Abstract 16401: Early Vascular Alterations and Obesity-Related Comorbidities in Childhood Obesity: Role of Adipocytokines
Adipokines contribute to development and progression of obesity-related disorders. Leptin, nampt and retinol binding protein 4 (RBP4) play an essential role in the regulation of insulin secretion. The impact of these adipokines on metabolic and cardiovascular alterations in childhood obesity is unknown. Therefore, aim of this study was to evaluate, whether already obese children are characterized by changes in adipokine levels and whether these correlate with parameters of obesity and vascular damage.
Methods: In 86 obese (12.2±0.3 years, BMI 28.3±0.5) and 70 lean children (12.9±0.4 years, BMI 18.4±0.3) glucose and insulin metabolism were evaluated by oral glucose tolerance testing (OGTT). Flow-mediated dilatation assessed by reactive hyperemia index (RHI) and carotid artery intima media thickness (cIMT) were obtained. Serum adipokines were assessed by ELISA.
Results: Childhood obesity is associated with peripheral insulin resistance (HOMA-IR: 2.6±0.2 in obese vs 1.3±0.1 in lean, p<0.01) and impaired insulin sensitivity (Matsuda ISI 5.1±0.3 in obese vs 7.3±0.6 in lean, p=0.001). Serum levels of adipokines are sign. elevated compared to leans. Leptin was nearly 5-fold increased in obese (29.39±2.06 ng/mL vs 6.32±0.81 ng/mL in lean, p>0.05), also nampt (3.78±0.25 vs 2.94±0.29 ng/mL, p<0.05) and RBP4 (32.24±1.22 vs 26.42±1.06 mg/L, p<0.05) were elevated in obese compared to leans. There are correlations between nampt and BMI SDS (r=0.35, p<0.0001) and parameters of glucose metabolism (blood glucose after 120 min in OGTT: r=0.23, p=0.006) and insulin metabolism (Matsuda ISI: r=-0.23, p=0.007). RHI was sign. impaired in obese compared to leans (1.30±0.03 vs 1.95±0.08, p<0.01). There is an inverse correlation between RHI and BMI SDS (r=-0.52, p<0.001). Obesity was accompanied by a gain in cIMT (0.41±0.01 mm vs 0.33±0.01 mm in lean, p<0.01). Also cIMT correlates with BMI SDS (r=0.49, p<0.0001) and HDL cholesterol (r=-0.47, p<0.05).
Conclusion: Already in children with obesity, serum levels of adipokines are elevated and correlate with classical obesity related comorbidities. These pronounced metabolic alterations might contribute to generalized vascular damages as endothelial dysfunction and pathologic cIMT as early stages of atherosclerosis.
- © 2011 by American Heart Association, Inc.