A double-blind randomized trial of fish oil to lower triglycerides and improve cardiometabolic risk in adolescents

To determine the efficacy of 4 g/day fish oil to lower triglycerides and impact lipoprotein particles, inflammation, insulin resistance, coagulation, and thrombosis.

Participants (n = 42, age 14 ± 2 years) with hypertriglyceridemia and low-density lipoprotein (LDL) cholesterol <160 mg/dL were enrolled in a randomized, double-blind, crossover trial comparing 4 g of fish oil daily with placebo. Treatment interval was 8 weeks with a 4-week washout. Lipid profile, lipoprotein particle distribution and size, glucose, insulin, high-sensitivity C-reactive protein, interleukin-6, fibrinogen, plasminogen activator inhibitor-1, and thrombin generation were measured.

Baseline lipid profile was total cholesterol 194 (5.4) mg/dL (mean [SE]), triglycerides 272 (21) mg/dL, high-density lipoprotein cholesterol 39 (1) mg/dL, and LDL cholesterol 112 (3.7) mg/dl. LDL particle number was 1614 (60) nmol/L, LDL size was 19.9 (1.4) nm, and large very low-density lipoprotein/chylomicron particle number was 9.6 (1.4) nmol/L. Triglycerides decreased on fish oil treatment but the difference was not significant compared with placebo (-52 ± 16 mg/dL vs -16 ± 16 mg/dL). Large very low-density lipoprotein particle number was reduced (-5.83 ± 1.29 nmol/L vs -0.96 ± 1.31 nmol/L; P < .0001). There was no change in LDL particle number or size. There was a trend towards a lower prothrombotic state (lower fibrinogen and plasminogen activator inhibitor-1; .10 > P > .05); no other group differences were seen.

In children, fish oil (4 g/day) lowers triglycerides slightly and may have an antithrombotic effect but has no effect on LDL particles.