Effect of Hyperlipidemia on Glycosylated Hemoglobin Determinations by Affinity Chromatography

To the Editor.  —Hypertriglyceridemia, a common finding in diabetes mellitus, has been shown to falsely elevate glycosylated hemoglobin (GHbA₁) levels when measured by cation-exchange column chromatography.^1,2 Falko et al¹ demonstrated this effect in vivo when triglyceride concentrations exceed 1,750 mg/dL (20 mmole/L) and confirmed this by the in vitro addition of lipemic plasma to a control sample. A triglyceride concentration of 9,316 mg/dL (105 mmole/L) produced an apparent eightfold increase in GHbA₁.Estimation of GHbA₁ levels by affinity chromatography as described by Hall et al³ is becoming increasingly used and it is, therefore, important to know whether the same effect is found.We have used this method to investigate the effects of lipemia on GHbA₁ estimations. Glycosylated hemoglobin levels were estimated on grossly lipemic samples (with plasma triglyceride concentrations of 43, 48, and 89 mmole/L, respectively) from three patients, using both washed and