Mission Statement

SCE Announcement

SCE-ESVE-ABEV endorsed comment regarding serum fructosamine measurement

For differentiating stress hyperglycemia from diabetes mellitus:

Increased serum fructosamine indicates the presence of chronic hyperglycemia and is consistent with the diagnosis of diabetes. For diagnosis of diabetes, it is highly recommended to correlate the fructosamine result with clinical signs. Note that hyperproteinemia or diseases associated with decreased protein turnover (e.g., hypothyroidism) can cause an increase in serum fructosamine.

For support of diagnosis of chronic hypoglycemia:

Decreased serum fructosamine indicates the presence of chronic hypoglycemia and is consistent with insulinoma as well as other causes of chronic hypoglycemia (e.g., paraneoplastic syndrome, liver failure, hypoadrenocorticism). For diagnosis of insulinoma, it is highly recommended to document increased or inappropriate serum insulin concentration with concurrent hypoglycemia. Note that increased protein turnover or low serum protein concentration can cause a decrease in serum fructosamine.

For diabetes monitoring:

Serum fructosamine concentrations (SF) reflect average blood glucose concentrations (BG) over 2-3 weeks. As such, it cannot be used to rule out episodic (but clinically important) hypoglycemia. Not all laboratories generate equivalent fructosamine results and so reference to previously published thresholds for ‘excellent’, ‘good’, and ‘poor’ glycemic control are not appropriate and not provided. Instead, it is recommended to compare SF in an individual to previous SF from that individual: Assuming results are obtained from the same analyzer, and serum proteins are not significantly different, an increase in SF would then indicate an increase in average BG while a decrease in SF would indicate a decrease in average BG. While low SF is consistent with chronic hypoglycemia, and insulin-treated animals with SF within the reference interval might be experiencing significant periods of hypoglycemia, episodic hypoglycemia cannot be ruled out with any SF value.

General comments:

Hemolysis and lipemia affect the laboratory’s ability to analyze serum fructosamine and should be avoided.

Diseases influencing plasma protein concentrations or metabolism could affect the fructosamine result:

Lower than expected/discordantly low (falsely low):

• Hyperthyroidism
• Hypoproteinemia/hypoalbuminemia
• Hypertriglyceridemia/hyperlipidemia
• Azotemia
• Prolonged storage at room temperature

Higher than expected/discordantly high (or falsely normal to high):

• Hyperproteinemia/hyperglobulinemia
• Hypertriglyceridemia/hyperlipidemia
• Hypothyroidism