Type 1 diabetes is as common in adults as in children, study finds

Type 1 diabetes is found in adults just as often as it’s found in children, researchers at the University of Exeter Medical School in the U.K. report, but it’s often initially misdiagnosed due to the historical stereotype that type 1 diabetes is a “disease of childhood.”

“Diabetes textbooks for doctors say that type 1 diabetes is a childhood illness,” study author Richard Oram, PhD, said in a release from the University of Exeter. “The assumption among many doctors is that adults presenting with the symptoms of diabetes will have type 2, but this misconception can lead to misdiagnosis with potentially serious consequences.”

The prime minister of England, Theresa May, is an example of this, Oram said—she was misdiagnosed with type 2 diabetes mellitus while struggling with her blood sugar and was treated with tablets, which didn’t properly treat her illness.

Oram and colleagues at Exeter published a recent study in the Lancet Diabetes & Endocrinology that focuses on the subject. Theirs is the first trial to use a novel genetic analysis to identify type 1 diabetes in adults, according to the release, allowing them to identify cases of type 1 diabetes that initially missed a primary physician’s radar.

Ninety-six percent of diabetes diagnoses in adults between 31 and 60 years old are attributable to type 2, and type 1 accounts for 85 percent of diabetes cases in young people under 20, which perpetuates the misconception that diabetes is an age-dependent condition. But Oram et al.’s research produced surprisingly diverse results—40 percent of type 1 diabetes cases present themselves in adults after the age of 30.

Due to the world’s growing obesity epidemic, doctors are quick to diagnose type 2 diabetes in adults, the researchers wrote, but that misdiagnosis could be a fatal mistake. Oram and his team found that one in nine adult patients with type 1 diabetes are admitted to hospitals with diabetic ketoacidosis, which is a life-threatening condition that develops when a type 1 diabetes patient doesn’t have access to insulin.

“Type 1 diabetes is often mistaken for type 2 in adults,” Exeter professor Andrew Hattersley said in the release. “The diagnosis of type 1 diabetes in middle and old age is very difficult because almost all patients with diabetes at this age have type 2. Failure to recognize that the diabetes is type 1 rather than type 2 and give appropriate insulin treatment can be dangerous. Type 1 diabetes should be considered for any patient who is rapidly failing to respond to increasing doses of tablets, especially if they are slim.”