Person: ÖZEN, AHMET OĞUZHAN
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
ÖZEN
First Name
AHMET OĞUZHAN
Name
6 results
Search Results
Now showing 1 - 6 of 6
Publication Metadata only Serum IGF-I and IGFBP-3 levels of Turkish children during childhood and adolescence: Establishment of reference ranges with emphasis on puberty(KARGER, 2006) BEREKET, ABDULLAH; Bereket, A; Turan, S; Omar, A; Berber, M3Aims/Methods: We established age- and sex-related reference ranges for serum insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) levels in 807 healthy Turkish children (428 boys, 379 girls), and constructed a model for calculation of standard deviation scores of IGF-I and IGFBP-3 according to age, sex and pubertal stage. Results: Serum IGF-I and IGFBP-3 concentrations tended to be higher in girls compared to boys of the same ages, but the differences were statistically significant only in pubertal ages (9-14 years) for IGF-I and only in prepubertal ages for IGFBP-3 (6-8 years) (p < 0.05). Peak IGF-I concentrations were observed earlier in girls than boys (14 vs. 15 years, Tanner stage IV vs. V) starting to decline thereafter. IGFBP-3 levels peaked at age 13 and at Tanner stage IV in both sexes with a subsequent fall. Serum levels of IGF-I and IGFBP-3 increased steadily with age in the prepubertal stage followed by a rapid increase in IGF-I in the early pubertal stages. A relatively steeper increase in IGF-I but not in IGFBP-3 levels was observed at age 10-11 years in girls and at 12-13 years in boys which preceded the reported age of pubertal growth spurt. At late pubertal stages, both IGF-I and IGFBP-3 either did not change or decreased by increasing age. Interrelationships between growth factors and anthropometric measurements have been described, and the physiologic consequences of these have been discussed in detail. Conclusions: Differences in the pattern of IGF-I and IGFBP-3 in the present paper and those reported in other studies emphasize the importance of locally established reference ranges. Establishment of this reference data and a standard deviation score prediction model based on age, sex and puberty will enhance the diagnostic power and utility of IGF-I and IGFBP-3 in evaluating growth disorders in our population. Copyright (c) 2006 S. Karger AG, Basel.Publication Metadata only Effect of Occupation and Smoking on Respiratory Symptoms in Working Children(WILEY, 2009) ÖZEN, AHMET OĞUZHAN; Cakir, Erkan; Uyan, Zeynep S.; Varol, Nezih; Ay, Pinar; Ozen, Ahmet; Karadag, BuIent; Ersu, Refika; Karakoc, Fazilet; Daglil, ElifObjectives To compare the respiratory symptoms and the lung function of children who work in different occupational groups. Methods The study was performed among children attending vocational training centers. The participants were evaluated in six different occupation groups. Chronic cough, wheezing and shortness of breath were evaluated by questionnaire. The association of independent variables with the respiratory symptoms was investigated through both univariate and multivariate methods. Results Among 642 children, 534 were males: the mean age was 17.7 +/- 1.0 years. Using an internal reference group, the odds ratios of chronic cough were significantly higher in the lathe (OR: 2.0, 95%CI: 1.07-3.74), coiffure (OR: 1.94. 95%CI: 1.01-3.70), and electricity-construction (OR: 2.63, 95%CI: 1.06-6.54) groups after adjustment for smoking, age, gender, and work characteristics. There were no significant differences in spirometric values between occupational groups in either smoking or non-smoking males. In non-smoking females, median values of FEV1 (P: 0.046), PEF (P: 0.0005) and FEF25-75% (P: 0.019) were lower in the textile compared to the coiffure group. There was no significant association between the total working time and spirometric values. There was no statistically significant relationship between the work-related factors and the smoking status. Conclusions The prevalence of chronic cough was higher in the lathe, coiffure, and electricity-construction groups and pulmonary function tests were lower in the non-smoking textile female group. Working children should be screened for respiratory symptoms and disease. Am. J. Ind. Med. 52:471-478, 2009. (c) 2009 Wiley-Liss, Inc.Publication Metadata only The effect of economic status on height, insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations in healthy Turkish children(NATURE PUBLISHING GROUP, 2007) BEREKET, ABDULLAH; Turan, S.; Bereket, A.; Furman, A.; Omar, A.; Berber, M.; Ozen, A.; Akbenlioglu, C.; Haklar, G.Objectives: The effect of economic status (ES) on growth, insulin-like growth factor (IGF)-I and IGF-binding protein (IGFBP)-3 in healthy children is not well characterized. We aimed to study the interrelationship between height, weight, IGF-I, IGFBP-3, mid-parental height (MPH) and ES. Design/ subjects: Eight hundred and fourteen healthy children (428 boys, 386 girls; age 3 -18 years) were classified according to income of the families as low, middle and high. Standard deviation scores (SDSs) of height, weight, MPH, IGF-I and IGFBP-3 were compared between the groups. The combined effect of these parameters and ES on height SDS was investigated with complex statistical models. Results: There was a significant trend for height and weight SDSs to increase with higher income levels in boys, but not in girls. Body mass index (BMI) SDSs were similar in three groups. There was a general trend for MPH SDS to increase with income levels in both sexes. In boys, IGF-I SDS was significantly higher in high ES group than low ES. In girls, IGFBP-3 SDSs were significantly higher in high ES group than in middle ES group. For both genders, height SDS was highly correlated with weight SDS and moderately correlated with BMI SDS, MPH SDS and IGF-1 SDS. All correlations were significant and positive. Complex models showed that MPH (19%), IGF-I (13%) and ES (3%) in boys, and MPH (16%) and IGF-I (7%) in girls have significant contribution to height SDSs. Conclusions: ES per se, independent of overt malnutrition, affects height, weight, IGF-I and IGFBP-3 with some gender differences in healthy children. Influence of income on height and weight show sexual dimorphism, a slight but significant effect is observed only in boys. MPH is the most prominent variable effecting height in healthy children. Higher height and MPH SDSs observed in higher income groups suggest that secular trend in growth still exists, at least in boys, in a country of favorable economic development.Publication Metadata only Upper segment/lower segment ratio and armspan-height difference in healthy Turkish children(WILEY, 2005) BEREKET, ABDULLAH; Turan, S; Bereket, A; Omar, A; Berber, M; Ozen, A; Bekiroglu, NAim: The determination of body proportions is an important part of the clinical evaluation of children with short stature. The upper segment/lower segment ratio (US/LS ratio) and armspan-height difference is commonly used for this purpose. However, reference data are scarce in this respect, and available standards do not include standard deviations for the measurements. We aimed to establish the normal values for upper segment/lower segment ratio and armspan-height difference in Turkish children. Methods: In the present study, height, upper and lower segment, and armspan were measured in 1302 healthy children (3-18 y). The age-related mean and standard deviation curves of the US/LS ratio and armspan-height difference were constructed for each sex. Results: The mean values of the US/LS ratio in boys were decreased from 1.108 at 3 y to 0.984 at 10 y. The nadir of the US/LS ratio (0.922) was reached at age 15 y. In girls, the mean value of the US/LS ratio gradually decreased to less than 1 at 9 y of age (1 y earlier than in boys). The nadir of the US/LS ratio (0.946) was reached at age 13 y in girls (2 y earlier than in boys). Armspan was shorter than height as expected in younger ages, but became slightly longer at around age 12 in girls and boys. Unlike boys, the armspan-height difference did not change much after puberty in girls. Conclusion: US/LS ratio and armspan-height difference are practical parameters and easy to perform in any setting. We hope that these standards will aid clinicians in the evaluation of children with short stature.Publication Metadata only Clinical and metabolic features of urolithiasis and microlithiasis in children(SPRINGER, 2009) ÖZEN, AHMET OĞUZHAN; Alpay, Harika; Ozen, Ahmet; Gokce, Ibrahim; Biyikli, NeseWe evaluated the clinical, radiological and metabolic features of 162 children with urolithiasis or microlithiasis who had been referred to our pediatric nephrology clinics between 1998 and 2008 with suspected urolithiasis. The medical histories of these children (78 girls, 84 boys), who ranged in age from 2 months to 16 years (mean age 5.59 +/- 0.35 years), were reviewed retrospectively for clinical and metabolic features of urinary tract calculi. Urinary tract infections (UTI) were present in 45.9% of the cases. The most common presenting symptoms were flank pain or restlessness (25.3%) and hematuria (21.6%), followed by UTI (16%), whereas 23.5% of the cases were detected incidentally during evaluation for other medical conditions. Other symptoms at presentation included dysuria, passing stones, penile edema, enuresis, vomiting and anorexia. Urine analysis revealed metabolic abnormalities in 87% of the cases, including hypercalciuria (33.8%), hypocitraturia (33.1%), hyperoxaluria (26.5%), hyperuricosuria (25.4%), hypocitraturia + hypercalciuria (21.1%), hyperphosphaturia (20.8%) and cystinuria (5.7%). Almost 50% of the patients had a positive family history for urolithiasis. The most frequently involved site was in the kidneys (86%). Ureters and bladder were involved in 12 and 2% of the cases, respectively. A family history of urolithiasis, presenting symptoms and underlying metabolic abnormalities were similar for microlithiasis and the patients with larger stones. However, in our study population, microlithiasis was mainly a disease of young infants, with a greater chance for remission and often not associated with structural changes. The presenting symptoms of urolithiasis show a wide spectrum, so that a high index of suspicion is important for early detection. A metabolic abnormality can be identified in 87% of cases of urolithiasis. Detection of microlithiasis may explain a number of symptoms, thus reducing invasive diagnostic procedures and allowing early recognition of metabolic abnormalities. These results draw attention to the importance of screening for UTIs in patients with urolithiasis.Publication Metadata only Natural history and symptomatology of Helicobacter pylori in childhood and factors determining the epidemiology of infection(2006) ÖZEN, AHMET OĞUZHAN; Özen A., Ertem D., Pehlivanoglu E.Background: High seroprevalence rates for Helicobacter pylori have been reported in developing countries, yet few studies exist determining the pattern of change in the epidemiology of H. pylori infection in children. The knowledge of acquisition and loss rates of H. pylori and the relevance to the sociodemographic properties and the symptomatology of infection may provide clues for lifestyle changes that might protect children from infection, and also, it may provide rationale for eradication, screening, and protection policies. Our aim was to conduct a prospective study to elucidate the outcome, rate of acquisition, and loss of H. pylori infection in a population of healthy children. Methods: This study is based on follow-up of 327 healthy Turkish children aged 3 to 12 years. The follow-up was conducted 6 years after the baseline examination. Helicobacter pylori status was determined by 13C-urea breath test. Children were investigated for sociodemographic variables and several symptoms. Results: Data from 136 (41%) of 327 children were available. The prevalence of infection increased from 52.9% to 56.6%, mainly increasing in children younger than 10 years. The incidence of H. pylori infection among previously uninfected children was 14%, and the loss rate of infection among previously infected children was 5.5% during the follow-up. Socioeconomic status, household density, and antibiotic use during last 6 months were inversely related to H. pylori prevalence. Children infected with H. pylori were complaining more often of headache but not of abdominal pain or dyspepsia. Conclusions: In this study, the acquisition rate of H. pylori infection was 2.5-fold higher than the loss of infection, and the acquisition mostly occurred before 10 years of age. Data regarding acquisition and loss of H. pylori infection are critical for understanding the epidemiology of infection and development of preventive and treatment strategies. © 2006 by Lippincott Williams & Wilkins.