Pilot study on omega-3 fatty acids in type I diabetes mellitus.

Patients with diabetes mellitus are prone to develop vascular complications. Because omega-3 polyunsaturated fatty acid (omega 3FA) intake has a potential protective effect on cardiovascular disease, we studied the influence of omega 3FA supplementation (5.4 g eicosapentaenoic acid and 2.3 g docosahexaenoic acid daily) for 4 wk in 13 well-controlled type I (insulin-dependent) diabetic subjects on a vascular risk profile. Each subject served as his/her own control in a pre- and post-omega 3FA-intake phase. In plasma and platelets, phospholipids eicosapentaenoic acid and docosahexaenoic acid increased at the expense of arachidonic acid and linoleic acid. There was no significant change in blood pressure and glycosylated proteins. Only small changes were noted in blood glucose levels and insulin dose. Side effects were not noted. Triglycerides decreased significantly in the first 14 days, and total cholesterol increased slightly, probably because of an elevation of high-density lipoprotein cholesterol, although low-density lipoprotein cholesterol remained unchanged. Platelet aggregation induced by low doses of ADP and collagen, which was higher in diabetic than nondiabetic subjects, decreased during omega 3FA intake to levels of healthy control subjects. Thromboxane production after ADP- and collagen-induced platelet aggregation decreased significantly. Thromboxane liberation during clotting of whole blood and urinary excretion of thromboxane were markedly lowered during omega 3FA supplementation. The results show that even short-term intake of omega 3FAs leads to beneficial changes of vascular risk factors without significant changes in glucose homeostasis.