Ferhan Karademir

Evaluation of new adipocytokines and insulin resistance in adolescents with polycystic ovary syndrome

AIM The aim of this study was to investigate the relationship between four circulating adipocytokines (apelin, vaspin, visfatin, adiponectin) and markers of insulin sensitivity, in the context of polycystic ovary syndrome (PCOS) in adolescents. SUBJECTS AND METHODS 48, obese, adolescent girls (mean age: 15.6±3.4 years, mean body mass index standard deviation score (BMI-SDS): 2.31±0.1), and 37 control subjects (mean age: 16.2±3 years, mean BMI-SDS: 2.17±0.05) were enrolled the study. The diagnosis of PCOS was established according to the Rotterdam criteria. Hyperinsulinism and insulin resistance was evaluated using the homeostasis model assessment (HOMA-IR) from fasting samples. Plasma adiponectin and vaspin levels were determined by radioimmunoassay. Determination of visfatin and apelin levels was performed by enzyme immunoassay. RESULTS HOMA-IR, apelin and visfatin levels (4.9±2 versus 1.4±0.7, p<0.001; 2.2±1.1 versus 0.58±0.16, p<0.001; 31.3±11.1 versus 18.5±10.7, p<0.001; respectively) were significantly elevated, and adiponectin levels (2.01±1.02 versus 12.5±6.2, p<0.001) were significantly lower in the PCOS group. Vaspin levels were higher in the PCOS group than in the control group, but the differences were not significant. Apelin and visfatin correlated positively and adiponectin correlated negatively with BMI-SDS and HOMA-IR. CONCLUSION Based on the findings of this study, apelin, visfatin and adiponectin levels can be used as specific markers for insulin sensitivity, and these adipocytokines might play a part in the pathogenesis of PCOS.

Elevated Plasma Levels of Apelin in Children with Type 1 Diabetes Mellitus

ABSTRACT Background: Apelin is a novel adipocytokine produced by white adipose tissue that binds the APJ receptor with high affinity. Insulin may have a role in regulation of apelin synthesis and secretion from the adipose tissue. Objective: To investigate blood apelin concentrations in children with type 1 diabetes mellitus (T1DM) and display association of apelin with adiponectin, body mass index (BMI), lipids and insulin sensitivity. Methods: Thirty patients with T1DM and 45 healthy controls were enrolled. Apelin levels were measured along with BMI, lipids, fasting plasma glucose, HbA1c and adiponectin levels. Results: Plasma apelin and adiponectin levels were significantly higher in the diabetic group when compared to controls. No correlation was found between the apelin blood concentrations and adiponectin, BMI, lipids and insulin sensitivity. Conclusions: Children with T1DM have significantly increased circulating apelin levels when compared to healthy controls. However, no significant relation was found between the apelin and BMI, glucose, lipids and adiponectin levels, and also insulin sensitivity.

Reference values of umbilical cord and third-day cystatin C levels for determining glomerular filtration rates in newborns.

The aim of this study was to determine reference values for serum cystatin C at, and 3 days after, birth, and to determine if the concentration was influenced by gender, gestational age or bilirubin level. Umbilical cord and peripheral venous blood was taken, and serum cystatin C, creatinine, and total and direct bilirubin levels were measured. The mean concentration of cystatin C was not significantly different between cord blood and blood taken on day 3 (1.36 ± 0.35 mg/l and 1.35 ± 0.33mg/l, respectively). Comparison of subgroups, divided by gender, duration of gestation and bilirubin levels, using the Mann-Whitney U-test and Wilcoxon analysis, showed no effect of these parameters on cystatin C levels.

Diagnostic value of resistin and visfatin, in comparison with C-reactive protein, procalcitonin and interleukin-6 in neonatal sepsis

AIM The aim of this study was to evaluate the predictive value of resistin and visfatin in neonatal sepsis, and to compare these adipocytokines with C-reactive protein (CRP), procalcitonin and interleukin 6 (IL-6). DONORS AND METHODS A total of 62 term or near term infants with sepsis proven by positivity of blood culture, and 43 healthy infants were included in this study. RESULTS There were no statistically significant differences between the two groups as regards birthweight and gestational age. White blood cell count (p= 0.039), CRP levels (p=0.01), procalcitonin levels (p=0.01), IL-6 levels (p= 0.01), visfatin levels (p=0.01) and resistin levels (p=0.01) were significantly higher in septic infants. There was a positive correlation between visfatin, resistin and other markers (WBC, CRP, procalcitonin and IL-6). A cut-off value of 10 ng/mL for visfatin, showed 92% sensitivity and 94% specificity, and a cut-off value of 8 ng/mL for resistin showed 93% sensitivity and 95% specificity for neonatal sepsis. CONCLUSION In the light of these results, visfatin and resistin can be used as a diagnostic marker similar to CRP, procalcitonin and IL-6 in neonatal sepsis. Further studies are needed to better understand the role and predictive value of these molecules in neonatal sepsis.

Vitamin B12, folate, homocysteine and urinary methylmalonic acid levels in infants.

Serum vitamin B12 and folate, and their functional markers, plasma homocysteine and urinary methylmalonate (uMMA) were measured in 204 healthy, term infants at birth, and at 2 and 6 months. Compared with infants receiving formula food, those fed mothers milk had lower vitamin B12 and folate at 2 and 6 months. In infants receiving mothers milk, vitamin B12 levels were similar at birth (238 pg/ml) and 2 months (243 pg/ml), whereas with formula milk the level was significantly higher at 2 months (558 pg/ml) than at birth (257 pg/ml). Vitamin B12 was negatively correlated with homocysteine at birth and 6 months. The level of uMMA (mmol/mol creatinine) was higher at 2 (mothers milk, 25.5; formula, 23.97) and 6 months (19.77; 15) than at birth (11.97; 10.88), and was not correlated with vitamin B12 levels. Homocysteine may be a reliable marker of vitamin B12 status in neonates and infants; however, uMMA is not suitable as a marker of vitamin B12 status.

The relationship between serum visfatin, adiponectin, and insulin sensitivity markers in neonates after birth.

Aim. The aim of this study was to assess the adiponectin and visfatin concentrations in small-for-gestational age (SGA), appropriate-for-gestational age (AGA), and large-for-gestational age (LGA) newborns and their mothers. Sixty parturients giving birth to 20 term AGA singleton infants, 20 term singleton SGA infants, and 20 term singleton LGA infants were included into the study. Results. Mean visfatin levels were found significantly higher in the SGA (p < 0.001) and LGA (p < 0.001) groups, and adiponectin levels were found significantly lower in the SGA group (p < 0.001) when compared with the AGA group. The SGA and LGA groups had higher insulin concentrations and HOMA-IR in comparison with the AGA group. The visfatin, glucose levels, and HOMA-IR (p < 0.001, p < 0.001, and p: 0.002, respectively) were higher in the LGA group than SGA group. Conclusion. We found significantly higher insulin and visfatin levels in LGA neonates and lower adiponectin levels in SGA neonates. We concluded that the relationship between adiponectin and visfatin and insulin sensitivity (metabolic disturbances) is very complex with little evidence of correlation in SGA and LGA neonates.

Ghrelin Levels and Postnatal Growth in Healthy Infants 0-3 Months of Age

Objective: The effect of ghrelin on growth of the newborn has long been argued, but not fully clarified. In this study, we aimed to investigate the relationship between ghrelin levels and growth parameters in the first 3 months of life. Methods: The study included 60 babies (27 girls and 33 boys) born at gestational ages between 38-42 weeks. The newborns were divided into three groups according to the Lubchenco curves as: small for gestational age (SGA), appropriate for gestational age (AGA) and large for gestational age (LGA). The relationship between ghrelin levels and growth parameters in the third month was investigated. Results: Ghrelin concentrations were significantly higher in SGA (2.4±2.6 ng/dL) babies than in AGA (1.3±0.9 ng/dL) and LGA (1.0±0.8 ng/dL) babies. The lowest ghrelin levels were in the LGA group. In SGA infants, ghrelin concentrations were inversely correlated with change in weight (r=-0.577; p=0.001), change in length (r=-0.361; p=0.005), and change in head circumference (r=-0.387; p=0.002). Conclusion: The results show that at age 3 months, SGA infants had higher ghrelin levels than AGA and LGA infants. Our findings indicate that ghrelin may be involved in the process of catch-up growth in these infants. Conflict of interest:None declared.

The Association between Serum 25-Hydroxy Vitamin D Level and Urine Cathelicidin in Children with a Urinary Tract Infection.

Objective: Cathelicidin is an important antimicrobial peptide in the urinary tract. Cathelicidin expression is strongly stimulated by 1,25-dihydroxy vitamin D in epithelial cells, macrophages/monocytes, and neutrophils. Vitamin D and cathelicidin status in children with urinary tract infection (UTI) caused by Escherichia coli is unknown. To establish the relationship between serum vitamin D and urine cathelicidin levels in children with a UTI caused by Escherichia coli. Methods: Serum 25-hydroxy vitamin D and urine cathelicidin levels were measured in 36 patients with UTI (mean age 6.8±3.6 years, range: 0.25-12.6 years) and 38 controls (mean age 6.3±2.8 years, range: 0.42-13 years). Results: There were no significant differences in urine cathelicidin levels between the study and control groups (p>0.05). Eight (22.2%) patients in the study group and 21 (58.3%) children in the control group were found to have sufficient vitamin D (≥20 ng/mL). Patients with sufficient vitamin D had higher urine cathelicidin levels than the controls with sufficient vitamin D (respectively 262.5±41.1 vs. 168±31.6 ng/mL, p=0.001). There were no significant differences between the patients and controls with insufficient vitamin D (p>0.05). Conclusion: The children with vitamin D insufficiency may not be able to increase their urine cathelicidin level during UTI caused by Escherichia coli. There is a need of prospective studies in order to prove a beneficial effect of vitamin D supplementation for the restoration of cathelicidin stimulation and consequently for prevention of UTI recurrence.

Correlation between cord blood apelin and IGF-1 levels in retinopathy of prematurity

AIM We hypothesized that circulating apelin concentrations in preterm babies might be linked with retinopathy of prematurity (ROP), similar to IGF-1 levels. PATIENTS & METHODS A total of 97 infants born with a gestational age before 32 weeks in 2007-2009 were screened for ROP at the Gata Haydarpasa Hospital (Turkey). Fourteen of them with classified ROP stage 3-5 comprised our study group. RESULTS The non-ROP group had higher apelin and IGF-1 levels than ROP neonates at birth. After 4-6 weeks, postnatal ROP subjects had lower apelin and IGF-1 levels than non-ROP controls. At the end of the study, the change in apelin levels was positively correlated with the change in IGF-1 levels (r = 0.852; p = 0.01). CONCLUSION We suggested that the pathogenesis of ROP, which is regarded as a neovascular retinal disorder, includes variations in the levels of apelin and IGF-1.

Time dependent impact of perinatal hypoxia on growth hormone, insulin-like growth factor 1 and insulin-like growth factor binding protein-3

Hypoxic-ischemia (HI) is a widely used animal model to mimic the preterm or perinatal sublethal hypoxia, including hypoxic-ischemic encephalopathy. It causes diffuse neurodegeneration in the brain and results in mental retardation, hyperactivity, cerebral palsy, epilepsy and neuroendocrine disturbances. Herein, we examined acute and subacute correlations between neuronal degeneration and serum growth factor changes, including growth hormone (GH), insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) after hypoxic-ischemia (HI) in neonatal rats. In the acute phase of hypoxia, brain volume was increased significantly as compared with control animals, which was associated with reduced GH and IGF-1 secretions. Reduced neuronal survival and increased DNA fragmentation were also noticed in these animals. However, in the subacute phase of hypoxia, neuronal survival and brain volume were significantly decreased, accompanied by increased apoptotic cell death in the hippocampus and cortex. Serum GH, IGF-1, and IGFBP-3 levels were significantly reduced in the subacute phase of HI. Significant retardation in the brain and body development were noted in the subacute phase of hypoxia. Here, we provide evidence that serum levels of growth-hormone and factors were decreased in the acute and subacute phase of hypoxia, which was associated with increased DNA fragmentation and decreased neuronal survival.