Researchers Chart Natural Course of Beta-Cell Function
Study finds that mean insulin sensitivity declines in both diabetic and non-diabetic patients
FRIDAY, April 21 (HealthDay News) -- New data sheds light on the natural course of beta-cell function in diabetic and non-diabetic patients, according to a study published in the April issue of Diabetes.
Steven M. Haffner, M.D., of the University of Texas Health Science Center in San Antonio, and colleagues studied longitudinal changes in beta-cell function (follow-up of 5.2 years) in black, Hispanic and non-Hispanic white subjects ages 40 to 69 years with normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and type 2 diabetes, using acute insulin response (AIR) and insulin sensitivity index (Si).
The researchers found a curvilinear relationship between Si and AIR as assessed by a direct measure of insulin resistance; a consistency of this finding across the three ethnic groups and across glucose tolerance categories (including type 2 diabetes); a decline in insulin sensitivity over time; and a change in AIR, which determined glucose tolerance status after 5.2 years.
"In summary, over 5.2 years, mean insulin sensitivity declined in each glucose tolerance category," the authors conclude. "The change in AIR, however, principally determined glucose tolerance status at follow-up; NGT was maintained by a compensatory increase in insulin secretion. Failure to increase insulin secretion led to IGT, and a decrease in insulin secretion led to overt diabetes. This data may have important implications for the prevention and treatment of type 2 diabetes."