Adipokines, asymmetrical dimethylarginine, and pulmonary function in adolescents with asthma and obesity

OBJECTIVE

This study was to investigate whether the metabolic abnormalities of adipokines and asymmetrical dimethylarginine (ADMA) associate with pulmonary function deficits in adolescents with obesity and asthma.

METHODS

This study enrolled 28 obese adolescents with asthma, 46 obese adolescents without asthma, 58 normal-weight adolescents with asthma, and 63 healthy control subjects. Serum levels of leptin, high-molecule-weight (HMW) adiponectin, retinol binding protein 4 (RBP4), asymmetrical dimethylarginine (ADMA), and pulmonary function were qualified.

RESULTS

The obese subjects had higher levels of leptin and ADMA but lower levels of HMW adiponectin than the normal-weight subjects with or without asthma. The subjects with asthma had higher levels of RBP4 than those without asthma. The obese adolescents with asthma had lowest forced expiratory lung volume in the first second (FEV₁)/forced vital capacity (FVC) ratio among the four study groups. In all the study subjects and in the subjects with asthma alone, the FEV₁/FVC ratio associated negatively with leptin, however, such association was rendered non-significant when adjusted for BMI. The pulmonary function deficits associated inversely with BMI percentile in the subjects with asthma. However, the decreased FEV₁/FVC ratio was not correlated with HMW adiponectin, RBP4 or ADMA.

CONCLUSIONS

Our present study confirmed obstructive pattern of pulmonary function characterized by the reduced FEV₁/FVC ratio in the obese adolescents with asthma. These pulmonary deficits were associated inversely with the increased BMI percentile.

Effect of six-month lifestyle intervention on adiponectin, resistin and soluble tumor necrosis factor-α receptors in obese adolescents

The aim of this study was to evaluate the effect of a six-month lifestyle intervention on adiponectin, resistin, and two soluble forms of tumor necrosis factor-α receptor (sTNFR) in obese adolescents. A total of 54 obese adolescents aged 10 to 16 years completed the program. Twenty-four adolescents with normal weight at baseline were used as a control group. Our results demonstrated that obese adolescents had abnormal lipid profile, homeostasis model assessment (HOMA) index, adiponectin level (5.6 ± 2.7 vs. 7.6 ± 2.9 μg/mL, p = 0.005) as well as resistin level (31.0 ± 9.0 vs. 24.3 ± 8.5 ng/mL, p = 0.003), whereas levels of both sTNFRs were similar to those in normal weight subjects. After the six-month lifestyle intervention, obese adolescents had a slight but significant drop in standard deviation score-body mass index (SDS-BMI), a significant decrease in waist circumference, total cholesterol, triglycerides, HOMA index, as well as resistin, and a significant increase in adiponectin and high-density lipoprotein-cholesterol. In adolescents without decreased SDS-BMI, no change was observed in adipokines. Changes in adiponectin correlated negatively with changes in waist circumference (r = -0.275, p = 0.044). Changes in resistin correlated positively with changes in triglycerides (r = 0.302, p = 0.027). The study demonstrated the increase of resistin and the decrease of adiponectin in obese adolescents. Lifestyle intervention improved adipokine abnormalities in obese subjects.