Endocrine Abstracts

Background: Many patients with Addison’s disease experience decreased general wellbeing, mood and physical activity. This decrease in Quality of Life (QoL) is probably related to suboptimal glucocorticoid replacement therapy (GRT). Overreplacement frequently occurs and this can lead to side effects on the long term. The objective of this study was to investigate the effect on QoL of individual adjustment of GRT in order to approach normal cortisol levels as closely as possible.

Methods: Nineteen patients with Addison’s disease on a stable replacement therapy with either twice or thrice daily hydrocortisone or cortisone acetate and without intercurrent disease were included in this prospective study. At the start of the study a salivary cortisol daycurve (SCDC) was obtained and compared to normal controls; general and disease specific QoL-questionnaires were completed. Based on SCDC assessment of over- and underreplacement (calculated as duration (h) x magnitude (nmol/l)) on different time points, glucocorticoid dose and regime were adjusted. After 4–6 weeks SCDC and QoL assessments were repeated and the effect of adjusting GRT was analysed.

Results: At baseline underreplacement was only present in 1 patient, but overreplacement in 16 patients; total calculated overreplacement was 31.8 h.nmol/l. There was no significant correlation between degree of suboptimal replacement and QoL. Overreplacement significantly (P=0.029) decreased to 18.2 h.nmol/l after adjustment of GRT, whereas QoL did not decrease after the changes in dosage and regime.

Conclusion: Individual adjustment of GRT based on SCDC to approach normal cortisol concentrations during the day can reduce overreplacement without leading to a decrease in QoL. This can prevent long-term complications of mild cortisol excess. A salivary cortisol daycurve is a simple and patient friendly tool for optimizing glucocorticoid replacement therapy and can be useful in the follow-up of patients with Addison’s disease.