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Featured researches published by Ahmet Ugur Demir.


Toxicology Letters | 2002

Lung diseases due to environmental exposures to erionite and asbestos in Turkey

Salih Emri; Ahmet Ugur Demir; Meral Dogan; Hadi Akay; B. Bozkurt; Michele Carbone; Izzettin Baris

Asbestos deposits have been used locally by the rural inhabitants of Central and Southeastern Anatolia for domestic purposes for many years. Mineralogical analysis revealed that tremolite is the most prominent asbestos type found in the region. There is in addition another mineral fiber found particularly in three villages located in the Cappadocian region of Central Anatolia (zeolite villages). This is a non-asbestos mineral, which has been identified as the fibrous zeolite, erionite. This fiber is present in the volcanic tuffs, which are used as building stone. Hence, exposure to erionite fibers is always possible in the houses, annexes, and streets of the villages. It has been demonstrated that both asbestos and erionite cause a variety of benign and malignant chest diseases. Among the diseases, calcified pleural plaques (CPP) are the most frequently seen and may be used as an indicator of mineral fiber exposure. Asbestos and erionite exposure are the main causes of malignant mesotheliomas in Turkey. In zeolite villages malignant mesothelioma is responsible for more than 50% of the total deaths. A recent study showed that simian virus 40 is not a cofactor in the pathogenesis of environmental malignant mesothelioma in Turkey. An additional recent genetic-epidemiological study showed that there are some families, which are genetically predisposed to mesothelioma.


Pediatric Allergy and Immunology | 1999

Prevalence of asthma and allergic diseases in primary school children in Ankara, Turkey: two cross-sectional studies, five years apart.

Ali Fuat Kalyoncu; Ziya Toros Selçuk; Enünlü T; Ahmet Ugur Demir; Lutfi Coplu; Altay Sahin; M. Artvinli

The prevalence of allergic diseases is reported to have increased worldwide. Two questionnaire surveys, five years apart, were conducted to evaluate the trend of prevalence rates and possible risk factors among primary school children in Ankara, Turkey. A previous survey in 1992 revealed the lifetime prevalences of asthma, wheezing, allergic rhinitis and atopic dermatitis were 17.4%, 23.3%, 28% and 6.1%, and the prevalences for the preceding 12 months were 8.3%, 11.9%, 15.4% and 4%, respectively. The survey was repeated with the same questionnaire in the same age group (6–13 years) of the same school in May 1997. The parents of 358 boys and 380 girls completed the questionnaire. The lifetime and last 12 months’ prevalences of asthma, wheezing, rhinitis and atopic dermatitis were 16.8%, 22.5%, 18.7%, 6.5%, and 9.8%, 13.3%, 14.1%, 4.3%, respectively. There was a significant change only for the lifetime prevalence of rhinitis (p < 0.001). The rate of indoor smoking had declined from 73.9% to 64%, and pet ownership had risen from 7.9% to 22.9% (p < 0.001 for both). Atopic family history was the most prominent risk factor for all types of allergic disorders. Male gender was a significant risk factor for current asthma and wheezing [odds ratio (OR) = 1.80 and 1.59; 95% confidence intervals (CI) = 1.09–2.98 and 1.01–2.48, respectively], and passive smoking affected the occurrence of allergic rhinitis (OR = 1.84; CI = 1.13–3.00). The prevalence rates of allergic diseases among primary school children in Ankara stabilized during a 5‐year period for all diseases other than allergic rhinitis. However, there are changing behavior patterns, i.e. indoor smoking and keeping pet animals, which that may have affected these rates.


International Journal of Cardiology | 2009

P-wave duration and dispersion in patients with obstructive sleep apnea

I. Can; Kudret Aytemir; Ahmet Ugur Demir; Ali Deniz; Orcun Ciftci; Lale Tokgozoglu; Ali Oto; Altay Sahin

AIM P-wave dispersion (Pd) has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. The purpose of this study was to investigate Pd in patients with obstructive sleep apnea (OSA) and to determine its relationship with severity of the disease. METHODS The study population included 67 patients referred to sleep laboratory. The Apnea-Hypopnea Index (AHI) was defined as the number of apneas and hypopneas per hour of sleep. Of the sixty-seven patients, 48 had AHI5 and were diagnosed as OSA. Nineteen of the patients had AHI<5 and were diagnosed as OSA (-) (Group 1), 32 of the patients had AHI between 5-30 (mild and moderate, group 2), 16 of the patients had AHI>30 (severe, group 3). The P-wave duration was calculated in all leads of the surface electrocardiogram. The difference between the maximum (Pmax) and minimum P (Pmin) wave duration was calculated and was defined as the P-wave dispersion (Pd). Echocardiographic examination was also performed. RESULTS Pmax was longer in group 3 compared to group 2 and group 1 (p=0.002, p<0.001 respectively). Pmax was longer in group 2 compared to group 1 (s<0.001). Pd was greater in group 3 compared to group 2 and group 1 (p<0.001 for both comparison). Pd was greater in group 2 compared to group 1 (p<0.001). Pmin did not differ between the groups. In patients with OSA, Pd was positively correlated with AHI (r=0.56, p<0.001), BMI (r=0.43, p=0.03), and mitral early diastolic to late diastolic velocity (E/A) ratio (r=0.37, p=0.01). Multiple linear regression analysis showed that only AHI was independently associated with Pd (beta=0.39, p=0.02). CONCLUSION Pd was found to be greater in patients with OSA than patients without OSA and to be associated with severity of the disease.


Pediatric Allergy and Immunology | 2004

Asthma and allergic diseases in schoolchildren: third cross-sectional survey in the same primary school in Ankara, Turkey

Ahmet Ugur Demir; Gül Karakaya; B. Bozkurt; Bulent Enis Sekerel; Ali Fuat Kalyoncu

We investigated prevalence and determinants of asthma and allergic diseases in a cross‐sectional survey of schoolchildren aged 6–14 in 2002. This was the third of a series of cross‐sectional surveys, conducted in 1992 and 1997, in the same school in Ankara, Turkey. Questionnaire including information on house characteristics, dietary habits, past and current exposures and diseases were distributed to 1064 children (523 boys, 541 girls) and filled by the parents at home. Percentage of children having a pet was significantly higher (1992: 7.9, 1997: 22.9, 2002: 21), but that of passive smoking was significantly lower (1992: 74, 1997: 64, 2002: 64.1) in 1997 and 2002 when compared with 1992. Current prevalence percentage of asthma (1992: 8.3, 1997: 9.8, 2002: 6.4), wheeze (1992: 11.9, 1997: 13.3, 2002: 6.4), hay fever (1992: 15.4, 1997: 14.1, 2002: 7.2), and eczema (1992: 4, 1997: 4.3, 2002: 1.8) were significantly lower in 2002 compared with 1992. Multiple logistic regression analysis model for current wheeze included ingestion of cows milk (no regular ingestion: reference, ORs and 95% CIs, <1 glass/day: 0.5, 0.3–1.0; at least 1 glass/day: 0.3, 0.2–0.7), ingestion of red meat (2.2, 1.2–3.8), and currently holding a dog (6.1, 1.6–23.4). Multiple logistic regression analysis model for current hay fever included ingestion of red meat (1.8, 1.1–2.9) and fathers education (none of the parents finished secondary school: reference, secondary school to university: 0.5, 0.2–1.0). Our findings suggested that current prevalence of asthma and allergic diseases decreased among schoolchildren in Ankara, in the last 10 yr, and ingestion of milk and red meat could have a role in the occurrence of asthma and hay fever. Detailed assessment of dietary habits is required to test this hypothesis.


Allergologia Et Immunopathologia | 2001

Asthma and allergy in Turkish university students: Two cross-sectional surveys 5 years apart

Ali Fuat Kalyoncu; Ahmet Ugur Demir; B. Ozcakar; B. Bozkurt; M. Artvinli

BACKGROUND prevalence of asthma and allergic diseases is increasing worldwide. We investigated the first-year university students to a) determine prevalence of asthma, and allergic diseases, b) compare prevalence with a similar study conducted in 1994, and c) investigate determinants of asthma, current wheeze and seasonal rhinitis. METHODS an ECRHS based questionnaire was distributed to 5,406 students and completed by 4,639 (response: 85.3 %) in september 1999. Information from the students residing in Turkey was used in the analyses (1,800 boys, 2,712 girls). RESULTS prevalence % of asthma (symptom and/or medicine), current wheeze and seasonal rhinitis were 2.1, 6.9 and 12.7 in boys, and 2.5, 7.2 and 14.5 in girls. Current smoking, pet ownership and family atopy was reported more frecuently in 1999 than 1994. Cough and seasonal rhinitis increased almost twofold. Asthma diagnosis and attack rate was similar in 1999 and 1994. Family atopy, pet in childhood, smoking and passive smoking in childhood increased the risk of asthma, and current wheeze. Family atopy, passive smoking and current pet ownership increased the risk of seasonal rhinitis. CONCLUSION increased rate of smoking and pet ownership could contribute to the increased prevalence of asthma and allergic diseases in the last 5 years.


International Archives of Allergy and Immunology | 2009

Association between asthma, rhinitis and NSAID hypersensitivity in chronic urticaria patients and prevalence rates.

S. Rana Isik; Gül Karakaya; Serhart Celikel; Ahmet Ugur Demir; A. Fuat Kalyoncu

Background: The coexistence of allergic diseases and chronic urticaria (CU) is not uncommon. Our aim was to show the prevalence of allergic diseases in chronic urticaria patients and whether possible risk factors precipitate the development of these conditions. Methods: The data of 953 patients diagnosed with CU in our adult allergy clinic between January 1991 and June 2006 were retrospectively evaluated. Results: The mean ages of the CU patients with and without non-steroidal anti-inflammatory drug hypersensitivity (NSAIDH) were 39.0 ± 11.8 and 36.7± 12.3, respectively (p = 0.014). There was a female predominance in both groups (74.6 and 68.2%, respectively, p = 0.06). Apparently, some conditions occurred significantly more often in CU patients with NSAIDH compared to those without NSAIDH: 16.4 and 8.4% for asthma (p < 0.001), 4.2 and 0.8% for nasal polyps (p < 0.01), 20.8 and 7.3% for antibiotic hypersensitivity (p < 0.001), 21.6 and 12.3% for metal sensitization (p < 0.01), and 8 and 0.6% for familial NSAIDH (p < 0.001), respectively. Dermographism was more common in CU patients without NSAIDH compared to those with NSAIDH (29.4 and 21.2%, respectively; p < 0.05). NSAIDH increased the risk of asthma and rhinitis development [odds ratios: 52.9 (18.1–154.6) and 5.2 (2.0–13.4)]. Conclusion: Based on our data, the incidence rates of asthma, nasal polyps, antibiotic hypersensitivity, metal sensitization and familial NSAIDH are increased in patients with CU with NSAIDH compared to those with CU only. Coexistence of NSAIDH and CU increases the risk of developing asthma and rhinitis.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 2009

Early myocardial functional alterations in patients with obstructive sleep apnea syndrome.

Alper Kepez; Elif Yelda Özgün Niksarlıoğlu; Tuncay Hazirolan; Ortenca Ranci; Hasan Kutsi Kabul; Ahmet Ugur Demir; E.B. Kaya; Uğur Kocabaş; Kudret Aytemir; Altay Sahin; Lale Tokgozoglu; N. Nazli

Background: There is limited information regarding myocardial alterations in patients with obstructive sleep apnea syndrome (OSAS) in the absence of pulmonary and cardiac comorbidity. In this study, we aimed to evaluate potential myocardial alterations of these patients and investigate the possible effects of OSAS‐related pathological variations on left and right ventricular functions. Methods: We studied 107 consecutive patients who were referred to our sleep laboratory for clinically suspected OSAS and 30 controls without any history or symptoms of sleep‐related disorders. Severity of OSAS was quantified by polysomnography. Patients with apnea–hypopnea index (AHI) < 5 were included in the OSAS (−) group (Group 1, n = 22). Subjects with AHI ≥ 5 were considered as OSAS and classified according to their AHI as mild‐to‐moderate (AHI ≥ 5 and AHI < 30) (Group 2, n = 45) and severe (AHI ≥ 30) OSAS groups (Group 3, n = 40). Conventional M‐mode, 2D, and Doppler mitral inflow parameters, tissue Doppler velocities, myocardial peak systolic strain, and strain rate values of various segments were measured and compared between groups. Results: Patients with OSAS displayed impairment of left ventricular diastolic function compared with controls. There were no significant differences between groups regarding parameters reflecting left ventricular systolic function. Myocardial strain analysis demonstrated significant decrement regarding apical right ventricular longitudinal peak systolic strain and strain rate values between groups in relation to the severity of OSAS. Conclusions: Patients with OSAS display a regional pattern of right ventricular dysfunction correlated with the severity of disease.


Psychiatry and Clinical Neurosciences | 2015

Prevalence of insomnia and its clinical correlates in a general population in Turkey.

Gulcin Benbir; Ahmet Ugur Demir; Murat Aksu; Sadik Ardic; Hikmet Firat; Oya Itil; Fuat Ozgen; Hikmet Yilmaz; Derya Karadeniz

The prevalence of insomnia is influenced by environmental factors. This study aimed to investigate the prevalence of insomnia and its sociodemographic and clinical correlates in a general population‐based survey in Turkey.


Journal of Asthma | 2010

Asthma and Allergic Diseases in School Children from 1992 to 2007 with Incidence Data

Ahmet Ugur Demir; Serhat Celikel; Gül Karakaya; A. Fuat Kalyoncu

Background. Information about change in the prevalence of asthma and allergic diseases and factors related with these diseases would be beneficial in decreasing the burden of these diseases. Objective.To assess (i) change in prevalence of asthma and allergic diseases; (ii) factors associated with asthma and wheeze; and (iii) incidence of asthma and wheeze. Methods. A questionnaire was administered to children aged 7–12 years in first five grades in the same primary school in 1992 (n: 1036), 1997 (n: 738), 2002 (n: 621), and 2007 (n: 422) and filled by the parents. A second survey in 2007 (n: 474, in eight grades) was conducted in the same schoolchildren, 6 months apart, to assess the incidence of asthma and wheeze and the associated factors. Results. Comparison of 1992, 1997, 2002, and 2007 surveys revealed that prevalence of asthma (8.3%, 9.8%, 6.4%, 3.3%, respectively), wheeze (11.9%, 13.3%, 6.4%, 3.1%, respectively), hay fever (15.4%, 14.1%, 7.2%, 3.1%, respectively), and eczema (4.0%, 4.3%, 1.8%, 1.2%, respectively) were significantly lower in 2002 and 2007 compared with that in 1992. Percentage of passive smoking decreased after 1992 (74.0%, 64.0%, 64.1%, and 65.5%, respectively). Incidence of asthma and wheeze in 2007 surveys were 0.9/100 and 1.1/100, respectively. After the adjustment for age and gender, infection in the past, family atopy, and presence of atopic disease (eczema or hay fever) were associated with asthma and wheeze. Maternal smoking and lack of breast feeding were associated with asthma. Male gender, pet ownership in the past, lack of health insurance coverage, snoring, and wood or coal used as fuel were associated with wheeze. Conclusions. Decreased prevalence of asthma and allergic diseases in the last 10 years could be related to decreased rate of passive smoking. Lower socioeconomic status and lack of breast feeding could increase the risk of asthma in children.


Journal of Clinical Sleep Medicine | 2013

Reliability of the Watch-PAT 200 in detecting sleep apnea in highway bus drivers.

Melike Yüceege; Hikmet Firat; Ahmet Ugur Demir; Sadik Ardic

OBJECTIVE To predict the validity of Watch-PAT (WP) device for sleep disordered breathing (SDB) among highway bus drivers. METHOD A total number of 90 highway bus drivers have undergone polysomnography (PSG) and Watch-PAT test simultaneously. Routine blood tests and the routine ear-nose-throat (ENT) exams have been done as well. RESULTS The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 89.1%, 76.9%, 82% and 85.7% for RDI > 15, respectively. WRDI, WODI, W < 90% duration and Wmean SaO2 results were well correlated with the PSG results. In the sensitivity and specificity analysis, when diagnosis of sleep apnea was defined for different cut-off values of RDI of 5, 10 and 15, AUC (95%CI) were found as 0.84 (0.74-0.93), 0.87 (95%CI: 0.79-0.94) and 0.91 (95%CI: 0.85-0.97), respectively. There were no statistically significant differences between Stage1+2/Wlight and Stage REM/WREM. The percentage of Stage 3 sleep had difference significant statistically from the percentage of Wdeep. Total sleep times in PSG and WP showed no statistically important difference. Total NREM duration and total WNREM duration had no difference either. CONCLUSION Watch-PAT device is helpful in detecting SDB with RDI > 15 in highway bus drivers, especially in drivers older than 45 years, but has limited value in drivers younger than 45 years old who have less risk for OSA. Therefore, WP can be used in the former group when PSG is not easily available.

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Ali Oto

Hacettepe University

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