Noninvasive Diabetes Monitoring Through Urine Analysis Using UV‐Vis Spectroscopy

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by impaired insulin secretion or utilization. Conventional glucose monitoring methods, including blood‐based assays such as HbA1c testing, are invasive and may reduce patient compliance. Therefore, the development of noninvasive analytical approaches is of considerable clinical interest. This study investigated the feasibility of ultraviolet–visible (UV–Vis) spectroscopy for estimating blood glucose levels using urine samples within a method‐comparison framework. Standard glucose solutions and urine samples from diabetic and nondiabetic individuals were analyzed to establish calibration and predictive models. A characteristic absorbance region associated with glucose was observed between 276.0 and 289.5 nm, and the calibration model demonstrated excellent linearity ( R 2 = 0.9996). Correlation between urine absorbance and reference blood glucose measurements followed an exponential trend ( R 2 = 0.9981). Agreement‐based evaluation yielded a mean absolute deviation (MAD) of 0.047 mmol/L and a root mean squared error (RMSE) of 0.068 mmol/L, indicating low prediction error within the physiological glucose range. Instrumental sensitivity assessed according to ICH guidelines resulted in a limit of detection (LoD) of 1.87 × 10 −7 mmol/L and a limit of quantification (LoQ) of 5.66 × 10 −7 mmol/L. Classification based on urine absorbance values after 500‐fold dilution showed trends consistent with established fasting glucose criteria in SI units. These findings provide preliminary evidence supporting the analytical feasibility and methodological consistency of UV–Vis spectroscopy as a minimally invasive screening approach for urine‐based glucose assessment.