Changes in glycated proteins during impaired glucose tolerance

In persons with impaired glucose tolerance, serum glycated proteins (9.44±1.46μg hexose/mg protein) increased 1.69-fold (P<0.001) over control subjects compared to an increase of 1.95-fold in overt diabetics. However, correlations between serum glycated protein values and 2 h blood sugar values during the tolerance test (r=0.39) and between the former and graph area (r=0.30) were not strong. Glycated albumin (2.25 mol hexose/mol protein) and glycated haemoglobin (0.398±0.07 mol hexose/mol protein) in the study group also showed 1.67 and 1.24-fold increase respectively compared to controls. Fairly good correlations between glycated serum protein and glycated albumin (r=0.50) and glycated haemoglobin (r=0.45) were observed during this study. The data suggest that measurement of glycated proteins will be a useful index to detect impaired glucose tolerance.     

A Case of Inappropriately High Glycated Hemoglobin

Hemoglobin is a tetramer formed of two alpha and two beta globin chains. On exposure to high levels of blood glucose, hemoglobin gets non-enzymatically glycated at different sites in the molecule. HbA1c is formed when glucose gets added on to the N-terminal valine residue of the beta chain of hemoglobin. The development of chronic vascular complications of diabetes such as retinopathy, nephropathy and cardiovascular disease is intimately linked to the level of glycemic control attained by the individual with diabetes. We report a case of convulsions and monoplegia admitted to emergency department, showing unusually high glycated hemoglobin but plasma glucose not as high. The patient was not a known diabetic and we could not find any of the other documented conditions that are known to elevate glycated hemoglobin to such disproportionately high levels. Screening for abnormal hemoglobins was negative in the patient. Oral hypoglycemic drug treatment over 3 months and withdrawal of other medications only marginally lowered glycated hemoglobin.     

Glycated nail proteins as a new biomarker in management of the South Kivu Congolese diabetics

Introduction

Diagnosis and monitoring of diabetes mellitus in sub-Saharan Africa, based on blood analyses, are hampered by infrastructural and cultural reasons. The first aim of this study was to evaluate the diagnostic accuracy of glycated nail proteins for diabetes mellitus. The second aim was to compare the course of short- and long-term glycemic biomarkers after 6 months of antidiabetic treatment. These objectives should support our hypothesis that glycated nail proteins could be used as an alternative glycemic biomarker.

Materials and methods

This case-control study consisted of 163 black diabetics and 67 non-diabetics of the South Kivu (Democratic Republic of Congo). Diagnostic accuracy of glycated nail proteins was evaluated using ROC curve analysis. At the start of the study, glycated nail protein concentrations were compared between diabetics and non-diabetics, using a nitro blue tetrazolium (NBT) colorimetric method. In a subgroup of 30 diabetics, concentrations of glycated nail proteins, fasting glucose (Accu-Chek® Aviva), serum fructosamine (NBT) and HbA1c (DCA-2000+®) were measured at start and after 6 months.

Results

ROC analysis yielded an AUC of 0.71 (95% confidence interval (CI): 0.65-0.76) and a cut-off point of 3.83 μmol/g nail. Concentration of glycated nail proteins was significantly higher (P < 0.001) in diabetics in comparison with non-diabetics. After 6 months of antidiabetic treatment, a significant drop in the fasting glucose concentration (P = 0.017) and concentration of glycated nail proteins (P = 0.008) was observed in contrast to serum fructosamine and HbA1c.

Conclusions

Measurement of glycated nail proteins could be used to diagnose and monitor diabetes mellitus in sub-Saharan Africa.Key words: fasting glucose concentration, fructosamine, hemoglobin A1c protein, nails, sub-Saharan Africa, diabetes mellitus     

Effect of vitamin C and E activity on surgically removed cataractous human lens epithelium cells

Oxidative stress has been proposed as a common underlying mechanism of cataractogenesis. Experimental and observational data suggest that micronutrients like vitamin C and vitamin E with antioxidant capabilities may retard the development of age-related cataract. Effect of these factors on lens epithelium cells, center of lens metabolic activities, is not completely elucidated. The aim of present study was to examine the effect of vitamin C and E on surgically removed lens epithelium cells of patients with cataract. Capsulorhexis samples were collected from 170 patients, admitted for cataract surgery. Catalase specific activity was estimated in lens epithelium cells with and without vitamin (C or E) treatment at different concentration for different time duration. Student’s t-test was employed for data analysis. We observed that in ex-vivo condition, a) both vitamin C and E bring about a decrease in catalase activity in lens epithelial cells. b) vitamin C showed toxic effect at high concentration. c) 100μM was the optimum concentration at which both vitamins showed maximum antioxidant activity. It was concluded that both vitamin C and E has direct effect on lens epithelium cells. At optimum concentration, they can reduce oxidative stress in these cells thus can support to prevent or delay cataract development.     

Relationship between free iron and glycated hemoglobin in uncontrolled type 2 diabetes patients associated with complications

Free iron in serum has been found in several disease conditions including diabetes. In the present work, we studied the relationship between free iron, fasting blood glucose (FBG) and glycated haemoglobin (HbA_1c). Study was carried out on 50 type 2 diabetes cases under poor glycemic control associated with complications, 53 type 2 diabetes cases under good glycemic control and 40 healthy controls. We estimated free iron, both ferrous (Fe⁺²) and ferric (Fe⁺³) form, protein thiols, lipid hydroperoxides, FBG, HbA1c and serum ferritin levels in serum. There was a significant increase in free iron in Fe⁺³ state (p <0.01), HbA_1c (p<0.01), serum ferritin (p<0.01), lipid hydroperoxides (p<0.01) and significant decrease in protein thiols (<0.01) in diabetes cases under poor glycemic control compared to diabetes cases under good glycemic control and healthy controls. Free iron correlated positively with HbA_1c (p<0.01). Poor glycemic control and increase in glycation of haemoglobin is contributing to the increase in free iron pool which is known to increase oxidant generation.     

Assessment of oxidative stress and antioxidant status in age related cataract in a rural population

Oxidative stress was assesed by estimating lipid peroxidation product (LPO) in the form of thiobarbituric acid reactive substances (TBARS), enzymatic antioxidants in the form of superoxide dismutase (SOD), catalase and nonenzymatic antioxidant vitamins e.g. vitamin C, β carotene and vitamin E in either serum or plasma or erythrocytes in 190 cases of age related cataract in the age group of 50–80 years. 190 cases were grouped into three morphological types namely, 73 cases of cortical, 77 cases of posterior subcapsular and 40 cases of nuclear cataract and values of LPO and antioxidants were compared with 78 cases of age matched healthy control groups. Plasma TBARS levels were cataract cases when compared with control groups. There were no significant differences in the erythrocyte levels of catalase and plasma levels of Vit E between cataract cases and control groups. No significant changes of parameters were seen among three different morphological types of age related cataract. The present study shows that the oxidative stress may play an important role in the age related cataract.     

Blood lipid peroxidation products and antioxidants in senile cataract

Lipid peroxidation products and antioxidants were estimated in either blood, serum or erythrocytes of 25 cases of early and 25 of advanced senile (50–60 years) cataract and 30 persons of age matched healthy controls. Serum lipid peroxidation products (as malondialdehyde) were significantly higher in patients with early senile (0.25±0.05 μm/dl, P<0.05) and advanced senile cataract (0.29±0.05 μm/dl, P<0.001) as compared to healthy controls (0.22±0.07 μm/dl). Erythrocyte superoxide dismutase levels were lower in patients with early senile (730±60.5 units/gm Hb) and significantly lower in advanced senile (712±50.2 units/gm Hb, P<0.05) cataract than those in healthy controls (767±59.5 units/gm Hb). Serum α-tocopherol was significantly lower (P<0.05) in only advanced senile cataract (0.69±0.08 mg/dl) but not in early senile cataract (0.75±0.08 mg/dl) when compared with healthy controls (0.75±0.09 mg/dl). There was no significant difference in the erythrocyte concentration of reduced glutathione and serum levels of total proteins, β-carotene, vitamin A, ascorbic acid, calcium, magnesium and zinc.     

Analysis of protein posttranslational modifications by mass spectrometry: With special reference to haemoglobin

Mass spectrometry provides a convenient platform for the study of different protein post translational modifications from clinical specimen. Analysis of different post translational modifications of hemoglobin like glycation and glutathionylation can provide useful information on the disease progression and the possible outcome of therapies. In the present study, we have addressed post translational modifications of hemoglobin like glutathionylation and glycation in relation to diabetes and chronic renal failure. We found that both alpha and beta chains of human hemoglobin are glycated irrespective of the extent of glycemia as evidenced by a mass increment of 162 Da. The phenomenon of glutathionylation was observed with only the beta globin chain of hemoglobin probably due to the presence of an accessible cysteine residue indicated by a mass increment of 305 Da. Also, the extent of gltuathionylation observed in the CRF patients could correlate with the severity of the oxidative stress owing to renal replacement therapies like dialysis and transplantation.     

Role of yoga in control of hyperglycemia in middle aged patients of non-insulin dependent diabetes mellitus

The effect of 40 days yoga training in 30 hospitalized non-insulin dependent diabetes mellitus (NIDDM) patients has been investigated after stopping the medication. Blood glucose response to oral glucose load measured as area index total (AIT), glycated haemoglobin (GHb) plasma lipids and lipoproteins measurements before and after yoga training have been compared. Yoga training resulted in a significant improvement in AIT, GHb and plasma triglycerides and cholesterol levels. The data suggest that yoga training along with diet and medical management provides an important metabolic control in NIDDM and may have a role in primary prevention of diabetes mellitus.     

Effect of ketoacids on H<Subscript>2</Subscript>O<Subscript>2</Subscript> induced cataract

Cataract is one of the leading causes of visual disability often leading to blindness in the elderly population. One of the causes is oxidation of proteins present in lens, by hydrogen peroxide (H₂O₂). In the present study 100 goat lenses were analyzed to determine the protective efficacy of ketoacids, against the oxidative insult by H₂O₂. The ketoacids used were (pyruvate, alpha ketoglutarate and oxaloacetate), that are constantly produced endogenously. The lenses were incubated as control and experimental groups in TC-199 media for 72 hrs. H₂O₂ concentration of 10mM was used to induce cataract. The biochemical parameters measured were levels of malondialdehyde (MDA), a lipid peroxidation product and activity of glutathione peroxidase (G-Px), an enzymatic antioxidant. The results showed a significant increase in the levels of MDA and significant decrease in the activity of G-Px in the cataractous lenses as compared to control. After addition of ketoacids (pyruvate (10mM), alpha ketoglutarate (20mM) and oxaloacetate (20mM)) separately, the levels of MDA decreased significantly and the activity of G-Px increased significantly. The results suggest that the ketoacids can be very promising antioxidants for the treatment of cataract. They may also be useful in treating other disabilities related to acute and chronic oxidative stress.     

Evaluation of serum zinc level and plasma SOD activity in senile cataract patients under oxidative stress

An imbalance in the systemic redox status leading to oxidative stress has been an important factor in development of senile cataracts, which is reflected by an increase in serum TBARS and a decrease in plasma SOD activity. Zinc has been an important cofactor required for structural stability of SOD. In the present study the role of serum zinc level and plasma SOD activity was analyzed in senile cataract patients showing significant oxidative stress. Serum TBARS, plasma SOD and serum zinc level was measured in thirty randomly selected senile cataract patients against properly matched controls. Although, the analysis of means showed a significant increase in serum TBARS and decrease in plasma SOD and serum zinc level in cases, but plasma SOD was found to be just significantly correlated (p=0.05) with the serum zinc only in the cases. The results of partial correlation studies and multiple regression analysis, also, showed only a significant correlation and predictable dependence between serum TBARS and plasma SOD, excluding any role of serum zinc level. The present study concludes that it is chiefly the plasma SOD activity, but not the serum zinc level, that determines the proneness of the patients for development of senile cataract.     

Assessment of Vitamin D status In Patients of Chronic Low Back Pain of Unknown Etiology

Low back pain is very disabling and dispiriting because of the physical impediment it causes and its psychological effects. Innumerable factors have been implicated in its etiology. In spite of improvements in diagnostic modalities, a considerable number of such cases fall in the ambiguous zone of unknown etiology or ‘idiopathic.’Early diagnosis of low back pain will allow effective prevention and treatment to be offered. This study was conducted to assess the contribution of vitamin D levels and other biochemical factors to chronic low back pain in such cases. All patients attending the orthopedics OPD for low back pain in whom a precise anatomical cause could not be localized, were prospectively enrolled in this study. We measured serum levels of glucose, calcium, phosphorus, uric acid, rheumatoid factor, C reactive protein, alkaline phosphatase, total protein, albumin and 25 (OH) D concentrations in 200 cases and 200 control samples. The patients showed significantly lower vitamin D levels compared to controls with p value < 0.0001. The maximum number of low back pain patients were in the age group of 31–50 years (42 %).The average BMI was 23.27 ± 5.17 kg/sq m, 73 % of total patient population were females and 27 % were known case of type 2 diabetes mellitus. Calcium, alkaline phosphatase, was positively correlated with vitamin D and glucose showed a negative correlation with vitamin D in the patient population. The problem of low back pain provides a challenge to health care providers. The problem in developing countries is compounded by ignorance to report for early treatment and occupational compulsions in rural areas and sedentary lifestyle in urban youth. The authors strongly recommend early frequent screening for vitamin D along with glucose, protein, albumin, calcium, phosphorus, CRP as part of general health checkup for non-specific body pain, especially low back pain.     

Unusual changes in colostrum composition in lactating Indian women having medical complications during pregnancy—A pilot study

Colostrum, the mammary secretion during first 2–4 days of lactation, provides all the essential components of nutrition and passive immunity required by the newborn. Pregnancy induced hypertension (PIH), glucose intolerance and anaemia are common medical complications observed during pregnancy in Indian women and their effects were studied on the composition of colostrum collected within 24 hours of delivery from lactating women included in the study. PIH during pregnancy significantly decreased colostrum IgA and total proteins, but showed a significant increase in K⁺ levels, where as women with glucose intolerance showed a significant decrease in total lipids and lactose and an increase in Na⁺ levels in colostrum compared to normal controls. The group with anaemia also showed a significant decrease in colostrum IgA and total protein levels when compared with the control group. Awareness about the changes that occur in the composition of colostrum during complicated pregnancies can be an important and useful tool for preventive and protective paediatrics.     

Influence of Bcl-1 Gene Polymorphism of Glucocorticoid Receptor Gene (NR3C1, rs41423247) on Blood Pressure,Glucose in Northern Indians

Glucocorticoids and its receptor are known to be involved in the dysregulation of hormone and lipid levels. Therefore, we evaluated the association of Bcl1 gene polymorphism of glucocorticoids receptor (GCR) gene variant with hormone and lipid levels in Northern Indians obese. A total of 435 obese and non-obese age matched subjects were included in the case–control study. Lipid and hormonal levels were estimated using standard protocols. Analysis of +646 C>G NR3C1 gene polymorphism was done using PCR–RFLP. The frequencies of GR Bcl1, C>G genotypes and alleles did not differ significantly (P > 0.05) between obese and non-obese. The +646 G allele carriers had higher waist to hip ratio, blood pressure, insulin and glucose levels than non-carriers in obese subjects while diastolic blood pressure and glucose in non-obese. The NR3C1, +646 C>G polymorphism did not associate with obesity. However, the GG genotype may modulate blood pressure, blood glucose and hormonal levels in northern Indians.     

A Study of Microalbuminuria (MAU) and Advanced Glycation End Products (AGEs) Levels in Diabetic and Hypertensive Subjects

The prevalence of non-communicable diseases like diabetes mellitus (DM) and hypertension (HTN) is growing worldwide. Both lead to nephropathy if not controlled effectively. Microalbuminuria (MAU) is recognized as an early predictor for nephropathy. Additionally, the timely detection of advanced glycation end products (AGEs) is also considered to be an important prognostic factor for diabetic nephropathies. Hence, screening for the early detection of MAU and AGEs would be an useful and relatively inexpensive laboratory test for early clinical diagnosis for the incidence of nephropathy in these diseases. This study was conducted in DM, HTN and pregnancy induced hypertensive (PIH) subjects. MAU and N^ε-Carboxymethyllysine (CML) levels were estimated by in-house RIA kits in the patient groups and controls, while the total AGEs level in serum was determined by ELISA. The levels of MAU, CML and AGE-BSA were observed to be significantly higher in DM, HTN and PIH subjects compared to controls (p < 0.001). Increased serum CML and AGEs levels in DM, HTN and PIH subjects indicated ongoing glycemic damage and their susceptibility to develop renal complications.     

Beneficial Effect of Aqueous Garlic Extract on Inflammation and Oxidative Stress Status in the Kidneys of Type 1 Diabetic Rats

One of the most important complications of diabetes is nephropathy. This study investigates the effects of aqueous garlic extract on inflammation and oxidative stress status in the kidneys of diabetic rats. Male rats were divided into four groups- control rats, diabetic rats, garlic extract-treated diabetic rats, garlic extract-treated normal rats. The glucose, urea, uric acid, and creatinine levels were measured in sera using colorimetric methods. To determine the oxidative stress condition in the kidney tissues, total antioxidant capacity (TAC), malondialdehyde (MDA), and total oxidant status (TOS) were measured using colorimetric methods. Inflammation status was evaluated by the determination of tumor necrosis factor-alpha (TNF-α) gene and protein expression using qRT-PCR and ELISA respectively, while nitric oxide (NO) level in these tissues was measured using the Griess method. Histological examination of Kidneys was carried out by H&E staining. The levels of glucose, urea, and uric acid were found to increase in the serum of diabetic rats and decrease in that of diabetic rats after treatment with garlic. Measurement of MDA, TOS, and TAC revealed oxidative stress in diabetic rats, which improved after receiving the extract. The NO and TNF-α protein levels in diabetic rats were higher than those in control rats. After treatment with garlic, the levels of TNF-α protein and NO became close to the normal levels. Histological results confirmed certain other data as well. Garlic has antioxidant properties; therefore, it can reduce oxidative stress, which plays an important role in the development of diabetic nephropathy. Reduction in oxidative stress has beneficial effects on inflammation because it leads to a decrease in the level of TNF-α.     

Diagnostic Dilemma of HbA1c Detection in Presence of a Hemoglobinopathy: A Case Report

We report a case of a diabetic, heterozygote with near normal hematology, marginally low level of hemoglobin A₂(HbA₂) having an increased level of hemoglobin F(HbF) that was pancellularly distributed among the red cells. BioRad DiaSTAT measurements gave a high glycated hemoglobin A1c(HbA1c) of 31.5% and the BioRad Variant analyzer recorded an HbA1c value which was very low, in discordance with the detected blood glucose levels. Flow cytometry and polymerization chain reaction (PCR) based studies were carried out which revealed the case to be that of the common hereditary persistence of fetal hemoglobin (HPFH)-3, an Asian Indian mutation. Fructosamine estimation and HbA1c by Boronate affinity chromatography were able to resolve the discordant value detected and was able to confirm the diabetes status. The case would have been a diagnostic dilemma, if reported without correlation.     

Estimation of glycated hemoglobin by 2,6-dimethylphenol: Sulphuric acid conventional method

Glycated hemoglobin levels in hemolysate of normal and diabetic patients were determined by the 2,6-dimethylphenol:57.5% sulphuric acid conventional method and the values were 0.39±025 and 0.69±0.21 moles of hydroxymethylfurfural(HMF)/mole of globin, respectively. The mean increase in glycated hemoglobin values in diabetics (1.8fold) was highly significant (p<0.001). A good correlation (r=0.95) was found between the glycated hemoglobin values obtained by this method and the phenol:sulphuric acid method. The values obtained by former method were about 1.2–1.4 times the values by the phenol:sulphuric acid method. This study indicates that conventional 2,6-dimethylphenol: 57.5% sulphuric acid method is more sensitive for the estimation of glycated hemoglobin than any other method based on the same principle. It is less time consuming, reliable and hence can be employed for the routine laboratory estimation of glycated hemoglobin for the assessment of glycemic control.     

Cerebrospinal fluid free sialic acid and aspartate transaminase levels in meningitis

Background  Sialic acid (SA) is a nine carbon sugar derived from mannosamine and pyruvate. High levels of sialic acid and aspartate transaminase (AST) levels in cerebrospinal fluid have been described in pyogenic meningitis (PM) compared to tubercular meningitis (TBM). Objectives  To evaluate the levels of CSF free SA in PM and TBM and to assess the correlation between CSF free SA and CSF glucose or total protein levels. Patients and Methods  A total of 122 subjects were studied and divided into children and adults. Further, these have been subdivided into controls, PM and TBM. CSF free SA was estimated by thiobarbituric acid assay of Warren and AST by Reitmann and Frankel method. Results  CSF free SA and AST levels in children and adults were significantly high in PM (p<0.001) as compared to TBM and controls. Conclusion  A very high CSF free SA and AST were found to be characteristic of PM, making them useful parameters to differentiate PM from TBM.     

Glycosylated proteins and serum lipid profile in complicated and uncomplicated NIDDM patients

In the present study, 58 diabetic patients (type II) comprising uncomplicated (27) and complicated (31) cases along with 38 healthy matched controls were investigated for glycosylated hemoglobin (HbA₁), glycosylated serum proteins (GSP) and serum lipid profile viz. triacylglycerol, total cholesterol, HDL-cholesterol (HDL-C), VLDL-C, LDL-C and their ratios. HbA₁ and GSP were significantly elevated in diabetic group as a whole when compared with controls (p<0.01), but comparison of mean values of complicated and uncomplicated group revealed (though higher in complicated) that the difference between two groups was not statistically significant (p>0.05). Follow-up studies showed that while GSP levels reflect variations in blood glucose over a shorter period of 15 days, those of HbA₁ do so for about 3 months. HbA₁ correlated with fasting blood glucose (p<0.01), whereas GSP showed correlation with both fasting (p<0.01) and postprandial (p<0.05) blood glucose. Hypercholesterolemia and hypertriacylglycerolemia were observed (p<0.01) in both the groups. However no significant change was seen in HDL-C (p>0.05) even after accounting for sex in both the groups. Interestingly TC:HDL-C was elevated significantly (p<0.01) in the above groups. These findings seem to suggest that at the levels of hyperglycemia, hypercholesterolemia and hypertriacylglycerolemia observed, some patients are prone to develop complications earlier.