Biomedical subjects

F Törüner

Publications and source records attributed to F Törüner.

5 recordsLinked to original sources

PubMed2005

The effects of rosiglitazone and metformin on insulin resistance and serum androgen levels in obese and lean patients with polycystic ovary syndrome.

AIM: The aim of this study was to assess the effects of metformin and rosiglitazone on insulin resistance and serum androgen levels in both obese and lean patients with polycystic ovary syndrome (PCOS). MATERIALS AND METHODS: Forty lean [body mass index (BMI) < 25 kg/m2] and 40 overweight and obese (BMI > 25 kg/m2) patients were included in the study. Waist and hip measurements, serum sex steroid levels, insulin response to 75-g oral glucose tolerance test, fasting insulin, fasting C-peptide levels and homeostasis model assessment of insulin resistance (HOMA-IR) were determined in all patients. The degree of hirsutism was determined by the Ferriman-Gallwey scoring system. Patients were divided into two groups, with 40 (20 overweight and obese; 20 non-obese) patients each. One group was treated with metformin (MET group) 850 mg bid while the other received rosiglitazone (ROSI group) 4 mg/day for 12 weeks. All measurements were repeated at the end of this period. RESULTS: After the 12-week treatment period, HOMA-IR, area under the curve of insulin, fasting insulin and C-peptide levels were observed to have be decreased significantly in all groups. The decrease in the parameters mentioned above was similar in the four groups. The serum levels of free testosterone, androstenedione and DHEA-S decreased in all groups, but the decrease was statistically significant only in the ROSI groups. Within the lean MET group one patient became pregnant and was hence excluded from the final data analysis. Menstruations became regular after metformin therapy in 41.6% of lean and 35.7% of obese patients who had menstrual disturbance prior to the study. Rosiglitazone therapy improved menstrual disturbance in 61.5 % of lean and 53.8% of obese patients. CONCLUSIONS: Our data showed that both metformin and rosiglitazone increased insulin sensitivity in obese patients with PCOS as expected, and in lean patients as well. Rosiglitazone seemed to be more effective in decreasing the androgen levels and in achieving slightly greater improvement in menstrual disturbance than metformin.

Adult↗

PubMed2004

Effects of PPARgamma and PPARalpha agonists on serum leptin levels in diet-induced obese rats.

Leptin and peroxisome proliferator-activated receptors are two important adipose tissue factors involved in energy metabolism regulation. It has been shown that PPARgamma agonists decrease leptin levels. However, the effects of PPARalpha agonists on leptin have not been investigated much. The aim of this study was to compare the effects of a PPARgamma agonist rosiglitazone (RSG) and PPARalpha agonist gemfibrozil (G) on body weight and serum insulin and leptin levels in diet-induced obese rats. Male Wistar rats were divided into six groups according to diet and drug therapy. After four weeks, serum glucose, triglyceride, insulin and leptin levels were significantly decreased in the high-fat-fed and RSG-treated groups compared to the group fed a high-fat diet only (162 +/- 19 vs. 207 +/- 34 mg/dl, 58 +/- 20 vs. 112 +/- 23 mg/dl, 3.1 +/- 1.0 vs. 15.2 +/- 4.0 ng/ml, 1.6 +/- 0.5 vs. 3.6 +/- 1.6 ng/ml, respectively). However, these parameters were not statistically different in RSG animals treated with a standard diet compared to the standard diet group. The high fat+RSG group gained much more weight compared to high-fat and high-fat+G groups (p > 0.05). Additionally, serum glucose, insulin and leptin levels were significantly decreased in the high-fat-fed and G-treated group compared to high-fat group (149 +/- 19 vs. 207 +/- 34 mg/dl, 57 +/- 16 vs. 112 +/- 23 mg/dl, 4.3 +/- 2.1 vs. 15.2 +/- 4.0 ng/ml, 1.6 +/- 0.4 vs. 3.6 +/- 1.6 ng/ml, respectively). These results suggest that PPARalpha agonists may decrease serum glucose, insulin and leptin levels as PPARgamma agonists do in diet-induced obese rats.

Adipose Tissue↗

PubMed2004

The relationship between levels of alpha1-acid glycoprotein and metabolic parameters of diabetes mellitus.

The aim of this study was to investigate the relationship of alpha1-acid glycoprotein (AGP, orosomucoid), which is an acute-phase reactant, in patients with Type 1 (T1DM) and Type 2 diabetes mellitus (T2DM), with the metabolic parameters and complications of diabetes mellitus. A total of 119 diabetic patients (89 T2DM, 30 T1DM) and 33 healthy controls were included in the study. The mean AGP level in the diabetic group was not different from the control group (82.4 +/- 28.9 and 81.6 +/- 16.6 mg/dl, respectively), but it was higher in T2DM than in T1DM subjects (86.6 +/- 28.3 and 69.7 +/- 26.9, respectively). AGP plasma levels showed a significant correlation with age and body mass index (r = +0.348 and r = +0.296, respectively). AGP plasma levels resulted higher in obese diabetic patients (97.7 +/- 28.0) than in non-obese diabetic patients (77.6 +/- 28.7 mg/dl) and controls (81.6 +/- 16.6), and also higher in diabetic subjects with poor glycaemic control (85.1 +/- 33.3 mg/dl) than in diabetic subjects with optimal glycaemic control (79.5 +/- 23.1 mg/dl). A relationship between AGP and macro- and microvascular complications of diabetes mellitus was not found. In conclusion, inflammatory findings were more prominent in obese diabetic patients.

Acute-Phase Proteins↗

PubMed2003

Insulin secretion and insulin sensitivity in normal pregnancy and gestational diabetes mellitus.

The purpose of this study was to evaluate insulin sensitivity, beta-cell function and islet-cell-directed autoimmunity in pregnant women with normal glucose tolerance and gestational diabetes mellitus (GDM). A total of 21 women with normal glucose tolerance and 21 women with GDM were evaluated at 24-36 weeks' gestation. Insulin resistance and beta-cell function were evaluated using the continuous infusion of glucose with model assessment (CIGMA) method, which aims to give a near-physiological stimulus and to evaluate the endogenous insulin and glucose response. Islet-cell autoantibody was positive in one woman with GDM, and glutamic acid decarboxylase autoantibodies were negative in both groups. The calculated CIGMA insulin resistance (CIGMA IR) was 2.04 +/- 1.74 and 1.08 +/- 1.22 in patients with GDM and in control subjects, respectively (p < 0.05). CIGMA percentage beta-cell values were 64.04 +/- 44.55% and 87.07 +/- 52.77% in patients with GDM and control subjects, respectively (p > 0.05). Decreased insulin sensitivity in late pregnancy was more evident in lean GDM subjects with mild hyperglycemia who did not require insulin therapy, and beta-cell function was partially preserved in this group of patients.

Adult↗

PubMed2002

Pattern visual evoked potential (PVEP) evaluation in hypothyroidism.

Dysfunction of the central nervous system (CNS) is an important consequence of thyroid hormone deficiency. Evoked potentials like visual evoked potentials (VEP) provide a reliable and objective measure of function in related sensory system and tracts. In this study pattern-shift VEP (PVEP) recordings were performed on 48 newly diagnosed hypothyroid patients. Twenty-four had sub-clinical and 24 had overt hypothyroidism. None of the patients had clinical symptoms or signs referable to CNS dysfunction. Their mean age was 44+/-12 yr. The response to pattern stimulation on the normal control subjects was a triphasic response with a prominent positive wave (P100) with a peak latency of 84-105 (mean: 96+/-4) milliseconds (ms). In patients with hypothyroidism mean P100 latency was (mean: 97+/-6) ms and the difference between the 2 groups was not statistically significant. (p>0.05) Delays above the average latency +/-2.5 SD of the mean of the control subjects was defined as a criteria for an abnormality. According to defined criteria 6 (12.5%) patients demonstrated abnormal PVEP at least on one tested side. Previous studies conducted on small patient populations stated there is high percentage of VEP abnormalities in hypothyroid patients. However, this fact was not confirmed by our study. We believe abnormalities of PVEP will be more prominent in untreated patients in the advanced stage of the disease, or in patients who have a neurological involvement; such as apathy, impaired memory or cerebellar dysfunction. Consecutive studies, in a more clearly defined and selected patient population, are needed to confirm and settle this issue.

Adult↗