Addison's disease. Challenges in treatment and follow up

Abstract

In the first part of this thesis we discuss a concise stepwise approach for the diagnostic evaluation of adrenal insufficiency (AI), taking into account the possible pitfalls associated with the different tests. The second part describes the history of replacement therapy, discusses the current imperfections and gives a perspective on future developments. Next, we discuss the results of the use of salivary cortisol day curves in the individual adjustment of therapy in AI, showing that over-replacement and sleep disturbances decreased significantly. We believe that a salivary cortisol day curve is a simple and patient friendly tool and can be useful in the follow-up of patients with AI. We performed a postal survey among patients with Addison’s disease (AD) and studied their ability to be physically active. Sixty-one percent of patients with AD had severe fatigue and we found reduced general subjective health related quality of life scores. We found that patients with AD are less physically active. Next, we assessed the prevalence of abnormal anthropometric and metabolic parameters and the metabolic syndrome in AD. We found that the prevalence of abdominal obesity, hypertension and hypertriglyceridemia was higher in female patients. The metabolic syndrome was not more prevalent. Epidemiological studies on the frequency of infections in AD were lacking. In our cohort study we found that the risk of infectious episodes, defined by the use of antimicrobial agents was 1.5 times higher and the risk of hospital admission as a result of infection was 4.5 times higher in AD as compared to sex and age matched controls. In case of illness or stress patients with AD have to increase their glucocorticoid dose to avoid a life threatening adrenal crisis (AC). We performed a retrospective analysis on the incidence, precipitating causes and risk factors of AC in Dutch patients with AI. We found an incidence rate of 5.2 AC/100 person years in primary, 3.6 AC/100 person years in secondary as compared to 15,1 AC/100 person years in tertiary AI (overall 4.1 AC/ 100 person years). The most important precipitating factor for AC was infection, mostly gastro-enteritis and bronchopulmonary infection. Patients with concomitant pulmonary, cardiac, malignant or neurological disease had a significantly higher risk for AC. We found a patient with primary AI caused by autoimmune adrenalitis in whom partial remission was observed after 7 years of treatment. This prompted us to perform a study aimed at finding more cases of (partial) recovery of adrenal function. More than 60% of participants did not have any response after a standard dosage (250 microgram) of ACTH. Ten patients only showed a slight increase in cortisol. In our study we found no new cases of (partial) adrenocortical recovery. In our opinion, the most plausible explanation for the absent cortisol responses was complete destruction of cortisol producing adrenocortical tissue. We concluded that recovery of adrenocortical function is probably very rare as opposed to the more frequently occurring recovery of Hashimoto’s thyroiditis. Based on our results, we cannot recommend to routinely test Addison’s patients for adrenocortical recovery.