Non-insulin-dependent diabetes mellitus (
NIDDM) is associated with elevated
very-low-density lipoprotein (
VLDL) triglyceride concentrations and abnormalities of
low-density lipoprotein (
LDL) composition. Because
fish oil supplementation may favorably affect
lipid and
lipoprotein concentrations in nondiabetic subjects, we determined the effect of
fish oil concentrate on plasma
lipids and
lipoprotein composition in patients with
NIDDM. Dietary-supplementation 1-mo periods of 4.0 and 7.5 g of
omega-3 fatty acids in
fish oil were compared with a placebo of 12 g
safflower oil by use of a single-blind crossover design. Medications, including
antidiabetic therapy, were continued through the study. Compared with
safflower oil treatment,
fish oil supplementation resulted in a significant reduction of total plasma
triglycerides of 24% at the 4-g dose and a larger reduction of 39% at the 7.5-g dose. These decreases were due to similar reductions in VLDL
triglycerides.
LDL cholesterol levels were mildly elevated, but a larger 20% increase in
LDL apolipoprotein B (
apoB) concentration was observed. During supplementation with the
fish oil concentrate, the
LDL cholesterol-to-
apoB ratio was significantly reduced when compared with pretreatment values, but not when compared with
safflower oil treatment.
High-density lipoprotein (
HDL) cholesterol and plasma apoA1 levels were not significantly changed during
fish oil treatment. At the 7.5-g dose, fasting
glucose and
glycohemoglobin levels increased by 20 and 12%, respectively, but were unchanged at the lower level of supplementation. Thus, in
NIDDM patients, dietary supplementation with
omega-3 fatty acids induces a reduction in total plasma and
VLDL triglyceride levels.(ABSTRACT TRUNCATED AT 250 WORDS)