In December, Nathan Mobley noticed he was thirstier than usual.
Mobley drank water constantly at work. He would finish two bottles of water about halfway through his 20-minute drive home, and then he'd want more. No matter how much water he drank, his throat was still dry.
“I just could not quench my thirst,” he said.
At first, he thought he was thirsty because of the dry weather, he said. But he was also tired most of the time, and needed to use the restroom more than usual. So he began looking online for an answer.
Everything he read told him his symptoms pointed toward diabetes. But he also knew he wasn't a likely candidate for Type 2 diabetes, the form that generally affects adults. He was slim, tried to stay active and avoided sugary foods like soda and candy, he said.
But Mobley, of Norman, was in his mid-30s at the time — too old to fit the model for Type 1 diabetes, which generally affects children.
In February, Mobley, now 35, was diagnosed with Latent Autoimmune Diabetes in Adults, or LADA, a type of diabetes that falls somewhere between Type 1 and Type 2 diabetes.
Known colloquially as Type 1.5 diabetes, the disease is essentially a form of Type 1 diabetes that doesn't present itself until the patient is an adult, said Dr. James Lane, an endocrinologist at the University of Oklahoma Health Sciences Center's Harold Hamm Diabetes Center.
Like Type 1 diabetes, LADA is an autoimmune disorder, a condition in which the body's immune system attacks insulin-producing beta cells in the pancreas. But unlike more common Type 1 diabetes, where the onset of symptoms is generally sudden and dramatic, patients with LADA may not experience symptoms for years after developing the disease, Lane said.
In some cases, he said, patients don't experience symptoms even when diagnosed. Many patients are diagnosed when their blood is tested for some other reason, he said.
It's also possible for a person to carry the genes for LADA and never experience symptoms, Lane said. Like Type 1 diabetes, LADA is caused by genes the patient inherits and then triggered by some environmental factor, like a virus or chemical the patient encounters.
Scientists don't know exactly why patients with LADA are able to produce insulin for so much longer than those with Type 1 diabetes, Lane said. The disease isn't well known or understood, he said, and patients who have it are often diagnosed as having Type 2 diabetes because of their age, he said.
That misdiagnosis can cause problems for patients, Lane said. Patients with Type 2 diabetes are often able to manage their disease with a combination of pills, diet and exercise, he said. But most patients with LADA will eventually need insulin, he said, so patients who are misdiagnosed often wind up frustrated when they don't see results.
Among the other questions they're seeking to answer, researchers are trying to find out whether LADA patients who start taking insulin see any difference from those who try to manage the disease through diet and exercise before using insulin.
Since his diagnosis, Mobley developed a better understanding of food, and tries to a better job of balancing proteins, carbohydrates and fats, he said. For now, he's managing his symptoms by exercising more and watching his diet closely.
That's a difficult task, he said — even before his diagnosis, he was active and ate well. But even that healthy lifestyle couldn't help him avoid the disease, he said.
“Sometimes, you can't help it,” he said. “Sometimes, it's in your genes.”