Blood pressure responses to cold pressor stress and its relation to sodium metabolism in salt-sensitive children

OBJECTIVE: To investigate the blood pressure responses to cold pressor stress and its relation to sodium metabolism in salt-sensitive children. METHOD: 268 children aged 10.6 +/- 1.1 years were detected salt-sensitivity with the tests of oral saline load and furosemde sodium-volume depletion. Cold pressor stress test, sodium metabolism, and the related factors were measured. RESULTS: 25% of the children were detected to be salt-sensitive. The increased extent of blood pressure and its recovery time from peak to baseline in salt-sensitive children were significantly higher than those in non-salt-sensitive children during the cold pressor stress test (t = 5.14, 3.94, P < 0.01 and t = 2.16, P < 0.05). The increased extent of blood pressure and its recovery time during cold pressor test were correlated positively with red-cell sodium content, and were correlated negatively with 2 hour urinary sodium excreation during the oral saline load test. CONCLUSION: Children with salt-sensitivity have a remarkably increased blood pressure responses to cold pressor stress (sympathetic activity), which is related with abnormal sodium metabolism.