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Serum to urinary sodium concentration ratio is an estimate of plasma renin activity in congestive heart failure
Author(s) -
Marenzi GianCarlo,
Lauri Gianfranco,
Assanelli Emilio,
Grazi Marco,
Campodonico Jeness,
Famoso Gabriella,
Agostoni Piergiuseppe
Publication year - 2002
Publication title -
european journal of heart failure
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.149
H-Index - 133
eISSN - 1879-0844
pISSN - 1388-9842
DOI - 10.1016/s1388-9842(02)00097-1
Subject(s) - plasma renin activity , medicine , heart failure , cardiology , renin–angiotensin system , endocrinology , blood pressure
We investigated the relationship between plasma renin activity (PRA) and serum ([sNa + ]) and urinary ([uNa + ]) sodium concentrations in 124 congestive heart failure (CHF) patients (II–IV NYHA class) and 20 healthy subjects. According to PRA (> or <3 ng ml −1 h −1 ) and [sNa + ] (> or <135 mEq l −1 ), patients were classified as Group A (normal PRA and normal [sNa + ], n =39), Group B (increased PRA and normal [sNa + ], n =62) and Group C (low [sNa + ], n =23). Measurements were performed at rest and, in 26 cases, after extracorporeal ultrafiltration (UF). At rest, [sNa + ] and [uNa + ], and their difference ([sNa + ]−[uNa + ]), were linearly correlated with PRA, but the values did not allow differentiation of control subjects from patients or differentiation of patients with from those without renin–angiotensin system (RAS) activation. Conversely, the [sNa + ]/[uNa + ] ratio showed the best correlation with PRA ( r =0.79, P <0.0001). UF‐induced PRA changes were linearly correlated with [sNa + ]/[uNa + ] ratio changes ( r =0.67, P =0.002), but not with those of [sNa + ], [uNa + ] and [sNa + ]−[uNa + ]. In CHF, the [sNa + ]/[uNa + ] ratio best correlates with PRA and reflects the basal activity as well as the rapid changes (as those induced by UF) of the RAS. Therefore, it can be considered a strong and easily available marker of PRA.