N-terminal pro-B-type natriuretic peptide as an indicator of possible cardiovascular disease in severely obese individuals: comparison with patients in different stages of heart failure.

Background: Mild stages of heart failure might be difficult to diagnose in severely obese individuals with a body mass index (BMI) >40 kg/m(2). Measurement of the N-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP) is feasible for detecting cardiac impairment. The aims of our study were to measure NT-proBNP in plasma of severely obese patients and to compare the results with results for patients in different stages of manifest cardiac dysfunction.

Methods: In 61 severely obese individuals (median BMI, 43.2 kg/m(2)) and 96 nonobese patients with existing heart failure [classified into New York Heart Association (NYHA) classes I-IV], NT-proBNP was measured in the fasting condition. A medical history, physical examination, electrocardiography, blood chemistry, and chest x-ray were performed in the obese group. In addition, echocardiography was performed in the NYHA group.

Results: In obese individuals, NT-proBNP was increased to a median of 356 (interquartile range, 221-458) pmol/L [854 (530-1099) ng/L] and was comparable (P >0.05) to the median value for NYHA I patients {289 (258-451) pmol/L [694 (619-1082) ng/L]}, but was significantly lower than in the other NYHA groups (P <0.001 for each).

Conclusion: The prognostic relevance of increased NT-proBNP for risk of developing cardiac insufficiency in severely obese patients needs to be further evaluated.