by What is Glycated Albumin?
Glycated albumin is a form of human serum albumin that has become attached or bound to glucose. Albumin is the most abundant protein found in blood plasma and helps transport substances like fatty acids, hormones, bilirubin, and pharmaceuticals through the bloodstream. In patients with diabetes, elevated blood glucose levels can cause albumin proteins to become glycated through a non-enzymatic reaction known as glycosylation. This leads to the formation of glycated albumin, which is also known as fructosamine.
How Does Glycation of Albumin Occur?
Glycated Albumin Assay process involves glucose or other aldose sugars binding non-enzymatically to the amino groups of proteins like albumin. This initially forms a reversible Schiff base, but then further rearrangement occurs to form a more stable ketoamine linkage known as the Amadori product. The rate at which albumin becomes glycated depends on both blood glucose and albumin concentrations as well as albumin turnover. Glycation occurs gradually over time as proteins circulate exposed to high blood glucose levels. The percentage of glycated albumin rises in proportion to average blood sugar levels over the preceding 2-3 weeks.
Why Measure Glycated Albumin?
Glycated albumin levels provide information about long-term glycemic control that is not influenced by recent fluctuations in blood sugar levels, unlike HbA1c. This makes it a more accurate marker for patients with conditions that can impact red blood cell lifespan and hemoglobin turnover rates—factors that can affect HbA1c readings. Measuring glycated albumin is particularly useful for monitoring diabetes control in patients with kidney disease, anemia, recent blood transfusions, or hemoglobinopathies that may limit the reliability of HbA1c testing. It can also help evaluate diabetes management in patients on treatment regimens like continuous glucose monitoring that aim to minimize glucose variability and improve glycemic stability between readings.
How is Glycated Albumin Analyzed?
There are a few different methods used clinically to measure glycated albumin levels. Early immunoassays employed antibodies specifically designed to detect and quantify the glycated form of albumin present in a blood sample. More recently developed enzymatic methods involve albumin-specific proteases that cleave glycated albumin sites, releasing aldehydes and ketones which can then react with a fluorogenic or chromogenic compound to generate a signal proportional to glycated albumin concentration. Automated laboratory instruments calibrate test results by comparing sample readings to reference standards of known glycated albumin content. Results are expressed either as apercentage of total albumin that is glycated or a milligram per deciliter absolute concentration value.
What Are Normal Glycated Albumin Assay Levels?
The reference range for normal glycated albumin levels can vary slightly depending on the assay method used and individual laboratory standards. In general:
– Less than 16-18% is considered normal or well-controlled diabetes.
– 16-18% to less than 22-24% indicates fair/moderate control of blood glucose levels.
– 22-24% or above suggests poor control and elevated average blood sugar over the prior 2-3 weeks.
For diabetic patients trying to optimize their blood glucose management, the goal glycated albumin level recommended by international clinical guidelines is usually below 18-20%. Levels below 16% indicate very good long-term blood sugar control approaching nondiabetic ranges. Periodic monitoring allows patients and their healthcare providers to assess treatment effectiveness and make adjustments as needed to maintain glycated albumin in the target range.
Correlating Glycated Albumin to HbA1c
Studies have found glycated albumin levels correlate reasonably well with measured HbA1c, especially for HbA1c values between 6-10%. However, the relationship depends on factors like kidney function. In general:
– A glycated albumin level below 16% typically correlates to an HbA1c less than 6.5%.
– 16-20% glycated albumin usually matches an HbA1c of 6.5-8%.
– Above 20% glycated albumin would suggest an HbA1c over 8%.
However, glycated albumin may register a higher percentage than implied by HbA1c alone in patients with poor glycemic control or albumin disorders. So direct correlation is inadvisable, and both tests provide independent verification of long-term glucose management when used together.
Role in Diabetes Management and Monitoring
Measuring glycated albumin assay fills an important niche by capturing glycemic control over a 2-3 week window not fully reflected by HbA1c. It can help:
– Detect problems between routine HbA1c tests done every 3-6 months.
– Adjust diabetes regimens and minimize glucose variability in patients using glucose monitoring and insulin pump technologies.
– Monitor treatment effects on glycemia in clinical trials of new diabetes medications.
– Gauge diabetes control in special populations where HbA1c may have limitations.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
