The effect of camelina oil on vascular function in essential hypertensive patients with metabolic syndrome: a randomized, placebo-controlled, double-blind study.

BACKGROUND: The effects of a dietary supplementation with the vegetable ω-3 α-linolenic acid (ALA) on cardiovascular homeostasis are unclear. In this context, it would be interesting to assess the effects of camelina oil. OBJECTIVE: This study aimed to assess the cardiovascular and metabolic effects of camelina oil in hypertensive patients with metabolic syndrome. METHODS: In a double-blind, placebo-controlled randomized study, treated essential hypertensive patients with metabolic syndrome received, during 6 mo, either cyclodextrin-complexed camelina oil containing ≈ 1.5 g ALA/d (n = 40) or an isocaloric placebo (n = 41), consisting of the same quantity of cyclodextrins and wheat starch. Anthropometric data, plasma lipids, glycemia, insulinemia, creatininemia, TBARs, high-sensitivity C-reactive protein, and n-3, n-6, and n-9 fatty acids in erythrocyte membranes were measured. Peripheral and central blood pressures, arterial stiffness, carotid intima-media thickness, and brachial artery endothelium-dependent flow-mediated dilatation (FMD) and endothelium-independent dilatation were assessed. RESULTS: Compared with placebo, camelina oil increased ALA (mean ± SD: 0 ± 0.04 compared with 0.08 ± 0.06%, P <0.001), its elongation product EPA (0 ± 0.5 compared with 0.16 ± 0.65%, P <0.05), and the n-9 gondoic acid (GA; 0 ± 0.04 compared with 0.08 ± 0.04%, P <0.001). No between-group difference was observed for cardiovascular parameters. However, changes in FMD were associated with the magnitude of changes in EPA (r = 0.26, P = 0.03). Compared with placebo, camelina oil increased fasting glycemia (-0.2 ± 0.6 compared with 0.3 ± 0.5 mmol/L, P <0.001) and HOMA-IR index (-0.8 ± 2.5 compared with 0.5 ± 0.9, P <0.01), without affecting plasma lipids, or inflammatory and oxidative stress markers. Changes in HOMA-IR index were correlated with the magnitude of changes in GA (r = 0.32, P <0.01). Nutritional intake remained similar between groups. CONCLUSION: ALA supplementation with camelina oil did not improve vascular function but adversely affected glucose metabolism in hypertensive patients with metabolic syndrome. Whether this adverse effect on insulin sensitivity is related to GA enrichment, remains to be elucidated.

Inflammation, arteriosclerosis, and cardiovascular therapy in hemodialysis patients.

BACKGROUND: Aortic stiffness and left ventricular hypertrophy (LVH) are predictors of mortality in hemodialysis (HD) patients. Attenuation of arterial stiffness and regression of LVH had a favorable effect on survival in these patients, but this favorable effect was observed in less than 50% of patients, the rest being resistant to therapeutical interventions. The aim of this study was to analyze the factors associated with this resistance to treatment. METHODS: 138 patients on HD were studied during a follow-up survey. From entry until the end of follow up, the changes of aortic pulse wave velocity (PWV) and of LV mass were measured in response to treatment with antihypertensive drugs and erythropoietin, together with measurements of blood chemistry, including high-sensitive C-reactive protein (CRP). Patients with decreased aortic PWV were considered to be responders (N = 68), the others to be nonresponders (N = 70). RESULTS: Nonresponders were older (P < 0.05) and had persistently higher systolic blood pressure (BP) and pulse pressure. Responders were treated more frequently with an ACE inhibitor (P < 0.001), and had lower serum CRP (P < 0.01). The baseline PWV, as well as the changes of PWV and LV mass during the follow-up were significantly and independently correlated with serum CRP level (P < 0.001). According to logistic regression after adjustment for age, gender, diabetes, history of CVD, and the nonspecific cardiovascular risk factors, the improvement of aortic stiffness and LV hypertrophy was positively associated with prescription of ACE inhibitor (P < 0.0001), and negatively with the serum CRP level (P < 0.01). CONCLUSION: These results indicate that in HD patients, the presence of low-grade inflammation decreases the efficiency of cardiovascular therapeutic interventions and participates in the persistence of cardiovascular hemodynamic overload.