Genetic polymorphisms (FTO rs9939609 and TMEM18 rs6548238), adipokines (leptin and adiponectin) and adiposity in children and adolescents with asthma.

OBJECTIVE

To describe independent factors related to the interaction of FTO rs9939609, TMEM18 rs6548238, leptin, and adiponectin in children/adolescents with asthma, under the influence of obesity.

METHODS

The authors performed a cross-sectional study with 57 children/adolescents, ages 8-19 years, at a tertiary hospital, from 2017 to 2018. Participants were classified by nutritional status, performed spirometry with a bronchodilator test and completed an asthma questionnaire, higher scores indicated more asthma symptoms. Two asthma groups were formed: Group 1(G1)-normal-weight; Group 2(G2)-overweight/obese. Serum was collected for adipokines (n = 32) and genetic polymorphisms (n = 53) dosages.

RESULTS

Age and body mass index (BMI) correlated directly in normal-weight (p = 0.009) and obese participants (p = 0.004). Girls reported more asthma complaints (p = 0.044). Participants with negative bronchodilator responses presented lower BMI (14.55-17.16) than responders (19.4-26.84) (p = 0.049). Leptin dosages are related directly to BMI (5,34-40 ng/ml in obese × 0,54-42 ng/ml in nonobese) (p = 0.003). Levels were high in girls (4.78-17.55 µg/ml) (p = 0.029) and low in nonobese boys (0.54-6.92 µg/ml) (p = 0.006). In obese, low leptin levels (< 10 ng/ml) were found in small airway dysfunction carriers (p = 0.025); elevated adiponectin (> 5 µg/ml) correlated with FEV1/FVC > 80 % (p = 0.035) and positive bronchodilator tests (8.84-13 µg/ml) (p = 0.039); and FTO A allele correlated with low adiponectin 0-8.84 µg/ml (p = 0.021) and low FEV1/FVC (46 %-88 %) (p = 0.023).

CONCLUSION

BMI correlated directly with age and leptin levels. Obese participants presented high serum levels of leptin and FTO A allele correlated with low FEV1/FVC. Larger cohorts are necessary for better elucidation of the role of adipokines and polymorphisms in the pathophysiology of asthma and obesity.