People with type 1 diabetes may also be more likely to have a diagnosis of another autoimmune disease, study data show.
Janet B. McGill, MD, FACE, professor of medicine at the Washington University School of Medicine in St. Louis and Endocrine Today Editorial Board member, and colleagues evaluated data from the T1D Exchange Registry on 25,759 people with type 1 diabetes (mean age, 23 years; range, 1-93 years; 28% aged at least 26 years) to determine the prevalence and factors that may predict association with other autoimmune diseases.
Half of the participants were female and 82% were non-Hispanic white; mean duration of diabetes was 10.6 years at data collection; mean HbA1c was 8.4%.
A diagnosis of at least one other autoimmune disease was found for 27% of participants; most had one additional diagnosis (20%) followed by 5% with two and less than 1% with three, four or five.
Older age (P < .0001), female sex (P < .001 after adjusting for age and duration) and white non-Hispanic race/ethnicity (P < .001 after adjustment for age and duration) were more frequent among participants with one or more additional autoimmune disease. At least one additional autoimmune disease was also common in participants who were Hispanic/Latino (21%), black non-Hispanic (12%) and other races (21%).
Longer type 1 diabetes duration (P < .001) and diagnosis of type 1 diabetes later in life (P < .001 after adjusting for duration) were also common among participants with one or more other autoimmune diseases.
Thyroid diseases were the most frequently diagnosed additional autoimmune diseases (20%); hypothyroidism or Hashimoto’s disease were most common (96% of all thyroid diseases), and hyperthyroidism or Graves’ disease were less common (8% of all thyroid diseases). Rheumatoid arthritis (< 1%), vitiligo (< 1%) and Addison’s disease (< 1%) were less common.
Of participants with thyroid diseases, 67% were female. Women and girls also had the highest prevalence of systemic lupus erythematosus (93%), scleroderma (91%), celiac disease (57%) and Addison’s disease (53%).
“Overall, the high prevalence (27%) and wide spectrum of autoimmune diseases in our study reinforces the need to identify [additional autoimmune diseases] during the follow-up of patients with [type 1 diabetes],” the researchers wrote. “The most frequent [type 1 diabetes]-associated autoimmune diseases include Hashimoto’s thyroiditis, celiac disease, Graves’ disease, [rheumatoid arthritis] and vitiligo. These findings have implications for screening practices and pretest probability of identifying autoimmune disease, suggesting that clinicians should remain vigilant to the possibility of other autoimmune disease even in older [type 1 diabetes] patients.” – by Amber Cox
Disclosure: The researchers report no relevant financial disclosures.