Meal test for glucose-dependent insulinotropic peptide (GIP) in obese and type 2 diabetic patients.

Glucose-dependent insulinotropic peptide (GIP) contributes to incretin effect of insulin secretion which is impaired in Type 2 diabetes mellitus. The aim of this study was to introduce a simple meal test for evaluation of GIP secretion and action and to examine GIP changes in Type 2 diabetic patients. Seventeen Type 2 diabetic patients, 10 obese non-diabetic and 17 non-obese control persons have been examined before and after 30, 60 and 90 min stimulation by meal test.

[Diagnostics and treatment of organic hyperinsulinism--experience in 105 cases].

Background: Organic hyperinsulinism causes hypoglycaemia manifesting mainly in the fasting state. We summarize our experience with diagnosis and treatment of 105 patients with organic hyperinsulinism.

Methods And Results: The diagnosis was confirmed in all patients by spontaneous hypoglycemia and neuroglycopenic symptoms, both developed during fasting test.

Gene polymorphisms of superoxide dismutases and catalase in diabetes mellitus.

Background: Reactive oxygen species generated by hyperglycaemia modify structure and function of lipids, proteins and other molecules taking part in chronic vascular changes in diabetes mellitus (DM). Low activity of scavenger enzymes has been observed in patients with DM. Protective role of scavenger enzymes may be deteriorated by oxidative stress.

Paraoxonase 1 gene polymorphisms and enzyme activities in diabetes mellitus.

Paraoxonase 1 (PON1), an antioxidant enzyme closely associated with HDL (high-density lipoproteins), preserves LDL (low-density lipoproteins) against oxidation. Less protection may be therefore supposed by decreased PON1 activity. This study was undertaken to investigate the association of PON1 gene polymorphisms with diabetic angiopathy and to evaluate the relationship of these polymorphisms with PON1 activity.

Oxidative stress and endothelium influenced by metformin in type 2 diabetes mellitus.

Objective: Metformin may influence atherogenesis but the mechanisms are not well understood. A pilot study was undertaken to determine whether metformin administration is associated with changes in oxidative stress and endothelial function.

Methods: Fifteen type 2 diabetic patients were treated for 3 months with metformin (1,700 mg daily) or with a placebo in a crossover study.

The influence of n-3 polyunsaturated fatty acids and very low calorie diet during a short-term weight reducing regimen on weight loss and serum fatty acid composition in severely obese women.

Polyunsaturated fatty acids of n-3 series (n-3 PUFA) were shown to increase basal fat oxidation in humans. The aim of the study was to compare the effect of n-3 PUFA added to a very low calorie diet (VLCD), with VLCD only during three-week inpatient weight reduction. Twenty severely obese women were randomly assigned to VLCD with n-3 PUFA or with placebo.

Screening for associated autoimmunity in type 1 diabetes mellitus with respect to diabetes control.

As an autoimmune disease, type 1 diabetes mellitus (DM) can be associated with other autoimmune disorders. The aim of this study was to detect subclinically associated autoimmune thyroid disease, coeliac disease, and Addison's disease. The presence of autoantibodies was evaluated with special regard to the control of diabetes and to the clinical status of the patient.

Short-term very low calorie diet reduces oxidative stress in obese type 2 diabetic patients.

Oxidative stress is higher in obese diabetic than in non-diabetic subjects. This pilot study evaluates oxidative stress during short-term administration of a very low calorie diet in obese persons. Nine obese Type 2 diabetic patients (age 55+/-5 years, BMI 35.

Effect of simvastatin and fenofibrate on endothelium in Type 2 diabetes.

Statins and fibrates influence endothelial activity and consequently atherogenesis but the mechanisms are not well understood. Twenty Type 2 diabetic patients with dyslipidemia were treated 3 months with simvastatin (20 mg daily) and then 3 months with fenofibrate (200 mg daily) with 2 months of wash-out between the two treatments. Laboratory parameters of oxidative stress, fibrinolysis and endothelial function were evaluated before and at the end of each treatment period.

Serum alpha-tocopherol and ascorbic acid concentrations in Type 1 and Type 2 diabetic patients with and without angiopathy.

Background: Alpha-tocopherol and ascorbic acid form a part of scavenger system influencing the level of oxidative stress in diabetes mellitus. The aim of this study was to evaluate serum concentrations of alpha-tocopherol and ascorbic acid in Type 1 and Type 2 diabetes mellitus and to compare them with the presence of vascular complications as well as with oxidative stress and endothelial dysfunction.

Methods: A total of 38 Type 1 and 62 Type 2 diabetic patients were subdivided into those with and without angiopathy.

The influence of short-term fasting on serum leptin levels, and selected hormonal and metabolic parameters in morbidly obese and lean females.

The aim of our study was to compare the changes of serum leptin levels after 24-h fasting in morbidly obese and lean females and to search for hormonal and metabolic factors responsible for the changes in serum leptin levels. Fourteen morbidly obese and twelve lean females were included in the study. The blood for leptin, insulin, cortisol, blood glucose (BG), beta-OH-butyrate (beta-OH), dehydroepiandrosterone (DHEA) and DHEA-sulphate (DHEA-S) measurements was withdrawn before and after a 24-h fast.

The evaluation of thyroid and islet autoantibodies in type 1 diabetes mellitus.

Type 1 diabetes mellitus is an autoimmune disease in which the presence of different autoantigens can often be found. The aim of our study was to evaluate the prevalence of antibodies against insulin (IA) and autoantibodies against glutamic acid decarboxylase (anti-GAD), tyrosine phosphatase IA-2 (anti-IA-2), thyroid microsomal peroxidase (anti-TPO) and thyroglobulin (anti-TG) in 55 randomly selected Type 1 diabetic patients (34 males, 21 females). Mean age of these patients was 39 +/- 12 yrs, mean duration of diabetes 18 +/- 13 yrs.

Impaired insulin action in primary hyperaldosteronism.

The presence of insulin resistance is frequently found in essential hypertension. There are, however, only sparse data with respect to the potential presence of insulin resistance in patients with secondary hypertension. We have therefore undertaken a study to reveal the potential occurrence of insulin resistance in primary hyperaldosteronism (PH).

[The effect of body weight on insulin activity].

Insulin resistance is found patients with diabetes mellitus type 2 as well as in obese subject without diabetes. The objective of our investigation was to compare the action of insulin in morbidly obese subject with and without diabetes and in diabetic subject with different degrees of obesity. A total of 36 diabetic were examined, divided according to the BMI into morbidly obese (DMTO: BMI > 40 kg/m-2.

Insulin action in primary hyperaldosteronism before and after surgical or pharmacological treatment.

The relationship between arterial hypertension and insulin resistance has long been established. We used primary hyperaldosteronism as a model of the relationship between secondary hypertension and insulin sensitivity. Our group consisted of 9 patients with arterial hypertension caused by primary hyperaldosteronism.

The effect of glycosaminoglycan sulodexide on oxidative stress and fibrinolysis in diabetes mellitus.

Glycosaminoglycan sulodexide may influence morphology and functional properties of the basement membranes in microvessels. The aim of this study was to evaluate the effect of sulodexide administration on albuminuria and on different biochemical variables indicating endothelial dysfunction, oxidative stress and fibrinolysis in diabetic patients. Twenty diabetic patients of both types with micro- or macroalbuminuria were selected for sulodexide treatment.

Insulin action and fibrinolysis influenced by vitamin E in obese Type 2 diabetes mellitus.

Increased oxidative stress, hypofibrinolysis and insulin resistance are present in obese Type 2 diabetic patients. It is supposed that treatment with antioxidant alpha-tocopherol (vitamin E) could not only decrease free radical production, but also ameliorate insulin action. We evaluated the effect of 3 months administration of vitamin E (600 mg daily) on insulin action examined by hyperinsulinemic clamp in 11 obese Type 2 diabetic patients.

Relationship of serum N-acetyl-beta-glucosaminidase activity to oxidative stress in diabetes mellitus.

Serum N-acetyl-beta-glucosaminidase activity was evaluated in 40 Type 1 and 40 Type 2 diabetic patients and compared with parameters of diabetes control and oxidative stress. Significantly increased mean serum N-acetyl-beta-glucosaminidase activity was found in both groups of diabetic patients as compared with the corresponding group of healthy persons (p < 0.01).

Development of lipid and glycide abnormalities in genetically hypertensive obese Koletsky rats and in their lean siblings.

Experiments were performed in the genetically hypertensive Koletsky rats and in their lean siblings at the age of two and three months. In the study of development of glycide and lipid abnormalities animal represents control for itself. At the age of two months Koletsky obese rats show relative to their lean controls elevation of plasma triglycerides (males +184%, female +152%) and insulin (males +169%, females +201%).

Muscle GLUT-4 and insulin binding to erythrocytes and to adipose, liver and muscle tissue in genetically hypertensive obese rats and in their lean siblings: effect of long lasting terguride treatment.

Experiments were performed in the genetically hypertensive obese rats of Koletsky type (SHR/N-cp) and in their lean siblings of both sexes. Insulin binding to erythrocytes and to adipose tissue, lever tissue and muscle tissue was monitored in the control animals and in the animals under the long lasting terguride treatment. In control animals insulin binding shows substrain and tissue dependence being elevated in lean rats except insulin binding to erythrocytes where inverse is true.

[Personal experience with the treatment of organic hyperinsulinism].

In 1981-1997 at the Third Medical Clinic 52 patients with confirmed organic hyperinsulinism were treated. Forty-three were operated and the remaining nine were treated conservatively. An insulinoma was removed surgically in 35 patients, in one female microadenomatosis was detected.

[The effect of insulin in primary hyperaldosteronism].

Background: Deteriorated insulin resistance was described in patients with essential hypertension. The objective of the present study was to test at the receptor and postreceptor level the presence of insulin resistance in hypertension with primary hyperaldosteronism.

Methods And Results: The diagnosis of primary hyperaldosteronism was assessed by means of biochemical and imaging methods in 123 hypertensive patients with a normal glucose tolerance (mean age 49.

Effect of long lasting terguride treatment on mutual relationship between glycide and lipid parameters in SHR/N-cp Koletsky rats.

Experiments were performed in the genetically hypertensive obese rats of Koletsky type (SHR/N-cp) and in their lean siblings. The effect of long lasting terguride treatment on glycide and lipid metabolism was monitored. Terguride decreases insulinemia in all groups of rats.

[The effect of a short-term reducing diet on the effect of insulin in type 2 diabetes mellitus].

Background: Insulin resistance is in addition to impaired beta-cell function decisive for the development of type 2 diabetes. It is also known that obesity creates conditions for the development of insulin resistance. The authors tried therefore to influence insulin sensitivity by short-term reducing diets in obese type 2 diabetics.