Fish oil amplifies the effect of propranolol in mild essential hypertension.

Abstract

Forty-seven male patients with mild essential hypertension were randomly allocated to three subgroups. After a run-in period of 4 weeks, the first subgroup (n=16) received propranolol (80 mg/day) for 36 weeks followed by a placebo period of 4 weeks. The second subgroup (n=15), after a run-in period of 4 weeks, was given a supplement of encapsulated fish oil (9 g/day) for 36 weeks with a subsequent period of 4 weeks in which fish oil placebo was given. The third subgroup (n=16), after a run-in period of 4 weeks, was given propranolol (80 mg/day) for 12 weeks, propranolol (80 mg/day) plus fish oil capsules (9 g/day equivalent to 1.8 g/day of eicosapentaenoic acid and 1.1 g/day of docosahexaenoic acid) for 12 weeks, propranolol plus fish oil placebo (same doses for 12 weeks) with a subsequent period of 4 weeks when propranolol placebo was administered. The results indicate a blood pressure-lowering effect of fish oil, which was comparable with that of propranolol. The simultaneous intake of fish oil plus propranolol was more effective than propranolol or fish oil alone. Propranolol treatment resulted in a decrease of plasma norepinephrine, plasma renin activity, and thromboxane B 2 formation. After fish oil supplementation, plasma norepinephrine and thromboxane B 2 formation were likewise reduced, whereas plasma renin activity appeared increased. The decrease of serum triglycerides, total and low density lipoprotein cholesterol as well as the rise of high density lipoprotein cholesterol are concomitant beneficial effects, which justify the consideration of fish oil alone or in combination with antihypertensive drugs for the treatment of mild hypertension. {Hypertension 1990;16:682-691)

The Effect of Docosahexaenoic Acid on Plasma Catecholamine Concentrations and Glucose Tolerance during Long-Lasting Psychological Stress: A Double-Blind Placebo-Controlled Study.

“…They found that, after fish oil supplementation, plasma NE levels were reduced to 80% of the baseline value in Group F and 56% of that in Group P+F. The reduction levels of plasma NE were similar to our study (18). However, their findings were excep tional because no other controlled studies have found any significant decreases in plasma NE during fish oil treatment with normal subjects (19,20) or mild hy pertensives (19,(21)(22)(23).…”

“…However, their findings were excep tional because no other controlled studies have found any significant decreases in plasma NE during fish oil treatment with normal subjects (19,20) or mild hy pertensives (19,(21)(22)(23). Although experimental protocols differed from study to study and no direct comparison of these studies seemed possible, the plasma NE levels before fish oil administration were rather high in the study of Singer et al (18) that found the NE-reducing activity of fish oil. Our subjects had also rather high baseline plasma NE levels.…”

“…There are several fish oil intervention trials measuring plasma NE. Singer et al (18) randomly allocated 47 hypertensives to the following three groups and treated them for more than 36 wk: Group P was treated with propranolol alone; Group F with fish oil alone; and Group P+F, which was first treated with propranolol, then with propranolol plus fish oil, and finally with propranolol plus fish oil placebo. They found that, after fish oil supplementation, plasma NE levels were reduced to 80% of the baseline value in Group F and 56% of that in Group P+F.…”

Can We Recommend Fish Oil for Hypertension?

“…This increase, together with a relative reduction in high density lipoprotein (HDL) cholesterol, has favoured the use of newer, 'lipid-neutral' antihypertensive drugs. With these metabolic effects in mind and considering evidence from Singer et al (1990) that fish oil can enhance the antihypertensive effect of the P-blocker propanolol, we set up another study in collaboration with general practitioners to test the effects of a fish oil supplement on both lipids and BP in hypertensives taking a P-blocker and/or diuretic (Lungershausen et al 1994).…”

Non Pharmacologic Therapy and Lifestyle Factors in Hypertension

“…Fish oil ampli ed the hypotensive action of the b-adrenergic receptor blocker propranolol, in mild-to-moderate hypertensives [48]. A study by Bao et al [9] demonstrated that blood pressure reduction was further enhanced in obese treated hypertensives, when sh oils were combined with a weight loss program.…”