SAN DIEGO – We all know about type 1 and type 2 diabetes. But when an adult patient comes in with symptoms suggestive of diabetes, it is never a good idea to assume it’s either one or the other. In fact, said physician assistant Ji Hyun “CJ” Chun, PA-C, MPAS, BC-ADM, there are plenty of other possibilities from cancer, to monogenetic diabetes, to a condition informally known as type 1.5.
Ji Hyun “CJ” Chun
“In most cases, it will be type 1 or type 2, but don’t default everything,” Mr. Chun said at the Metabolic & Endocrine Disease Summit by Global Academy for Medical Education.
He offered the following advice on the diagnosis of adult-onset diabetes:
- Don’t forget the 5% ... and the other 5%. In adults, an estimated 90% of cases of diabetes are type 2, but 5% are type 1 and another 5% are secondary to other conditions, said Mr. Chun, who is based at OptumCare Medical Group, Laguna Niguel, Calif., and has served as president of the American Society of Endocrine PAs. In the past, age seemed to be an important tool for diagnosis, because younger patients typically had type 1 diabetes and older patients typically had type 2, he said. But age alone is no longer useful for diagnosis. Cases of type 2 diabetes are much more common in children these days because of the prevalence of obesity in that population, and an estimated 60% of cases of type 1 disease are diagnosed after the age of 20. In fact, patients may develop type 1 into their 30s, 40s, or 50s, he said, depending on the severity of their autoimmunity.
- Keep ‘type 1.5’ in mind. Latent autoimmune diabetes in adults (LADA), also known as type 1.5, is a slowly developing subtype of type 1 diabetes, Mr. Chun said. There is reason to suspect LADA in lean patients, those younger than 50, and those with personal or family histories of autoimmunity, Mr. Chun said.
- Consider monogenetic diabetes. Many conditions can cause secondary diabetes, among them, monogenetic diabetes, which is caused by a single genetic mutation, whereas type 1 and type 2 diabetes are caused by multiple mutations. Monogenetic diabetes causes an estimated 1%-2% of diabetes cases, said Mr. Chun. Research findings have suggested that it is most likely to be misdiagnosed in younger adults, and that patients may go many years without receiving a correct diagnosis. Maturity-onset diabetes of the young (MODY) is a kind of monogenetic diabetes and typically occurs before the age of 25. There are many subtypes, of which one – MODY 2 – requires no treatment at all. In those patients, said Mr. Chun, “you do nothing. You leave them alone.” It is important to keep in mind that the genetic testing for MODY is expensive, Mr Chun cautioned. Some labs charge between $5,000 and $7,000 for panels, so “look for labs that perform cheaper tests,” he advised, adding that he has found a lab that charges just $250.
- Watch out for cancer. There is a long list of other possible causes of secondary diabetes, including Cushing’s syndrome, hyperthyroidism, hemochromatosis (iron overload), and pancreatic cancer. Mr. Chun said he has lost three patients to pancreatic cancer, while two other patients did well. “Keep in mind that these cases aren’t that common, but they’re there.” He suggested that pancreatic cancer should be considered in patients with rapid onset or worsening of diabetes without known cause, abnormal weight loss, abnormal liver/biliary studies, and jaundice.
Global Academy and this news organization are owned by the same parent company. Mr. Chun disclosed that he is on the AstraZeneca speakers bureau and the Sanofi advisory board.