Community-based epidemiological study of glucose tolerance in Kin-Chen, Kinmen: support for a new intermediate classification

In this population-based survey, we investigated the prevalence of varying degrees of glucose tolerance among residents of Kin-Chen, Kinmen, as well a s the association of glucose tolerance status with potential risk factors f or type 2 diabetes and cardiovascular disease (CVD). We focused particularl y on subjects with normal 2-h postload glucose level (<7.8 mmol/l) but pers istent fasting hyperglycemia (PFH) (5.6-7.8 mmol/l), to examine whether PFH represents an intermediate state between normal glucose tolerance (NGT) an d impaired glucose tolerance (IGT). The target population comprised 6346 re sidents aged 30 years and older. A total of 4354 subjects could be classifi ed into categories of NGT, PFH, IGT, new diabetes, and known diabetes accor ding to medical history, fasting plasma glucose levels, and the results of a 75-g oral glucose tolerance test (OGTT). The potential cardiovascular ris k factors assessed included age, obesity (general and central), systolic bl ood pressure, and fasting levels of insulin, C-peptide, triglyceride, chole sterol, and high-density lipoprotein cholesterol (HDL-C). The age-standardi zed prevent cs of PFH, IGT, new diabetes, and known diabetes were 2.9%, 3.5 %, 4.0%, and 3.0%, respectively. Among nondiabetic subjects, the cardiovasc ular risk factor profiles worsened with decreasing glucose tolerance, with most values differing significantly among the NGT, PFH, and IGT groups. Sub jects with PFH, who would be classified as having NGT according to conventi onal WHO criteria, had physical and biochemical features between those of t he NGT and IGT groups. These findings support our previous observation that PFH may be a transition state between NGT and IGT in the progression towar d type 2 diabetes. (C) 2000 Elsevier Science Inc. All rights reserved.