RESUMEN
Current guidelines lack sufficient evidence to recommend a specific blood pressure lowering strategy to prevent cardiovascular disease after preeclampsia. We conducted a double-blind cross-over trial to identify the most potent antihypertensive strategy: renin-angiotensin-aldosterone system (RAAS) inhibition (losartan), sympathoinhibition (moxonidine), low sodium diet and placebo (n = 10). Due to low inclusion rate our study stopped prematurely. Initiatory analyses showed no significant effect of antihypertensive strategy on office blood pressure and 24-hour blood pressure. However, nocturnal dipping was significantly higher on RAAS inhibition and low sodium diet compared to placebo and sympathoinhibition. Optimal cardiovascular prevention after preeclampsia should be further explored.
Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/administración & dosificación , Enfermedades Cardiovasculares/prevención & control , Imidazoles/administración & dosificación , Losartán/administración & dosificación , Preeclampsia , Adulto , Presión Sanguínea , Estudios Cruzados , Enfoques Dietéticos para Detener la Hipertensión/métodos , Método Doble Ciego , Femenino , Edad Gestacional , Humanos , Periodo Posparto , Preeclampsia/dietoterapia , Preeclampsia/tratamiento farmacológico , Embarazo , Sistema Renina-Angiotensina/efectos de los fármacosRESUMEN
BACKGROUND: In hypertension, sodium sensitivity (SS) of blood pressure is associated with renal hemodynamic abnormalities related to increased activity of the renal renin-angiotensin aldosterone system (RAAS). The renal mechanisms of SS in normotensives are unknown. Therefore, we studied whether SS is related to renal hemodynamics and renal responsiveness to angiotensin II (AngII) in young healthy adults. METHODS: Blood pressure (mean arterial pressure (MAP)) and renal function were measured in 34 healthy men after 1-week low-sodium diet (LS; 50 mmol Na(+)/24 h), 1-week high-sodium diet (HS; 200 mmol Na(+)/24h), and 1-week HS-ACEi (enalapril 20 mg/day). The responses of effective renal plasma flow (ERPF; (131)I-Hippuran clearance) to graded infusion of AngII were assessed during each condition. RESULTS: The sodium-induced change in MAP ranged from -7 to +14 mm Hg. SS (a sodium-induced increase in MAP >3 mm Hg) was present in 13 subjects. ERPF was lower in SS subjects during LS and during HS-ACEi. The AngII-induced decrease in ERPF was blunted in SS on LS (-25 +/- 6 vs. -29 +/- 7% in sodium-resistant (SR) subjects, P < 0.05) and on HS (-30 +/- 5 vs. -35 +/- 6%, P < 0.05). The blunting was corrected by angiotensin-converting enzyme inhibitors (ACEi) (-36 +/- 6 vs. -37 +/- 7%). CONCLUSION: SS normotensive subjects have a blunted renal response to exogenous AngII. This is ameliorated by ACEi, supporting a role for inappropriately high intrarenal RAAS activity. As these findings cannot be attributed to subclinical renal hypertensive damage, high intrarenal RAAS activity and altered renal hemodynamics may be primary phenomena underlying SS.