Context
Patients with Addison’s disease (AD) report impaired subjective health status (SHS).1,2 Since cortisol exhibits a robust circadian cycle which entrains other biological clocks, impaired SHS may be due to the non-circadian cortisol profile achieved with conventional glucocorticoid replacement. Continuous subcutaneous hydrocortisone infusion (CSHI) reproduces a circadian cortisol profile, but its effects on SHS have not been objectively evaluated.3,4
Objective
To determine the effect of CSHI on SHS in AD.
Design
This was a multicentre, double-blind, placebo-controlled trial of CSHI versus oral glucocorticoid therapy. Participants received in random order four weeks of: CSHI and oral placebo, and subcutaneous placebo and oral hydrocortisone, separated by a two week washout period. SHS was assessed using: the Short-Form 36 (SF-36), General Health Questionnaire (GHQ-28), Fatigue Scale (FS), Gastrointestinal Symptom Rating Scale (GSRS); and Addison’s Quality of Life Questionnaire (AddiQoL). Participants were asked their (blinded) treatment preference. Twenty-four hour urine free cortisol (UFC) and diurnal salivary cortisol collections compared cortisol exposure during each treatment.
Results
Ten participants completed the study. Baseline SHS scores (mean ± standard error) were consistent with mild impairment: SF-36 physical component summary 48.4 (±2.4), mental component summary 53.3 (±3.0); GHQ-28 18.1 (±3.3); GSRS 3.7 (±1.6) and AddiQoL 94.7 (±3.7). FS was similar to other AD cohorts 13.5 (±1.0) (p=0.82). UFC between treatments was not different (p=0.87). The 0800h salivary cortisol was higher during CSHI (p=0.03), but not at any other time-points measured. There was no difference between the treatments in the SHS assessments. Five participants preferred CSHI, four oral hydrocortisone and one was uncertain.
Conclusions
Biochemical measurements indicate similar cortisol exposure during each treatment period, although a more circadian pattern was evident during CSHI. CSHI does not improve SHS in AD with good baseline SHS. This casts some doubt on the potential benefit of circadian cortisol delivery on SHS.