Frequency of impaired glucose tolerance and diabetes mellitus in subjects with fasting blood glucose below 6.1 mmol/L [110 mg/dL]

ABSTRACT

The diagnosis of diabetes mellitus by the available criteria is controversial and relies heavily on fasting glucose results. This cross-sectional study in 2010-2011 aimed to measure the frequency of impaired glucose tolerance and diabetes mellitus in 127 subjects having fasting blood glucose < 7.0 mmol/L and to measure the agreement between different standard diagnostic criteria. Subjects presenting to a laboratory for analysis of fasting blood glucose for excluding diabetes meilitus underwent a 2-hour 75 g oral glucose challenge. A total of 40.6% of subjects with fasting blood glucose from 5.6-6.0 mmol/L had abnormal glucose regulation on the basis of the gold standard glucose challenge. Agreement between American Diabetes Association and World Health Organization diagnostic criteria was only fair [kappa = 0.32]. Abnormalities of glucose metabolism including impaired glucose