Early cardiac abnormalities and serum N-terminal pro B-type natriuretic peptide levels in obese children.

OBJECTIVE

The aim of this study was to evaluate early cardiac abnormalities in obese children by the conventional echocardiography and to verify whether N-terminal pro B-type natriuretic peptide (NT-proBNP) differ between obese and healthy children.

METHODS

We started this study with 68 obese children and 35 healthy controls matched for age and sex. Body mass index (BMI) was calculated. Children with a BMI > or = 95th percentile were considered obese. Thirty children in the obese group were also diagnosed with metabolic syndrome, according to the International Diabetes Federation criteria. Standard echocardiographic study was performed on each patient and control subject. Diastolic filling parameters were evaluated using pulsed-wave tissue Doppler method. Blood samples were taken at 8 a.m. to study blood biochemistry tests, including insulin, lipids, glucose, and NT-proBNP. Serum NT-proBNP levels were measured by a solid-phase, enzyme-labeled chemiluminescent immunometric assay. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Children with HOMA-IR > 3.16 were considered insulin-resistant.

RESULTS

There were diastolic filling abnormalities in obese children, as shown by a decreased mitral valve early filling (E) wave/late filling (A) ratio and a prolongation in E-wave deceleration time. The levels of NT-proBNP were not statistically different among the groups. The levels of NT-proBNP were not different between obese children with and without metabolic syndrome, those with and without hypertension, and those with and without insulin resistance, respectively.

CONCLUSION

Although there were diastolic filling abnormalities in obese children, their NT-proBNP levels were not different from healthy controls. It seems that there is no diagnostic value in NT-proBNP levels between obese children and healthy controls.