Type 2 diabetes isn't one of those illnesses that strikes suddenly. Years of overeating, excessive weight and lack of physical activity get the process rolling and, a new study shows, blood glucose and insulin sensitivity begin to change several years before the full onset of the disease.
The study began with 6,538 adults without Type 2 diabetes. Over a 10-year follow-up period, researchers diagnosed 505 cases of Type 2 diabetes. They then looked back at the trajectories of the patients' fasting blood glucose levels, glucose levels after a standard glucose test, insulin sensitivity and the function of the insulin-producing beta cells of the pancreas. They found that in the diabetic patients, a linear increase was seen in fasting glucose followed by a steep increase starting three years before their diagnoses. Post-meal glucose levels also showed a rapid increase starting three years before diagnosis. Beta-cell function increased three to four years before diagnosis but then decreased in the final three years before diagnosis.
The research, by scientists in the United Kingdom and Denmark, may help doctors design models to predict diabetes. If people can be identified in these early stages of the disease, treatment may help prevent full onset.
"Although most prevention studies focused on prediabetic people, our findings suggest that people with prediabetes are already on the steep part of the glucose trajectory," the authors said.
The study was presented today at the American Assn. of Diabetes annual meeting in New Orleans and is published online today in the Lancet.
-- Shari Roan
Photo: A person with diabetes uses a makeshift tourniquet to draw her blood for blood-sugar testing. Credit: Tom Strickland / AP