COMPARISON OF EFFECTS OF N-3 TO N-6 FATTY-ACIDS ON SERUM LEVEL OF LIPOPROTEIN(A) IN PATIENTS WITH CORONARY-ARTERY DISEASE

The influence of dietary supplementation with n-3 versus n-6 fatty aci ds on plasma lipoprotein(a) (Lp[a]) levels was studied. Thirty-five ma le hospitalized patients with coronary artery disease were treated for 4 weeks with 12 g/day of fish oil (approximate to 8.5 g of n-3 fatty acids) in combination with a 5,000 kilojoule, 30% fat diet and moderat e exercise. Eighteen control patients given the same dietary and train ing program were treated with 12 g/day of rapeseed oil. Plasma Lp(a), in addition to several lipids and lipoproteins, blood clotting factors , and platelet reactivity, were measured before and at the end of ther apy. Results can be summarized as follows: total cholesterol, low-dens ity lipoprotein cholesterol, and apolipoprotein B levels decreased sig nificantly in both the rapeseed oil (-14.4%, -20.3%, -15.2%, respectiv ely) and fish oil (-12.2%, -16.0%, and -14.2%, respectively) groups. T riglycerides decreased (-20.3%) and high-density lipoprotein cholester ol increased (+8.3%) significantly only in patients treated with fish oil. Plasma Lp(a) levels were reduced by 14% in the fish oil group, bu t unaffected in the rapeseed oil group. Patients treated with fish oil could be categorized into 2 subgroups: ''responders,'' with a reducti on in Lp(a) by 24% and ''nonresponders,'' with a small nonsignificant increase in serum Lp(a). Responders and nonresponders exhibited a mark ed reduction in cholesterol, low-density lipoprotein cholesterol, apol ipoprotein B, and triglycerides, and an increase in high-density lipop rotein, cholesterol. There was a large reduction in tissue plasminogen activator in the fish oil group, which correlated significantly with reduction in Lp(a). Platelet number and aggregation behavior were not significantly changed in either group. No physiologic differences were seen between responders and nonresponders.