Elderly Onset Type 2 Diabetes Pathologically Distinct, Researchers Find

Researchers have found that elderly onset type 2 diabetes (eT2DM) is distinct from middle-age-onset type 2 diabetes (mT2DM), according to a study published recently in The Journal of Clinical Endocrinology & Metabolism.

The investigators, led by Hiroki Mizukami, MD, PhD, of the Hirosaki University Graduate School of Medicine, in Hirosaki, Japan, point out that as people are living longer, clinicians are beginning to see more cases of eT2DM. Japan especially, where these researchers are based, has a large elderly population, since the life expectancy is so long there. “Japan is a country with a superaged society composed of >25% of people aged ≥65 years,” the authors write. “Such a superaged society itself experiences high frequencies of a variety of age-related diseases with a reduced population of active workers.” The authors also note that while eT2DM does differ in clinical presentation, they wanted to look at the specific pathological features of what makes that so.

The team collected pancreata from 13 young nondiabetic (age, 20 to 29 years), 27 patients with mT2DM (age, 45 to 87 years), 22 middle-age subjects without T2DM, 15 subjects with eT2DM (age, 85 to 100 years), and 30 elderly subjects. They analyzed the tissue samples from these donors, looking at islet cells and amyloid deposition.

They found that in the eT2DM group, the average age of diabetes onset was about 81 years, and in the mT2DM group, the average age of diabetes onset was about 50 years. The older patients’ pancreases weighed less and had reduced islet cell mass. Their pancreases showed duct obstruction with epithelial hyperplasia, marked acinar atrophy, fibrosis, and amyloid deposition in the islet. “The amyloid volume density correlated inversely with the β-cell volume density but not with the body mass index in the eT2DM group,” the authors write. “Laboratory data showed mild elevation of serum amylase in the eT2DM group, although clinical signs and symptoms of pancreatitis were not apparent.”

Based on these findings, the researchers conclude that eT2DM is distinct from mT2DM. They also write that there could be an exocrine component in the disease course of eT2DM, “and/or that it shares some features with pancreatic diabetes but that it does not truly resemble the diabetes that develops secondary to profound exocrine pancreatic disease.” They also admit that they would have liked to compare eT2DM patients with patients who were the same age but developed diabetes in middle age, but it’s impossible since the latter patients unfortunately don’t live long enough.