Refik Demirtunc

Istanbul Training and Research Hospital, İstanbul, Istanbul, Turkey

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Publications (30)30.55 Total impact

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    ABSTRACT: Abstract Objective: We aimed to evaluate acute kidney injury (AKI), occurrence of recovery and risk factors associated with permanent kidney injury and mortality in the elderly individuals. Design: Evidence for this study was obtained from retrospective cohort study from our center. Patients: A total of 193 patients (>65 years, mean age: 79.99 ± 6.93) with acute kidney injury were enrolled in this study between 2011 and 2012. Patients with kidney failure or renal replacement therapy (RRT) history at admission were excluded. Intervention: Main outcome measurements: serum creatinine (SCr), estimated GFR (with CKD-Epi) and complete blood counts were evaluated at baseline and daily basis thereafter. The AKI was defined based on Kidney Disease Improving Global Outcomes (KDIGO) classification. Results: Among 193 patients, 43 (22%) patients required RRT. Mortality rate was 18% (n = 36) SCr levels were restored within 9.9 ± 6.7days on average (8-39 days). Sixteen patients (12.7%) required RRT after discharge. The mean hospital stay was 10.1 ± 8.6 days (7-41 days). Mortality rate of patients who have no renal recovery was higher (44.8% vs. 4.8%) than renal recovery group (p < 0.01). Conclusion: The AKI represents a frequent complication in the elderly patients with longer hospital stay and increased mortality and morbidity. Our results show that dialytic support requirement is an independent predictor of permeant kidney injury in the elderly AKI patients. Older age, low diastolic blood pressure, high CRP and low hemoglobin levels were independent risk factors for mortality.
    Renal Failure 07/2014; · 0.94 Impact Factor
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    ABSTRACT: Aims: To investigate the levels of mean platelet volume (MPV) and beta-thromboglobulin (β-TG), two of platelet activation markers, in non-diabetic patients in different stages of chronic kidney disease (CKD), who were receiving or not receiving hemodialysis. Material and methods: This prospective study included 122 subjects (88 CKD patients and 34 healthy controls). Analyses were performed among three groups: dialysis group including patients (n=50) with nondiabetic stage 5 CKD and receiving hemodialysis, non-dialysis group including patients (n=38) with nephropathy of nondiabetic stage 1-4 CKD and not receiving hemodialysis, and healthy controls (n=34). Demographic data, medical history, and cardiac risk factors were recorded. Physical examinations and measurements of complete blood count, and MPV and β-TG levels were performed. Plasma β-TG levels were determined by the enzyme- linked immunosorbent assay method. Results: The mean age of the study subjects (n=122; 78 females) were 54.56±17.20 years. Hypertension (38.6%) and polycystic kidney disease (13.6%) were the major etiologies of CKD. The β-TG level of the non-dialysis group was significantly higher than those of the dialysis (p=0.001) and control groups (p<0.01). The MPV levels of the non-dialysis and dialysis groups were significantly higher than that of the control group (p=0.001and p=0.011, respectively). Conclusion: Both MPV and β-TG levels were higher in the non-dialysis CKD patients than in the control group. Monitoring of these two markers (MPV and β-TG) in early-stage CKD patients would be beneficial as these markers may be useful in early detection of the cardiovascular risks and as their measurements are non-invasive and easily applicable.
    Acta Medica Mediterranea 05/2014; 30(4):929-933. · 1.05 Impact Factor
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    ABSTRACT: A relapsing systemic inflammatory process is a well-known feature of Behcet's disease. Because systemic inflammation and dyslipidemia are involved in the pathogenesis of atherosclerosis, Behcet's disease may play a part in the development of atherosclerosis. Lipid profile in Behcet's disease and the development of atherosclerosis remain to be controversial. In order to learn more about this relationship, our study compared blood lipid levels in healthy controls to those in patients with Behcet's disease during both their active and inactive stages. Between December 2010 and March 2012, this prospective, observational study was designed to evaluate three groups The study included 91 Behcet's patients (36 in active and 55 in inactive period) and 61 healthy control subjects matched for age, gender, and body mass index. Data from lipid profiles included total cholesterol, triglyceride, low-density lipoprotein, and high-density lipoprotein. Acute phase reactants were also recorded, including high sensitive C-reactive protein and erythrocyte sedimentation rate levels. Total cholesterol, low density lipoprotein, and high density lipoprotein cholesterol levels of patients in active stage were significantly lower than those in inactive stage, while total cholesterol and low density lipoprotein levels were lower in the control group (p < 0.05). Patients with Behcet's disease in the active period may be less susceptible to atherogenic events as compared with the controls and those in the inactive period of the disease.
    European review for medical and pharmacological sciences 09/2013; 17(17):2330-4. · 1.09 Impact Factor
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    ABSTRACT: OBJECTIVE: This study aims to investigate long-term effects of iodinated radiographic contrast media used for coronary angiography (CAG) on the thyroid function in euthyroid patients. METHODS: In a prospective observational cohort study, nonionic iodinated contrast material was electively used in 101 patients for coronary angiography. The patients were recruited without age restrictions and, at baseline, all had normal levels of free triiodothyronine (FT3), free thyroxine (FT4) and thyrotropin (TSH). The morphology of the thyroid was evaluated by thyroid ultrasonography (USG). Four and eight weeks after CAG, serum TSH, FT3 and FT4 levels were assessed. RESULTS: Compared to a mean baseline level of 1.49 (25%-75%, range 13-2.21), follow-up TSH levels decreased significantly to 1.45 (25%-75%, range 1.98-0.92, p=0.017) and 1.40 (25%-75%, range 1.89-0.87, p=0.003) at 4 weeks and 8 weeks, respectively (p=0.008). No significant diffe-rence was observed in TSH levels between the 4th and 8th weeks (p=0.833). CONCLUSION: Iodinated radiographic contrast agents may cause subclinical hyperthyroidism in euthyroid patients undergoing CAG.
    Anadolu kardiyoloji dergisi: AKD = the Anatolian journal of cardiology 04/2013; · 0.72 Impact Factor
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    ABSTRACT: Chronic skin ulcers require extensive, systemic differential diagnosis; thus, they are difficult to diagnose and treat. Transient or persistent hypercoagulable states are among the rare causes of skin ulcers. Here, we present the case of a 27-year-old woman patient with recurrent, nonhealing skin ulcers of 8 years' duration, who had been treated unsuccessfully with various medications under different diagnoses at different clinics. On admission, a skin biopsy demonstrated occlusive vasculopathy, and the search for an inherited hypercoagulable state revealed a heterozygous factor V Leiden mutation. The patient was treated with anticoagulants and hyperbaric oxygen. On treatment, the skin lesions healed and did not recur.
    The International Journal of Lower Extremity Wounds 02/2013; · 1.25 Impact Factor
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    ABSTRACT: OBJECTIVES: The present study aimed to investigate the effect of smoking on thyroid nodule formation and goiter development in healthy subjects living in Istanbul, an iodine-sufficient region. This study was designed as a prospective, randomized, and observational study. METHODS: Included in the study were voluntary hospital staff and relatives of patients between the ages of 28 and 71 who had no known disease or drug use, who have been living in Istanbul and had been smoking more than 10 cigarettes per day for at least 10years. Nonsmoker volunteers (45) shared similar demographic characteristics and were matched for age to the (46) smokers. By means of thyroid ultrasounds performed in all participants, volumes of the right and left lobes of the thyroid gland, and number, diameter and characteristics of nodules were evaluated. RESULTS: Comparing the smokers and nonsmokers, no statistically significant difference was determined in terms of presence of nodules and volumes of the left and right thyroid lobes (P=0.68, P=0.09, and P=0.63, respectively). Making enhanced diffuse enlargement of the thyroid gland, but not to a statistically significant degree. Smoking was observed to have no effect on non-toxic nodules, or the levels of thyroid-stimulating hormone, free thyroxin, free triiodothyronine, anti-thyroid peroxidase, or anti-thyroglobulin antibodies. CONCLUSIONS: Smoking does not effect, to a statistically significant degree goiter development thyroid nodule formation in iodine-sufficient regions like Istanbul.
    Annales d Endocrinologie 11/2012; · 1.02 Impact Factor
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    ABSTRACT: The activation of the platelets plays a key role in the formation of thrombosis. The variables such as mean platelet volume, platelet factor 4 and β-thromboglobulin have been used in the demonstration of the platelet activation. However, when the literature was reviewed, there was not found any study investigating the level of β-thromboglobulin in patients with rheumatoid arthritis. Our goal is to evaluate the β-thromboglobulin levels together with mean platelet volume in patients with arthritis. This study is a clinical study which has a control group that has been designed prospectively, and in this study, Rheumatology Outpatient Clinic follow-up patients with rheumatoid arthritis and healthy control group were studied. All patients and healthy volunteers were examined β-thromboglobulin and mean platelet volume. Twenty-two patients with rheumatoid arthritis and 21 healthy volunteers participated in the study. β-Thromboglobulin mean was found as 98.00 ± 60.49 ng/mL in rheumatoid arthritis group and it was 62.38 ± 30.41 ng/mL in healthy control group. The differences between these groups were significant in terms of the levels of β-thromboglobulin (p = 0.02). We found significant differences between the groups in terms of mean platelet volume (p = 0.049). In this study, the level of β-thromboglobulin was found significantly higher in patients with rheumatoid arthritis, which is a chronic inflammatory disease. This result could be an indicator, such as platelet activation in patients with rheumatoid arthritis, or it may be a helper marker in the follow-up and treatment of developing cardiovascular risk.
    Rheumatology International 10/2012; · 2.21 Impact Factor
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    ABSTRACT: Many studies have shown that subclinical inflammation persisted during remission period of Familial Mediterranean Fever (FMF) patients but long term effects of subclinical inflammation in these patients aren't clearly known. Besides, a few of the recent studies revealed that risk of atherosclerosis had increased in FMF patients. β-Thromboglobulin (β-TG) is considered as a sensitive marker of platelet activation. In this study Mean Platelet Volume (MPV) and β-TG levels were evaluated in FMF patients. Following the Local Ethics Committee's consent, 25 FMF patients were included in the study. Twenty eight age and sex matched healthy volunteers were recruited as a control group. Lipid profile, inflammatory parameters, hemogram, β-TG, MPV were assessed. Statistical analysis was performed with SPSS for Windows 16.00. Group I consisted of 25 FMF cases (16 females, 9 males; mean age: 35.72 ± 12.34 years), Group II consisted of 28 cases (22 females, 6 males; mean age 31.78 ± 10.31 years). There was no statistically significant difference between the groups in terms of age and gender distribution, smoking status, total cholesterol, triglyceride, LDL and MPV (p>0.05). HDL levels were found to be statistically lower in Group I (p:0.04). Median β-TG levels was significantly higher in Group II than Group I (129.50 (range:372.00) ng/mL versus 104.00 (range:212.80) ng/mL respectively; p:0.03). In this study MPV and β-TG were evaluated for FMF cases and healthy controls, β-TG levels were found significantly lower among patients; we hypothesized that this difference may have resulted from the effect of colchicine use on platelet functions.
    European Journal of Internal Medicine 10/2012; 23(7):661-4. · 2.05 Impact Factor
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    ABSTRACT: Osteoporosis that is by far the most common metabolic bone disease, has been defined as a skeletal disorder characterized by compromised bone strength predisposing a person to an increased risk of fracture. Anabolic therapy with teriparatide, recombinant human parathyroid hormone (PTH 1-34), stimulates bone formation and resorption and improves trabecular and cortical microarchitecture. Teriparatide is indicated for the treatment of men and postmenopausal women with osteoporosis who are at high risk for fracture, including those who have failed or are intolerant of previous osteoporosis therapy. In conclusion, although teriparatide seems quite effective in the treatment of osteoporosis, it may cause life-threatening hypercalcemia. Therefore, patients should be closely monitored if symptoms of hypercalcemia are present during teriparatide treatment. Sustained hypercalcemia due to teriparatide treatment can not be seen in literature so we wanted to emphasize that severe hypercalcemia may develop due to teriperatide.
    Indian Journal of Pharmacology 03/2012; 44(2):270-1. · 0.58 Impact Factor
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    ABSTRACT: Studies concerning red cell distribution width (RDW) for use in the assessment of inflammatory bowel disease (IBD) activity are limited. We investigated whether RDW is a marker of active disease in patients with IBD. In total, 61 patients with ulcerative colitis (UC) and 56 patients with Crohn's disease (CD) were enrolled in the study group, and 44 age- and-sex-matched healthy volunteers were included as the control group. A CD activity index >150 in patients with CD indicated active disease. Patients with moderate and severe disease based on the Truelove-Witts criteria were considered to have active UC. In addition to RDW, serum C-reactive protein levels, erythrocyte sedimentation rates, and platelet counts were measured. Twenty-nine (51.7%) patients with CD and 35 (57.4%) patients with UC had active disease. The RDW was significantly higher in patients with CD and UC than in controls (p<0.001 and p<0.001, respectively). A subgroup analysis indicated that for a RDW cut-off of 14%, the sensitivity for detecting active CD was 79%, and the specicity was 93% (area under curve [AUC], 0.935; p<0.001). RDW was the most sensitive and specific marker for active CD. However, it was not valid for UC, as the ESR at a cutoff of 15.5 mm/hr showed a sensitivity of 83% and a specicity of 76% (AUC, 0.817; p<0.001), whereas the RDW at a cutoff of 14% showed 17% sensitivity and 84% specicity for detecting active UC. RDW was elevated in IBD in comparison with healthy controls and increased markedly in active disease. RDW may be a sensitive and specific marker for determining active CD, whereas ESR is an important marker of active UC.
    Gut and liver 12/2011; 5(4):460-7. · 1.31 Impact Factor
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    ABSTRACT: Systemic amyloidosis with AA-type amyloid deposition is the major complication of FMF, leading to end stage renal disease. There is no clear data on the prevalence of adrenal involvement in patients with FMF amyloidosis. The aim of this study is to determine the adrenal axis function in patients FMF with amyloidosis. Twenty patients with FMF with amyloidosis (F/M: 10/10, mean age; 38 ± 11 SD years), twenty without amyloidosis (F/M: 14/6, mean age 32 ± 10 years), and healthy controls (F/M: 12/8, mean age: 30 ± 7.6 SD years) were recruited. A dose of 250 mg tetracosactide (Synacthen) was then administered intravenously and further blood samples collected 30 and 60 min later. Blood samples were separated and collected at 4°C, and serum cortisol levels were measured. A normal cortisol response to Synacthen was defined as a post-stimulation peak cortisol value of >18 mg/d either at 30 or 60 min. sample. The mean disease duration was 8.8 ± 6 SD years, (range, 2-21) in FMF patients without amyloidosis compared to 16 ± 9.5 years (range, 0-30) in FMF with amyloidosis (P = 0.001). The cortisol concentrations increased significantly at 30 and 60 min compared to baseline after injection of synacthen in all groups. There were no statistically significant differences found among three groups, for basal, 30 and 60 min for cortisol levels (P = 0.154). FMF patients with amyloidosis do not exhibit overt adrenal insufficiency even though their basal cortisol levels were mildly lower.
    Rheumatology International 11/2011; · 2.21 Impact Factor
  • European Journal of Internal Medicine - EUR J INTERN MED. 01/2009; 20.
  • European Journal of Internal Medicine - EUR J INTERN MED. 01/2009; 20.
  • Refik Demirtunc, Arzu Adık, Gul Babacan Abanonu
    European Journal of Internal Medicine - EUR J INTERN MED. 01/2009; 20.
  • European Journal of Internal Medicine - EUR J INTERN MED. 01/2009; 20.
  • European Journal of Internal Medicine - EUR J INTERN MED. 01/2009; 20.
  • European Journal of Internal Medicine - EUR J INTERN MED. 01/2009; 20.
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    ABSTRACT: The pathogenesis of dialysis-induced hypotension (DIH) is multifactorial and may include increased aortic stiffness. This study was undertaken to determine aortic elastic properties in patients undergoing hemodialysis with and without DIH, and to assess the effects of DIH on mortality. Aortic stiffness and left ventricular functions were evaluated in 70 patients undergoing hemodialysis with (n=34) and without DIH (n=36). We also evaluated total mortality at 36 months. Patients with DIH in comparison with patients without DIH, had lower aortic strain (5.0+/-3.8 vs. 7.8+/-3.0%, P<0.005) and distensibility (2.3+/-1.9 vs. 3.2+/-1.7 cm2/dyn/10(3), P<0.01). In univariate analysis, age, aortic stiffness and left ventricular systolic dysfunction, and coronary artery disease were also found to be the main factors associated with DIH. On multivariate logistic regression analysis, aortic distensibility [odds ratio (OR): 0.61; 95% confidence interval (95% CI): 0.40-0.93; P=0.01] and the coronary artery disease (OR: 6.46; 95% CI: 1.62-25.73; P=0.009) remained as significant variables associated with DIH. During follow-up period, 12 out of 34 patients with DIH died compared with 4 out of 36 patients without DIH (log rank, P=0.02). Our data suggest that DIH is strongly associated with increased aortic stiffness and poor outcome. Larger long-term follow-up studies, however, investigating whether the DIH plays a surrogate or causative role on mortality in patients undergoing hemodialysis should be designed.
    Blood Pressure Monitoring 04/2008; 13(2):73-8. · 1.80 Impact Factor
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    ABSTRACT: Platelet activity and aggregation potential, which are essential components of thrombogenesis and atherosclerosis, can be conveniently estimated by measuring mean platelet volume (MPV) as part of whole blood count. It has been shown that MPV was significantly higher in diabetes mellitus (DM); however, the effect of glycemic control on MPV has not been studied. The aim of this study was to investigate the relationship among MPV, glycemic control, and micro- and macrovascular complications in type 2 DM. Seventy patients with type 2 DM and 40 age- and sex-matched healthy individuals were enrolled. Diabetic patients were grouped into those with glycated hemoglobin (HbA1c) levels <or=7% (Group A, n=35 patients) and those with HbA1c >7% (Group B, n=35 patients). Initially, both groups were compared with regard to MPV, HbA1c, serum lipid levels, coronary artery disease, retinopathy, neuropathy, and nephropathy. Thereafter, Group B was called to monthly visits to obtain improved control glycemic control, which was defined as achievement of HbA1c <or=7%. At the end of 3 months of follow-up, Group B was reevaluated. MPV was significantly higher in patients with DM than in controls (8.7+/-0.8 fl vs. 8.2+/-0.7 fl, P=.002). In diabetic patients, there was a significant positive correlation between MPV and HbA1c levels (r=.39, P=.001) but not diabetic vascular complications. When we compared the two diabetic groups, Group B patients had significantly higher MPV than Group A (9.0+/-0.7 fl vs. 8.4+/-0.8 fl, P=.01). Thirty patients (86%) of Group B achieved improved glycemic control at the end of the 3 months. MPV of the patients with improved glycemic control were significantly decreased compared to baseline MPV (8.4+/-0.8 fl vs. 9.0+/-0.7 fl, P=.003). Our results suggested a close relationship between poor glycemic control and increased platelet activity in patients with type 2 DM. Furthermore, platelet activity recovered through improved glycemic control, which may prevent the possible role of platelets in cardiovascular events in these patients.
    Journal of diabetes and its complications 03/2008; 23(2):89-94. · 2.11 Impact Factor
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    ABSTRACT: Pulmonary hypertension and right ventricular (RV) dysfunction are severe complications of systemic lupus erythematosus (SLE). The role of increased pulmonary artery stiffness (PAS) has not been studied in RV dysfunction. We investigated the relationship between PAS and RV function in SLE patients without cardiovascular symptoms. The study included 32 patients with SLE (30 males, 2 females; mean age 34+/-9 years) and 30 age- and sex-matched healthy controls (28 males, 2 females; mean age 36+/-5 years). All the subjects underwent echocardiographic examination. Using Doppler echocardiography, PAS was calculated by dividing maximal frequency shift of the pulmonary flow by the acceleration time. To assess RV function, RV myocardial performance index (MPI) was determined by the sum of isovolumetric contraction and relaxation times divided by the ejection time. In addition, tricuspid annular plane systolic excursion (TAPSE) was measured on two-dimensional M-mode recordings. Compared to the control group, patients with SLE exhibited significantly higher PAS (p=0.004) and RV MPI (p=0.001), and lower TAPSE (p=0.001). In univariate correlation analysis, SV MPI was significantly correlated with PAS (r=0.60, p=0.001), age (r=0.48, p=0.003), SLE duration (r=0.51, p=0.002), and pulmonary artery systolic pressure (r=0.36, p=0.03). Multivariate linear regression analysis showed that PAS (95% CI 0.002-0.005; p=0.001) and SLE duration (95% CI 0.001-0.004; p=0.004) were independently associated with RV MPI. In addition, a significant inverse relationship was found between TAPSE and RV MPI (r= -0.48, p=0.005). Twenty-four SLE patients had normal RV function (TAPSE > or = 17 mm). Eight patients with RV dysfunction (TAPSE <17 mm) had significantly different RV MPI (p=0.001), PAS (p=0.002), age (p=0.04), and SLE duration (p=0.004). Our data suggest that increased PAS is strongly associated with the development of RV dysfunction in patients with SLE.
    Turk Kardiyoloji Dernegi arsivi: Turk Kardiyoloji Derneginin yayin organidir 03/2008; 36(2):82-9.

Publication Stats

104 Citations
30.55 Total Impact Points

Institutions

  • 2013
    • Istanbul Training and Research Hospital
      İstanbul, Istanbul, Turkey
  • 2012
    • Bezmiâlem Vakif Üniversitesi
      • Faculty of Medicine
      İstanbul, Istanbul, Turkey
    • Istanbul Medical University
      İstanbul, Istanbul, Turkey
  • 2007–2012
    • Haydarpasa Numune Research and Teaching Hospital
      İstanbul, Istanbul, Turkey