Dose-Dependent Effects of n-3 Polyunsaturated Fatty Acids on Platelet Activation in Mildly Hypertriglyceridemic Subjects

The purpose of this study was to determine dose effects of n-3 polyunsaturated fatty acids (PUFAs) on mean platelet volume (MPV) and platelet count (PLT-CT) in mildly hypertriglyceridemic subjects. Subjects with a serum triglyceride level between 100 and 300 mg/dL were placed on a corn oil placebo for 4 weeks and then randomly assigned to groups taking seven capsules per day of placebo (n = 47) or one of the following doses of n-3 PUFAs for 20 weeks: 0.5 g (n = 50), 1 g (n = 23), or 2 g (n = 12). At the end of both the placebo period and the treatment period, MPV and PLT-CT were measured without stimulation ( baseline 1 following placebo period, baseline 2 following n-3 supplement period) and after ex vivo stimulation with collagen (10 mu g/mL), cold (4 degrees C), and heat (37 degrees C). Collagen and cold significantly increased MPV, whereas heat lowered MPV regardless of treatment. All stimuli decreased PLT-CT. Only the 2 g/day dose of n- 3 PUFAs increased MPV at baseline 2 (7.2 +/- 0.5 vs. 7.5 +/- 0.5 fL) and after the cold stimulus (7.5 +/- 0.5 vs. 7.8 +/- 0.5 fL). There was no dose-dependent effect of n-3 PUFAs on platelet activation; rather, 2 g of n-3 PUFAs increased MPV slightly in mildly hypertriglyceridemic subjects.This work was supported by Roche Vitamins, Inc. The work was done in the Lipid and Diabetes Research Center, Saint Luke's Hospital, Kansas City, MO