Esma Altunoglu

Ischemia‐modified albumin and advanced oxidation protein products as potential biomarkers of protein oxidation in Alzheimer's disease

The aim of the present study was to determine the systemic levels of oxidative stress markers, such as ischemia‐modified albumin (IMA), advanced oxidation protein products (AOPP), ferric reducing antioxidant power (FRAP) and the prooxidant–antioxidant balance (PAB), to clarify protein redox homeostasis in patients with Alzheimers disease, and to compare them with mentally healthy persons of the same age.

The efficacy of donepezil administration on acetylcholinesterase activity and altered redox homeostasis in Alzheimer’s disease

Alzheimers disease (AD) is a serious multifactorial disorder with progressive neurodegenerative outcomes related with impaired redox homeostasis. Inhibition of the enzyme acetylcholinesterase (AChE), as one of the major therapeutic strategies, is considered to be offering only symptomatic relief and moderate disease modifying effect. We intended to investigate the effects of acetylcholinesterase inhibition via donepezil on protein carbonyl (PCO), advanced protein oxidation products (AOPP) and ischemia modified albumin (IMA) as protein oxidation markers and ferric reducing antioxidant power (FRAP), prooxidant-antioxidant balance (PAB), total thiol (T-SH), protein thiol (P-SH) as antioxidant status markers and also kynurenine (KYN), N-formyl kynurenine (N-FKYN) and protein bound dityrosine (DT) levels all in one demonstrating the redox homeostasis in Alzheimer patients also correlated with AChE activity. The AChE activity and PCO, KYN, N-FKYN and DT levels were found to be significantly higher in the AD group than the control group. The FRAP, T-SH and P-SH levels were significantly lower in the AD group than in the control group. The AChE activity was significantly higher both in donepezil treated and untreated groups when compared with the control group. PCO levels were significantly higher in Alzheimers untreated group than the healthy control and donepezil treated groups. AChE activity was positively correlated with PCO, IMA, PAB, KYN and N-FKYN levels and negatively correlated with FRAP, T-SH and P-SH levels in all participants. Our data showed that treatment with donepezil had ameliorating effects on redox homeostasis in Alzheimer patients. AChE inhibition seems to be exhibiting a potent antioxidant role and may inhibit protein oxidation by decreasing AChE activity in AD, thus medicinal natural substances exhibiting the similar mechanism of action with their antioxidant behaviours can be recommended for the emphasis on new drug new drug development. Further clinical and experimental studies are needed to support our current findings and conclusions.

The Impact of Obesity and Insulin Resistance on Iron and Red Blood Cell Parameters: A Single Center, Cross-Sectional Study

Objective: Obesity and iron deficiency (ID) are the 2 most common nutritional disorders worldwide causing significant public health implications. Obesity is characterized by the presence of low-grade inflammation, which may lead to a number of diseases including insulin resistance (IR) and type 2 diabetes. Increased levels of acute-phase proteins such as C-reactive protein (CRP) have been reported in obesity-related inflammation. The aim of this study was to investigate the impact of obesity/IR on iron and red blood cell related parameters. Materials and Methods: A total of 206 patients and 45 control subjects of normal weight were included in this cross-sectional study. Venous blood samples were taken from each patient to measure hemoglobin (Hb), serum iron (Fe), iron-binding capacity (IBC), ferritin, CRP, fasting blood glucose, and fasting insulin. Body mass index (BMI) and waist-to-hip ratio (WHR) were calculated for each patient. IR was determined using the HOMA-IR formula. Results: Subjects were divided into 3 groups according to BMI. There were 152 severely obese (BMI: 42.6±10.1), 54 mildly obese (BMI: 32.4±2.1), and 45 normal-weight (BMI: 24.3±1.3) patients. Hb levels in severely obese patients and normal controls were 12.8±1.3 g/dL and 13.6±1.8 g/dL, respectively. We found decreasing Fe levels with increasing weight (14.9±6.9 µmol/L, 13.6±6.3 µmol/L, and 10.9±4.6 µmol/L for normal controls and mildly and severely obese patients, respectively). Hb levels were slightly lower in patients with higher HOMA-IR values (13.1±1.5 g/dL vs. 13.2±1.2 g/dL; p=0.36). Serum iron levels were significantly higher in the group with low HOMA-IR values (13.6±5.9 µmol/L vs. 11.6±4.9 µmol/L; p=0.008). IBC was found to be similar in both groups (60.2±11.4 µmol/L vs. 61.9±10.7 µmol/L; p=0.23). Ferritin was slightly higher in patients with higher HOMA-IR values (156.1±209.5 pmol/L vs. 145.3±131.5 pmol/L; p=0.62). Conclusion: Elevated BMI and IR are associated with lower Fe and hemoglobin levels. These findings may be explained by the chronic inflammation of obesity and may contribute to obesity-related co-morbidities. People with IR may present with ID without anemia.

Serum Osteoprotegerin Levels Related With Cardiovascular Risk Factors in Chronic Kidney Disease

To evaluate osteoprotegerin (OPG) levels in relation to cardiovascular (CV) risk factors in patients with chronic kidney disease (CKD) on different regimens of renal replacement therapy.

The relationship between circulating irisin, retinol binding protein-4, adiponectin and inflammatory mediators in patients with metabolic syndrome

OBJECTIVE We wanted to investigate whether there is a relationship between circulating irisin, retinol binding protein-4 (RBP-4), adiponectin and proinflammatory mediators implicated in the development of insulin resistance (IR) in metabolic syndrome (MetS). SUBJECTS AND METHODS In 180 individuals, including controls and patients with MetS, we measured fasting plasma insulin, high sensitivity C-reactive protein (hsCRP), pentraxin-3 (PTX-3), interleukin-33 (IL-33), irisin, RBP-4, and adiponectin using ELISA kits. RESULTS While fasting plasma hsCRP, PTX-3, IL-33, irisin, RBP-4 concentrations were higher, adiponectin levels were lower in patients with MetS than in controls. A correlation analysis revealed that plasma irisin levels were positively associated with MetS components such as waist circumference and waist-hip ratio, low density lipoprotein (LDL) and markers of systemic inflammation such as PTX-3, hsCRP, uric acid, and RBP-4. Adiponectin levels were negatively associated with waist circumference, waist-hip ratio, PTX-3 and LDL. CONCLUSIONS Although the precise mechanisms are still unclear, irisin, RBP-4, adiponectin and PTX-3 are hallmarks of the MetS, which is related to low-grade inflammation. It is conceivable that irisin and adiponectin might contribute to the development of MetS and may also represent novel MetS components. Future clinical studies are needed to confirm and extend these data.

Association of Plasma Pentraxin-3 Levels with Retinopathy and Systemic Factors in Diabetic Patients

BACKGROUND Diabetic retinopathy (DR) is mainly caused by metabolic factors, vascular inflammation, and endothelial dysfunction. We aimed to evaluate the relationship of DR with inflammatory and biochemical alterations in type 2 diabetics. METHODS A total of 89 diabetic patients with retinopathy [(DR (+) (n = 30)], without retinopathy [(DR (-) (n = 32)], and 27 control subjects were involved in the study. Demographic properties, biochemical values, ophtalmologic evaluation, C-reactive protein (CRP), and pentraxin-3 (PTX-3) levels were recorded. RESULTS There was significant difference between controls, DR (-) and DR (+) groups with regard to serum PTX-3 levels. Control group had the lowest and DR (+) group revealed the highest PTX-3 levels. Severity of retinopathy was not related with CRP or PTX-3 levels. Duration of diabetes was longer, systolic blood pressure (SBP) and urinary albumin-creatinine ratio (UACR) were significantly higher in DR (+) subjects than DR (-) subjects. Multivariate analysis revealed that PTX-3 level and SBP were the variables that had a significant effect on DR (P = 0.002, OR = 1.61, and P = 0.021, OR = 1.06, respectively). CONCLUSIONS Plasma PTX-3 levels may be a valuable predictor of DR-like factors such as duration of diabetes, hypertension, and UACR. Although inflammation has an important role in DR, we think that biomarkers reflecting inflammation is not sufficient to predict development and progression of DR; but follow up with PTX-3 levels along with ophthalmological evaluation may be useful. A single determination may not reflect the variations over time, so repeat measures may provide knowledge if PTX-3 is just a biomarker or has a causal role.

Is automated kinetic measurement superior to end-point for advanced oxidation protein product?

BACKGROUND Advanced oxidation protein product (AOPP) was first described as an oxidative protein marker in chronic uremic patients and measured with a semi-automatic end-point method. Subsequently, the kinetic method was introduced for AOPP assay. We aimed to compare these two methods by adapting them to a chemistry analyzer and to investigate the correlation between AOPP and fibrinogen, the key molecule responsible for human plasma AOPP reactivity, microalbumin, and HbA1c in patients with type II diabetes mellitus (DM II). The effects of EDTA and citrate-anticogulated tubes on these two methods were incorporated into the study. METHODS This study included 93 DM II patients (36 women, 57 men) with HbA1c levels > or = 7%, who were admitted to the diabetes and nephrology clinics. The samples were collected in EDTA and in citrate-anticoagulated tubes. Both methods were adapted to a chemistry analyzer and the samples were studied in parallel. RESULTS In both types of samples, we found a moderate correlation between the kinetic and the endpoint methods (r = 0.611 for citrate-anticoagulated, r = 0.636 for EDTA-anticoagulated, p = 0.0001 for both). We found a moderate correlation between fibrinogen-AOPP and microalbumin-AOPP levels only in the kinetic method (r = 0.644 and 0.520 for citrate-anticoagulated; r = 0.581 and 0.490 for EDTA-anticoagulated, p = 0.0001). CONCLUSIONS We conclude that adaptation of the end-point method to automation is more difficult and it has higher between-run CV% while application of the kinetic method is easier and it may be used in oxidative stress studies.

In Patients with Type-2 Diabetes, Diabetes Regulation, Hba1c, Duration of Diabetes, BMI, Dyslipidemia, and Microalbuminuria Compared with Macrovascular Complications

Bulgular: Bir çok çalışmada glisemi kontrolünün komplikasyon sıklığını azalttığı gösterilmiştir. Çalışmamızda da çıkan en önemli sonuçlardan biri glisemik kontrolün makrovasküler komplikasyonlar üzerindeki olumlu etkisiydi. HbA1c düzeyi 8 ve üstünde olan olgularda hipertansiyon ve koroner arter hastalığı sıklığını, HbA1c %8’in altında olan olgulara göre anlamlı derecede daha fazla bulduk. Diyabet süresi ile makrovasküler komplikasyon gelişimi arasında ilişki bilinmektedir. Glisemik maruziyetin süresinin bu süreçte ana neden olduğu düşünülmektedir. Çalışmamızda diyabet süresi 5 yıl üzerinde olan olgularda 5 yıl ve altı olan olgulara göre makrovasküler komplikasyon sıklığı anlamlı derecede yüksek saptandı. Hipertansiyon ve koroner arter hastalığı gelişimiyle diyabet süresinin istatiksel olarak anlamlı derecede paralel olduğu görüldü. Diyabet yaşı 5 yıl üzerinde olanlarda periferik arter hastalığı ve serebrovasküler hastalık sıklığı yüksek saptanırken istatistiksel olarak anlamlı saptanmadı. Obezite tip 2 diyabet gelişimi için önemli risk faktörlerinden olup kardiyovasküler hastalıklar açısından bağımsız bir risk faktörüdür. Bizim çalışmamızda BMI ve bel çevresi grupları ile komplikasyonlar arasında anlamlı ilişki saptanmadı. Lipid düzeyleri ile makrovasküler komplikasyonlar arasındaki ilişki birçok çalışmada gösterilmiştir. LDL kolesterol yüksekliği, HDL kolesterol düşüklüğü, trigliserid yüksekliği ateromatöz süreci hızlandırmaktadır. Çalışmamızda total kolesterol, LDL ve HDL kolesterol grupları arasında anlamlı bir farklılık saptanamamıştır. Yalnızca trigliserid düzeyi yüksekliği ile hipertansiyon arasında anlamlı ilişki saptanmıştır. Mikroalbuminüri diyabetli hastalarda kardiyovasküler hastalık için risk faktörleri kompleks sendromunun önemli bir komponenti ve yaygın endotel hasarının göstergesi olarak düşünülmektedir ve diyabetli hastalarda nefropatiye yol açmaktadır. Mikroalbümin tip 2 diyabette kan basıncı ve sigara gibi diğer faktörlerden bağımsız bir risk faktörüdür. Bizim çalışmamızda da makrove mikroalbuminüri ile hipertansiyon ve koroner arter hastalığı arasında anlamlı derecede ilişki gözlendi.

Comparison of adiponectin values in obese and nonobese diabetics and relationship with metabolic parameters

Gerec ve Yontem: Calismaya hastanemiz diyabet ve endokrinoloji polikliniklerine basvuran 46 obez, 38 obez olmayan hasta alindi. Antropometrik ve metabolik degiskenleri adiponektin duzeyleri ile karsilastirildi. Hastalarin aclik kan sekeri, tokluk kan sekeri, ure, kreatinin, toplam protein, albumin, toplam kolesterol, LDL-kolesterol, HDL-kolesterol, trigliserid, HbA1c degerleri spektrofotometrik yontemle olculdu. Insulin duzeyleri elektrokemiluminesans, adiponektin ise sandvic-ELISA yontemi ile olculdu.

Obesity and Thyroid Function

Amaç: Obezite tüm dünyada giderek artan sağlık sorunlarından biridir. Yağ dokusunun birçok hormon, sitokin ve kimyasalların homeostaz ve regülasyonunda önemli rolü bulunmaktadır. Obezite tüm sistemleri etkilemektedir. Tiroid fonksiyonları da etkilenen sistemlerden biridir. Tiroid hormonlarının adaptif termogenezis, istirahat enerji gereksinimi üzerinde belirleyici etkileri vardır. Bu nedenle obezite ile tiroid fonksiyonları arasında belirgin bir korelasyon beklenir. Biz de obezite ile tiroid fonksiyonları arasındaki ilişkiyi incelemeyi amaçladık.