AUSTRALIAN DIABETES SCREENING STUDY - IMPAIRED GLUCOSE-TOLERANCE AND NON-INSULIN-DEPENDENT DIABETES-MELLITUS

In preventing non-insulin-dependent diabetes mellitus (NIDDM) and its complications, screening high-risk individuals complements public heal th measures. Our screening instrument for patients of general practiti oners was a questionnaire for self-determined high-risk groups plus a laboratory measurement of a random venous plasma glucose level. Collab orating practitioners evaluated 100 consecutive outpatients aged 40 ye ars or older. The questionnaire identified patients with two or more d iabetic symptoms or with two or more risk factors, and they were recom mended to have their blood tested. For those with a random plasma gluc ose greater than 5.5 mmol/L, oral glucose tolerance tests (OGTTs) were advised. Of 50,859 subjects completing the study, there were 1,013 ca ses (2.0%) of new diabetes, 1,704 cases (3.4%) of impaired glucose tol erance (IGT), end 5,508 cases (10.8%) of previously diagnosed diabetes . Symptoms alone were a relatively poor discriminant. Almost all newly identified NIDDM and IGT patients had two or more risk factors for NI DDM. The risk ratios for abnormal glucose tolerance were as follows: h igh blood pressure, 2.4; overweight, 2.0; and positive family history, 1.7. Selection of cutoff points higher than 5.5 mmol/L would have sub stantially reduced the rate of newly discovered NIDDM and IGT. Screeni ng for NIDDM and IGT in general practice is feasible and can be achiev ed with little disruption of office procedures. In preventive programs of this nature, the low screening threshold of 5.5 mmol/L for random venous plasma glucose maximizes the case-finding rate. Copyright (C) 1 997 by W.B. Saunders Company.