Browsing by Author "Kabak, Mehmet"

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Diagnostic and Pathophysiological Significance of Serum Myeloperoxidase, Ischemia-Modified Albumin, Paraoxonase-1 and Galectin-3 in COVID-19-Parallels with Myocarditis
(BMC, 2026) Yildiz, Songul Cetik; Cil, Baris; Dundar, Ahmet; Kabak, Mehmet; Cetik Yildiz, Songul
Background COVID-19 has emerged as a complex disease extending beyond respiratory involvement and is characterized by systemic inflammation and oxidative stress, which may also affect the cardiovascular system. Our study sought to elucidate the function of biomarkers serum myeloperoxidase (MPO), ischemic modified albumin (IMA), paraoxonase-1 (PON-1) and galectin-3 (GAL-3) in the pathophysiology of COVID-19 to explore their potential associations with pathophysiological mechanisms commonly involved in myocardial injury. Methods Our prospective case-control study assessed biomarker discrimination between hospitalized COVID-19 patients and healthy controls. Serum levels of biomarkers were measured using ELISA and enzymatic reaction products were assessed using spectrophotometric methods. Results Our findings showed that serum MPO, IMA, and GAL-3 levels were significantly higher in the COVID-19 group compared with control, while PON-1 levels were significantly lower. Subgroup analyses based on disease severity revealed that changes in these biomarkers were more pronounced in patients with severe COVID-19. Conclusions The significant increase in GAL-3 and MPO levels in severe cases supports the role of inflammatory burden and oxidative stress in disease progression, while the decrease in PON-1 levels indicates a decrease in antioxidant defense capacity. Overall, these findings indicate the presence of shared pathophysiological mechanisms between COVID-19 and myocardial injury, rather than providing direct evidence of myocarditis. The observed biomarker alterations are compatible with mechanisms implicated in myocarditis and may be of interest for future myocarditis research; however, direct evaluation in well-characterized myocarditis cohorts is required.
Diagnostic Shifts in Extrapulmonary Tuberculosis during COVID-19: Evidence of Vulnerability among Migrants in a Border Province
(BMC, 2026) Kabak, Mehmet; Bodur, Mehmet Sinan; Cil, Baris
BackgroundThe diagnosis of extrapulmonary tuberculosis (EPTB) often depends on advanced imaging, invasive tissue sampling, and multidisciplinary referral pathways. These complex, procedure-dependent diagnostic processes are particularly vulnerable to disruption during periods of health system strain. During the COVID-19 pandemic, the reallocation of healthcare resources, restrictions on elective procedures, and delays in diagnostic services may have disproportionately affected EPTB detection, leading to missed or delayed diagnoses. Migrant populations, who already face structural barriers to healthcare access related to language, socioeconomic factors, and referral processes, may be especially vulnerable to such diagnostic disruptions during public health emergencies.MethodsWe conducted a retrospective observational study using complete provincial tuberculosis dispensary records from Mardin, a border province in southeastern Turkey. All tuberculosis cases diagnosed between 2017 and 2025 were included. Diagnostic periods were defined as pre-COVID (2017-2019), COVID (2020-2022), and post-COVID (2023-2025). Cases with concomitant pulmonary and extrapulmonary involvement were classified as pulmonary tuberculosis (PTB). Distributions of PTB and EPTB by diagnostic period and nationality (local vs. migrant) were compared using chi-square or exact tests, as appropriate. For microbiological analyses, hypothesis testing was restricted to cases with available results. Factors associated with EPTB were evaluated using Firth penalized logistic regression to reduce small-sample bias and separation.ResultsA total of 525 tuberculosis cases diagnosed between 2017 and 2025 were included (mean age 37.8 +/- 19.3 years; 51.2% male), of whom 49 (9.3%) were migrants. Overall, 235 cases (44.8%) were classified as extrapulmonary tuberculosis (EPTB). In the local population, EPTB proportions varied across periods (47.4% pre-COVID, 35.2% during COVID, and 54.9% post-COVID; p = 0.0034). Among migrants, EPTB proportions also differed across periods (26.9%, 16.7%, and 63.6%, respectively; exact p = 0.0425), although estimates were imprecise due to small strata sizes. Among locals, AFB positivity among performed tests and culture positivity among determinate results varied across periods (p = 0.0041 and p = 0.0001, respectively). In Firth penalized logistic regression male sex and the COVID period were associated with lower odds of EPTB. Migrant status showed lower odds but did not reach statistical significance, and the post-COVID period was not statistically significant. These findings reflect changes in the PTB/EPTB case-mix among notified TB cases rather than population incidence.ConclusionWe observed a transient shift in the PTB/EPTB case-mix during the COVID period with a post-COVID rebound. While these patterns are compatible with pandemic-related changes in diagnostic pathways, mechanisms cannot be directly assessed in registry data without denominators and service-level diagnostic volumes. Maintaining access to referral- and procedure-dependent diagnostic pathways remains important, particularly for vulnerable populations.Clinical trailNot applicable.
Evaluation of Sexual Dysfunction and Its Predictors in Men with Obstructive Sleep Apnea Syndrome: A Multidimensional Clinical and Psychological Approach
(Frontiers Media SA, 2026) Kabak, Mehmet; Çil, Barış
Background: Obstructive sleep apnea syndrome (OSAS) is a common sleep-related breathing disorder associated with significant cardiovascular, metabolic, and neuropsychological consequences. Increasing evidence suggests that OSAS may also adversely affect male sexual function; however, sexual health remains underrecognized in routine clinical practice. This study aimed to evaluate the prevalence of sexual dysfunction in men with OSAS and to identify its clinical, psychological, and polysomnographic predictors using a multidimensional approach. Methods: This cross-sectional study included 52 men diagnosed with OSAS and 40 age-matched healthy controls. All participants underwent overnight type 1 polysomnography. Daytime sleepiness, anxiety, depression, sexual function, and quality of life were assessed using the Epworth Sleepiness Scale (ESS), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Arizona Sexual Experience Scale (ASEX), and SF-36 questionnaire, respectively. Associations between sexual dysfunction and demographic, psychological, and sleep-related parameters were analyzed. Receiver operating characteristic (ROC) curve analysis was performed to evaluate predictive factors. Results: Sexual dysfunction was significantly more prevalent in men with OSAS compared to controls (p = 0.04) and was strongly associated with increasing OSAS severity. Men with sexual dysfunction exhibited significantly higher apnea-hypopnea index (AHI), ESS, anxiety, and depression scores, along with lower physical functioning, vitality, and mental health scores (all p < 0.05). ROC analysis demonstrated that AHI was a significant associated factor of sexual dysfunction (AUC = 0.709), with a sensitivity of 91% and specificity of 81% at a cutoff value of 59.75. Conclusion: Sexual dysfunction in men is closely related to the severity of OSAS rather than its mere presence. AHI emerges as a key associated factor, highlighting the importance of comprehensive sexual and psychological assessment in the clinical management of men with OSAS.
Predicting Positive Airway Pressure Appointment Attendance Using Machine Learning and Deep Learning: The Role of Clinical and Oximetric Indicators
(Springer Heidelberg, 2026) Baran, Mehmet Tarık; Kabak, Mehmet; Çi̇l, Barış
Introduction Participation in positive airway pressure (PAP) therapy is essential for improving long-term health outcomes in individuals diagnosed with obstructive sleep apnea syndrome (OSAS). This study aimed to identify clinical, physiological, and behavioral factors influencing attendance at initial PAP appointments and to develop and compare predictive models using machine learning and deep learning techniques. Methods A total of 369 patients with obstructive sleep apnea syndrome (OSAS) were retrospectively analyzed. Among them, 39.2% attended their scheduled PAP therapy appointment and initiated treatment, whereas 60.8% did not. Correlation analyses were performed, and predictive models including logistic regression, decision trees, random forests, support vector machines, and a deep neural network were developed and compared to predict appointment attendance. Results A high Epworth Sleepiness Scale (ESS) score and greater time spent in the 80-90% nocturnal oxygen saturation range were positively associated with PAP therapy attendance. In contrast, alcohol consumption was a significant behavioral predictor of non-attendance. Hypoxemia-related metrics, such as average nocturnal oxygen saturation, were found to be stronger predictors than the apnea-hypopnea index (AHI). Anthropometric variables-waist circumference, body mass index (BMI), and neck circumference-showed only weak positive correlations with treatment participation. Conclusion This study is among the few to focus on initiation of PAP therapy, rather than long-term adherence, which is the typical focus of most existing research. The machine learning and deep learning models developed here have the potential to support clinical decision-making systems by identifying high-risk individuals early and enabling timely intervention. Integrating these tools into clinical workflows may improve patient engagement and outcomes from the very first step of treatment.
Predicting the Severity of Obstructive Sleep Apnea Using Artificial Intelligence Tools
(Wolters Kluwer Medknow Publications, 2025) Cil, Baris; Irmak, Halit; Kabak, Mehmet
BACKGROUND:We developed an artificial intelligence (AI) model to predict the severity of obstructive sleep apnea syndrome (OSAS).METHODS:We used data from 750 inpatients at a research hospital between 2021 and 2023. The dataset comprises 20 attributes, including demographic information, medical history, anthropometric measurements, and polysomnography (PSG) data. The target attribute was the apnea-hypopnea Index (AHI), from which OSAS severity was determined. Data preprocessing included min-max scaling for normalization and the Synthetic Minority Over-sampling Technique algorithm to address the class imbalance, increasing the dataset size to 1250. We invented and further developed a multilayer artificial neural network (ANN) model to predict OSAS severity and evaluated its performance using k-fold cross-validation. We also performed an information gain analysis to rank the features by importance.RESULTS:The ANN model accurately predicted OSAS severity (area under the receiver operating characteristic curve: 0.966, CA: 0.880). Information gain analysis revealed strong associations between OSAS severity and the Epworth Sleepiness Scale, lowest nighttime oxygen saturation, percentage of sleep time with oxygen saturation between 80% and 90% during the night, and neck thickness. These identified features represent important risk factors for early OSAS diagnosis and treatment.CONCLUSION:Our findings suggest that AI-based models can effectively predict OSAS severity. This research may contribute to the development of next-generation diagnostic tools for OSAS diagnosis and risk assessment. AI can readily determine OSAS severity from overnight pulse oximetry recordings, combined with other risk factors, in patients with suspected OSAS.
Citation - Scopus: 1
Radiologic Severity Index Can Be Used To Predict Mortality Risk in Patients With Covid-19
(Turkish Assoc Tuberculosis & Thorax, 2024) Sahutoglu, Elif; Kabak, Mehmet; Cil, Baris; Atay, Kadri; Peker, Ahmet; Guler, Suekran; Sahutoglu, Tuncay; Kara, Ekrem; Eldes, Tugba; Kara, Bilge Yılmaz; Tahtabaşı, Mehmet
Introduction: Pneumonia is a common symptom of coronavirus disease-2019 (COVID-19), and this study aimed to determine how analyzing initial thoracic computerized-tomography (CT) scans using semi-quantitative methods could be used to predict the outcomes for hospitalized patients. Materials and Methods: This study looked at previously collected data from adult patients who were hospitalized with a positive test for severe acute respiratory syndrome coronavirus-2 and had CT scans of their thorax at the time of presentation. The CT scans were evaluated for the extent of lung involvement using a semi-quantitative scoring system ranging from 0 to 72. The researchers then analyzed whether CT score could be used to predict outcomes. Results: The study included 124 patients, 55 being females, with a mean age of 46.13 years and an average duration of hospitalization of 11.69 days. Twelve patients (9.6%) died within an average of 17.2 days. The non-surviving patients were significantly older, had more underlying health conditions, and higher CT scores than the surviving patients. After taking age and comorbidities into account, each increase in CT score was associated with a 1.048 increase in the risk of mortality. CT score had a good ability to predict mortality, with an area under the curve of 0.857 and a sensitivity of 75% and specificity of 85.7% at a cut-off point of 25.5. Conclusion: Radiologic severity index, which is calculated using a semi-quantitative CT scoring system, can be used to predict the mortality of COVID-19 patients at the time of their initial hospitalization.
Syrian Civil War and Assessment of Tuberculosis Among Syrian Refugees and Local Citizens in Mardin
(Frontiers Media SA, 2025) Cil, Baris; Kabak, Mehmet; Bodur, Mehmet Sinan; Sanmak, Erkan; Gunes, Guldan; Alakas, Yusuf; Oktay, Hamza
Background: We compared tuberculosis (TB) characteristics and outcomes between Syrian refugees and local citizens in Mardin, Turkey (2016-2023), a border province with substantial population mobility. Methods: Retrospective, registry-based cross-sectional analysis of 491 patients (locals n = 456; refugees n = 35). Descriptive comparisons used chi(2)/Fisher (categorical) and Mann-Whitney U (age). Annual incidence per 100,000 used mid-year denominators (locals: ABPRS/NVI; refugees: DGMM/PMM and UNHCR). For outcomes with significant crude differences (treatment success, BCG scar, transferred-out), age- and sex-adjusted bias-reduced (Firth) logistic regression was applied; p-values from penalized likelihood-ratio (PLR) tests. Results: BCG-scar positivity was lower in refugees than locals (62.9% vs. 93.2%, p < 0.001). Microbiological confirmation remained below WHO targets in both groups. Crude treatment success was lower in refugees (68.6%) than locals (90.4%, p = 0.03), while transferred-out was higher (25.7% vs. 5.3%, p = 0.001). In adjusted Firth models including all cases, refugee status was associated with lower odds of success (aOR 0.224, 95% CI 0.103-0.488; PLR p < 0.001); after excluding transferred-out cases the association attenuated and was not significant (aOR 0.562, 95% CI 0.121-2.605; PLR p = 0.42). In pulmonary-only analyses, the association persisted (aOR 0.216, 95% CI 0.083-0.567; PLR p = 0.002). Refugee incidence dipped in 2020-2021 and rebounded in 2022-2023. Conclusion: Differences likely reflect operational barriers-especially transfers disrupting continuity-rather than intrinsic factors. Refugee-inclusive TB services with robust inter-provincial transfer tracking, patient navigation, and expanded bacteriological testing (notably for extrapulmonary disease) should be prioritized. Given the small refugee subgroup and denominator uncertainties, findings are hypothesis-generating.
Underutilization of Bacteriological Testing in Extrapulmonary Tuberculosis: A Retrospective Single-Center Study from Mardin, Türkiye
(Galenos Publ House, 2026) Kabak, Mehmet; Bodur, Mehmet Sinan; Cil, Baris
OBJECTIVE: Extrapulmonary tuberculosis (EPTB) poses diagnostic challenges due to the low bacillus burden of the disease and the limited use of bacteriological tests. The aim of this study was to evaluate bacteriological confirmation rates, diagnostic methods, and sampling practices among patients diagnosed with tuberculosis (TB) in a southeastern province of Türkiye. MATERIAL AND METHODS: This retrospective study included a total of 456 TB cases diagnosed between 2014 and 2019. The cases were classified as pulmonary tuberculosis (PTB), EPTB, and cases with both types of involvement. Bacteriological and histopathological confirmation rates were compared between the groups. RESULTS: 41.0% of all cases were classified as EPTB. The most commonly involved site was lymph node TB (22.4%). Bacteriological confirmation rates were significantly lower in EPTB cases: acid-fast bacilli (AFB) smear positivity was 3.2% and culture positivity was 4.3%, whereas the histopathological confirmation rate was 88.8%. No bacteriological samples were taken from 63.1% of patients in the EPTB group. Among PTB cases, AFB smear positivity (71.4%) and culture positivity (66.5%) were significantly higher (P < 0.001). CONCLUSION: The findings suggest that bacteriological tests are both underused and of low diagnostic efficiency in EPTB cases. Most diagnoses are based on histopathology rather than on bacteriological confirmation. Strengthening sampling strategies and promoting the use of rapid molecular testing are critical for enhancing bacteriological validation in EPTB.