Lezzan Keskin

Evaluation of in vivo cerebral metabolism on proton magnetic resonance spectroscopy in patients with impaired glucose tolerance and type 2 diabetes mellitus

The aim of this study was to investigate possible metabolic alterations in cerebral tissues on magnetic resonance spectroscopy (MRS) in patients with impaired glucose tolerance (IGT) and with type 2 diabetes mellitus (T2-DM). Twenty-five patients with T2-DM, 13 patients with IGT, and 14 healthy volunteers were included. Single-voxel spectroscopy (TR: 2000 ms, TE: 31 ms) was performed in all subjects. Voxels were placed in the frontal cortex, thalamus, and parietal white matter. N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, and myo-inositol (MI)/Cr ratios were calculated. Frontal cortical Cho/Cr ratios were increased in patients with IGT compared to control subjects. Parietal white matter Cho/Cr ratios were significantly higher in patients with IGT when compared to patients with T2-DM. In the diabetic group, frontal cortical MI/Cr ratios were increased, and parietal white matter Cho/Cr ratios were decreased when compared to the control group. Frontal cortical NAA/Cr and Cho/Cr ratios and parietal white matter Cho/Cr ratios were decreased in diabetic patients with poor glycemic control (A1C>10%). A1C levels were inversely correlated with frontal cortical NAA/Cr and Cho/Cr ratios and with parietal white matter Cho/Cr ratios. T2-DM and IGT may cause subtle cerebral metabolic changes, and these changes may be shown with MRS. Increased Cho/Cr ratios may suggest dynamic change in membrane turnover in patients with IGT. Diabetic patients with poor glycemic control may be associated with neuronal dysfunction/damage in brain in accordance with A1C levels and, in some, extend with insulin resistance.

Epicardial adipose tissue, hepatic steatosis and obesity

Objective: Hepatic steatosis is a common companion of obesity. Moreover, the measurement of epicardial adipose tissue (EAT) has been reported to be related with both obesity and insulin resistance. Therefore, we aimed to evaluate the relationship between hepatic steatosis, EAT and insulin resistance in obese patients. Methods: Sixty-three obese subjects were enrolled in the study. Patients were divided into 3 groups according to body mass index (BMI) as follows: 20 patients with 30≤BMI<35 kg/m2 (Group 1, mean age 39.3±12.9 yr), 25 patients with 35≤BMI<40 kg/m2 (Group 2, mean age 41.7±9.3 yr), and 18 patients with BMI≥40 kg/m2 (Group 3, mean age 36.8±13.9 yr). EAT and grade of hepatic steatosis were assessed sonographically. Anthropometrical measurements were assessed with the foot-to-foot bioelectrical impedance analysis. Insulin resistance was assessed according to basal insulin, quantitative insulin sensitivity check index (QUICKI) and homeostasis model assessment (HOMA) equations. Results: Although EAT was similarly higher in both groups 2 and 3, these groups were found to be similar in terms of the grade of hepatic steatosis. Both EAT and the grade of hepatic steatosis were correlated with whole body fat mass, abdominal adiposity, insulin resistance, and triglyceridemia but waist circumference was the only factor affecting EAT thickness. Highly sensitive C-reactive protein (hsCRP) was the only metabolic parameter that was significantly higher in Group 3 than in Group 1 (p=0.02). Conclusion: Hepatic steatosis should be assessed as a valuable predictor that reflects the increments of whole body fat mass as well as abdominal adiposity. However, in an attempt to demonstrate marginal differences between patients with similar obesity levels, epicardial adipose tissue appears to be a more sensitive marker compared to hepatic steatosis.

Serum leptin, resistin, and lipid levels in patients with end stage renal failure with regard to dialysis modality.

Little information is available on the relationship between serum resistin levels and other adipokines with serum lipid levels and insulin resistance in uremic patients under different dialysis modalities. Methods. This study investigated the effects of dialysis modality on serum leptin, adiponectin, resistin, interleukin 6 (IL-6), and tumor necrosis factor (TNF) α levels in age, sex, and total adipose tissue mass (TATM); matched 30 hemodialysis (HD) patients, 30 continuous peritoneal dialysis (CAPD) patients, and 30 healthy controls; and evaluated the relationship between these adipokines and dyslipidemia and insulin resistance. Results. Serum resistin, adiponectin, IL-6, TNF-α, and high sensitive C reactive protein (hsCRP) levels were significantly increased in dialysis patients compared to controls (p < 0.05). In CAPD patients, serum leptin, resistin, triglycerides, and total cholesterol levels were higher than those in HD patients (p < 0.05). Leptin levels were positively correlated with TATM, serum triglycerides, total cholesterol, and low density lipoprotein (LDLc) levels in both dialysis groups. Resistin levels were found to positively correlate with TATM and triglycerides in CAPD patients. No relationship was found between the homeostasis model assessment-insulin resistance index (HOMA-IR) and adipokines studied. Conclusion. Serum leptin, resistin, triglycerides, and total cholesterol levels were higher in CAPD patients. Leptin levels were positively correlated with TATM, serum triglycerides, total cholesterol, and LDLc levels in dialysis patients. Resistin levels were positively correlated with TATM and triglycerides in CAPD patients. Glucose load during CAPD may be an important factor in increased in leptin, resistin, triglycerides, and total cholesterol levels in CAPD patients. These results highlight the importance of leptin and resistin as determinants of dyslipidemia, especially in CAPD patients.

Oxidant/antioxidant Parameters and their Relationship with Chemotherapy in Hodgkin's Lymphoma

This study investigated changing levels of serum oxidant/antioxidant with chemotherapy and their relation to treatment in 34 Hodgkins lymphoma patients. The patient population consisted of 19 males and 15 females. Mean age was 30.41 ± 12.08 years. All patients received the adriamycin, bleomycin, vincristine and dexamethasone (ABVD) treatment protocol. Blood samples were taken before treatment, and on days 1 and 7 during treatment for measurement of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), malondialdehyde (MDA), nitric oxide (NO) and enzyme activities. After ABVD treatment, mean free radical levels were increased and antioxidant levels were significantly decreased in the serum. ABVD treatment results in an increase of free radical levels and a decrease of antioxidant levels in the serum of patients with Hodgkins lymphoma.

Angiotensin-converting enzyme gene polymorphism and risk of insulin resistance in PCOS

The aim of this study was to establish the frequency of angiotensin-converting enzyme (ACE) insertion (I) or deletion (D) gene polymorphism in women with polycystic ovary syndrome (PCOS) and to examine the association of this polymorphism with insulin resistance. A total of 32 women with PCOS and 31 healthy, age- and body mass index-matched controls were studied. Serum lipids, fasting glucose, insulin and other hormones concentrations were measured. Homeostasis model assessment was used to estimate insulin resistance (HOMA-IR). DNA was extracted from peripheral blood leukocytes and genotyping of ACE I/D polymorphism was carried out by polymerase chain reaction. ACE genotypes were distributed as follows: DD was present in 16 (50%), ID in 12 (37.5%) and II in four (12.5%) PCOS patients, and DD in seven (22.6%), ID in 20 (64.5%) and II in four (12.9%) of healthy subjects. The frequency of D and I alleles were found in 69% and 31% of the PCOS group and 55% and 45% in the control group, respectively. There were no significant differences regarding the genotypic distribution and allelic frequency between the groups. However the ACE DD genotype was significantly associated with serum insulin concentrations and HOMA-IR measurement (both P=0.005). ACE DD genotype is associated with an increased insulin resistance in women with PCOS.

Adrenomedullin: Possible predictor of insulin resistance in women with polycystic ovary syndrome

The aim of the study was to investigate adrenomedullin (ADM) levels and its relation with insulin resistance in women with polycystic ovary syndrome (PCOS). Twenty-nine women with PCOS and 29 age- and body mass index (BMI)-matched control subjects were included in the study. PCOS was defined according to criteria by the Rotterdam European Society of Human Reproduction and Embryology/American Society for Reproductive Medicine (ESHRE/ASRM)-sponsored PCOS consensus workshop group. A full clinical and biochemical examination including basal hormones and metabolic profile was performed. Insulin resistance was calculated by using the homeostasis model assessment of insulin resistance index (HOMA-IR). Plasma ADM levels were measured by high performance liquid chromatographic (HPLC) method. Plasma ADM, fasting insulin levels and HOMA-IR were significantly higher in patients with PCOS than the control group. ADM levels were positively correlated with insulin levels and HOMA-IR index. The best cut-off value of ADM levels to identify the presence of insulin resistance (HOMA-IR≥2.7) was 30.44 ng/ml. Calculated odds ratio of insulin resistance by using logistic regression analysis, as predicted by ADM, was 0.15 (95% confidence interval, 0.037–0.628; p=0.009). In multiple regression analysis, ADM level was an independent predictor of HOMA-IR index. Our finding indicated that ADM levels increased in women with PCOS in accordance with HOMA-IR. ADM could be a significant independent determinant of insulin resistance in women with PCOS.