To study the associations between sodium intake and target organ damage in patients with refractory hypertension (RH).Methods:
We consecutively recruited 147 RH patients (47.6% male, age 54.14 ± 16.15 years) who took at least three antihypertensive drugs including diuretics. 24-hour urinary sodium excretion (24hUNa) was measured to estimate the daily sodium intake. The left ventricular inner diameter and wall thickness were measured at end-diastole with Two-dimensionally guided M-mode echocardiography (GE vivid E9). Left ventricular mass index (LVMI) was calculated using the American Society of Echocardiography Convention. 24-hour urinary proteinuria(24hUPr) and the urinary albumin-creatinine ratio (ACR) were detected to evaluate the proteinuria, including microalbuminuria(MAlb). Logistic regression analysis was performed to determine independent risk factors related to target organ damage. The variables included in the model were: age, body mass index(BMI), current smoking, alcohol consumption, diabetes mellitus, office blood pressure (BP) and 24hUNa.Results:
Logistic regression analysis showed that 24hUNa was an independent correlative factor of increased LVMI (OR 1.008, 95% CI 1.000–1.016, P = 0.039), 24hUPr (OR 1.017, 95% CI 1.004–1.029, P = 0.008) and increased ACR (OR 1.008, 95%CI 1.001–1.015, P = 0.035). The attainment of office BP target favorably affected LVMI (OR 0.136, 95% CI 0.034–0.546, P = 0.005). The analysis also revealed that diabetes mellitus was associated with abnormally increased ACR (OR 5.85, 95% CI 1.634–19.789, P = 0.006) and MAlb (OR 5.363, 95% CI 1.355–21.231, P = 0.017).Conclusion:
In patients with RH, high sodium intake unfavorably affected left ventricular hypertrophy and proteinuria. Diabetes mellitus was closely related to the renal impairment.