A descriptive study of adrenal crises in adults with adrenal insufficiency: Increased risk with age and in those with bacterial infections

Abstract

Background: An adrenal crisis (AC) is a major cause of morbidity in hypoadrenal patients. However, there is littleinformation available on the incidence and underlying causes of AC.Methods: The aim of the present study was to describe the incidence of AC in New South Wales (NSW), Australia.Using a health department database, we selected de-identified data on all adults aged 20 years and over who weretreated in any hospital in NSW between July1, 2000-June 30, 2011, with either a principal or secondary diagnosis ofan AC. AC admission rates were calculated overall and within age categories. Frequencies of co-morbid diagnoseswere analysed by age and sex groups. Poisson regression was used to assess the significance of the observedchange in AC related admissions with age, while controlling for any secular trends by including year in the model.Chi sq tests were used to assess the differences in frequencies of categorical variables between groups.Results: 824 patients received treatment for an AC in hospital, corresponding to 74.9 admissions/year. The majority(62.5%) of the patients were women and 52.8% were aged 60 years and over. Admission rates were significantlyassociated with increasing age (p < 0.0001). Patients in the 60-69, 70-79 and 80+ age groups had the highestaverage admission rates (24.3, 35.2 and 45.8 per million/year). A principal or secondary diagnosis of an infection wasreported in 317 (38.5%) patients and infection was significantly associated with age (p < 0.0001) with older patientshaving the highest proportion of cases. The most frequent infections were pneumonia/lower respiratory tractinfection in 85 (10.3%) cases and urinary tract infection (UTI) in 82 (10.0%) patients. Women experienced 78.0% ofthe reported UTIs. There were 125 patients (15.2%) with an AC and a record of gastroenteritis. Twenty-six (3.2%)patients died in hospital but, of these, only 4 deaths (0.9%) were recorded among the 467 patients with a principaldiagnosis of an AC.Conclusions: The incidence of AC increases with age. Infections, especially bacterial infections, are associated with theincidence of ACs and this increases with age.