PURPOSE: to determine the existence of association between blood pressure rise and plasma ANP and BNP levels in pregnancies complicated by preeclampsia, considering the existence of a hypertensive state before pregnancy and supportive drug influence on these hormones. METHODS: in a case-control transversal study, 86 pregnant women were assessed regarding arterial pressure level and plasma ANP and BNP levels. Clinical and laboratory tests were carried out to diagnose preeclampsia and the use of hypotensive drugs and magnesium sulfate was considered. Hormone determinations were obtained through radioimmunoassay, after extraction in C18 Sep-pak columns. Correlation was investigated by means and regression analysis in the whole group of pregnant women and in specific groups, considering prior hypertension. RESULTS: plasma ANP values were 41.5±7.3, 78.4±13.1 and 89.2±13.4pg/mL (p<0.00001) and plasma BNP values were 79.5±15.8, 176.7±42.2 and 208.3±63.5 pg/mL (p=0.005), respectively, for mean blood pressure =107 mmHg, 107-139 mmHg and =140 mmHg. It was verified that the positive correlation between plasma ANP concentrations and pressure levels in preeclampsia did not depend on the existence of a hypertensive state before pregnancy (p<0.0001: preeclampsia and p<0.01: preeclampsia superimposed on chronic hypertension), whereas BNP dosages were not associated with the arterial pressure in the group with arterial hypertension prior to pregnancy (p=0.004: preeclampsia and p=0.18: preeclampsia superimposed on chronic hypertension). CONCLUSION: aggravation of hypertension in preeclampsia correlates with serum ANP and BNP concentrations, although BNP values may be influenced by the existence of a prior hypertensive state.
Pregnancy; Blood pressure; Preeclampsia; Atrial natriuretic peptide/type B natriuretic peptide
