Patients with chronic adrenal insufficiency (Addisons) have mildly but significantly increased mortality from cardiovascular, malignant, and infectious diseases, predominantly pneumonia (Bergthorsdottir et al. 2006). Death from adrenal crisis is rare and largely preventable, but life-threatening adrenal crisis is a regular event in treated Addisons with a previously reported annual incidence of 8% in the UK.
We analysed the frequency of adrenal crises reported by patients belonging to support groups in the UK, Canada, Australia and New Zealand against their years of post-diagnosis life and demographic variables taken from responses to a written questionnaire (N=841). Overall 46% of patients (N=386) reported one or more crisis since diagnosis, at an average of 12 years since diagnosis. There was no significant difference between genders and no detectable effect of coincident hypothyroidism.
Patients with conditions such as Type 1 or 2 diabetes (61%), a body mass index >30 kg/m2 (55%), asthma (53%) or premature ovarian failure (53%) were significantly more likely to report adrenal crises (confidence >95%), as were patients reporting inability to work or disablement (52%). Manual/shop workers reported the lowest incidence (35%) while 46% of health care workers had suffered from at least one crisis.
We also found significant national variation in the proportion of adrenal crises caused by winter influenza (range 520%) suggesting that influenza vaccination, as well as variation in the severity of circulating influenza strains, are important factors influencing the risk of adrenal crisis.
These findings suggest that patients who are immuno-compromised, have reduced fitness or whose occupations entail frequent exposure to infection are at above average risk of adrenal crisis. Endocrinologists should remain vigilant in ensuring adrenal insufficiency patients are well-versed in the sick-day rules for glucocorticoid dosage adjustment, well-trained in emergency self-injection technique and receive an annual influenza vaccination.