Effect of aspirin on determinations of glycosylated hemoglobin.

We investigated the in vivo and in vitro effects of aspirin on several clinical assays of glycosylated hemoglobin. Acetylation of hemoglobin falsely increased the glycosylated hemoglobin fraction measured by "high-performance" liquid chromatography and electrophoresis, but isoelectric focusing and colorimetric techniques differentiated between acetylated and glycosylated fractions. Aspirin ingestion may result in an apparent increase in glycosylated hemoglobin measured with common clinical assays.