Worse pancreatic β-cell function and better insulin sensitivity in older chinese without diabetes

Abstract

Background.Whether insulin secretion and insulin sensitivity in older Chinese differ from younger persons without diabetes has not been examined and is unknown to us.Methods.Oral glucose tolerance test was performed in a total of 32,245 Chinese without diabetes history. Insulin sensitivity was estimated by Matsuda's insulin sensitivity index (Matsuda ISI), and insulin secretion was measured by the insulinogenic index. The insulin secretion and sensitivity were compared among three age groups: 20-39 (the young), 40-59 (the middle), and greater than or equal to 60 years (the older).Results.A higher proportion of postchallenge hyperglycemia (PH), both in prediabetes and in diabetes stage, was associated with older age. In the young, middle, and older age groups, the insulinogenic index median was 10.64, 8.40, and 6.67, respectively, in individuals with normal glucose tolerance (NGT); it was 8.56, 6.12, and 4.98 in individuals with prediabetes, respectively (p