The Level of N-Carboxymethyllysine and C-Reactive Protein in Type 2 Diabetes Mellitus and it’s Association with HbA1c in Diabetic Nephropathy

@#Introduction: N-Carboxymethyllysine (CML) is involved in diabetic nephropathy (DN) via production of oxidative stress, growth factors and cytokines. C-reactive protein (CRP) is an inflammatory marker associated with diabetes risk. This study is to determine the level of serum CML and CRP in Type 2 diabetes mellitus (T2DM) patients and healthy subjects and to determine the correlation between CML and CRP with glycated haemoglobin (HbA1c) in T2DM patients. Methods: This is a case-control study on 73 T2DM patients without nephropathy, 74 T2DM patients with nephropathy and 73 healthy subjects, aged from 18 to 65 years old. Fasting venous blood was taken and analysed for CML, CRP, HbA1c, and creatinine. The comparisons of serum CML and CRP among the three groups and the correlation between CML and CRP with HbA1c (in T2DM patients) were determined. Results: The differences in CML [median (Interquartile Range) (IQR)] between healthy subjects [131.80 (73.56) ng/ml] and T2DM patients without nephropathy [188.80 (55.95) ng/ml]; between healthy subjects and T2DM patients with nephropathy [237.70 (439.04) ng/ml] were statistically significant (P<0.001). The differences in CRP [median (IQR)] between healthy subjects [1.64 (1.91) ng/ml] and T2DM patients without nephropathy [2.15 (5.64) ng/ml]; between healthy subjects and T2DM patients with nephropathy [4.75 (6.91) ng/ml] were statistically significant (P<0.001). Logistic regression showed CML and CRP are independent predictors of diabetic groups. There was no correlation between HbA1c with CML and CRP in T2DM groups. Conclusion: Since serum CML and CRP are independent predictors of DN, their levels can be used to identify high-risk diabetic patients prone to developing DN.

Diabetic nephropathy patients show hyper-responsiveness to N6-carboxymethyllysine

The aim of this study was to evaluate the impact of N6-carboxymethyllysine (CML) on NF-κB gene expression and tumor necrosis factor (TNF) production in diabetic nephropathy. This was an observational study comprised of three groups: diabetic nephropathy (n=30), type II diabetes mellitus (n=28), and healthy volunteers (n=30). Blood samples collected from the study participants were cultured for 24 h in the presence of CML or an appropriate control. After incubation, the cultures were centrifuged to separate the cells from the conditioned media. cDNA was prepared from the cell pellet and used to quantify NF-κB gene expression by quantitative real-time polymerase chain reaction (PCR). The conditioned media were used to measure TNF production by enzyme-linked immunosorbent assay (ELISA). The CML-induced fold change in NF-κB gene expression was significantly different among the study groups (P=5.4×10-5). Also, the CML-induced fold change in TNF levels was significantly different among the three groups (P=4.3×10-8). These results imply that patients with diabetic nephropathy and type II diabetes mellitus showed an elevated response to CML.

Produtos da reação de Maillard em alimentos industrializados / Maillard reaction products in processed food

The ingestion of Maillard-reaction products (MRP) has increased over thelast decades in the urban areas and there are evidences that these substancesmay be absorbed and can play an important role in pathologies. PRM determination in processed foods, as well as their ingestion level from the daily diet, have been evaluated by several studies in countries within the Northern hemisphere, but there are no equivalent studies in South America. In this study, we evaluated the contents of furosine (FUR), hydroxymethylfurfural(HMF), carboxymethyllysine (CML) and fluorescent substances in flake cereals, granola-type cereals, medium-roasted coffee and powder milk from different brands. Fluorescent spectrophotometry, high performance liquid chromatography and immunoenzymatic methods were employed. Data were analyzed by descriptive statistics and principal component analysis. A great variation in MRP content for the same food product was observed. Powder milk, despite being the food product with the highest lipid content, has a low MRP content (average 7.6 mg/100g), while coffee has the highest amount (278.6 mg/100g) due to the severe thermal treatment it undergoes.These data are representative of these food products available in the marketand may be used for estimating MRP intake by the population.

El consumo de productos de la reacción de Maillard (PRM) en las áreas urbanas aumentó en las últimas décadas y hay evidencias de que estas substancias son absorbidas y pueden participar en procesos patológicos. La determinación del teor de PRM en alimentos industrializados, así como el consumo de estos compuestos a partir de la dieta ha sido evaluado en estudios conducidos en países del hemisferio Norte, pero no hay estudios equivalente en la America del Sur. En este trabajo analizamos los tenores de substancias fluorescentes, furosina, hidroximetilfurfural y carboximetillisina encereales del tipo escamas, cereales del tipogranola, café en polvo de torrefacción media, gelatina "diet" y leche en polvo integral dediferentes marcas y lotes. Las técnicas utilizadas fueron espectrofotometría de fluorescencia, cromatografía líquida de alto desempeño y teste inmunoenzimático. Los datos fueron analizados mediante estadística descriptiva y análisis decomponentes principales (PCA). Se observó grande variación en el contenido de PRM en los alimentos analizados. La leche en polvo, apesar de ser al alimento con mayor contenido de lípidos, presentó baja concentración de PRM (tenor medio 7,6mg/100g) mientras el café en polvo presentó el mayor contenido de PRM (278,6mg/100g) debido a la severidad del tratamiento térmico a que es sometido. Los datos obtenidos son representativos de los productos disponibles al consumidor y pueden ser utilizados para estimar el consumo de PRM por la población.

O consumo de produtos da reação de Maillard (PRM), nas áreas urbanas, aumentou nas últimas décadas e há evidências de que estas substâncias são absorvidas e podem tomar parte em processos patológicos. A determinação do teor de PRM em alimentos industrializados, assim como o consumo destes compostos a partir da dieta, têm sido avaliados em estudos conduzidos em países do hemisfério Norte. Não há estudos equivalentes na América do Sul. Neste trabalho, analisamos os teores de substâncias fluorescentes, furosina, hidroximetilfurfural e carboximetillisina em cereais do tipo flocos e do tipo granola, café em pó torra média, gelatina diet e leite integral em pó integral de diferentes marcas e lotes. As técnicas utilizadas foram espectrofotometria defluorescência, cromatografia líquida de alta eficiência e teste imunoenzimático. Os dados foram submetidos à análise estatística descritiva e Análise de Componentes Principais (ACP). Observou-se grande variabilidade no teor de PRM, nos alimentos analisados. O leite em pó, apesar de ser o alimento com maior teor delipídios, apresentou baixa concentração de PRM(teor médio 7,6mg/100g) enquanto o café em pó, apresentou o maior teor de PRM (278,6mg/100g) devido à severidade do tratamento térmico ao qual é submetido. Os dados obtidos são representativos dos produtos disponíveis ao consumidor e podem ser utilizados para estimar o consumo de PRM pela população. Palavras-chave: Reação de Maillard.