N-terminal pro brain natriuretic peptide increases after 1-h scuba dives at 10 m depth

The N-terminal pro brain natriuretic peptide (N-BNP) is a promising cardiac natriuretic peptide used as a clinical hormonal marker in cardiac dysfunction. The main stimulus for N-BNP synthesis and secretion is cardiac wall stress, which is recognized as a common denominator of many cardiac diseases. Diving is associated with environmental factors leading to variations in thoracic blood volume and hemodynamic changes. The purpose of the present study was to examine the changes in the concentration of N-BNP in healthy men during and after scuba diving.

There were 10 healthy military divers (mean age 33 yr) who performed a dive in the sea for 1 h at 10 m depth. Venous blood samples were taken at timed intervals to allow evaluation of plasma levels of N-BNP at different steps, namely at To (before immersion), at T30 min (during the dive, after a short surfacing), at T60 min (right after surfacing), at T300 min (post-dive), and finally at T24 h. Peptide blood concentrations were determined by electrochemoluminiscence immunoassay. Data were analyzed using parametric statistics.

When compared with To, the results show a significant increase of N-BNP levels (in % of baseline levels) at T60(128 +/- 5%, p < 0.043) and at T300 (149 +/- 8%, p < 0.001).

This preliminary study reveals that N-BNP rises with scuba diving. Our findings suggest that diving involves a mechanical strain on the heart with a persistent endocrine myocardial activity post-dive.