Effects of whole blood viscosity and plasma NOx on cardiac function and cerebral blood flow in children with chronic kidney disease

Background/aim: The aim of the study was to investigate the effects of whole blood viscosity and plasma nitric oxide on cerebral and cardiovascular risks associated with chronic kidney disease. Materials and methods: The study group consisted of 40 pediatric patients and 21 healthy control subjects. Hematologic and biochemical variables, viscosity and plasma nitric oxide levels, echocardiographic findings, and middle cerebral artery blood flow velocity were examined. Results: Viscosity values of patients were significantly lower than those of the control group. Lower values of hematocrit, total protein, and albumin and higher values of ferritin in all patient groups resulted in significantly low viscosity levels. Plasma nitric oxide levels were higher in all patient groups than those in the controls. No statistically significant difference was present in middle cerebral artery blood flow velocity between the patient and control groups. Even when systolic functions were normal, the patient group had significant deterioration in diastolic functions, suggesting morbidity and mortality risks. Conclusions: Cerebral blood flow velocities were not affected by viscosity and nitric oxide levels, suggesting that cerebral circulation has the ability to make adaptive modulation. The metabolism of nitric oxide levels needs further investigation and studies in patients with chronic renal disease.

Effect of plasma NOx values on cardiac function in obese hypertensive and normotensive pediatric patients.

BACKGROUND: Hypertension (HT) is a major comorbidity of obesity that is associated with an increased risk of cardiovascular disease and higher mortality. The aim of our study was to evaluate cardiac function in obese hypertensive (OHT) and obese normotensive (ONT) pediatric patients and determine the effects of plasma nitric oxide (NOx) values on cardiac function, while demonstrating the role of plasma NOx in HT in obese pediatric patients. METHODS: The study population consisted of 62 patients (27 boys, 35 girls), aged 13-18 years and 21 age-matched healthy controls. All subjects enrolled in the study underwent echocardiography (Echo) evaluation and ambulatory blood pressure monitoring for HT. Plasma NOx and biochemical values were studied in both patient groups separately. RESULTS: Plasma NOx levels were found to be lower in the OHT group than in the ONT and control groups (p < 0.001) and to be negatively correlated with left ventricular mass index values (p < 0.05). Both the OHT and ONT groups had concentric hypertrophy of the heart. CONCLUSIONS: Plasma NOx plays an essential role in obesity-induced HT. Concentric hypertrophy of the left ventricle was found in both the OHT and ONT groups, indicating structural deformation of the heart.

The Effect of Hepcidin on Cardiac Ischemia-Reperfusion Injury.

Background/aim: Hepcidin is the main hormone in the regulation of iron metabolism which is also released from the heart. The aim of our study was to investigate the effects of hepcidin on the cardiac ischemia-reperfusion injury.Materials and methods: In this study, 12 Wistar albino rats were divided into two groups (n = 6 each): 1) The ischemia-reperfusion group (Group 1); 2) Hepcidin-treated group (Group 2). Rat hearts were perfused on Langendorff system with KH (Krebs-Henseleit) and subjected to 30 min stabilization, 30 min global ischemia, and 30 min reperfusion. Hepcidin (- M) was applied to group 2 at the onset of ischemia. Malondialdehyde (MDA), glutathione (GSH), and nitric oxide (NOx) levels were measured in heart tissue for NOx levels, viscosity, and ion content of perfusate were collected before ischemia and the 1st, 5th, 10th, 20th, and 30th minutes of reperfusion were determined. Apoptosis in heart was evaluated.Results: NOx and MDA levels significantly decreased in heart tissue in Hepcidin-treated group. NOx and viscosity of perfusate were not significantly different between the groups. Perfusate iron, calcium, magnesium, potassium, and sodium levels in group 2 were more homogeneous. Histologic structures of heart tissue were regularly in group 2. Apoptosis were increased in control group compared to hepcidin treated group.Conclusion: These results suggest that hepcidin may have a protective effect on the heart for the ischemia-reperfusion injury.

Whole blood viscosity and cerebral blood flow velocities in obese hypertensive or obese normotensive adolescents.

BACKGROUND: Obesity affects all major organ systems and leads to increased morbidity and mortality. Whole blood viscosity is an important independent regulator of cerebral blood flow. The aim of the present study was to evaluate the effect of whole blood viscosity on cerebral artery blood flow velocities using transcranial Doppler ultrasound in pediatric patients with obesity compared to healthy controls and analyze the effect of whole blood viscosity and blood pressure status to the cerebral artery blood flow velocities. METHODS: Sixty patients with obesity diagnosed according to their body mass index (BMI) percentiles aged 13-18 years old were prospectively enrolled. They were grouped as hypertensive or normotensive according to their ambulatory blood pressure monitoring. Whole blood viscosity and middle cerebral artery velocities by transcranial Doppler ultrasound were studied and compared to 20 healthy same aged controls. RESULTS: Whole blood viscosity values in hypertensive (0.0619±0.0077 poise) and normotensive (0.0607±0.0071 poise) groups were higher than controls (0.0616±0.0064 poise), with no significance. Middle cerebral artery blood flow velocities were higher in the obese hypertensive (73.9±15.0 cm/s) and obese normotensive groups (75.2±13.5 cm/s) than controls (66.4±11.5 cm/s), but with no statistical significance. CONCLUSIONS: Physiological changes in blood viscosity and changes in blood pressure did not seem to have any direct effect on cerebral blood flow velocities, the reason might be that the cerebral circulation is capable of adaptively modulating itself to changes to maintain a uniform cerebral blood flow.

The effects of iron treatment on viscosity in children with cyanotic congenital heart disease.

OBJECTIVE: This study was planned to determine the effects of iron treatment in children with cyanotic congenital heart disease. METHOD AND MATERIALS: A total of 39 patients with cyanotic congenital heart disease including 20 (51%) females, 19 (49%) males and whose mean age was 9.9 ± 6.2 years, average weight was 33 ± 18.4 kg were evaluated. Patients were categorized into two groups as having iron deficiency and no iron deficiency with respect to their ferritin levels. 4 mg/kg/day iron treatment with two valences was applied to the groups with iron deficiency for 3 months. Clinical and laboratory findings of both groups were assessed at the outset and 3 months later and viscosity measurements were carried out. RESULTS: Iron deficiency was identified in 21 (53.8%) out of 39 patients. Average Hb and Hct values following 3-month iron treatment increased from 14.8 ± 2.4 g/dl to 16.0 ± 2.0 (P = 0.003) and from %45.8 ± 7.5 to %47.6 ± 7.2 (P = 0.052), respectively. Average viscosity value, however, was 5.6 ± 1.0 cP, it reduced to 5.5 ± 1.0 cP value by demonstrating very little reduction (P = 0.741). Nevertheless, O2 sat value increased from 71.7 to 75% and complaints such as headache, visual blurriness, having frequent sinusitis decreased. CONCLUSIONS: It was observed that iron treatment increased Hb and Hct levels in patients with cyanotic congenital heart disease without raising viscosity and it ensured improvement in clinical symptoms.

Endothelial dysfunction and insulin resistance in young women with polycystic ovarian syndrome.

BACKGROUND/AIM: To evaluate whether there is a correlation between insulin resistance and nitric oxide-related endothelial dysfunction in patients with polycystic ovarian syndrome (PCOS). MATERIALS AND METHODS: The study was conducted with 25 young women with PCOS and 25 young healthy women, between 18 and 35 years of age. Plasma asymmetric dimethylarginine (ADMA) levels, serum nitric oxide (NO) levels, and homeostatic model assessment of insulin resistance (HOMA-IR) rates were measured in both the patient and control groups. RESULTS: Plasma ADMA levels were significantly higher in PCOS patients than in the controls (P = 0.001). Serum NO levels were significantly lower in patients than in the controls (P = 0.008). The HOMA-IR rates, accepted as an insulin resistance parameter, were significantly higher in patients than in the controls (P = 0.001). CONCLUSION: Results of the present study indicate that, independent of age, body mass index, and blood lipid profile, there is significant insulin resistance in PCOS patients. However, no correlation was found between HOMA-IR as an insulin resistance determinant and altered ADMA and NO levels. This finding may indicate that there are additional mechanisms of cardiovascular risks in PCOS patients other than insulin resistance.

Are serum nitric oxide and vascular endothelial growth factor levels affected by packed red blood cell transfusions?

BACKGROUND: Nitric oxide (NO) and vascular endothelial growth factor (VEGF) are important mediators for hemodynamics and angiogenesis in the body. NO coming from endothelial cells and red blood cells is particularly effective in hypoxic vasodilation. VEGF has known effects on the induction of NO synthesis and is also known to be affected by blood product transfusions. The objectives of this study were to measure NO and VEGF levels before and after packed red blood cell (PRBC) transfusions. STUDY DESIGN AND METHODS: Blood was drawn from preterm newborns before and 30 min after PRBC transfusions and samples were used for NO and VEGF measurements. NO end products nitrite and nitrate were measured by modified Greiss method, VEGF levels measured by double sandwitch ELISA method. Vital signs including heart rate and blood pressure were also recorded. RESULTS: Thirty four newborns were included in the study and overall 54 transfusion episodes were assessed for mediator levels. No difference was observed between the mediator levels before and after PRBC transfusions. Vital signs were also unchanged. CONCLUSION: As there was no change in NO end product levels with PRBC transfusions, it might suggest that hypoxia was not severe enough to cause nitrite increase; however, other NO sources might still be active. VEGF levels were found to be unchanged and may reflect a delayed effect of transfusion on VEGF induction.