Fructosamine

Fructosamine means your glycated serum proteins, chiefly albumin, formed when glucose sticks on non-enzymatically and rearranges into a stable ketoamine (the Amadori product). Because albumin turns over in about 14 to 21 days, fructosamine reflects your glucose over the past 2 to 3 weeks. HbA1c, by contrast, covers 8 to 12 weeks. Reference values run 200 to 285 µmol/L. Its main use is to stand in for HbA1c when red blood cells turn over abnormally. Several conditions distort HbA1c: hemolytic anemia, sickle-cell disease, iron- or B12-deficiency anemia, EPO-treated kidney disease, and pregnancy. But fructosamine itself is unreliable below a serum albumin of 3.0 g/dL (as in cirrhosis, nephrotic syndrome, or protein-losing gut disease). In that case, a separately measured glycated albumin is preferred. In ARIC (Selvin et al., 2014; about 12,300 people; up to 20 years), high fructosamine predicted new diabetes and small-vessel complications about as well as HbA1c. Its links to retinopathy and kidney disease held even after adjusting for HbA1c. In AMORIS (Malmström et al., 2015; 338,443 people; median 19 years), heart-attack and all-cause death risk rose at 2.30 mmol/L and above. The highest tier (2.70 mmol/L or more) carried a hazard ratio of 2.88 for heart attack and 2.31 for all-cause death, after adjustment. In people in their 80s without diabetes, albumin-corrected fructosamine predicted all-cause death (HR 1.27 per 1 µmol/g; Zhou et al., 2022). One caveat: fructosamine assays are not standardized across labs. And no trial has shown it adds causal risk beyond the high blood sugar it reflects.

Last reviewed: June 22, 2026

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