Screening performance of the FINDRISC score for identification of undiagnosed type 2 diabetes in persons with severe obesity

Background: Type 2 diabetes mellitus (T2DM) and prediabetes are common complications of severe obesity. Although the Finnish Diabetes Risk Score (FINDRISC) is a widely used tool for diabetes risk assessment, its performance has not been specifically evaluated in populations with severe obesity. Methods: In this cross-sectional study, 632 adults with severe obesity (median BMI 46.2 kg/m²) underwent oral glucose tolerance testing (OGTT) and HbA1c assessment. FINDRISC was calculated for each participant. The primary endpoint was the ability of FINDRISC to identify previously undiagnosed T2DM. Secondary endpoints included the prevalence of glycemic categories and the associations between FINDRISC and circulating adipokines. Results: Normoglycemia, prediabetes, and previously undiagnosed T2DM were identified in 44%, 46%, and 10% of participants, respectively. FINDRISC values increased progressively with worsening glucose tolerance (p < 0.001). The area under the ROC curve for detection of undiagnosed T2DM was 0.72 (95% CI 0.65-0.78). A FINDRISC cut-off of 13 showed high sensitivity (95.1%) and negative predictive value (98.2%), allowing 26% of individuals to be spared additional blood testing. Adiponectin and leptin levels were significantly lower in participants with diabetes compared with those with normoglycemia or prediabetes. Conclusions: Approximately one in ten persons with severe obesity had previously undiagnosed T2DM. In this population, FINDRISC demonstrated good performance as a rule-out screening tool, supporting its use to reduce unnecessary diagnostic testing and to guide targeted diabetes screening in severe obesity.