Changes in ghrelin and asymmetrical dimethylarginine in obese Mexican adolescents after six-month lifestyle intervention

The aim of this study was to evaluate the effect of a six-month lifestyle intervention on ghrelin and asymmetrical dimethylarginine (ADMA) in obese Mexican adolescents. A total of 65 obese Mexican adolescents aged 10-16 years completed a six-month lifestyle intervention. Anthropometric and biochemical parameters were assessed at baseline and at six months. Twenty normal-weight adolescents were also evaluated at baseline. Insulin resistance (IR) was determined by the homeostasis model assessment of IR (HOMA-IR). Ghrelin and ADMA were determined by enzyme-linked immunosorbent assay. Obese adolescents presented significantly higher triglycerides, cholesterol, glucose, insulin, HOMA-IR, and ADMA levels, while ghrelin was significantly lower. The lifestyle intervention led to a significant improvement in HOMA-IR, ghrelin, and ADMA in the whole studied obese subjects. ADMA and ghrelin levels were associated with BMI and IR components. According to the value of HOMA-IR, the obese subjects were divided into subjects with or without IR, no difference in ghrelin and ADMA was observed in these two subgroups. After intervention, the obese with IR showed increased ghrelin and decreased ADMA, while the obese without IR only showed improvement in ghrelin. The multiple linear regression analysis revealed that the changes of systolic blood pressure were the only predictor for the changes of ghrelin in the obese with IR. Our study demonstrated the increase of ADMA and the decrease of ghrelin in obese adolescents. Lifestyle intervention improved insulin resistance, decreased ADMA, and increased ghrelin in obese subjects with IR although no significant weight loss was observed.

Plasminogen activator inhibitor-1, fibrinogen, and lung function in adolescents with asthma and obesity

BACKGROUND

Obesity promotes a low-grade systemic inflammatory state that may act on the lung to exacerbate asthma. There is little information on the relationship between systemic inflammation and lung function in children and adolescents.

OBJECTIVES

To explore the relationship among fibrinogen, plasminogen activator inhibitor-1 (PAI-1), lung function in adolescents with the presence of asthma, and/or obesity.

METHODS

Totally 178 adolescents (boys and girls) were involved; four groups were divided according to their diagnosis: non-obese and non-asthmatic controls (n = 38), non-obese asthmatics (n = 31), obese non-asthmatics (n = 62), obese asthmatics (n = 47). The levels of PAI-1 and fibrinogen were determined in blood samples. The lung function was evaluated with spirometry by measuring forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and forced expiratory flows between 25 and75% (FEF(25-75%)).

RESULTS

Compared to healthy controls, obese adolescents with or without asthma show higher levels of fibrinogen (289.2 ± 61.5, 328.4 ± 54.9, and 324.9 ± 68.9 mg/dL, respectively), PAI-1 (36.0 ± 17.3, 53.2 ± 22.3, and 52.6 ± 24.7 ng/mL, respectively), and the reduced FEV1/FVC ratio (87.7 ± 7.7, 81.6 ± 8.6, and 81.7 ± 6.9, respectively). In the whole studied subjects, FEV1/FVC ratio shows significant inverse correlation with PAI-1 (r = -0.185), fibrinogen (r = -0.157), body mass index (BMI; r = -0.303), insulin(r = -0.198), and HOMA (r = -0.173). In the 78 asthmatic subjects, FVC correlates positively with BMI.

CONCLUSION

Our data demonstrate that the degree of systemic inflammation and the degree of obesity in the whole studied adolescents groups correlate negatively with lung function, suggesting an obstructive pulmonary pattern. Further studies are needed to identify the pathophysiological mechanism for such association.

Weight loss induced by 6-month lifestyle intervention improves early endothelial activation and fibrinolysis in obese adolescents

BACKGROUND

Adolescent obesity is associated with an increased risk of adult obesity and subsequent cardiovascular diseases. The present study aimed to assess the effect of weight loss after 6-month lifestyle intervention in obese adolescents on biomarkers of endothelial activation and fibrinolytic system.

METHODS

Eighty-five obese adolescents aged 10 to 16 years were assigned to a 6-month lifestyle intervention and 61 completed the programme. We examined the effect of the intervention on adhesion molecules (selectin E, soluble intercellular adhesion molecule 1 and soluble vascular adhesion molecule 1) and fibrinolytic parameters [plasminogen activator inhibitor-1 (PAI-1) and fibrinogen]. Thirty-six lean adolescents were studied only at baseline as a comparison group.

RESULTS

Compared with lean participants, obese adolescents at baseline demonstrated significantly higher levels of triglycerides, glucose, insulin, homeostasis model assessment, soluble intercellular adhesion molecule 1, PAI-1 and fibrinogen. After 6-month lifestyle intervention, those obese adolescents with decreased standard deviation score-body mass index (SDS-BMI) displayed significant decreases in insulin (19.2 ± 11.2 vs. 26.8 ± 13.2 mU/L, P≤ 0.01), homeostasis model assessment (4.24 ± 3.19 vs. 6.58 ± 4.08, P≤ 0.01), selectin E (100.2 ± 60.9 vs. 116.0 ± 69.0 ng/mL, P≤ 0.01) and PAI-1 (39.6 ± 38.0 vs. 51.8 ± 25.6 ng/mL, P≤ 0.05) with respect to the baseline levels. No changes in these parameters were observed in the obese adolescents with stable or increased SDS-BMI. The changes of triglycerides after intervention in subgroup with decreased SDS-BMI were significantly greater than those in subgroup with stable SDS-BMI.

CONCLUSIONS

The present study demonstrated increased endothelial activation and impairment of the fibrinolytic system in early life, which is in part reversible by a 6-month lifestyle intervention.

Endothelial activation and systemic inflammation in obese asthmatic children

Asthma and obesity are prevalent disorders, each with a significant impact on the public health. The causality relating obesity and asthma has not been established. The objective of this article is to investigate whether asthma could exacerbate the endothelial activation and to determine the relationship between systemic inflammation and endothelial activation in obese asthmatic children. Eighty-nine children (10-16 years old) were divided according to their diagnosis (asthma, obese nonasthmatic, and obese asthmatic children). Twenty healthy children formed the control group. Three adhesion molecules (E-selectin, sICAM-1, and sVCAM-1) and C-reactive protein (CRP) were measured in serum samples. The levels of sICAM-1 were significantly higher in obese nonasthmatic and obese asthmatic children versus control and lean asthmatic children (414.7+/-154.7, 434.9+/-181.1, 238.6+/-117.8, and 351.2+/-153.5 ng/mL, respectively). No difference was observed between obese nonasthmatic and obese asthmatic groups. No difference of the levels of CRP, E-selectin, and sVCAM-1 was found among the study groups. Correlation analysis showed that E-selectin associated significantly with body mass index (BMI), CRP and the other two adhesion molecules. CRP depended on BMI. sICAM-1 associated with CRP, BMI, and triglycerides. Correlations were verified in multiple regression analysis models in the whole study groups: CRP levels depended on sICAM-1, E-selectin, and sICAM-1 concentrations depended on BMI. Correlations were verified in asthmatic subjects: CRP depended on sICAM-1. These results confirmed the endothelial activation in obese children. Mild nonallergic asthma in our study did not exacerbate the endothelial activation in obese or lean asthmatic children. Significant association between systemic inflammation and endothelial activation was observed in asthmatic children.