OBJECTIVETo evaluate the value of serum brain natriuretic peptide (BNP) in the diagnosis of hyperthyroid heart disease in children.

METHODSFifty-eight children with hyperthyroidism were assigned to two groups according to their cardiac functions: hyperthyroid heart disease (n=28) and hyperthyroidism alone (n=30). Thirty healthy children served as the control group. Serum BNP level, left ventricular ejection fraction (LVEE) and E/A ratio were measured before and after treatment. The diagnostic value of BNP was evaluated in children with hyperthyroid heart disease.

RESULTSThe serum BNP level in the hyperthyroid heart disease and the hyperthyroidism alone groups before treatment was significantly higher than that in the control group (P<0.05), while the LVEF and the E/A ratio were significantly lower than those in the control group (P<0.05). Serum BNP level was positively correlated with the TT3 (r=0.801, P<0.05) and TT4 levels (r=0.578, P<0.05) and negatively with the LVEF (r=-0.48, P<0.05) and the E/A ratio (r=-0.35, P<0.05) in the hyperthyroid heart disease group. The serum BNP, TT3 and TT4 levels in the hyperthyroid heart disease and the hyperthyroidism alone groups were reduced and the LVEF and the E/A ratio increased significantly three months after treatment (P<0.05). When serum BNP level of >323.62 pg/mL was proposed as a cutoff point, the sensitivity, specificity, positive predictive value and negative predictive value were 92.86%, 90.00%, 89.66% and 93.10% respectively for the diagnosis of hyperthyroid heart disease.

CONCLUSIONSBNP may serve as a reliable marker for the diagnosis of hyperthyroid heart disease in children. Serum BNP level along with the LVEF and the E/A ratio may be useful in the evaluation of the severity and the cardiac function in children with this disease.