Biomedical subjects

J Skrha

Publications and source records attributed to J Skrha.

At least 55 records · Page 3Linked to original sources

PubMed2001

[Can hormonal contraceptives affect plasma levels of IGF-1 and IGFBP-1 in slim women with polycystic ovary syndrome?].

BACKGROUND: Polycystic ovary syndrome (PCOS) represents a frequent endocrinopathy among fertile women. Ethiopathogenesis of the syndrome is multifactorial and it is a subject of scientific discussions. Considered is the possibility of intraovarial IGF system disorder affecting maturation of ovarial folicles. The aim of our work was to determine effects of peroral contraceptives with low-androgen progestin on IGF system in PCOS patients and healthy woman controls. METHODS AND RESULTS: 14 patients fulfilling diagnostic criteria of PCOS and 7 healthy controls were included into the study. All persons were examined before and after six months lasting administration of monophasic estrogen-progesteron contraceptive therapy with 35 micrograms of ethinylestradiol per day and 250 micrograms of low-androgen progestin norgestimate per day. In PCOS patients low increase of basal insulinemia levels occurred (16.3 +/- 4.8 vs. 20.8 +/- 4.8 mU.l-1, p < 0.05). IGF-1 serum levels were not influenced (230 +/- 70 vs. 235 +/- 112 pg.ml-1, n.s.), IGFBP-1 serum concentration significantly increased (46.3 +/- 24.1 vs. 75.6 +/- 24.0 pg.ml-1, p < 0.001). Insulinemia in healthy women also slightly increased (15.9 +/- 4.0 vs. 18.4 +/- 4.0 pg.ml-1, p < 0.05). IGF-1 serum concentration significantly increased (140 +/- 65 vs. 241 +/- 89 pg.ml-1, p < 0.001). IGFBP-1 was also higher (45.0 +/- 19.19 vs. 80.0 +/- 15.6 pg.ml-1, p < 0.001). Influence of the hormonal contraception on the followed parameters was estimated using Wilcoxon's test. While BP-1 increase was significant in both groups, the increase of IGF-1 was significant only in healthy controls. CONCLUSIONS: Increased levels of IGFBP-1 were found in both studied groups of women. Women with PCOS had higher serum levels of IGF-1 before the therapy and the treatment did not influence it. Contrary to it, in healthy women the increased value was observed. Explanation of that finding will become the aim of our next study.

Body Mass Index↗

PubMed2001

[Changes in microcirculation and selected laboratory parameters in the early stages of diabetic microangiopathy].

BACKGROUND: Early stages of diabetic microangiopathy are accompanied with dysfunction, manifested by changes of some biochemical parameters. Parallel changes were observed in microcirculation. The aim of this study was to compare microcirculation in the skin of a forearm evaluated by laser Doppler with selected laboratory markers of endothelial dysfunction in Type 1 diabetes mellitus without microangiopathy or with incipient microangiopathy. METHODS AND RESULTS: Group of 43 Type 1 diabetic patients was examined in this study. 20 of them had no signs of microangiopathy and in 23 patients a simple diabetic retinopathy (background retinopathy) was diagnosed. Control group consisted of 25 healthy persons of comparable age, sex, and body mass index. All persons involved in this study were examined by laser Doppler and by biochemical examination and the results were compared. In comparison with control group, in diabetic patients the arm occlusion significantly lowered the increase of perfusion (29 +/- 12 vs. 41 +/- 18 perfusion units (PU) p < 0.01). Similarly the perfusion velocity increase was significantly lower in diabetic patients than in healthy controls (p < 0.01). Also the velocity of the perfusion increase after the warming up was lower in the diabetic than in non-diabetic persons (p < 0.01). Such changes of perfusion or those of velocity of perfusion increase were significantly lower in diabetic patients with microangiopathy than in those without this complication. Perfusion increases after both stimuli highly correlated (r = 0.86, p < 0.001). In diabetic patients with microangiopathy significantly higher N-acetyl-beta-glucosaminidase (NAG) activities in serum and E-selection or ICAM-1 concentrations were found as compared with patients without microangiopathy, whereas plasma concentrations of tissue plasminogen activator (tPA) or inhibitor (PAI-1) were comparable with those in the control group. NAG activity inversely correlated with velocity of the perfusion increase after both the occlusion (r = -0.41, p < 0.01) and the warming (r = -0.38, p < 0.05). Similar relationship was found between tPA or E-selectin and the velocity of the perfusion increase after the occlusion (r = -0.48, p < 0.01). CONCLUSIONS: Our results confirm that biochemical parameters and microcirculation are impaired in the early stage of microangiopathy in Type 1 diabetic patients. Detailed analysis showed that both types of examination offer slightly different information on the vascular status. A long prospective study in diabetic patients without incipient vascular changes will be necessary to evaluate if biochemical or microcirculatory changes can bring an earlier information on the developing angiopathy.

Acetylglucosaminidase↗

PubMed2001

[IGFBP-1 and its protective role in the pathogenesis of microangiopathy in type 1 diabetes mellitus].

BACKGROUND: The role of IGF-I/IGFBP's system in the pathogenesis of diabetic vascular complications is widely discussed in the literature. We studied the influence of this system on microvasculature in patients with type 1 diabetes with respect to the effect of IGFBP-1. METHODS AND RESULTS: 17 patients with type 1 diabetes were included in the study. We examined IGF-I, IGFBP-1 and IGFBP-3 serum levels, parameters of compensation of diabetes and basic values of lipid metabolism. The function of microvasculature was examined using the laser-Doppler system Periflux. We didn't found any relation between the total IGF-I serum levels, parameters of lipid metabolism or level of diabetes compensation and the degree of impairment of the function of microcirculation. IGFBP-1 serum levels positively correlated with the peak perfusion in thermal hyperaemia (r = 0.39; p < 0.03). IGFBP-3 serum levels did not affect the function of microcirculation. CONCLUSION: We can conclude that the activity of IGF-I/IGFBP's system belongs to factors contributing to the development of diabetic microangiopathy in type 1 diabetes. IGFBP-1 as the modulator of IGF-I activity plays probably protective role against the progression of microangiopathy. These results correspond with observations of some other authors.

Blood Flow Velocity↗

PubMed2001

[Effect of insulin in hypertension with high and low levels of renin].

BACKGROUND: Setback in insulin resistance has been described in patients with essential hypertension. The aim of our study was to verify at the receptor and postreceptor levels the presence of insulin resistance in patients with high or low renin activity. METHODS AND RESULTS: Six patients with the renal artery stenosis (20 to 65 years, average age was 51 +/- 12 years, BMI: 27 +/- 2.0 kg.m2) and six patients with primary hyperaldosteronism (28 to 61 years, average age was 50 +/- 13 years, BMI: 26.9 +/- 3.2 kg.m2) were investigated. Their diagnose was confirmed by laboratory examination, computer tomography, and duplex sonography. Blood pressure was monitored for 24 hours with Spacelab tonometer (SBP: 161 +/- 29 mmHg, DBP: 98 +/- 12 mmHg versus SBP: 168 +/- 21 mmHg, DBP: 103 +/- 9 mmHg; plasma renin activity was 8.1 +/- 5.6 versus 0.3 +/- 0.4 ng.ml-1.h-1, p < 0.001; recumbent plasma aldosterone level was 98 +/- 31 versus 358 +/- 103 pg.ml-1, p < 0.001, normal value till 150 pg/ml, serum potassium was 3.9 +/- 0.4 and 3.5 +/- 0.6 mmol/l). All patients had normal course of the oral glucose tolerance test. Six volunteers of corresponding age and BMI formed the control group. Patients had normal values of the basal morning glycemia (4.9 +/- 0.5 and 5.0 +/- 0.6 versus 4.9 +/- 0.6 mmol/l), basal insulinemia level was 28.8 +/- 12.4 and 21.0 +/- 10.2 versus 15.9 +/- 8.8 mU.l-1 in healthy controls. Insulin effect was tested using isoglycemic hyperinsulinemic clamp method on Biostator with insulin infusion of 1 mU.kg.min-1. Plasma potassium concentration was kept at constant physiological levels using linear infusion pump (in patients with primary hyperaldosteronism after the prior supplementation). In patients with high-renin or low-renin hypertension, the glucose consumption during clamping was lower than that of healthy controls (M, glucose disposal rate: 23.7 +/- 4.8 and 19.5 +/- 3.4 versus 33.0 +/- 5.7 mumol.kg.-1.min-1, p < 0.001), increase of the metabolic glucose clearance (MCRG: 5.1 +/- 1.5 and 3.9 +/- 0.7 versus 7.9 +/- 1.4 ml.kg-1.min-1, p < 0.001) and tissue insulin sensitivity index (M/I: 24.3 +/- 10.1 and 26.4 +/- 8.3 versus 38.4 +/- 10.1 mumol.kg-1.min-1 to mU.l-1 x 100, p < 0.001). CONCLUSIONS: Patients with high-renin and low-renin hypertension have the insulin effectiveness significantly impaired. Such insulin resistance probably does not depend on the renin activity, plasma aldosterone concentration or on serum potassium level. The ethiopathogenesis of the described changes will be the aim of our next study.

Adult↗

PubMed2001

[Diabetes mellitus--a risk factor for cardiovascular diseases].

Hyperglycemia besides typical changes of lipids, especially of LDL and HDL-cholesterol and triglycerides, arterial hypertension and smoking is another factor causing greater morbidity and mortality of diabetic patients with cardiovascular disease. Significant association was found between the insulin resistance and atherosclerosis. Some studies evaluating the tight relationship between diabetes and cardiovascular diseases are selected in this overview and they demonstrate the necessity of the complex therapeutic and preventive approaches.

Blood Glucose↗

PubMed2001

Can primary hyperaldosteronism be considered as a specific form of diabetes mellitus?

Aldosterone-producing adenoma (aldosteronoma)--the most frequent form of primary hyperaldosteronism (PH)--is considered a specific form of diabetes mellitus (DM). In a previous study we demonstrated insulin resistance in patients with PH. We have therefore undertaken a study to evaluate the incidence of abnormalities of glucose metabolism in patients with PH (36 subjects) compared to control subjects with essential hypertension (EH) (21 patients). The following parameters were measured in all studied subjects: office blood pressure (by mercury sphygmomanometer in the sitting position), body mass index (BMI), plasma potassium, plasma glucose and insulin levels during oral glucose tolerance test (OGTT) (0, 60, 120 min), plasma renin activity and plasma aldosterone. Although patients with PH tended to have higher stimulated plasma glucose levels after 60 and 120 min compared to EH, these differences did not attain statistical significance. Patients with EH tended to have higher insulin levels at each measured interval, but due to a high variability these differences were again not significant. There were no significant differences between PH and EH in the proportion of diabetics (20% vs. 14%) or patients with impaired glucose tolerance (18% vs. 10%). In conclusion, we have found the absence of significant differences in the frequency of diabetes mellitus, impaired glucose tolerance and insulin resistance in patients with EH and PH. Our data thus do not support the idea of primary hyperaldosteronism as a specific type of diabetes mellitus. Furthermore, our results indicate that glucose metabolic characteristics in essential hypertension and primary hyperaldosteronism tend to be similar. The definitive conclusion with respect to the possible causal relationship between DM and PH, however, can be obtained only on larger groups of subjects, in particular after the evaluation of the effect of surgical/pharmacological treatment of primary hyperaldosteronism.

Adenoma↗

PubMed2001

[Personal experience with surgical treatment of insulinoma].

In 1981-2000 at the IIIrd Medical Clinic 60 patients were treated with confirmed organic hyperinsulinism. A surgical operation was indicated in 51 patients. In 42 a localized tumour was removed, in one diffuse adenomatosis was involved. In three of the operated patients a malignant, enddocrinologically active insulinoma was confirmed. Two patients were re-operated on account of a relapse. The remaining 9 patients were treated conservatively from the onset. For localization of the tumour before operation US, CT and angiographic examinations were used. US and angiography were an asset in 25 patients (49%). In some instances we encountered however on angiography falsely positive findings. US was positive before surgery in 12 patients (23%), angiography in 21 (41%) and CT only in 2 (4%). The insulinoma was detected only on surgery in 14 patients (33%) of the operated insulinomas. The tumour was found in the head of the pancreas in 13 patients (31%), in the body of the pancreas in 14 (33%) and in the tail of the pancreas in 15 (36%). Surgery was successful in 82%, while the topographic preoperative examination aroused suspicion of a focus (i.e. insulinoma) only in 49% of the operated patients. A total of 17 patients (8 after surgery and 9 without surgery) were successfully treated with diazoxide, in 9 patients this treatment is still administered. According to the response to diazoxide insulinomas can be divided into "responsive" and "non-responsive" ones. Pharmacological treatment is therefore justified only in the first group of patients. Operated and pharmacologically treated patients have no signs of hyperinsulinism. Our experience indicates that a surgical approach is suitable when the diagnosis is unequivocal, even when there is a negative topographic finding of imaging methods as in 33% of the operated patients the insulinoma was detected only on operation.

Adolescent↗

PubMed2000

[Microcirculation in the skin of the upper extremities in type 1 diabetics using the laser doppler method].

BACKGROUND: Diabetic microangiopathy is a very frequent complication of both types of diabetes mellitus. Detection of early microcirculation impairment may identify patients at high risk of severe complications and may have a great value for prevention of these complications. The aim of the study was to evaluate the skin microcirculation in upper extremities in Type 1 diabetic patients and in healthy volunteers with laser Doppler technique. Parameters of microcirculation were compared between these two groups and with diabetes control expressed by glycated hemoglobin, fructosamin and fasting glycaemia. Relationship between perfusion parameters, the age of patients and the duration of diabetes was analysed as well. METHODS AND RESULTS: Thirty-eight Type 1 diabetic patients (18 men, 20 women) and twenty-six healthy persons (16 men, 10 women) were evaluated in this study. Differences of high statistical significance in many parameters of perfusion were found between these groups. A significant negative relationship was found between the percentage perfusion increase during postocclusive hyperaemia in forearm and HbA1c and fructosamine (r = -0.52, p < 0.001 and r = -0.47, p < 0.01, respectively), between percentage perfusion increase during local hypertermia and HbA1c (r = -0.47, p < 0.001). Negative correlation was also found between maximal perfusion during postocclusive hyperaemia in finger and fructosamine (r = -0.4, p < 0.01) and between the same parameter in forearm and fasting glycaemia (r = -0.62, p < 0.001). Skin perfusion was independent on age and duration of diabetes. CONCLUSIONS: Significant differences between diabetic patients and healthy controls and a relationship between perfusion parameters and compensated diabetes status were described in the current study. Laser Doppler fluxmetry is a non-invasive method comfortable for patients and it can be used for detection of microangiopathy in diabetology.

Adult↗

PubMed2000

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. Five of these patients with aldosterone producing adenoma were operated on and four patients with idiopathic hyperaldosteronism were treated with spironolactone. Hyperinsulinaemic euglycaemic clamp technique was performed before and at least 6 months following the treatment to evaluate the insulin action. Significantly lower glucose disposal rate (M), insulin sensitivity index (M/I) and decreased metabolic clearance rate of glucose (MCR(G)) were found in patients before treatment as compared to healthy controls. In both treated groups the blood pressure and plasma potassium concentrations returned to normal values, whereas plasma aldosterone levels were normalised only after surgical removal of the adenoma. Significantly improved insulin action (M/I: 30.2 +/- 5.9 vs. 51.4 +/-12.2 micromol.kg(-1).min(-1) per mU.l(-1) x 100, p = 0.017) was observed in patients after operation of aldosterone producing adenoma. In contrast, spironolactone treatment of patients with idiopathic hyperaldosteronism did not significantly influence insulin action (M/I: 24.5 +/- 7.3 vs. 18.7 +/- 7.6 micromol.kg(-1).min(-1) per mU.l(-1) x 100, p = 0.198). Since plasma aldosterone concentrations have been normalised only in patients after removal of the adenoma whereas they remained increased in spironolactone treated group, we suppose that aldosterone itself could play a role in the development of impaired insulin action.

Adenoma↗

PubMed2000

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 hyperinsulinemic euglycemic clamp technique together with the evaluation of insulin receptor characteristics were used to study insulin resistance in 12 patients with PH. The measured parameters were compared to normal values in control subjects. We have found a significantly lower glucose disposal rate (M, micromol/kg/min) (18.7+/-6 vs. 29.3+/-4), decreased tissue insulin sensitivity index (M/I, micromol/kg/min per mU/l x100) (23.7+/-9.8 vs. 37.5+/-11.6) and also lower metabolic clearance rate of glucose (MCRg, ml/kg/min) (3.8+/-1.5 vs. 7.0+/-1.1) in patients with primary hyperaldosteronism. The insulin receptor characteristics on erythrocytes did not differ in primary hyperaldosteronism as compared to control healthy subjects. We thus conclude that insulin resistance is also present in secondary forms of hypertension (primary hyperaldosteronism) which indicates the heterogeneity of impaired insulin action in patients with arterial hypertension.

Adult↗

PubMed1999

[Autoantibodies in the pathogenesis and diagnosis of insulin-dependent diabetes mellitus].

Insulin-dependent diabetes mellitus is considered an autoimmune disease. The immune response is targeted on autoantigens of B-cells of the islets of Langerhans. The most important autoantigens are glutamic acid decarboxylase, protein tyrosine phosphatase and insulin. Despite the fact that their role in the pathogenesis of insulin-dependent diabetes mellitus is not clear, they are used in diagnosis and can identify subjects at high risk for the development of the disease.

Autoantibodies↗

PubMed1999

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). Oxidative stress measured by plasma malondialdehyde concentration was significantly higher in Type 2 than in Type 1 diabetic patients (p < 0.01) but in comparison with control subjects it was higher only in Type 2 diabetes. Plasma malondialdehyde concentration positively correlated with body mass index (r=0.77, p<0.001) and with serum N-acetyl-beta-glucosaminidase activities (r=0.57, p <0.001). Treatment of 10 Type 2 diabetic patients with antioxidant alpha-tocopherol caused a significant decrease in malondialdehyde concentration (p < 0.001) which was accompanied by a decrease of N-acetyl-beta-glucosaminidase activity (p < 0.01). We conclude that serum N-acetyl-beta-glucosaminidase activity may be influenced by oxidative stress which is more pronounced in Type 2 than in Type 1 diabetic patients.

Acetylglucosaminidase↗

PubMed1999

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. Oxidative stress and fibrinolysis were also determined. The administration of vitamin E caused a decrease of glucose disposal rate (26.6 +/- 9.5 vs 21.3 +/- 7.5 micromol/kg/min, P < 0.02) and of metabolic clearance rate of glucose (3.7 +/- 1.6 vs 2.9 +/- 0.8 ml/kg/min. P < 0.02). A decrease of insulin receptor number was observed on erythrocytes after vitamin E (284 +/- 84 vs 171 +/- 59 pmol/l, P < 0.01). Significantly higher plasma malondialdehyde (MDA) concentration documented an increased oxidative stress in diabetic patients as compared with healthy persons (3.13 +/- 0.68 vs 1.89 +/- 0.18 micromol/l, P<0.001). An inverse relationship was found between MDA concentration and insulin sensitivity expressed by glucose disposal rate (r = -0.73). Vitamin E further worsened the hypofibrinolysis documented by a decrease of tissue plasminogen activator (P < 0.01) without changes in its inhibitor PAI-1. In conclusion. our results demonstrate that higher doses of vitamin E may further deteriorate insulin action and fibrinolysis in obese Type 2 diabetic patients.

Adult↗

PubMed1999

Treatment with the NO-synthase inhibitor, methylene blue, moderates the decrease in serum leptin concentration in streptozotocin-induced diabetes.

It was previously reported that serum leptin concentrations were decreased in rats with streptozotocin-induced diabetes. Also, simultaneous nitric oxide (NO)-synthase inhibitor treatment is known to partially attenuate streptozotocin-induced diabetes development. The aim of our study was to investigate the influence of the NO-synthase inhibitor, methylene blue, on serum leptin concentration and diabetes development. Body weight, blood glucose, glycated hemoglobin and leptin concentration were measured in a control group, diabetic (streptozotocin 70 mg/kg i.p.) group, methylene blue (40 mg/kg in the food) treated group and a diabetic group treated with methylene blue. After six weeks of experiments, blood glucose and glycated hemoglobin increased significantly in the diabetic group vs controls (27.31 vs 5.49 mmol.l(-1), 14.11 vs 6.79%, respectively) and this increase was partially attenuated by simultaneous methylene blue treatment (16.8 vs 27.31 mmol/l, p < 0.05). Body weight and serum leptin fell in diabetic rats vs controls (248.9 vs 342.8 g, 0.57 vs 3.46 ng.ml(-1)). Treatment with methylene blue significantly suppressed the drop of body weight and the increase in blood glucose and glycated hemoglobin concentrations in the diabetic group. The decrease of serum leptin levels was significantly inhibited by methylene blue in the first experiment (1.1 vs 0.57 ng. ml(-1), p < 0.05); the same trend was found in a second experiment but the differences did not reach statistical significance. We conclude that the drop of serum leptin levels in diabetic rats is probably mainly due to streptozotocin-induced insulin deficiency, which is partially attenuated by NO-synthase inhibitor treatment.

Animals↗

PubMed1999

[Diagnosis and treatment of pancreatic islet cell tumors producing vasoactive intestinal polypeptide (VIPoma)].

The incidence of VIPoma is approximately one per 10 million population. Thus in the Czech Republic this rare disease should be diagnosed once per year. The authors present their experience with the diagnosis and treatment of patient born in 1956, who suffered since 1990 from diarrhoea, at first episodically. In 1992-1994 the diarrhoea was profuse, caused dehydration, hypokalaemia and severe metabolic acidosis without an increase of the anion gap. As a result of dehydration the patient developed acute renal insufficiency. Due to hypokalaemia he developed paroxysmal atrial fibrillation. The diagnosis was based on the clinical finding and later confirmed on laboratory examination by a high VIP serum concentration. For treatment of diarrhoea Sandostatin was used. The tumour was located only after a scan with 123I-VIP in the cauda of the pancreas. Scintigraphy with labelled octreotide, similarly as other imaging methods (sono, X-ray and CT) were not effective. In 1994 left-sided hemipancreatectomy was performed. Although the patient was operated four years after the onset of the disease, no secondaries were detected. After surgery the diarrhoea stopped and no further treatment was necessary.

Humans↗

PubMed1999

[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.n = 6) those with medium severe obesity (DMSO: BMI 31-40 kg.m-2.n = 16), with slight overweight DMLO. BMI 26-91 kg.m-2.n = 9) and non-obese diabetics (DMBO). BMI 21-26 kg.m-2.n = 5). The group of morbidly obese non-diabetic subject (NDTO, BMI > 40 kg.m-2.n = 5) and non-obese healthy subject (C, BMI < 26 kg.m-2, n = 12) served as control. All examined subject were of similar age the diabetic subject had similar values of indicator of diabetic control (HbA1c was 7.1 +/- 0.5%). The examination was made using the method of an isoglycaemic hyperinsulinaemic clamp on a Biostator at an insulin infusion rate of 1mU.kg-1.min-1 for a period of 20 minutes. The results of the index of tissue sensitivity to insulin revealed a markedly deteriorated action of insulin in morbidly obese diabetes and non-diabetics in relation to control group of healthy slim controls (M/I, DMTO: 12.4 +/- 7.3 and NDTO: 9.2 +/- 4.1, p < 0.001, mumol.kg-1.min-1 na mU.l-1 x 100), in midly and medium obese diabetics the insulin resistance was of difference grades (M/I, DMLO: 34.2 +/- 9.3, p < 0.05, and DMSO: 25.9 +/- 18.5 p < 0.001 mumol.kg-1.min-1 na mU.l-1 x 100. Non-obese diabetic and non-diabetic subject had a normal insulin action (M/I, DMBO: 58.3 +/- 29.4 and C: 48.9 +/- 5.0 mumol.kg-1.min-1 per mU.l-1 x 100. The metabolic glucose clearance differed however between diabetic and non-diabetic subject (MCRG, DMTO: 2.0 +/- 0.4, p < 0.001, DMSO: 3.8 +/- 2.4, p < 0.001, DMSO: 5.4 +/- 1.7, p < 0.05 v.s. C: 8.6 +/- 1.1 and NDTO: 3.8 +/- 1.5, p < 0.001 ml.kg-1.min-1). The statistical significance is related to the control group of slim healthy subject. From this ensues that no significant difference was found between slim diabetic and non-diabetic subjects in the majority of parameters expressing the action of insulin with the exception of the metabolic glucose clearance. At the same time the authors found in the whole group of 53 examined subject a statistically significant correlation between the BMI and the index of tissue sensitivity for insulin (M/I) (r = -0.55, p < 0.001). On examination of characteristics of insulin receptors on erythrocytes the authors found a reduced number in diabetic subject as compared with the two control groups (p < 0.05). It may thus be concluded from this investigation that the BMI has a decisive role in the action insulin.

Body Mass Index↗

PubMed1999

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. Positivity of anti-GAD was found in 29 (58%) patients, anti-IA-2 in 13 (25%) patients, IA in 46 (85%) patients, anti-TPO in 10 (21%) and anti-TG in 11 (23%) patients. Simultaneous positivity of thyroid and islet autoantibodies was found in 6 (11%) patients whereas the positivity at least one of them was in 38 (69%) patients. No relationship between glycated hemoglobin and autoantibody concentration was found in the whole group of patients. The autoimmune thyroid disease was newly detected in 4 patients from high concentration of thyroid autoantibodies together with impaired TSH and T4 values and ultrasonography finding. No clinical evidence of thyroid disease was previously found in these patients. Positivity of anti-GAD or anti-IA-2 was found in almost 65% and of any thyroid autoantibody in almost 30% of our patients. Four patients with autoimmune thyroid disease were newly identified. We conclude that the evaluation of thyroid autoantibodies in Type 1 diabetic patients may improve the diagnosis of thyroid disease in very early stage and thus prevent consequent complications.

Adult↗

PubMed1999

The influence of methylene blue and L-NAME on the development of streptozotocin-induced diabetes in rats.

The cytokine-induced overproduction of nitric oxide by immunocompetent cells with subsequent development of oxidative stress is suggested to be one of important pathophysiological mechanisms of the pancreatic beta cells damage in streptozotocin-induced experimental diabetes. The aim of our study was to compare the influence of two nitric oxide inhibiting compounds: methylene blue and L-NAME (N-omega-nitro-L-arginine-methyl ester) on the streptozotocin diabetes development and the oxidative stress parameters in male rats. Blood glucose, glycated haemoglobin, serum malondialdehyde concentration and erythrocyte superoxide dismutase activity were measured in control, diabetic (streptozotocin 70 mg/kg i.p.), methylene blue (50 mg/kg in the food), and diabetic group treated simultaneously with methylene blue (10 animals in each group). In the second experiment the L-NAME was used instead of methylene blue. It was found that both methylene blue and L-NAME partially suppressed the development of diabetes, but did not unambiguously influence the oxidative stress parameters. We conclude, that both methylene blue and L-NAME partially suppress the development of streptozotocin-induced diabetes in rats. The precise mechanism of this effect is not clear. We failed to demonstrate clear effect of methylene blue and/or L-NAME on oxidative stress development in diabetic rats.

Animals↗