Random capillary whole blood glucose test as a screening test for diabetes mellitus in an elderly population

We assessed the adequacy of the random capillary whole blood glucose (RCBG) test as a screening test for estimating the prevalence of diabetes mellitus in an elderly Finnish population (aged 70 years or over). Both the screening test and a standard 2 h oral glucose tolerance test made according to the WHO criteria were administered to all participants. By using a cut-off point of 7.4 mmol/l for men, 7.1 mmol/l for women and 7.2 mmol/l for the total population, the RCBG test determined the prevalence of diabetes accurately. The prevalence determined by the RCBG test was 25.8% (men 21.0% and women 28.6%) and that determined by the 2 h oral glucose tolerance test 26.1% (men 21.7% and women 28.6%). The study also indicated that the RCBG levels elevated with the increase of the severity and duration of diabetes and with the presence of hypertension. The conclusion is that the RCBG test with a proper cut-off point is an optimal test for the estimation of the prevalence of diabetes and that the other properties of the test should be assessed according to the clinical outcomes and later signs of the disease.