Assessment of glycerol-related analytical bias in triglyceride estimation for patients with type 2 diabetes.

INTRODUCTION

Standard triglyceride assays may overestimate true triglyceride concentrations due to endogenous glycerol interference, particularly in type 2 diabetes, where enhanced lipolysis elevates circulating free glycerol. We compared glycerol-blanked and non-blanked triglyceride assays in patients with type 2 diabetes to quantify analytical bias and assess impact on cardiovascular risk indices.

METHODS

This cross-sectional study enrolled 200 patients with type 2 diabetes and 200 healthy control individuals. Serum triglyceride levels were measured using glycerol-blanked (Sekisui) and nonblanked (Beckman Coulter) enzymatic assays. Bias assessment, correlation analysis, and impact on atherogenic index of plasma were evaluated.

RESULTS

Median nonblanked triglyceride values were substantially higher than glycerol-blanked triglyceride values in control individuals (129.5 vs 120.95 mg/dL, P = .02) and patients with type 2 diabetes (158.5 vs 136.85 mg/dL, P = .0019). Overestimation was greater in patients (median difference, 16.1 mg/dL) than in control individuals (9.95 mg/dL, P = .0001). Bland-Altman analysis showed higher mean (SD) bias in patients with type 2 diabetes (-21.25 [41.51] mg/dL) than in control individuals (-13.26 [31.26] mg/dL). The triglyceride- glycerol-blanked triglyceride difference correlated with glycated hemoglobin values in individuals with type 2 diabetes (ρ = 0.141, P = .0473).

DISCUSSION: Glycerol-blanked triglyceride assays provide more accurate lipid assessment in type 2 diabetes, improving cardiovascular risk stratification and therapeutic decision-making.