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Featured researches published by Nujen Colak Bozkurt.


Endocrine Practice | 2013

The Association Between Severity of Vitamin D Deficiency and Hashimoto's Thyroiditis

Nujen Colak Bozkurt; Basak Karbek; Bekir Ucan; Mustafa Sahin; Erman Cakal; Mustafa Ozbek; Tuncay Delibasi

OBJECTIVE The relation between vitamin D and autoimmune disorders has long been investigated regarding the important roles of this hormone in immune regulation. We evaluated 25-hydroxyvitamin D (25OHD) status in subjects with Hashimotos thyroiditis (HT) and healthy controls. METHODS Group-1 included 180 euthyroid patients (123 females/57 males) with HT who were on a stable dose of L-thyroxine (LT). A total of 180 sex-, age-, and body mass index (BMI)-matched euthyroid subjects with newly diagnosed HT were considered as Group-2, and 180 healthy volunteers were enrolled as controls (Group-3). All 540 subjects underwent thyroid ultrasound and were evaluated for serum 25OHD, anti-thyroid peroxidase (anti-TPO), and anti-thyroglobulin (anti-TG) levels. RESULTS Group-1 had the lowest 25OHD levels (11.4 ± 5.2 ng/mL) compared to newly diagnosed HT subjects (Group-2) (13.1 ± 5.9 ng/mL, P = .002) and to control subjects (15.4 ± 6.8 ng/mL, P<.001). Serum 25OHD levels directly correlated with thyroid volume (r = 0.145, P<.001) and inversely correlated with anti-TPO (r = -0.361, P<.001) and anti-TG levels (r = -0.335, P<.001). We determined that 48.3% of Group-1, 35% of Group-2, and 20.5% of controls had severe 25OHD deficiency (<10 ng/mL). Female chronic HT patients had the lowest serum 25OHD levels (10.3 ± 4.58 ng/mL), and male control subjects had the highest (19.3 ± 5.9 ng/mL, P<.001). CONCLUSIONS We demonstrated that serum 25OHD levels of HT patients were significantly lower than controls, and 25OHD deficiency severity correlated with duration of HT, thyroid volume, and antibody levels. These findings may suggest a potential role of 25OHD in development of HT and/or its progression to hypothyroidism.


Cardiovascular Diabetology | 2011

Heart-Type Fatty Acid Binding Protein (H-FABP): Relationship with arterial ıntima-media thickness and role as diagnostic marker for atherosclerosis in patients with ımpaired glucose metabolism

Basak Karbek; Mustafa Ozbek; Nujen Colak Bozkurt; Zeynep Ginis; Askin Gungunes; İlknur Öztürk Ünsal; E. Cakal; Tuncay Delibasi

BackgroundHeart type fatty acid binding protein (H-FABP) has been closely associated with acute coronary syndrome, cardiac abnormalities, stroke, and obstructive sleep disorder in previous studies. The aim of this study was to evaluate and compare the serum H-FABP levels and carotid artery intima-media thickness (CIMT) between patients with prediabetes and control subjects.Research design and methodsWe measured serum H-FABP levels in 58 prediabetic patients, 29 with impaired fasting glucose (IFG) and 29 with impaired glucose tolerance (IGT) and 28 age-, sex- and body mass index-matched control subjects using a sandwich enzyme-linked immunosorbent assay (ELISA), and in order to measure CIMT, all participants underwent high-resolution B-mode ultrasonography.ResultsSerum H-FABP levels were significantly elevated in pre-diabetic patients when compared with that of control subjects (IFG: 32.5 ± 34.2 ng/dL, IGT: 45.4 ± 45.8 ng/dL, control: 16.8 ± 14.9 ng/dL; p = 0.011). The difference in means of H-FABP levels between patients with IGT or IFG and control subjects was significant (p = 0.010 and p = 0.009, respectively). CIMT was higher in the pre-diabetic groups compared with the control group (IFG: 0.6 ± 0.1, IGT: 0.6 ± 0.1, control: 0.5 ± 0.1; p < 0.001), and H-FABP level was positively correlated with CIMT (p < 0.001, rho = 0.626).ConclusionOur results indicate that patients with pre-diabetes are at increased risk for cardiovascular disease. In addition, serum H-FABP levels could represent a useful marker for myocardial performance in patients with IFG and IGT.


Journal of Ovarian Research | 2014

Copeptin, a surrogate marker for arginine vasopressin, is associated with cardiovascular risk in patients with polycystic ovary syndrome.

Basak Karbek; Mustafa Ozbek; Melia Karakose; Oya Topaloglu; Nujen Colak Bozkurt; Evrim Cakir; Muyesser Sayki Aslan; Tuncay Delibasi

BackgroundWomen with polycystic ovary syndrome (PCOS) have higher risk for cardiovascular disease (CVD). Copeptin has been found to be predictive for myocardial ischemia. We tested whether copeptin is the predictor for CVD in PCOS patients, who have an increased risk of cardiovascular disease.MethodsThis was a cross sectional controlled study conducted in a training and research hospital. The study population consisted of 40 reproductive-age PCOS women and 43 control subjects. We evaluated anthropometric and metabolic parameters, carotid intima media thickness and copeptin levels in both PCOS patients and control group.ResultsMean fasting insulin, homeostasis model assessment insulin resistance index (HOMA-IR), triglyceride, total cholesterol, low density lipoprotein cholesterol (LDL-C), free testosterone, 17-OH progesterone, Dehydroepiandrosterone sulfate (DHEAS), carotid intima media thickness (CIMT) levels were significantly higher in PCOS patients. Mean copeptin level was in 12.61 ± 3.05 pmol/L in PCOS patients while mean copeptin level was 9.60 ± 2.80 pmol/L in healthy control women (p < 0.001). After adjustment for age and BMI, copeptin level was positive correlated with fasting insulin, free testosterone levels, CIMT, and HOM A-IR.ConclusionsCopeptin appeared to have an important role in metabolic response and subsequent development of atherosclerosis in insulin resistant, hyperandrogenemic PCOS patients.


Arquivos Brasileiros De Endocrinologia E Metabologia | 2014

Papillary thyroid cancer case masked by subacute thyroiditis

Bekir Ucan; Tuncay Delibasi; Erman Cakal; Muyesser Sayki Arslan; Nujen Colak Bozkurt; Taner Demirci; Mustafa Ozbek; Mustafa Sahin

Subacute thyroiditis (SAT) association with thyroid carcinoma has been rarely reported in the literature. We present a patient with SAT and papillary thyroid cancer that was suspected by ultrasonographic evaluation (US) following SAT treatment. A fifty-four-year old female patient referred to our department due to tachycardia, jitteriness and pain in cervical region for the past one month. SAT diagnosis was established by physical examination, laboratory and ultrasonographic findings. After treatment, control thyroid US revealed regression of the hypoechogenic regions seen in both lobes, and a previously unreported hypoechogenic lesion with microcalcification focus that had irregular borders and was not clearly separated from the surrounding parenchyma located in the posterior aspect of the lobe (Elasto score: 4, Strain index: 7.08). Fine needle aspiration biopsy was taken from this nodule; cytology was assessed to be compatible with papillary thyroid carcinoma. Postsurgical pathology evaluation showed a papillary microcarcinoma. SAT may produce ultrasound changes that obscure the coexistence of papillary carcinoma. We recommend that patients with SAT have ultrasonography after they recover. Hypoechogenic regions bigger than 1 cm that are present in the follow-up post-therapy US should be assessed by biopsy.


Ultrasonic Imaging | 2015

Elastography in the differential diagnosis of thyroid nodules.

Erman Cakal; Mustafa Şahin; İlknur Öztürk Ünsal; Askin Gungunes; Esra Tutal Akkaymak; Evrim Çakır Özkaya; Nujen Colak Bozkurt; Mustafa Ozbek; Tuncay Delibasi

Despite the publication of a recent meta-analysis of elastography in thyroid nodules, further work is necessary on this issue in different populations. In this study, we aimed to evaluate the clinical value of elastography on nodular goiters in mild iodine-deficient regions without excluding patients according to nodule characteristics. This prospective study was conducted between April 2010 and December 2011 in Yıldırım Beyazıt Dıskapı Research Hospital Endocrinology outpatient clinic. Five hundred twenty-eight nodular goiter patients who underwent thyroid fine-needle aspiration biopsy were included in our study. Elastography scores and indexes were measured with real-time ultrasound elastography (Hitachi® EUB 7000 HV machine with 13 MHz linear transducer). There were 471 females and 57 males and their ages ranged from 45 years to 78 years. A total of 601 nodules were evaluated in these patients. The area under the curve (AUC) for the elasto score was 0.91 (p < 0.0001) and AUC for the strain index (SI) was 0.96 (p < 0.0001). We suggest that the SI reflects malignancy better than the elasto score. We conclude that elastography scores greater than 3 have 76% sensitivity and 96% specificity for diagnosing malignancy. For SI, we conclude that 3.75 (83% sensitivity and 95% specificity) is the cutoff point. Elasto score and SI measurements of thyroid nodules in our population are efficient and increase the diagnostic performance of the sonography.


Archives of Endocrinology and Metabolism | 2015

Circulating E-selectin levels and insulin resistance are associated with early stages of atherosclerosis in nonfunctional adrenal incidentaloma

Tuncay Delibasi; Basak Karbek; Nujen Colak Bozkurt; Evrim Cakir; Askin Gungunes; Ölknur Öztürk Ünsal; Muyesser Sayki Aslan; Erman Cakal

OBJECTIVE To evaluate circulating E-selectin levels in patients with nonfunctional adrenal incidentaloma (NFA) in relation to insulin resistance and early atherosclerosis. SUBJECTS AND METHODS A total of 40 patients with NFA (mean [SD] age: 55.6 [10.7] years; 70% were females) and 35 controls (mean [SD] age: 51.5 [8.1] years; 71.4% were females) selected from age-, gender- and body mass index (BMI)- matched healthy subjects were enrolled. Serum hsCRP, lipid profile, insulin levels and the homeostasis model assessment of insulin resistance (HOMA-IR) were evaluated. High-resolution B-mode ultrasonography was performed. Serum levels of E-selectin were evaluated by enzyme-linked immunosorbent assay. RESULTS Patients with NFA had significantly higher values for E-selectin (14.9 (4.8) vs. 12.2 (4.1) ng/mL, p < 0.01) and CIMT (0.6 (0.1) vs. 0.5 (0.1) mm, p < 0.05) than controls. Serum E-selectin levels showed a statistically significant association with hsCRP (r = 0.751, p < 0.001), HOMA-IR (r = 0.575, p < 0.001) and CIMT (r = 0.762, p < 0.001). CIMT (Carotid intima media thickness) was increased in patients with NFA patients with NFA were more insulin resistant than controls and statistically significant relationship was found between size of tumor and HOMA-IR (r = 0.361, p < 0.001). CONCLUSION In conclusion, based on significantly higher values for E-selectin, CIMT and HOMA-IR in patients with NFA than controls along with significant correlation of E-selectin levels to CIMT, HOMA-IR and hs-CRP, our findings seems to indicate an increased risk of early atherosclerosis and impaired endothelial function in NFA patients, particularly in case of insulin resistance.


Journal of Medical Case Reports | 2011

Struma ovarii presenting with Hashimoto's thyroiditis: a case report

Nujen Colak Bozkurt; Basak Karbek; Evrim Çakır Özkaya; E. Cakal; Tuncay Delibasi

IntroductionWe report the case of a patient diagnosed with a struma ovarii with lymphocytic thyroiditis of her ectopic thyroid tissue. We believe that this case presents an unusual variation of a struma ovarii and a rare presentation of subclinical hyperthyroidism.Case presentationA 17-year-old Caucasian female patient who had undergone an ovariectomy and been diagnosed with a struma ovarii was subsequently found to have persistent subclinical hyperthyroidism with a low radioiodine uptake. Abdominal magnetic resonance imaging and iodine-131 whole body scanning showed no residue or recurrence and a thyroid ultrasonography was normal. Laboratory and histopathological findings suggested Hashimotos thyroiditis as the cause of the subclinical thyrotoxicosis, which had presumably started at the ectopic tissue.ConclusionStruma ovarii is a rare cause of thyrotoxicosis, and can be difficult to diagnose in the presence of co-existing thyroid disorders. In patients with a struma ovarii who have not undergone thyroidectomy, there is no common consensus on management in terms of residue, recurrence or metastasis. Autoimmune thyroiditis must be kept in mind for a differential diagnosis.


International Journal for Vitamin and Nutrition Research | 2017

Vitamin D Treatment in Patients with Hashimoto’s Thyroiditis may Decrease the Development of Hypothyroidism

Bekir Ucan; Mustafa Sahin; Muyesser Sayki Arslan; Nujen Colak Bozkurt; Muhammed Kizilgul; Askin Gungunes; Erman Cakal; Mustafa Ozbek

The relationship between Hashimotos thyroiditis and vitamin D has been demonstrated in several studies. The aim of the present study was to evaluate vitamin D concentrations in patients with Hashimotos thyroiditis, the effect of vitamin D therapy on the course of disease, and to determine changes in thyroid autoantibody status and cardiovascular risk after vitamin D therapy. We included 75 patients with Hashimotos thyroiditis and 43 healthy individuals. Vitamin D deficiency is defined as a 25-hydroxy vitamin D (25(OH)D3) concentration less than 20ng/mL. Vitamin D deficient patients were given 50.000 units of 25(OH)D3 weekly for eight weeks in accordance with the Endocrine Society guidelines. All evaluations were repeated after 2 months of treatment. Patients with Hashimotos thyroiditis had significantly lower vitamin D concentrations compared with the controls (9.37±0.69 ng/mL vs 11.95±1.01 ng/mL, p < 0.05, respectively). Thyroid autoantibodies were significantly decreased by vitamin D replacement treatment in patients with euthyroid Hashimotos thyroiditis. Also, HDL cholesterol concentrations improved in the euthyroid Hashimoto group after treatment. The mean free thyroxine (fT4) concentrations were 0.89±0.02 ng/dL in patients with Hashimotos thyroiditis and 1.07±0.03 ng/dL in the healthy control group (p < 0.001). The mean thyroid volumes were 7.71±0.44 mL in patients with Hashimotos thyroiditis and 5.46±0.63 mL in the healthy control group (p < 0.01). Vitamin D deficiency is frequent in Hashimotos thyroiditis and treatment of patients with this condition with Vitamin D may slow down the course of development of hypothyroidism and also decrease cardiovascular risks in these patients. Vitamin D measurement and replacement may be critical in these patients.


Journal of Medical Disorders | 2014

Effect of L-thyroxin therapy on thyroid volume and carotid artery lntima-media thickness in the patients with subclinical hypothyroidism

İlknur Öztürk Ünsal; Oya Topaloglu; Evrim Cakir; Nujen Colak Bozkurt; Basak Karbek; Askin Gungunes; Muyesser Sayki Arslan; Esra Tutal Akkaymak; Bekir Ucan; Taner Demirci; Melia Karakose; Mustafa Caliskan; Erman Cakal; Tuncay Delibasi

Abstract Background: Subclinical hypothyroidism (SCH) is mild-to-moderate thyroid insufficiency that is characterized by thyrotropin (TSH) level higher than the upper limit despite normal serum free thyroxin (fT4)


Medical Oncology | 2013

Vitamin D3 levels and insulin resistance in papillary thyroid cancer patients

Mustafa Şahin; Bekir Ucan; Zeynep Ginis; Oya Topaloğlu; Askin Gungunes; Nujen Colak Bozkurt; Muyesser Sayki Arslan; İlknur Öztürk Ünsal; Esra Tutal Akkaymak; Taner Demirci; Melia Karakose; Mustafa Caliskan; Erman Cakal; Mustafa Ozbek; Tuncay Delibasi

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Mustafa Ozbek

Turkish Ministry of Health

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Mustafa Sahin

Boston Children's Hospital

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Oya Topaloglu

Yıldırım Beyazıt University

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Mehmet Dogan

Military Medical Academy

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