No effect of n-3 fatty acids supplementation on NT-proBNP after myocardial infarction: the Alpha Omega Trial.

BACKGROUND: heart failure is a major risk factor for cardiovascular mortality, for which n-3 fatty acids may have beneficial effects. We examined the effect of marine eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and plant-derived alpha-linolenic acid (ALA) on N-Terminal-pro Brain Natriuretic Peptide (NT-proBNP), a biomarker of heart failure. METHODS: we randomly assigned 4837 post-myocardial infarction patients, aged 60-80 years (82% men), to margarines supplemented with a targeted additional intake of 400 mg/day EPA and DHA, 2 g/day ALA, EPA-DHA plus ALA, or placebo for 40 months. In a random selection of 639 patients, NT-proBNP was determined both at baseline and at the end of follow-up. NT-proBNP was loge-transformed and analysed by type of treatment using analysis of covariance adjusting for baseline NT-proNBP. RESULTS: patients consumed on average 19.8 g margarine/day, providing an additional amount of 238 mg/day EPA with 158 mg/day DHA, 1.98 g/day ALA, or both, in the active-treatment groups. In the placebo group, the geometric mean level NT-proBNP increased from 245 ng/l (95%-confidence interval [CI]: 207-290) to 294 ng/l (95%-CI: 244-352) after 40 months (p = 0.001). NT-proBNP levels were not affected by ALA (+8% versus placebo; 95%-CI: -8% to +25%; p = 0.34), EPA-DHA (+2% versus placebo; 95%-CI: -14% to +18%; p = 0.78), nor EPA-DHA plus ALA (+9% versus placebo; 95%-CI: -8% to +25%; p = 0.31) treatment. CONCLUSIONS: supplementation with modest amounts of EPA-DHA, with or without ALA, did not have a significant effect on NT-proBNP levels in patients with a history of myocardial infarction.

Hypouricemia, abnormal renal tubular urate transport, and plasma natriuretic factor(s) in patients with Alzheimer's disease.

OBJECTIVE: To study tubular urate transport in Alzheimer's disease (AD) and measure sodium and lithium transport rates in rats exposed to AD plasma. DESIGN: Cross-sectional study in three comparison groups. SETTING: Referral private institution involving outpatient and hospitalized patients. PATIENTS: AD, multi-infarct dementia (MID) and non-demented controls (C) were selected and evaluated by a geriatrician and a psychiatrist according to availability and willingness to participate in the study. Demented patients had brain imaging, categorized according to NINCDS-DSM III criteria, and had Mini-mental status examination (MMSE) scores determined. INTERVENTIONS: Injection of 0.5 mL of plasma I.P. followed 120 minutes later by an IV plasma injection of 0.2 mL priming dose and infusion of 1.8 mL of plasma at 0.01 mL/min in Sprague Dawley rats. MEASUREMENTS: Renal clearance studies were performed in subjects and in rats exposed to the plasma of study subjects. We measured serum urate concentration and fractional excretion (FE) of urate in subjects and FE sodium and FE lithium in rats. RESULTS: Serum urate was lower and FE urate higher in 18 AD patients compared with six patients with MID, P < 0.05 and P < 0.005, and 11 C, P < 0.02 and P < 0.005, respectively. Higher FE sodium and FE lithium were noted in rats given plasma from 19 AD patients compared with 12 with MID, P < 0.005 and P < 0.0025, and 14 C, P < 0.0025 and P < 0.0005, respectively. FE sodium and FE lithium decreased progressively after serial dilutions of three AD plasmas and FE lithium was negatively correlated with MMSE scores only in AD, r = -0.71 and P < 0.0005. CONCLUSIONS: In AD there is defective tubular urate transport and a plasma natriuretic factor(s). FE sodium and/or FE lithium in rats exposed to plasma of demented patients may differentiate AD from MID and estimate the severity of AD.

Endogenous natriuretic factors: atrial natriuretic hormone and digitalis-like substance in Cushing's syndrome.

In order to investigate the effect of chronic hypercortisolaemia on endogenous natriuretic factors (atrial natriuretic hormone (ANH) and the Na+/K+ pump inhibitor) digitalis-like substance (DLS), and their relation to hypertension, 28 patients with pituitary- or adrenal-dependent Cushing's syndrome and six patients on high-dose prednisone treatment were studied. Plasma ANH levels were increased in patients with Cushing's syndrome (36.0 +/- 1.4 (S.E.M.) ng/l) compared with those in healthy controls (28.6 +/- 1.3 ng/l, P less than 0.01). In prednisone-treated patients, ANH levels (43.8 +/- 4.5 ng/l) were higher than those in patients with Cushing's syndrome and in controls (P less than 0.05 and P less than 0.01 respectively). DLS measured by radioimmunoassay and binding of [3H]ouabain to erythrocytes was not altered in patients with hypercortisolaemia. Slightly decreased DLS activity in the erythrocyte 86Rb uptake inhibition assay was found in patients with Cushing's syndrome (52.9 +/- 2.7%) compared with that in controls (60.9 +/- 1.8%, P less than 0.02). With the exception of cortisol (r = 0.52, P less than 0.01), none of the other factors determined correlated with the mean arterial pressure in patients with Cushing's syndrome. Thus, a chronic excess of endogenous and exogenous glucocorticoids increases plasma levels of ANH, but does not substantially influence DLS activity or plasma levels. Neither natriuretic factor is directly related to hypertension in Cushing's syndrome.