Higher Rate of Addison’s Disease Seen in Patients Born in Winter Months

Researchers from the United Kingdom and Poland found an uptick in the number of patients with autoimmune Addison disease born in winter months and a decrease in summer months, indicating season-related environmental exposure may play a role in the development of the disease, according to recent research published in the Journal of Clinical Endocrinology & Metabolism.

“This is the first such environmental influence documented in the pathogenesis of autoimmune Addison’s disease,” Agnieszka Pazderska, MD, from the Institute of Genetic Medicine at Newcastle University in Newcastle upon Tyne, United Kingdom, and colleagues wrote in their study. “Exposure to seasonal viral infections in the perinatal period coupled with vitamin D deficiency leading to dysregulation of innate immunity could be the potential initial triggers for the eventual development of autoimmune Addison’s disease, although this requires further exploration.”

Dr Pazderska and colleagues evaluated a cohort of patients from the United Kingdom and Poland against the live-birth rate from the Office of National Statistics in the United Kingdom and the Polish Statistical Annals. There were 415 patients in the UK group matched against control live-birth rates from 1963 to 1972, and 231 patients in the Polish cohort matched against the live-birth rates in 1980, 1990, 2000, 2010, and 2012.

In the UK group, the researchers found an increased likelihood of being born in December (odds ratio [OR]: 1.41; 95% CI, 1.035–1.92; P =.029) and a decreased likelihood of being born in May (OR: 0.61; 95% CI, 0.4–0.93; P =.019). For Polish patients, there was an increased likelihood of being born in January (OR: 1.5; 95% CI, 1.02–2.1; P =.04) and a decreased likelihood of being born in June (OR: 0.56; 95% CI, 0.31–0.99; P =.046). When analyzed by gender, women in the UK group had increased likelihood of being born in December (OR: 1.47; 95% CI, 1.03–2.01; P =.032), while women in the Polish group had an increased likelihood of being born in December (OR: 1.8; 95% CI, 1.15–2.73; P =.009).

“The month-of-birth effect in immune mediated diseases has been long explored and a number of such studies show a reverse pattern of seasonality with a peak in spring/summer and a trough in autumn/winter. However, a number of studies on autoimmune conditions commonly associated with autoimmune Addison’s disease reported similar patterns to that observed in our study, with a peak in the number of births observed in autumn and winter in populations of patients with Graves’ hyperthyroidism and Hashimoto’s hypothyroidism,” Dr Pazderska and colleagues wrote. “It is plausible that in different autoimmune diseases various environmental triggers play a role during different stages of gestational and early postnatal development to influence disease susceptibility later in life.”

Study limitations include the relatively small sample size due to the rarity of Addison’s disease; the lack of recruitment from a formal registry; and the likelihood of the inclusion of patients with Addison disease in the control group, as they were obtained from the Office for National Statistics and the Polish Statistical Annals. The researchers noted, however, that the number of patients with the disease in the control group would likely be very small because the disease is so rare.

Disclosures: The researchers report no financial disclosures.

Reference

1. Pazderska A, et al. Impact of month-of-birth on the risk of development of autoimmune Addison’s disease [published online August 30, 2016]. J Clin Endocrinol Metab. doi:10.1210/jc.2016-2392.