Background: It is known that inflammatory responses play an important role in the pathophysiology of COVID‐19.Aims: In this study, we aimed to examine the role of kynurenine (KYN) metabolism on the severity of COVID‐19 disease AQ5.Materials & Methods: Seventy COVID‐19 patients of varying severity and 30 controls were included in the study. In addition to the classical laboratory parameters, KYN, tryptophan (TRP), kynurenic acid (KYNA), 3 hydroxykynurenine (3OHKYN), quinolinic acid (QA), and picolinic acid (PA) were measured with mass spectrometry.Results: TRP, KYN, KYN:TRP ratio, KYNA, 3OHKYN, PA, and QA results were found to be significantly different in COVID‐19 patients (p < 0.001 for all). The KYN:TRP ratio and PA of severe COVID‐19 patients was statistically higher than that of mild‐moderate COVID‐19 patients (p < 0.001 for all). When results were examined, statistically significant correlations with KYN:TRP ratio, IL‐6, ferritin, and procalcitonin were only found in COVID‐19 patients. ROC analysis indicated that highest AUC values were obtained by KYN:TRP ratio and PA (0.751 vs 0.742). In determining the severity of COVID‐19 disease, the odd ratios (and confidence intervals) of KYN:TRP ratio and PA levels that were adjusted according to age, gender, and comorbidity were determined to be 1.44 (1.1–1.87, p = 0.008) and 1.06 (1.02–1.11, p = 0.006), respectively.Discussion & Conclusion: According to the results of this study, KYN metabolites play a role in the pathophysiology of COVID‐19, especially KYN:TRP ratio and PA could be markers for identification of severe COVID‐19 cases.

The harmful or beneficial effect of obesity on bone mineral density (BMD) remains controversial in children and adolescents. Fibroblast growth factor 21 (FGF21) is a metabolic factor that plays a specific role in the regulation of carbohydrate and lipid metabolism. However, the role of FGF21 in bone metabolism appears paradoxical and is complex. To determine whether serum FGF21 level was associated with BMD in obese children and adolescents. The study was conducted with the participation of children and adolescents aged 8-18 years. Ninety-eight obese children were included in the study group and 44 children were included in the control group. BMD, in addition to the routine obesity workup, which includes fasting blood glucose, fasting insulin levels, lipid profile, and liver enzymes; serum FGF21 levels have been analyzed. The mean age of the obese group (n=98) was 13.34±2.24 years and the mean age of controls (n=44) was 13.48±2.87 years. Based on International Diabetes Federation criteria, 15 of 98 (15.3%) patients were metabolically unhealthy. FGF21 levels were 193.54±139.62 mg/dL in the obese group and 158.69±151.81 mg/dL in the control group (p=0.06). There was no difference between the FGF21 and BMD z-score values of girls and boys in the obese and control groups (p>0.05). BMD-z-score was increased in obese children compared to healthy control. Moreover, BMD-z-score tended to be higher when more metabolic risk factors were present. However, there was no significant relationship between FGF21 levels and BMD z-score values in obese children.

BackgroundOxidative and nitrosative stress is well believed to play a role in the pathogenesis of ischemic stroke. This study aims to evaluate the time course of oxidative and nitrosative stress in ischemic stroke.MethodsIn total, 27 healthy individuals, 22 individuals with high risk of ischemic stroke due to hypertension and diabetes mellitus, and 20 patients with acute ischemic stroke hospitalized at the Neurology Department of the Kırıkkale University School of Medicine were enrolled in the study. Venous blood was collected at admission (hour 0) and again at hours 24, 48, 72, and 96. Nitric oxide (NO), malondialdehyde (MDA), total oxidative stress (TOS), oxidative stress index (OSI), and total antioxidant status (TAS) were measured and compared among stroke patients and control groups.ResultsBlood NO was significantly higher in the patient group at 0, 24, 48, and 72 h compared to the healthy and high-risk control groups, and lower at 96 h than at early times within the patient group (pConclusionsThese findings suggest a substantial early increase in oxidative and nitrosative stress in ischemic stroke patients during the first 2 days post-admission. However, TOS was lower by days 3–4, likely due to pathological recovery and local/systemic defense systems. The correlation between elevated serum NO during the acute phase of stroke and duration of hospitalization suggests NO as a potentially valuable predictor of ensuing oxidative damage and clinical outcome.