The prevalence of autoimmune disease in patients with type 1 diabetes

The authors aimed to determine the prevalence and associated predictive factors for autoimmune diseases in children and adults with type 1 diabetes.

The authors concluded that the diagnosis of one or more autoimmune disease was common in type 1 diabetes, particularly in women, non-Hispanic whites and the elderly. 

Autoimmune (AI) diseases are diseases that affect the immune system, which defends the body against infection. An AI disease can cause the immune system to respond too poorly or too aggressively, decreasing the body's ability to fight infection and attacking healthy tissue. Type 1 diabetes is a type of AI disease that occurs in both children and adults. Additional AI diseases in type 1 diabetes are a significant cause of complication. These include inflammation of the bowel, skin disease, celiac disease (when the small intestine is hypersensitive to gluten), thyroid disease (controls the body's metabolism) and others. 

In some type 1 diabetes patients additional AI diseases are difficult to diagnose. This can become life-threatening in some circumstances depending on the type and severity. Early diagnosis is important. 

The aim of this study was to determine the prevalence of AI diseases in patients with type 1 diabetes.

25,759 patients with type 1 diabetes were included in this study. The average duration of diabetes was 10.6 years. 

27% of patients had at least 1 AI disease. Of these, 20% had 1 and 5% had 2 AI diseases. Less than 1% had 3, 4 or 5 other AI diseases. Patients with more than 1 AI disease were more likely to be older, female and of white non-Hispanic race. 29% of white non-Hispanic patients were affected with 1 or more AI disease. 

Patients with 1 or more AI disease were more likely to have a longer type 1 diabetes duration and diagnosed with diabetes later in life. There was an age-dependent increase in the number of patients affected with 1 or more AI disease starting in patients over the age of 18 years. A 10.4% increase in AI diseases was seen in patients over 50 years. 

Thyroid disease was the most common AI disease (24%) and stomach/bowel disease (6%). This was followed by arthritis (less than 1%), skin disease (less than 1%) and Addison's disease (less than 1%). 67% of patients with thyroid disease were female.

The authors concluded that the diagnosis of one or more autoimmune disease was common in type 1 diabetes, particularly in women, non-Hispanic whites and the elderly.