Test Center

My Recent Searches

  • No Recent Search.

My Tests Viewed

  • No Test Viewed.

GlycoMark (1,5-Anhydroglucitol)

GlycoMark (1,5-Anhydroglucitol)

Test Summary

GlycoMark® (1,5-Anhydroglucitol)


Clinical Use

  • Intermediate-term monitoring of glycemic control in patients with moderate- to well-controlled diabetes

Clinical Background

Tight glycemic control is essential for preventing the complications of diabetes. The clinical standard for evaluating glycemic control is the measurement of hemoglobin A1c (HbA1c); elevated levels (>7.0%) indicate significant hyperglycemia. However, even in patients with well-controlled HbA1c levels, postprandial glucose levels may be significantly elevated and lowering these will further improve control.

1,5-Anhydroglucitol (1,5-AG) is a glucose-like monosaccharide contained in food. Intake is normally balanced with urinary excretion; however, during periods of hyperglycemia, glucose blocks reabsorption of 1,5-AG in the renal tubules. Thus, low blood levels of 1,5-AG are associated with hyperglycemia. 1,5-AG levels change more rapidly than HbA1c levels and reflect glycemia over the previous 1-2 week period.

Individuals Suitable for Testing

  • Patients with type 1 or 2 diabetes mellitus


  • Enzymatic release of hydrogen peroxide followed by colorimetric detection

  • Analytical sensitivity: 0.2 µg/mL

  • Reportable range: 0.2-110 µg/mL

Interpretive Information

In patients with moderate- to well-controlled diabetes (HbA1c <8.0%), increasing 1.5-AG levels reflect a positive short- to intermediate-term response to changes in diet or medication. In patients with poorly-controlled diabetes, in vivo levels of 1,5-AG may be depleted; thus, in this group 1,5-AG measurements may not accurately reflect therapeutic response. Increased levels are also associated with intravenous hyperalimentation and some Chinese medicines (eg, polygala tenuifolia and senega syrup).

Low levels (<8 μg/mL) of 1,5-AG primarily reflect postprandial hyperglycemia (ie, glucose >180 mg/dL). They are also associated with pregnancy, kidney disease, advanced cirrhosis, prolonged inability to intake food orally, and with steroid therapy.


  1. Dungan KM, Buse JB, Largay J, et al. 1,5-Anhydroglucitol and postprandial hyperglycemia as measured by continuous glucose monitoring system in moderately controlled patients with diabetes. Diabetes Care. 2006;29:1214-1219.

  2. McGill JB, Cole TG, Nowatzke W, et al. Circulating 1,5-anhydroglucitol levels in adult patients with diabetes reflect longitudinal changes of glycemia. Diabetes Care. 2004;27:1859-1865.

  3. Nguyen TM, Rodriguez LM, Mason KJ, et al. Serum 1,5-anhydroglucitol (Glycomark) levels in children with and without type 1 diabetes mellitus. Pediatr Diabetes. 2007;8:214-219.

Content reviewed 12/2012

top of page

* The tests listed by specialist are a select group of tests offered. For a complete list of Quest Diagnostics tests, please refer to our Directory of Services.