Association of current HbA1c with concurrent multiorgan screening abnormalities and the incremental value of routine clinical characteristics in type 2 diabetes: a single-center cross-sectional study in Wenzhou, China

Background Glycated hemoglobin A1c (HbA1c) is central to glycemic management but mainly reflects recent average glycemia rather than long-term cumulative exposure or existing organ abnormalities. We assessed whether adding age, sex, diabetes duration, body mass index (BMI), and systolic blood pressure to HbA1c improved the identification of concurrent vascular, renal, and peripheral nerve abnormalities in patients with type 2 diabetes mellitus (T2DM). Methods This was a single-center cross-sectional analysis of a prospectively maintained clinical registry at a standardized metabolic disease management center. Adults with T2DM assessed between January 10, 2022, and April 30, 2026, were included, and each patient contributed one standardized visit selected for analysis (the index assessment). The primary outcome was a screening abnormality in at least two of three organ domains: vascular, renal, and peripheral nerve. We used multivariable logistic regression to estimate adjusted cross-sectional associations and 20 repeats of stratified fivefold cross-validation to assess the discrimination and calibration of three prespecified nested models. Results The analysis included 674 patients with a mean age of 52.6 years, of whom 62.9% were men. Among them, 342 (50.7%) had abnormalities in at least two organ domains. Of the 112 patients with current HbA1c <7.0%, 44 (39.3%) had multiorgan abnormalities. Current HbA1c was not clearly associated with the outcome after adjustment (adjusted odds ratio [OR] per 1-percentage-point increase, 1.04; 95% confidence interval [CI], 0.96–1.13), whereas age, diabetes duration, and systolic blood pressure were independently associated with it. The cross-validated area under the receiver operating characteristic curve (AUC) was 0.523 (95% CI, 0.479–0.568) for HbA1c alone and 0.775 (95% CI, 0.740–0.810) after age, sex, diabetes duration, BMI, and systolic blood pressure were added. The difference in AUC was 0.251 (95% CI, 0.195–0.304). Conclusions A single current HbA1c measurement had limited discriminatory ability for concurrent clustering of multiorgan screening abnormalities in adults with T2DM. Adding age, sex, diabetes duration, BMI, and systolic blood pressure to HbA1c substantially improved discrimination of this clustering phenotype. Age, diabetes duration, and systolic blood pressure were independently associated with multiorgan abnormalities.