rotein glycation, insulin sensitivity and pancreatic beta cell function in high-risk, non-diabetic, first degree relatives of patients with type 2 diabetes.

Insulin resistance and impaired beta cell function are widely recognized as features of type 2 diabetes. But it is still debated whether insulin resistance or beta cell dysfunction constitutes the primary abnormality. This study was done to evaluate the impact of family history of type 2 diabetes on insulin resistance, beta cell function and glycation of proteins. A total of 30 healthy subjects with a positive family history of type 2 diabetes and thirty two healthy age-matched subjects without any family history of type 2 diabetes were enrolled in this study. Fasting glucose, post prandial glucose, fasting plasma insulin, fructosamine and glycated hemoglobin were evaluated in both the study groups. The mean fasting glucose, fasting Insulin and HOMA-IR were significantly higher among the first-degree relatives of type 2 diabetics, but there was no alteration in HOMA-B. The levels of both glycated hemoglobin and fructosamine were significantly increased in the test group when compared with controls. In conclusion the results from the present study suggest that Indian subjects with family history of type 2 diabetes are associated with insulin resistance and enhanced glycation of proteins, but with no evidence of beta cell defect.

Altered oxidant-antioxidant status in non-obese men with moderate essential hypertension.

BACKGROUND: Although a wide number of experimental evidences are available regarding oxidant-antioxidant disturbance in hypertension, clinical data supporting it is lacking in men in early stages of hypertension. AIMS: The objective of the study was to evaluate oxidative status and antioxidant activities in males with stage I essential hypertension. MATERIALS AND METHODS: Thirty hypertensives and 21 normotensives were included in the study. Protein carbonyl, reduced glutathione, glutathione peroxidase, catalase and fasting glucose were assessed in both the groups. STATISTICAL ANALYSIS: Results were analyzed by student's 't' test and linear regression analysis test. RESULTS: Plasma protein carbonyl and glutathione peroxidase were significantly increased and catalase and GSH were significantly reduced in the hypertensive group compared to normotensive subjects. There was a significant negative correlation between glutathione peroxidase and catalase in the test group. CONCLUSIONS: The data from the present study indicates an alteration in oxidant-antioxidant status in non-obese men in early stages of essential hypertension.

Increased glycated hemoglobin level in non-diabetic nephrotic children is associated with oxidative stress.

Glycation and lipid peroxidation are spontaneous reactions believed to contribute to the pathogenesis of nephrotic syndrome. Possible interrelations of glycated hemoglobin with reduced glutathione and malondialdehyde were evaluated in nephrotic syndrome patients. Eighteen nephrotic syndrome patients and 15 healthy controls were enrolled for this study. Glycated hemoglobin, reduced glutathione, malondialdehyde and fasting glucose were analyzed for their correlation in both the groups. In nephrotic syndrome patients, while glycated hemoglobin and malondialdehyde levels were found to be significantly increased, glutathione levels decreased significantly when compared with controls. Glycated hemoglobin was found to have a significant positive correlation with malondialdehyde and a negative correlation with glutathione. Erythrocytes depleted of glutathione, by pre-treatment with 1-chloro-2, 4-dinitrobenezene, were found to have higher glycated hemoglobin levels when compared with erythrocytes incubated with glucose alone. These data suggest that glycated hemoglobin levels are closely associated with malondialdehyde and glutathione in nephrotic syndrome patients.

Antioxidant response to oxidative stress induced by smoking.

Oxygen free radicals have been hypothesized to play a pivotal role in the deleterious effects of smoking on health. The present study was undertaken to examine the oxidant and antioxidant system among smokers and nonsmokers. Fourteen smokers and 11 nonsmokers were enrolled for this study. The protein carbonyl levels in smokers were found to be significantly higher than in nonsmokers. The levels of plasma ascorbic acid, free sulfhydryl group, and erythrocyte reduced glutathione were lower in smokers compared to nonsmokers. In smokers the erythrocyte activities of both glutathione peroxidase and catalase were decreased when compared to that in nonsmokers. The data from the study reemphasizes the presence of oxidative stress in smokers. The concomitant decrease in the activities of both catalase and glutathione peroxidase found in the erythrocytes of smokers raises rational grounds for expressing concern over the increased susceptibility towards oxidative stress in these subjects.

Nonenzymatic glycation of plasma proteins in smokers.

Glycation is known to play a key role in complications of many pathophysiological processes. The present study was carried out to assess whether there are abnormalities of nonenzymatic glycation of proteins in smokers. Fourteen current smokers and 10 healthy nonsmokers were enrolled for the present study. Fasting plasma glucose, insulin, fructosamine and total plasma glycated proteins were evaluated. A significant rise in the mean levels of fructosamine and total plasma glycated proteins were found in smokers when compared with controls. Significant difference in insulin values was observed between these two groups. When Pearson's correlation analysis was performed, no significant correlation was found between fasting plasma glucose with either fructosamine or total plasma glycated protein levels. These data suggest an increased glycation of proteins in smokers independent of glucose concentration.

Effect of smoking on lipid profile and lipid peroxidation in normal subjects.

The aim of the present study was to assess the association between smoking and the alteration in plasma concentration of lipid profile and lipid peroxides. Fourteen smokers and 11 age matched control were enrolled. Plasma levels of fasting cholesterol, triglycerides, lipoprotein cholesterol and malondialdehyde were estimated. In smokers the levels of total cholesterol, LDL cholesterol, Non-HDL cholesterol and MDA were significantly elevated when compared with the controls. The atherogenic index as indicated by various risk ratios were also found to be increased in smokers as compared to controls. These findings indicate that current smokers are at a pro- atherogenic state and as in other countries, in India smokers require particular attention in terms of public health interventions.