Autoimmune diabetes (type 1): half develops after age 30
Autoimmune diabetes (type 1), earlier thought to occur almost exclusively in the pediatric population, is dramatically increasing among adults. Data recently presented at the 2016 Annual Meeting of the European Association for the Study of Diabetes (EASD) and reported in Medscape confirms that it now occurs as frequently in adults over 30 as it does in children.
"Onset of type 1 diabetes is just as likely to occur in people older than 30 years of age as in those younger, new research shows."
This is a manifestation of the giant increase in autoimmune and autoinflammatory conditions present but too often overlooked in clinical practice.
Autoimmune diabetes lurks in the general population
Practitioners active in case management of autoimmune conditions are already aware of this, but to many it may come as a surprise.
"Obtained using genetic data from the UK Biobank, the startling results refute the long-held belief that type 1 diabetes is primarily a "juvenile" condition...Clinically, the findings are particularly relevant for primary care, where people who develop autoimmune-mediated diabetes in adulthood are often misdiagnosed as having type 2 and prescribed metformin instead of insulin."
Dr Nicholas JM Thomas, of the Institute of Biomedical and Clinical Science, University of Exeter Medical School, United Kingdom, who presented the data, is quoted in Medscape:
"I think it's an eye-opener and obviously has implications for how we diagnose and manage people and also the education people receive. We very much focus on childhood and adolescence and perhaps people diagnosed later don't get the same education."
Autoimmune diabetes can be mixed with type 2 (metabolic)
Experienced clinicians will recognize that HgbA1c going up in a lean adult almost always implies an autoimmune component. Harder to recognize is a person for whom both are occurring: there is insulin resistance with compensatory elevated insulin forcing the storage of calories as fat resulting in overweight or obesity but combined with further carbohydrate intolerance due to an autoinflammatory attack on beta cells, insulin, the GAD enzyme, or other factors that further damage blood glucose regulation. It can develop rapidly or slowly as LADA (latent autoimmune diabetes of adults). I am seeing this in practice and I'm sure others paying attention are too.Medscape further quotes Dr. Thomas:
"He advised that clinicians should at least be aware that adults can develop autoimmune diabetes, as either classic type 1 or the slower-onset phenomenon known as "latent autoimmune diabetes of adulthood (LADA).""It's knowing this does happen, and therefore just keeping an open mind when you spot someone who's not behaving like type 1 or not responding as you would anticipate when you go through the usual treatment guidelines for type 2," he said, citing the example of British Prime Minister Theresa May, who was diagnosed with type 1 diabetes at age 56 and who "progressed very rapidly."He reiterated that type 1 diabetes is evenly distributed within the first 6 decades of life, but after age 30, the increase in type 2 diabetes makes the type 1 cases harder to recognize and treat correctly.
Diagnosis
Antibody measurements, particularly to the islet cells, insulin and glutamic acid decarboxylase 65 are a mainstay even though subject to the vulnerabilities of antibody expression. And there is a new approach:
"Dr Thomas and colleagues used a "robust, novel, genetic approach" using a risk score comprising 30 single nucleotide polymorphisms associated with type 1 diabetes (T1D-GRS)."
Firstly the clinician should be alert to impaired blood glucose control in adult patients who are not overweight or for whom the correct diet (LCHF) and targeted therapies are not yielding the result they should. This is a tipoff that the case has to be managed as autoimmune diabetes or LADA with the underlying causes for loss of immune tolerance investigated and targeted for therapy.The session comoderator Catharine Owen, MD, associate professor of diabetes at the Oxford Center for Diabetes, Endocrinology, and Metabolism, United Kingdom, is also quoted in Medscape:
"I think it's absolutely crucial for people to be aware that type 1 diabetes can present at any age. Physicians shouldn't be complacent when people aren't responding to oral agents, or they're not bringing A1c down to target when they should."