Glucose screening and the risk of complications in Type 2 diabetes mellitus.

It is unknown whether glucose screening for Type 2 diabetes mellitus (DM2) reduces the risk of diabetic complications. We conducted a case-control study using 303 cases with DM2 and at least one symptomatic microvascular diabetic complication, matched 1:1 to control subjects. All subjects' blood glucose tests for the decade before the first clinical suspicion of DM2 were categorized as screening or not based on the presence of symptoms suggestive of DM2. Approximately 90% of case subjects and control subjects had been screened for diabetes. After adjusting for multiple covariates in a logistic regression model, the odds ratio of developing a complication associated with screening was 0.87 (95% confidence interval 0.38-1.98), suggesting that screening may be associated with a modest reduction in the risk of certain diabetic complications. However, the confidence limits were wide and consistent with no true benefit. Further studies are needed to establish whether the small reduction we observed is genuine.