Abstract
OBJECTIVE: To analyze the period of time between the first occasional fasting hyperglycaemia (OFH) and the diagnosis of type 2 diabetes mellitus (DM2), using the World Health Organization (WHO) criteria or the American Diabetes Association (ADA) criteria. DESIGN: Retrospective, observational study. SETTING: Urban primary care centre. SUBJECTS: 104 patients with DM2 diagnosed between 1991 and 1995 who had a previous OFH. MEASUREMENTS: Age, gender and other risk factors, dates of the first OFH (fasting plasma glucose >= 110 mg/dl), the diagnosis according to WHO criteria (2 fasting plasma glucose >= 140 mg/dl or >= 200 mg/dl two hours after the oral glucose test tolerance (OGTT)) or with the ADA criteria (2 fasting plasma glucose >= 126 mg/dl), and the intervals in months between them. RESULTS: Of the 222 diagnosed patients, 104 (47%) had previous OFH. Age at diagnosis was 60.8 (SD 10.1) and 53% were women. OGTT was performed in 51 cases (49%). The median (range) of the interval between the first OFH and diagnosis was 16 months (0-101) for those who were undertaken an OGTT, and 45 months (1-104) for those who were not (p = 0.003). In these last ones, ADA criteria reduced the interval to 31 months (0-97) (p < 0.001). In 27 of these patients who did not satisfy both criteria at the same time, ADA criteria reduced the interval to 10 months (0-93) (p < 0.001). CONCLUSIONS: Not performing the OGTT means a delay in diagnosis which can be countered by applying the ADA criteria.