Antihypertensive effect of oral potassium aspartate supplementation in mild to moderate arterial hypertension.

BACKGROUND: Previous studies showed that potassium chloride (48-120 mmol/day) supplementation reduced arterial blood pressure (BP) in hypertensive patients. OBJECTIVES: Our aim was to evaluate the effect of a lower dose of potassium aspartate salt on BP in individuals with essential arterial hypertension. METHODS: One hundred and four patients (65 males, age 53 +/- 12 years) with mild to moderate essential hypertension (systolic/diastolic BP 154.2/96.2 +/- 10.8/5.4 mmHg) were allocated in two comparable groups of 52 to receive or not 30 mmol/day per os of potassium aspartate supplementation for four weeks. Office and 24-h BP, as well as serum and urinary electrolytes, were measured at baseline and at the follow-up visit after four weeks. RESULTS: Office and 24-h BP did not change in the control group, while these values were significantly reduced in the potassium supplementation group. Changes in office (systolic BP: 154.4 +/- 8.2 vs. 142.2 +/- 7.6 mmHg; diastolic BP: 95.0 +/- 5.6 vs. 87.2 +/- 4.3 mmHg, P < 0.001 for both) and 24-h BP (systolic BP: 142.7 +/- 8.2 vs. 134.8 +/- 6.3 mmHg; diastolic BP: 90.8 +/- 4.4 vs. 84.6 +/- 3.8 mmHg, P < 0.001 for both) following potassium supplementation were highly significant. The changes in day time and night time BP were similar. The treated group showed significantly increased potassium serum level and 24-h urinary excretion of potassium (P < 0.01 in both cases) after four weeks, while the untreated group showed no significant changes of the same parameters. Urinary Na/K ratio decreased significantly with potassium supplementation (P < 0.001). In the treated group changes in office (r = 0.58, P < 0.001) and 24-h SBP (r = 0.51, P < 0.001), but not in DBP (r = 0.29 and r = 0.25, n.s.), correlated positively with the urinary Na/K ratio at baseline. CONCLUSIONS: A relatively low supplementation of 30 mmol/day of potassium as aspartate lowered office and 24-h ambulatory BP in subjects with mild to moderate essential hypertension. The antihypertensive effect was sustained throughout the day, and was greater in the patients with high basal urinary Na/K ratio.

Noninvasive detection of vascular dysfunction in alcoholic patients.

Vasodilation is impaired in various conditions, such as hypercholesterolemia and tobacco use. We evaluated brachial artery flow-mediated vasodilation (FMD) after blood pressure (BP) cuff occlusion using high-resolution B-mode ultrasound in 20 alcoholics, without any coexisting conditions such as smoking, hypertension, or cholesterolemia, after a 3-month period of abstinence. They were compared with a control group of 20 alcohol-free healthy subjects. We measured the diameter of the brachial artery under baseline conditions, during reactive hyperemia (with increased flow causing endothelium-dependent dilatation), and after administration of sublingual glyceryl trinitrate (GTN), an endothelium-independent dilator. We performed an echocardiographic study (Esaote Au3) according to guidelines of the American Society of Echocardiography to assess left ventricular mass (LVM), wall thickness, systolic stress, and diastolic function changes. FMD (% diameter change) was significantly less in the alcoholic patients than in the controls (6.03+/-3.67 v 13.7+/-4.65; P < .05), whereas no difference was noted after GTN administration (13.7+/-7.97 v 16.0+/-5.12, P = NS). Echocardiographic study showed no differences between the study group for LVM, wall thickness, and systolic stress; diastolic function expressed as E/A ratio inversion was significantly impaired. These data demonstrate an impairment of endothelial-dependent vasodilatation in chronic alcohol abusers, which may contribute to the excess prevalence of cardiovascular diseases in these individuals.

Effect of alcohol consumption versus abstinence on 24-h blood pressure profile in normotensive alcoholic patients.

The aim of this study was to evaluate 24-h ambulatory blood pressure monitoring in 15 male alcoholic normotensive subjects during alcohol consumption and following an abstinence phase and the effects of alcohol consumption compared with a period of 1 week of abstinence. The average 24-h BP was not different, but the diurnal pattern showed a fall in systolic BP early (06:00 to noon; P < .005) and late (18:00 to 22:00; P < .002) in the day during abstinence. BP variability was increased during the alcohol phase (P < .05). This study showed that 1 week of abstinence does not influence 24-h BP levels in normotensive subjects, but alters the diurnal pattern, characterized by a fall in systolic BP and increased BP variability.