisone dose even within the physiological range affects several pathways involved in BP regulation.
Trial registration: ClinicalTrials.gov NCT01546922.