OBJECTIVETo observe the changes of plasma renin activity, antidiuretic hormone and brain natriuretic peptide in chronic heart failure (CHF) and their correlation with hyponatremia.

METHODSPlasma levels of PRA, ADH, and BNP were measured by radioimmunology in 76 CHF patients. Forty-one out of 76 CHF patients with hyponatremia and 35 CHF patients without hyponatremia were identified by serum sodium. The rates of rehospitalization within 3 months were compared in two groups.

RESULTSLevels of plasma renin activity, ALD, and BNP in CHF patients with hyponatremia were notably higher than those in patients without hyponatremia classified by New York Heart Association (NYHA) grade II - IV: PRA [(2.7 +/- 1.0) ng.ml(-1).h(-1) vs. (1.8 +/- 0.7) ng.ml(-1).h(-1), (4.3 +/- 1.2) ng.ml(-1).h(-1) vs. (3.0 +/- 0.9) ng.ml(-1).h(-1), (5.6 +/- 1.3) ng.ml(-1).h(-1) vs. (3.5 +/- 1.1) ng.ml(-1).h(-1), respectively, P < 0.05], ADH [(59.7 +/- 17.4) ng/L vs. (48.6 +/- 15.3) ng/L, (68.4 +/- 17.6) ng/L vs. (56.3 +/- 19.2) ng/L, (75.3 +/- 20.0) ng/L vs. (51.4 +/- 16.2) ng/L, respectively, P < 0.05] and BNP [(276.4 +/- 75.2) ng/L vs. (185.3 +/- 55.3) ng/L, (380.1 +/- 113.6) ng/L vs. (258.5 +/- 62.1) ng/L, (564.0 +/- 125.2) ng/L vs. (405.3 +/- 102.9) ng/L, respectively, P < 0.05]. In the simple regression analyses, hyponatremia was negative correlated with PRA, ADH and BNP (r = -0.31, P < 0.05; r = -0.28, P < 0.05, r = -0.80, P < 0.01). The rate of rehospitalization within 3 months in hyponatremia group was higher than that in control group.

CONCLUSIONSThere is relation of hyponatremia to the changes of plasma renin activity, antidiuretic hormone and brain natriuretic peptide in chronic heart failure. Hyponatremia may accelerate the excretion of plasma PRA, ADH and BNP in chronic heart failure. Neuroendocrine activation in patients of congestive heart failure with hyponatremia is higher than that of normal natremia group.