http://www.revistadechimie.ro REV.CHIM.(Bucharest)♦68♦No. 4 ♦2017 758 Vascular Reactivity and Proinflammatory Cytokines in the Obese Children LAURA ANCA POPESCU 1 , BOGDANA VIRGOLICI 1 *, DACIANA COSTINA ANDRADA STEFAN 1 , DANIELA LIXANDRU 1 , OLIVIA TIMNEA 2 , HORIA VIRGOLICI 1 , DUMITRU ORASEANU 1 , CRINA SINESCU 1 , MARIA MOHORA 1 1 Carol Davila University of Medicine and Pharmacy, 4 Traian Vuia Str., 020956, Bucharest, Romania 2 Ecologic University of Bucharest, Faculty of Physical Educational and Sports, 1G Vasile Milea Blvd., 061345, Bucharest, Romania The aim of this study was to evaluate the relation between inflammatory markers and the preatherosclerotic marker - flow mediated dilation (FMD). Thirty obese children (10-16 years old) and twenty controls were involved. The plasma inflammatory markers: CRP, fibrinogen, leptin, TNF- α, IL-6 were measured. Ultrasounds were used for FMD measurement, chemiluminescence for monocyte respiratory burst (RB), ELISA for C peptide and spectrophotometry for usual parameters. In the obese children versus the lean ones, the FMD was lower (p< 0.001), the plasma values for TNF-α were similar (1.68 pg/mL vs 1.54 pg/mL), while plasma IL-6 was increased (4.01 pg/mL vs. 2.02 pg/mL, p< 0.05). These cytokines were negatively correlated with FMD (r= -0.42, p< 0.05) and positively with RB (r= 50, p< 0.05). The FMD was negatively correlated (p< 0.05) with the values for diastolic blood pressure (r = -0.47), waist circumference (r = -0.55), uric acid (r = - 0.47) and atherosclerotic index (r = -0.37). In conclusion, in the obese children, inflammation, dyslipidaemia, blood pressure and oxidative stress act in a cluster reducing the elasticity of the vessel walls. Keywords: childhood obesity, FMD, inflammation In obese subjects, the adipose tissue, especially the visceral fat is infiltrated by macrophages. Adipocytes, but mainly macrophages from the adipose tissue secrete proinflammatory cytokines like TNF-α, IL-6. TNF-α acts more as an autocrin and paracrin hormon, while high plasma IL-6 can stimulate the hepatic synthesis of acute phase proteins, augmenting inflammation [1,2]. The mRNA expression of IL-6 and TNF-α is higher in the adipose tissue of overweight and obese children versus normal weight ones[3]. TNF-α stimulates lipolysis through activation of extracellular signal-related kinase and elevation of AMPc, controlling the gatekeeper proteins on the surface of the lipid droplets [2]. Like TNF-α, IL-6 stimulates lipolysis and inhibits lipoprotein lipase and both cytokines contribute to the high plasma levels of triglycerides. The imbalance of adipocytokines (high leptin and resistin versus low adiponectin), of cytokines (TNF-α, IL-6, IL-1 versus low IL- 10) contribute also to the chronic inflammatory status in obesity [4]. Vascular dysfunction is present in the first stages of atherosclerosis development. Flow-mediated dilation FMD is a subclinical marker of atherosclerosis, estimating the increase in brachial arterial diameter in response to brief arterial occlusion [5] and it has a predictive value for future cardiovascular events [6]. The recruitment and the activation of monocytes are present in the first stages of atherosclerosis [7]. Also, under certain stimuli, monocytes undergo an oxidative burst during which free radicals, as superoxide anion, are released and the increased oxidative stress contributes to the vascular dysfunction [8]. In childhood obesity, the inflammation, insulin resistance and dyslipidaemia increase the risk of cardiovascular disease in adults, leptin was proposed as a strong predictor of overweight status among children [9] and interleukin-6 and CRP levels are associated with the development of type 2 diabetes mellitus [10]. The aim of this study was to evaluate the relation between inflammatory markers and the preatherosclerotic marker, flow mediated dilation (FMD). Experimental part Materials and methods A total of 30 overweight and obese children (obese group, 12 boys and 18 girls, 10-16 years old) and 20 healthy lean children (control group, 9 boys and 11 girls, 10-16 years old) were enrolled. Children under chronic medication, with acute or chronic inflammation were excluded. All subjects were non-smokers. The study protocol was approved by the Ethical Commission of Grigore Alexandrescu University Hospital, Bucharest and a written informed consent was obtained from each parent. Clinical characteristics Anthropometric measurements: weight, height, waist circumference (WC) were assessed. The BMI was calculated as the ratio between weight (kg) divided by square height (m 2 ). Overweight is defined as 85-95 th BMI percentile and obesity as ≥ 95 th BMI percentile. Biochemical measurements Fasting blood samples were taken. The usual plasma variables were measured by using an automatic analyser HITACHI and kits with standard methods from Diasys (Germany). Inflammatory markers TNF-α, IL-6 and leptin were determined by ELISA methods. Cayman ELISA kits, no. 589201 and no. 583361 were used for TNF-α and IL-6, respectively, following the manufacturer’s guidelines. EIA- 2395 kit for leptin and EIA 1293 kit for C peptide (a surrogate marker of insulin resistance) were purchased from DRG Instruments GmbH, Germany. Low-density lipoprotein- cholesterol (LDL-C) was calculated according to the Friedewald equation [11] and HOMA-IR (homeostatic model assasement-insulin resistance) was calculated according to Matthews DR formula: Glicemia(mg/dL) x insulin(IU/L)/405 [12]. Respiratory burst RB was measured by chemiluminiscent method. For this method, peripheral blood mononuclear cells isolated by density centrifugation were resuspended in phosphate-buffered saline and dark- adapted luminol was added. Spontaneous chemi- * email: hvirgolici@yahoo.com