Measuring Glycated Proteins: Clinical and Methodological Aspects

Abstract

The recognition that nonenzymatic glycation, wherein free sugar condenses with certain reactive protein amino groups, is increased in hyperglycemic states has led to improved means for assessing diabetic control through the measurement of concentrations of glycated proteins in the circulation. This article reviews the chemistry, methods for measurement, and clinical relevance of circulating glycated proteins in the management of diabetes.

Risk indicators of metabolic syndrome in young adults: A preliminary investigation on the influence of tobacco smoke exposure and gender

“…Although less widely used, percentage of glycated albumin has been shown to be highly correlated with HbA1c 76 and more reliable than HbA1c in evaluating mean blood glucose from week to week. 16 The suggestion of lowered mean blood glucose as indicated by percentage of glycated albumin in smokers supports the findings of some researchers 42,44,45 but not others. 39,41 The conflicting nature of these results may be related to the age of the participants, with the current study the only one to investigate the interaction in smokers during their early years of tobacco use (ie, younger than middleaged).…”

“…Proteins in the blood are glycated by a nonenzymatic reaction, the rate of which is dependent on the concentration of glucose in the blood. 16 Two proteins are commonly measured for glycation: hemoglobin and albumin. HbA1c, the most commonly measured glycated protein, has a half-life of 2 months, and the percentage of glycated albumin provides inference regarding mean blood glucose for the preceding 2-month period.…”

“…3,4 Although not essential to the diagnosis of metabolic syndrome, many other variables have been shown to be highly associated with the presence of the syndrome as well. These include elevated plasma levels of C-reactive protein (CRP) and proinflammatory cytokine interleukin 1-beta (IL1␤), [5][6][7][8][9][10][11][12] reduced levels of anti-inflammatory cytokines including IL-10, 13,14 elevated plasminogen activator inhibitor type-1, 10,15 elevated hemoglobin A1c (HbA1c) or glycated albumin, 16 elevated leptin, [17][18][19] and elevated homocysteine. 20,21 In addition, a body mass index (BMI) greater than 25 and age greater than 40 years are identified risk factors for metabolic syndrome.…”

The role of ribosylated-BSA in regulating PC12 cell viability

“…Thus, the influence of protein ribosylation on protein conformation and function cannot be ignored. Human serum albumin (HSA), the most abundant plasma protein is synthesized in the liver and circulates in the body for 12-19 days before being degraded (Brownlee 1995;Cohen and Clements 1999). Glycated HSA has been shown to accounts for 80 % of the circulating glycated protein (Cohen 2003) and is also a factor in antioxidants (Coussons et al 1997).…”

Glycated proteins: Clinical utility and analytical approaches

“…This product accounts for approximately 80% of HgbA1 and about half of the total GHb (Benjamin and Sacks, 1994). Other glycohemoglobin species products have glucose linked to an ϵ-amino group of one or more of their lysine residues on their α or β chain (Cohen and Clements, 1999).…”