Effects of ω-3 Fish Oils on Plasma Lipids, Lipoprotein Composition, and Postheparin Lipoprotein Lipase in Women With IDDM

Because the apparent reduction in cardiovascular risk noted in nondiabetic populations that ingest diets rich in marine lipids containing ω-3 fatty acids is believed to result in part from their capacity to modify the composition and physicochemical behavior of lipoproteins, we sought to determine whether dietary supplementation with marine lipids might favorably affect lipoprotein composition in insulin-dependent diabetes mellitus (IDDM). Eight normolipidemic IDDM women (mean ± SD age 29.8 ± 4.7 yr) were studied before and 3 mo after receiving a marine-lipid concentrate (Super-EPA) containing 6 g ω-3 fatty acids and a total of 12 mg of cholesterol daily. Weight, insulin requirements, and glycosylated hemoglobin remained stable. After treatment, mean ± SD plasma triglyceride (TG) levels fell (before, 81.7 ± 22 mg/dl; after, 69.19 ± 17; P < 0.025). High-density lipoprotein₂ (HDL₂) cholesterol (before, 10.98 ± 5.45 mg/dl; after, 18.43 ± 7.93; P < 0.01), its major apolipoprotein A-I (apoAl), and the major phospholipids (sphingomyelin and lecithin) all rose significantly. ApoB and plasma and low-density lipoprotein cholesterol levels and HDL₃ composition were unchanged. Postheparin hepatic and lipoprotein lipase activities were unaffected by marine lipids. These data indicate that women with IDDM experience apparently beneficial effects on TG and HDL₂ from dietary supplementation with ω-3 fatty acids administered in a low-cholesterol–containing oil without adversely affecting overall diabetes management. If these changes in lipoprotein concentration and composition prove to have antiatherogenic consequences and are free of long-term toxicity, these agents may have a role in the therapy of IDDM patients.