SCREENING FOR DIABETES-MELLITUS IN ADULTS - THE UTILITY OF RANDOM CAPILLARY BLOOD-GLUCOSE MEASUREMENTS

OBJECTIVE-Because half of the people with non-insulin-dependent diabet es mellitus (NIDDM) are undiagnosed and because near-normal glycemic c ontrol can prevent diabetic complications, we evaluated the use of fie ld-based random capillary blood glucose measurement as a screening tes t for NIDDM. RESEARCH DESIGN AND METHODS-A cross-sectional sample of 8 28 Egyptians greater than or equal to 20 years of age underwent both a random capillary blood glucose measurement performed with a portable reflectance meter in the field and an oral glucose tolerance test in t he laboratory. The sensitivity and specificity of random capillary blo od glucose measurements in predicting the presence of NIDDM were evalu ated. RESULTS-Multivariate analyses showed that the screening test per formed better when subjects had eaten shortly before the test (area un der receiver operating characteristic curve, 0.87 for a 1-h postprandi al period compared with 0.69 for an 8-h postprandial period) and that the optimal capillary blood glucose cutoff points to define a positive test increased with age. For a postprandial period of 1 h, cutoff poi nts of 115 mg/dl for individuals 30 years of age and 140 mg/dl for tho se 75 years of age yielded similar performance characteristics (sensit ivity 82% and specificity 78% for those 30 years old; sensitivity 81% and specificity 80% for those 75 years old). CONCLUSIONS-Adjusting ran dom capillary blood glucose measurements for the postprandial period a nd using age-specific cutoff point values can improve performance of t he screening test.