Glycated Protein Precipitation Index: Bridging the Gap Between Short-Term and Long-Term Glycemic Markers

BackgroundCurrent glycemic monitoring exhibits a critical temporal gap between fructosamine (14-21 days) and HbA1c (90-120 days), limiting timely therapeutic adjustments. The Glycated Protein Precipitation Index (GPPI) represents a novel biomarker potentially bridging this interval. ObjectiveTo validate GPPIs correlation with established glycemic markers and determine its clinical utility for intermediate-term glycemic assessment. Methods: This prospective validation study will enroll 200 diabetic patients and 100 normoglycemic controls. GPPI leverages differential precipitation of glycated versus native serum proteins using trichloroacetic acid at optimized concentrations, followed by colorimetric quantification with bromophenol blue at 595nm. Primary endpoint: correlation coefficient between GPPI and HbA1c (target r>0.85). Secondary endpoints include analytical precision (CV<5%), interference assessment, reference interval establishment, and cost-effectiveness analysis. Simultaneous HbA1c, fasting glucose, and continuous glucose monitoring (subset n=50) will provide comparative data. Deming regression, Bland-Altman analysis, and ROC curves will assess method agreement and diagnostic performance. Expected OutcomesGPPI should reflect 6-8 week glycemic control with strong HbA1c correlation, offering cost reduction from $15-30 to $0.24 per test. Simplified visual interpretation enables field deployment in resource-limited settings, potentially democratizing diabetes monitoring for underserved populations globally.