Zelal Tandoğan
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Zelal Tandoğan has a total of 15 co-authors. Here are the top co-authors by number of shared publications:
- Arzu Selamioğlu
Department of Rare Diseases , Institute of Health Sciences, Istanbul University , Istanbul , Türkiye
2 shared publications Mehmet Cihan Balcı
Department of Basic Sciences , Child Health Institute, Division of Genetics, Istanbul University , Istanbul , Türkiye
2 shared publicationsMeryem Karaca
Department of Basic Sciences , Child Health Institute, Division of Genetics, Istanbul University , Istanbul , Türkiye
2 shared publicationsTuğba Kozanoğlu
Department of Basic Sciences , Child Health Institute, Division of Genetics, Istanbul University , Istanbul , Türkiye
2 shared publications- Agnes Dadak
Institute of Pharmacology and Toxicology, Clinical Pharmacology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
1 shared publication Alihan Yesil
Istanbul University, Faculty of Medicine, Pediatric Nutrition and Metabolism Division, Istanbul, Turkey
1 shared publication
Latest Publications
- Open Access
- 30 June 2026
- Published by Walter de Gruyter GmbH in Journal of Pediatric Endocrinology and Metabolism
Factors affecting the success of follow-up and treatment of adults with phenylketonuria diagnosed by newborn screening
Objectives: Phenylketonuria (PKU) is an autosomal recessive metabolic disorder caused by phenylalanine hydroxylase deficiency, leading to elevated phenylalanine (Phe) levels in blood and brain. Lifelong dietary treatment is required to prevent neurotoxicity, yet adherence often declines during adulthood. This study aimed to evaluate follow-up and treatment adherence in adults with PKU and to explore strategies to improve long-term metabolic control. Methods: This cross-sectional study included adult PKU patients followed at the Division of Pediatric Nutrition and Metabolism, Istanbul Medical Faculty. Data were collected between April and July 2021 using retrospective medical records and online questionnaires. Follow-up and treatment success rates were assessed according to blood Phe monitoring frequency and results within the target range. Participants completed the Adult Attention Deficit Hyperactivity Disorder Self-Report Scale and the Phenylketonuria Quality of Life Questionnaire. Results: Data were collected from 134 of the 198 registered patients. The average age was 23.25 ± 2.92 years, and 50 % were female. Classical PKU was present in 68.7 %. Patients with classical PKU demonstrated higher follow-up success than those with mild PKU. Individuals who self-managed their diet showed significantly higher follow-up and treatment success. No significant associations were observed between success rates and age at diagnosis, residence, working status, family education, or ADHD scores. A significant negative correlation was found between success rates and quality-of-life subdomains related to dietary management and daily life burden. Conclusions: Treatment success in adults with PKU may be improved by promoting dietary self-management, increasing awareness of treatment options, facilitating dietary implementation, and reducing disease-related burden. This study demonstrates that in adults with phenylketonuria, follow-up and treatment success are primarily influenced by disease severity and patients’ ability to self-manage their diet, highlighting the need for strategies that reduce daily disease burden and support long-term dietary adherence.
- 30 June 2026
- Published by Walter de Gruyter GmbH in Journal of Pediatric Endocrinology and Metabolism
Open AccessFactors affecting the success of follow-up and treatment of adults with phenylketonuria diagnosed by newborn screening
Objectives: Phenylketonuria (PKU) is an autosomal recessive metabolic disorder caused by phenylalanine hydroxylase deficiency, leading to elevated phenylalanine (Phe) levels in blood and brain. Lifelong dietary treatment is required to prevent neurotoxicity, yet adherence often declines during adulthood. This study aimed to evaluate follow-up and treatment adherence in adults with PKU and to explore strategies to improve long-term metabolic control. Methods: This cross-sectional study included adult PKU patients followed at the Division of Pediatric Nutrition and Metabolism, Istanbul Medical Faculty. Data were collected between April and July 2021 using retrospective medical records and online questionnaires. Follow-up and treatment success rates were assessed according to blood Phe monitoring frequency and results within the target range. Participants completed the Adult Attention Deficit Hyperactivity Disorder Self-Report Scale and the Phenylketonuria Quality of Life Questionnaire. Results: Data were collected from 134 of the 198 registered patients. The average age was 23.25 ± 2.92 years, and 50 % were female. Classical PKU was present in 68.7 %. Patients with classical PKU demonstrated higher follow-up success than those with mild PKU. Individuals who self-managed their diet showed significantly higher follow-up and treatment success. No significant associations were observed between success rates and age at diagnosis, residence, working status, family education, or ADHD scores. A significant negative correlation was found between success rates and quality-of-life subdomains related to dietary management and daily life burden. Conclusions: Treatment success in adults with PKU may be improved by promoting dietary self-management, increasing awareness of treatment options, facilitating dietary implementation, and reducing disease-related burden. This study demonstrates that in adults with phenylketonuria, follow-up and treatment success are primarily influenced by disease severity and patients’ ability to self-manage their diet, highlighting the need for strategies that reduce daily disease burden and support long-term dietary adherence.
- Open Access
- 15 October 2024
- Published by Elsevier in Molecular Genetics and Metabolism Reports
- Vol. 41, 101154
The relationship between menstrual cycle characteristics, premenstrual syndrome prevalence and blood phenylalanine level in women with PKU
- 15 October 2024
- Published by Elsevier in Molecular Genetics and Metabolism Reports
- Vol. 41, 101154
Open AccessThe relationship between menstrual cycle characteristics, premenstrual syndrome prevalence and blood phenylalanine level in women with PKU
- Open Access
A Comparison Study of Nutritional Assessment, Diet and Physical Activity Habits, Lifestyle and Socio-Demographic Characteristics in Individuals with and without Dizziness/Vertigo
Dizziness and vertigo are growing health problems and have become responsible for increases in health expenditures. In this context, a case-control study has been conducted by nutritional assessment, including dietary and physical activity habits, lifestyle, and socio-demographic characteristics in adults with (patient group) and without (control group) dizziness or vertigo, and the outcomes were compared between these groups. The patient (n = 150) and control (n = 150) groups included 300 participants. The 24-h Dietary Recall and the food frequency questionnaire (FFQ-21) were conducted in order to gain detailed information about foods and beverages consumed by the participants. Additionally, a questionnaire was completed, assessing general socio-demographic (age, gender, etc.) and lifestyle (smoking, alcohol consumption, and obesity) characteristics, anthropometric measurements, and dietary and physical activity habits. The results revealed that there is an association between dizziness/vertigo and female gender and increasing age. Smoking status and alcohol consumption did not differ between the groups, whereas differences in body mass index and obesity were significantly higher in the patient group (65%; n = 98) than the control group (46%; n = 69) (p = 0.001). Skipping meals “everyday” was significantly high (p = 0.044), and lunch was the most skipped meal in the patient group. The three most preferred cooking methods were oven baking, boiling, and frying for both groups. Daily water intake in the patient group was lower than in the control group (p = 0.026). Dietary intake for carotene and vitamin K were significantly lower in the patient group than the control group, but the opposite was true for vitamin D intake (p < 0.05). Daily consumption of bread and dairy products were highest in the patient group (p < 0.05). The physical activity rate was 35% (n = 53) in the control group and 28% (n = 42) in the patient group. Regular walking was the most preferred activity in both groups (p = 0.037). Active monitoring of individual diet and hydration along with supporting professional counseling are advisable. In addition, a healthy lifestyle including weight control and regular physical activity can be helpful to reduce symptoms of dizziness/vertigo.
Open AccessA Comparison Study of Nutritional Assessment, Diet and Physical Activity Habits, Lifestyle and Socio-Demographic Characteristics in Individuals with and without Dizziness/Vertigo
Dizziness and vertigo are growing health problems and have become responsible for increases in health expenditures. In this context, a case-control study has been conducted by nutritional assessment, including dietary and physical activity habits, lifestyle, and socio-demographic characteristics in adults with (patient group) and without (control group) dizziness or vertigo, and the outcomes were compared between these groups. The patient (n = 150) and control (n = 150) groups included 300 participants. The 24-h Dietary Recall and the food frequency questionnaire (FFQ-21) were conducted in order to gain detailed information about foods and beverages consumed by the participants. Additionally, a questionnaire was completed, assessing general socio-demographic (age, gender, etc.) and lifestyle (smoking, alcohol consumption, and obesity) characteristics, anthropometric measurements, and dietary and physical activity habits. The results revealed that there is an association between dizziness/vertigo and female gender and increasing age. Smoking status and alcohol consumption did not differ between the groups, whereas differences in body mass index and obesity were significantly higher in the patient group (65%; n = 98) than the control group (46%; n = 69) (p = 0.001). Skipping meals “everyday” was significantly high (p = 0.044), and lunch was the most skipped meal in the patient group. The three most preferred cooking methods were oven baking, boiling, and frying for both groups. Daily water intake in the patient group was lower than in the control group (p = 0.026). Dietary intake for carotene and vitamin K were significantly lower in the patient group than the control group, but the opposite was true for vitamin D intake (p < 0.05). Daily consumption of bread and dairy products were highest in the patient group (p < 0.05). The physical activity rate was 35% (n = 53) in the control group and 28% (n = 42) in the patient group. Regular walking was the most preferred activity in both groups (p = 0.037). Active monitoring of individual diet and hydration along with supporting professional counseling are advisable. In addition, a healthy lifestyle including weight control and regular physical activity can be helpful to reduce symptoms of dizziness/vertigo.
- 13 November 2022
- Published by Istanbul University in The Journal of Child
- Vol. 22 (3) , 191-199
Fenilketonüri Hastalarının Beslenme Alışkanlıkları ve Besin Tüketim Düzeylerinin Değerlendirilmesi
- 13 November 2022
- Published by Istanbul University in The Journal of Child
- Vol. 22 (3) , 191-199
Fenilketonüri Hastalarının Beslenme Alışkanlıkları ve Besin Tüketim Düzeylerinin Değerlendirilmesi