Limits...
Glycation of nail proteins: from basic biochemical findings to a representative marker for diabetic glycation-associated target organ damage.

Kishabongo AS, Katchunga P, Van Aken EH, Speeckaert R, Lagniau S, Coopman R, Speeckaert MM, Delanghe JR - PLoS ONE (2015)

Bottom Line: A significant higher amount of glycated eye lens proteins was found in diabetes mellitus patients (mean: 3.80 ± 1.57 μmol/g eye lens) in comparison with nondiabetics (mean: 3.35 ± 1.34 μmol/g eye lens) (P<0.05).The concentration of glycated eye lens proteins and the HbA1c level were found to be predictors of the concentration of glycated nail proteins.Glycation of nail proteins can be regarded as a representative marker for diabetic glycation-associated target organ damage.

View Article: PubMed Central - PubMed

Affiliation: Department of Laboratory Medicine, Catholic University of Bukavu, Bukavu, Democratic Republic of the Congo.

ABSTRACT

Background: Although assessment of glycated nail proteins may be a useful marker for monitoring of diabetes, their nature and formation are still poorly understood. Besides a detailed anatomical analysis of keratin glycation, the usefulness of glycated nail protein assessment for monitoring diabetic complications was investigated.

Methods: 216 patients (94 males, 122 females; mean age ± standard deviation: 75.0 ± 8.7 years) were enrolled. Glycation of nail and eye lens proteins was assessed using a photometric nitroblue tetrazolium-based assay. Following chromatographic separation of extracted nail proteins, binding and nonbinding fractions were analyzed using one-dimensional gel electrophoresis. Using a hand piece containing a latch-type-bur, a meticulous cutting of the nail plate into superficial and deep layers was performed, followed by a differential analysis of fructosamine.

Results: Using SDS PAGE, four and two bands were identified among the nonglycated and glycated nail fraction respectively. Significantly lower fructosamine concentrations were found in the superficial nail layer (mean: 2.16 ± 1.37 μmol/g nails) in comparison with the deep layer (mean: 4.36 ± 2.55 μmol/g nails) (P<0.05). A significant higher amount of glycated eye lens proteins was found in diabetes mellitus patients (mean: 3.80 ± 1.57 μmol/g eye lens) in comparison with nondiabetics (mean: 3.35 ± 1.34 μmol/g eye lens) (P<0.05). A marked correlation was found between glycated nail and glycated eye lens proteins [y (glycated nail proteins) = 0.39 + 0.99 x (eye lens glycated proteins); r2 = 0.58, P<0.001]. The concentration of glycated eye lens proteins and the HbA1c level were found to be predictors of the concentration of glycated nail proteins.

Conclusions: Glycation of nail proteins takes place in the deep layer of finger nails, which is in close contact with blood vessels and interstitial fluid. Glycation of nail proteins can be regarded as a representative marker for diabetic glycation-associated target organ damage.

Show MeSH

Related in: MedlinePlus

Correlation between glycated nail proteins and glycated eye lens proteins in the combined group of diabetes patients and nondiabetics (n = 51).The equation of linear regression is y (glycated nail proteins) = 0.39 + 0.99 x (glycated eye lens proteins) (r2 = 0.58; P<0.001).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4363324&req=5

pone.0120112.g003: Correlation between glycated nail proteins and glycated eye lens proteins in the combined group of diabetes patients and nondiabetics (n = 51).The equation of linear regression is y (glycated nail proteins) = 0.39 + 0.99 x (glycated eye lens proteins) (r2 = 0.58; P<0.001).

Mentions: As already demonstrated in our previous work, the concentration of glycated nail proteins is significantly higher in patients with diabetes mellitus type than in nondiabetics [1]. However in this study, we showed that after meticulous cutting of nail clippings into superficial and deep layers (n = 12), a significantly lower concentration of fructosamine was found in the superficial layer of the nail (mean: 2.16 ± 1.37 μmol/g nails) in comparison with the deep layer of the nail (mean: 4.36 ± 2.55 μmol/g nails) (P<0.05) (Fig. 2). Moreover, the measurement of glycated eye lens proteins revealed a significant difference between diabetes mellitus type 2 patients (n = 63, mean: 3.80 ± 1.57 μmol/g eye lens) and nondiabetics (n = 153, mean: 3.35 ± 1.34 μmol/g eye lens) (P<0.05). In a subgroup of 51 cataract patients, the concentration of glycated nail and eye lens proteins was determined. A marked correlation was found between glycated nail proteins and glycated eye lens proteins [y (glycated nail proteins) = 0.39 + 0.99 x (glycated eye lens proteins); r2 = 0.58, P<0.001] (Fig. 3). This correlation was even stronger in diabetes mellitus type 2 patients [n = 35, y (glycated nail proteins) = 0.26 + 1.12 x (glycated eye lens proteins), r2 = 0.71, P<0.001] than in nondiabetics [n = 16, y (glycated nail proteins) = 0.19 + 0.83 x (glycated eye lens proteins), r2 = 0.56, P = 0.001] (Fig. 4). By using multiple regression analysis (Table 1), the concentration of glycated nail proteins was found to be a predictor of the concentration of glycated lens proteins and the HbA1c level. Age and sex did not reach significance in this model.


Glycation of nail proteins: from basic biochemical findings to a representative marker for diabetic glycation-associated target organ damage.

Kishabongo AS, Katchunga P, Van Aken EH, Speeckaert R, Lagniau S, Coopman R, Speeckaert MM, Delanghe JR - PLoS ONE (2015)

Correlation between glycated nail proteins and glycated eye lens proteins in the combined group of diabetes patients and nondiabetics (n = 51).The equation of linear regression is y (glycated nail proteins) = 0.39 + 0.99 x (glycated eye lens proteins) (r2 = 0.58; P<0.001).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4363324&req=5

pone.0120112.g003: Correlation between glycated nail proteins and glycated eye lens proteins in the combined group of diabetes patients and nondiabetics (n = 51).The equation of linear regression is y (glycated nail proteins) = 0.39 + 0.99 x (glycated eye lens proteins) (r2 = 0.58; P<0.001).
Mentions: As already demonstrated in our previous work, the concentration of glycated nail proteins is significantly higher in patients with diabetes mellitus type than in nondiabetics [1]. However in this study, we showed that after meticulous cutting of nail clippings into superficial and deep layers (n = 12), a significantly lower concentration of fructosamine was found in the superficial layer of the nail (mean: 2.16 ± 1.37 μmol/g nails) in comparison with the deep layer of the nail (mean: 4.36 ± 2.55 μmol/g nails) (P<0.05) (Fig. 2). Moreover, the measurement of glycated eye lens proteins revealed a significant difference between diabetes mellitus type 2 patients (n = 63, mean: 3.80 ± 1.57 μmol/g eye lens) and nondiabetics (n = 153, mean: 3.35 ± 1.34 μmol/g eye lens) (P<0.05). In a subgroup of 51 cataract patients, the concentration of glycated nail and eye lens proteins was determined. A marked correlation was found between glycated nail proteins and glycated eye lens proteins [y (glycated nail proteins) = 0.39 + 0.99 x (glycated eye lens proteins); r2 = 0.58, P<0.001] (Fig. 3). This correlation was even stronger in diabetes mellitus type 2 patients [n = 35, y (glycated nail proteins) = 0.26 + 1.12 x (glycated eye lens proteins), r2 = 0.71, P<0.001] than in nondiabetics [n = 16, y (glycated nail proteins) = 0.19 + 0.83 x (glycated eye lens proteins), r2 = 0.56, P = 0.001] (Fig. 4). By using multiple regression analysis (Table 1), the concentration of glycated nail proteins was found to be a predictor of the concentration of glycated lens proteins and the HbA1c level. Age and sex did not reach significance in this model.

Bottom Line: A significant higher amount of glycated eye lens proteins was found in diabetes mellitus patients (mean: 3.80 ± 1.57 μmol/g eye lens) in comparison with nondiabetics (mean: 3.35 ± 1.34 μmol/g eye lens) (P<0.05).The concentration of glycated eye lens proteins and the HbA1c level were found to be predictors of the concentration of glycated nail proteins.Glycation of nail proteins can be regarded as a representative marker for diabetic glycation-associated target organ damage.

View Article: PubMed Central - PubMed

Affiliation: Department of Laboratory Medicine, Catholic University of Bukavu, Bukavu, Democratic Republic of the Congo.

ABSTRACT

Background: Although assessment of glycated nail proteins may be a useful marker for monitoring of diabetes, their nature and formation are still poorly understood. Besides a detailed anatomical analysis of keratin glycation, the usefulness of glycated nail protein assessment for monitoring diabetic complications was investigated.

Methods: 216 patients (94 males, 122 females; mean age ± standard deviation: 75.0 ± 8.7 years) were enrolled. Glycation of nail and eye lens proteins was assessed using a photometric nitroblue tetrazolium-based assay. Following chromatographic separation of extracted nail proteins, binding and nonbinding fractions were analyzed using one-dimensional gel electrophoresis. Using a hand piece containing a latch-type-bur, a meticulous cutting of the nail plate into superficial and deep layers was performed, followed by a differential analysis of fructosamine.

Results: Using SDS PAGE, four and two bands were identified among the nonglycated and glycated nail fraction respectively. Significantly lower fructosamine concentrations were found in the superficial nail layer (mean: 2.16 ± 1.37 μmol/g nails) in comparison with the deep layer (mean: 4.36 ± 2.55 μmol/g nails) (P<0.05). A significant higher amount of glycated eye lens proteins was found in diabetes mellitus patients (mean: 3.80 ± 1.57 μmol/g eye lens) in comparison with nondiabetics (mean: 3.35 ± 1.34 μmol/g eye lens) (P<0.05). A marked correlation was found between glycated nail and glycated eye lens proteins [y (glycated nail proteins) = 0.39 + 0.99 x (eye lens glycated proteins); r2 = 0.58, P<0.001]. The concentration of glycated eye lens proteins and the HbA1c level were found to be predictors of the concentration of glycated nail proteins.

Conclusions: Glycation of nail proteins takes place in the deep layer of finger nails, which is in close contact with blood vessels and interstitial fluid. Glycation of nail proteins can be regarded as a representative marker for diabetic glycation-associated target organ damage.

Show MeSH
Related in: MedlinePlus