A controlled study on the effects of n-3 fatty acids on lipid and glucose metabolism in non-insulin-dependent diabetic patients. [The effect of fish oil on the secretion and effect of insulin in patients with type II diabetes]. Supplementation with n-3 fatty acids reduces triglycerides but increases PAI-1 in non-insulin-dependent diabetes mellitus. A comparison of the effects of n-3 fatty acids from linseed oil and fish oil in well-controlled type II diabetes. Effects of a small quantity of omega-3 fatty acids on cardiovascular risk factors in NIDDM. A randomized, prospective, double-blind, controlled study. Effect of fish oil concentrate on lipoprotein composition in NIDDM. Effect of fish oil versus corn oil supplementation on LDL and HDL subclasses in type 2 diabetic patients. Effects of purified eicosapentaenoic and docosahexaenoic acids on glycemic control, blood pressure, and serum lipids in type 2 diabetic patients with treated hypertension. A comparison of fish oil or corn oil supplements in hyperlipidemic subjects with NIDDM. The hypotriglyceridemic effect of fish oil in adult-onset diabetes without adverse glucose control. Effect of dietary fish oil supplementation on peroxidation of serum lipids in patients with non-insulin dependent diabetes mellitus. Effect of omega 3 fatty acid on plasma lipids, cholesterol and lipoprotein fatty acid content in NIDDM patients. Effects of fish oil supplementation on glucose and lipid metabolism in NIDDM. [Effects of diet therapy including eiconol on clinical and metabolic parameters in patients with type 2 diabetes mellitus]. Dietary supplementation with n-3 fatty acids may impair glucose homeostasis in patients with non-insulin-dependent diabetes mellitus. Effects of n-3 fatty acids in subjects with type 2 diabetes: reduction of insulin sensitivity and time-dependent alteration from carbohydrate to fat oxidation. Effects of low-dose omega-3 fatty acid substitution in type-2 diabetes mellitus with special reference to oxidative stress--a prospective preliminary study. Moderate intake of n-3 fatty acids for 2 months has no detrimental effect on glucose metabolism and could ameliorate the lipid profile in type 2 diabetic men. Results of a controlled study. Effects of low-dose EPA-E on glycemic control, lipid profile, lipoprotein(a), platelet aggregation, viscosity, and platelet and vessel wall interaction in NIDDM. Dietary supplementation with n-3 fatty acids increases gluconeogenesis from glycerol but not hepatic glucose production in patients with non-insulin-dependent diabetes mellitus. Effects of fish oil supplements in NIDDM subjects. Controlled study.
Eight male non-insulin-dependent diabetic patients participated in a double-blind randomized cross-over study (2 weeks for each period) evaluating the effects of 10 g/day fish oil dietary supplementation on glucose and lipid metabolism. Fasting serum triglyceride concentrations were decreased by fish oil because of a reduction in VLDL (1.4 +/- 0.2 vs. 1.9 +/- 0.2 mmol/l, P less than 0.025). LDL cholesterol concentration was instead increased (3.4 +/- 0.3 vs. 2.8 +/- 0.3 mmol/l, P less than 0.025) and net changes in VLDL triglyceride and in LDL cholesterol were inversely correlated (r = -0.86, P less than 0.01). Plasma free fatty acids concentrations and turnover rate [( 3H]palmitate method) were similar after fish oil and placebo. Fish oil supplement did not induce significant changes in fasting blood glucose (8.1 +/- 1.1 vs. 8.5 +/- 1.2 mmol/l) and average daily blood glucose (BG) (9.4 +/- 3.2 vs. 9.3 +/- 3.5 mmol/l). Glucose stimulated plasma insulin response during a hyperglycemic clamp was not significantly influenced by fish oil both in the early phase and during steady state. Insulin sensitivity (M/I index) was also unchanged. In conclusion, this study shows that a dietary supplement of fish oil decreases plasma triglyceride levels in non-insulin-dependent diabetic patients, an increased conversion rate of VLDL to LDL playing a role in this change. With this dosage of fish oil no relevant variations in glycemic control, insulin secretion and insulin sensitivity occurred. The metabolic effect of 3-week dietary supplementation with a fish oil concentrate was examined in not markedly obese, not hypertriglyceridemic men with non-insulin-dependent diabetes mellitus (NIDDM) treated with hypoglycemic agents. Ten patients were given 15 ml/d of fish oil (Martens Oil, Norway) equivalent to 3.1 g of n-3 fatty acid (FA) per day, and compared to 10 diabetics treated with placebo (15 ml/d saline). While fish oil leads to expected increase in the ratio of n-3 to n-6 FA intake, it does not alter fasting and mixed meal stimulated blood glucose, plasma insulin and C-peptide concentrations. There were no changes in insulin action estimated by the metabolic clearance rates of glucose at plasma insulin levels of about 100 microU/ml and 1400 microU/ml during hyperinsulinemic isoglycemic clamp, and no changes were seen in insulin binding to erythrocytes. Even though our short-term study does not warrant authoritative conclusions, no adverse effects of low-dose fish oil on glucose homeostasis have been found in not markedly obese NIDDM patients treated with oral hypoglycemics. The effects of dietary supplementation with n-3 fatty acids on lipid and glucose metabolism and on fibrinolysis were evaluated in 14 non-insulin-dependent diabetic patients who were given 10 g of MaxEPA (3 g n-3 fatty acids) or placebo (olive oil) per day in a randomized double-blind cross-over study during two consecutive 8-week periods. The serum triglyceride (TG) concentrations decreased by 27% (P < 0.01) after addition of MaxEPA with a reduction of VLDL TG by 36% (P < 0.05) while LDL cholesterol increased by 6% (P = 0.05). The fasting blood sugar and HbA1c concentrations increased significantly after addition of MaxEPA but the changes were not significantly different from those during the placebo period. The highest glucose concentrations at fasting and after an i.v. glucose injection were seen after MaxEPA while the serum insulin concentrations were unchanged. The peripheral insulin sensitivity, as measured by a euglycaemic, hyperinsulinaemic clamp technique, did not change during the study. The mean plasminogen inhibitor-1 (PAI-1) activity of the patients was elevated compared with healthy controls. In spite of the reduction of the triglyceride concentrations and unchanged insulin levels, there was a significant increase of the activity of PAI-1 (+21%, P < 0.01) after MaxEPA suggesting a possible impairment of the fibrinolytic capacity. In many situations there seems to be a reduction of PAI-1 when the triglycerides are lowered. In the diabetic patients given n-3 fatty acids this was not the case. Supplementation of type II diabetic diets with n-3 fatty acids (FAs) from fish oil (FO) has been associated with lowered triglyceride and VLDL levels, although reports of impaired glycemic control have limited their use. Effects of n-3FAs from nonmarine sources are less well documented. Therefore, an investigation comparing the effects of linseed oil (LO) with FO supplementation was undertaken in subjects with type II diabetes.
                Eleven subjects with type II diabetes were given supplements with LO and FO for 3 months each in a randomized double-blind crossover fashion after 3 months of olive oil placebo. Oils were given as 35 mg FA.kg body wt-1.day-1. After each 3-month period, fasting glucose and insulin levels, HbA1c, lipid profiles, insulin sensitivity (SI), glucose effectiveness (SG), and acute insulin response to glucose (AIRG) were evaluated.
                HbA1c and lipid values were within the normal range at randomization. Repeated measures analysis of variance testing found no significant differences in weight; fasting glucose and insulin levels; HbA1c; total, LDL, and HDL cholesterol levels; SI; SG; or AIRG with either active oil. FO was associated with significant reductions in triglycerides and a trend toward decreased SI.
                In a population with well-controlled type II diabetes, 3 months of FO but not LO resulted in lowered triglyceride levels. Neither LO nor FO significantly affected glycemic control, cholesterol values, SG, or insulin secretion, while a nonsignificant trend toward decreased insulin sensitivity was found with FO. To study the effects of a low dose of omega-3 fatty acids on platelet function and other cardiovascular risk factors in patients with non-insulin-dependent diabetes mellitus (NIDDM).
                We performed a randomized, prospective, double-blind, controlled study of a low dose of omega-3 fatty acids (2.5 g/day) in 20 ambulatory subjects with NIDDM. Subjects ingested five 1-g fish oil capsules each containing 0.5 g omega-3 fatty acids or five 1-g safflower oil capsules per day for 6 weeks followed by a 6-week washout period.
                Nine subjects completed the study in each group. Both groups exhibited moderate control of glucose levels; modest elevations in baseline total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride (TG) levels; and normal blood pressure values. In the fish oil group, plasma omega-3 fatty acid levels increased significantly. Fish oil significantly reduced the slope of the dose-response curves for collagen-induced platelet aggregation to one-third the value observed with safflower oil. No difference was observed in collagen-induced production of thromboxane A2 (TXA2, measured as the stable derivative TXB2), or in adenosine-5'-diphosphate- (ADP) induced platelet aggregation or TXA2 generation. Patients with high initial collagen-induced platelet TXA2 production showed a significantly larger drop after fish oil than safflower oil. Fish oil significantly reduced TG levels by 44 mg/dl and decreased upright systolic blood pressure (sBP) by 8 mmHg compared with safflower oil. Fish oil caused a significant but small increase in HbA1c (0.56%) and total cholesterol (20 mg/dl) but had no effect on fasting glucose, high-density lipoprotein cholesterol, or LDL-cholesterol levels.
                Small doses of fish oil inhibit platelet aggregation and TXA2 production, reduce upright sBP and TG levels, and have only a small effect on glucose and cholesterol levels in patients with moderately controlled NIDDM. Small quantities of omega-3 fatty acids or dietary fish are safe and potentially beneficial in NIDDM patients. 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) The increased risk of coronary heart disease associated with type 2 diabetes may be partially explained by dyslipidemia characterized by high plasma triacylglycerol (TAG), low HDL cholesterol, and a predominance of atherogenic small dense LDLs. Fish oil reduces plasma TAG and has previously been shown to improve the distribution of LDL subclasses in healthy subjects and might, therefore, be a good nonpharmacological treatment for type 2 diabetic patients. In the present study, we investigate the effect of fish oil supplementation on the fasting lipid profile, including LDL and HDL subclasses.
                A total of 42 type 2 diabetic patients were randomized to supplementation (capsules) with 4 g daily of either fish oil (n = 20) or corn oil (n = 22) for 8 weeks preceded by a 4-week run-in period of corn oil supplementation. Blood was drawn before and after the 8-week intervention period. Plasma lipoproteins, including LDL and HDL subclasses, were separated by ultracentrifugation.
                Fish oil lowered TAG (group difference: P = 0.025) and raised HDL-2b cholesterol (P = 0.012) and HDL-2a cholesterol (P = 0.007) concentrations as compared with corn oil. We observed no significant effects of fish oil on LDL cholesterol, HDL cholesterol, or the concentration of small dense LDL particles.
                Fish oil supplementation may partially correct the dyslipidemia of type 2 diabetic patients. However, the putative very important aspect of diabetic dyslipidemia-the predominance of small dense LDL particles-was unaffected by fish oil. n-3 Fatty acids lower blood pressure, improve lipids, and benefit other cardiovascular disease risk factors. Effects on glycemia in patients with type 2 diabetes are uncertain.
                We determined whether purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have differential effects on glycemic control, including insulin sensitivity and stimulated insulin secretion; 24-h ambulatory blood pressure; and serum lipids in type 2 diabetic patients with treated hypertension.
                In a double-blind, placebo-controlled trial of parallel design, 59 subjects were randomly assigned to consume 4 g EPA, DHA, or olive oil/d for 6 wk while continuing to consume their usual diet.
                Thirty-nine men and 12 postmenopausal women with a mean (+/- SE) age of 61.2 +/- 1.2 y completed the study. In comparison with the change from baseline in fasting glucose in the olive oil group, fasting glucose in the EPA and DHA groups increased 1.40 +/- 0.29 mmol/L (P = 0.002) and 0.98 +/- 0.29 mmol/L (P = 0.002), respectively. Neither EPA nor DHA had significant effects on glycated hemoglobin, fasting insulin or C-peptide, insulin sensitivity or secretion, or blood pressure. Serum triacylglycerols in the EPA and DHA groups decreased 19% (P = 0.022) and 15% (P = 0.022), respectively. There were no significant changes in serum total, LDL, or HDL cholesterol, although HDL(2) cholesterol in the EPA and DHA groups increased 16% (P = 0.026) and 12% (P = 0.05), respectively. HDL(3) cholesterol decreased 11% (P = 0.026) with EPA supplementation.
                EPA and DHA had similar benefits on lipids but adverse effects on short-term glycemic control in hypertensive diabetic patients. The overall implications for cardiovascular disease require long-term evaluation. To examine the effects on blood lipids and glycemic control of fish oil and corn oil supplementation at two levels in subjects with hyperlipidemia and non-insulin-dependent diabetes mellitus (NIDDM).
                Forty subjects (18 men and 22 women; aged 53.9 +/- 7.0 years) with NIDDM and hyperlipidemia were randomly assigned to one of four treatment groups: 9 g of fish oil, 18 g of fish oil, 9 g of corn oil, or 18 g of corn oil daily supplementation for 12 weeks.
                The level of oil supplements (9 g compared with 18 g) did not have a significant effect within each oil group on glycemic control and lipids. Significant differences (P < 0.05) in lipids were found when the 9-g and 18-g groups were combined. In subjects consuming fish oil, plasma very-low-density lipoprotein (VLDL) cholesterol (P = 0.0001), plasma triglyceride (TG) (P = 0.0001), and plasma VLDL TGs (P = 0.02 at 6 weeks and P = 0.0001 at 12 weeks) were significantly lowered compared with subjects consuming corn oil. Plasma VLDL cholesterol increased across time in the corn oil group (P = 0.04). Plasma low-density lipoprotein (LDL) cholesterol was temporarily increased (P = 0.008) in the fish oil group at 6 weeks, but the effect was no longer present at 12 weeks. No significant differences between fish oil- or corn oil-supplemented diets were found in total plasma cholesterol, high-density lipoprotein cholesterol, fasting plasma glucose, glycosylated HbA1c, weight, and blood pressure.
                In this study, fish oil supplementation improved plasma VLDL cholesterol, VLDL TGs, and total TGs while having a transient deterioration in LDL cholesterol in subjects with NIDDM. Furthermore, fish oil supplementation had no significant deleterious effect on glycemic control. Diabetic control as judged by five criteria did not deteriorate after 6 months of fish oil compared to 6 months of olive oil supplementation in 16 patients with NIDDM who were eating a low fat, high complex carbohydrate diet. Plasma total and VLDL triglyceride and cholesterol decreased significantly after fish oil supplementation; plasma total and HDL cholesterol concentrations did not change. The LDL cholesterol level was significantly increased with fish oil supplementation, suggesting that patients with NIDDM who are given a fish oil supplement to decrease the plasma total and VLDL triglyceride levels may also need further dietary and/or pharmaceutical therapy to maintain an LDL cholesterol level compatible with a low risk of coronary disease. The study emphasizes the safe use of fish oil over a 6-month period in diabetic patients. Lipid peroxidation may be important in the development of cardiovascular disease, a common cause of mortality and morbidity in non-insulin dependent diabetes mellitus (NIDDM). We assessed the degree of lipid peroxidation by measuring plasma malondialdehyde, as thiobarbituric acid reacting substances (TBARS), in 23 non-insulin diabetic patients. Plasma levels of standardised alpha-tocopherol (vitamin E), lipid content of whole plasma and lipoprotein fractions, glycosylated haemoglobin, glycosylated low density lipoprotein (LDL) and fasting blood glucose were also measured. On completion of the baseline studies patients randomly received either fish oil or matching olive oil capsules in a double blind crossover fashion for 6 weeks followed by a 6 week washout period and a final 6 week treatment phase. Studies, identical to the initial baseline studies, were performed at the end of the of the active treatment periods at 6 and 18 weeks. Treatment with olive oil did not change levels of TBARS, vitamin E or indices of glycaemic control compared with baseline. Total cholesterol and triglyceride (TG) content of plasma and lipoprotein fractions were not significantly altered. Treatment with fish oil resulted in elevation of TBARS (P < 0.001) and reduction of vitamin E (P < 0.01) compared with baseline and olive oil treatment. Plasma cholesterol was unchanged. A reduction in plasma TG compared with baseline occurred but failed to reach significance (P =0.07). Changes in apo B containing lipoproteins induced by fish oil failed to reach significance. No significant changes were observed in concentration or composition of high density lipoprotein (HDL). Fish oil treatment showed no change in glycaemic control as assessed by glycosylated haemoglobin and LDL although a rise in fasting blood glucose just failed to reach significance (P = 0.06). Lipid peroxidation in NIDDM can be exacerbated by dietary fish oil. This potentially adverse reaction may limit the therapeutic use of fish oils in such patients. This study was conducted to examine the effect of omega 3 fatty acid supplementation on plasma lipid, cholesterol and lipoprotein fatty acid content of non-insulin-dependent diabetic individuals consuming a higher (0.65, n = 10) or lower (0.44, n = 18) ratio of dietary polyunsaturated to saturated fatty acid (P/S). The participants were initially given an olive oil supplement (placebo) equivalent to 35 mg of 18:1. kg body weight-1.day-1 for 3 months. This was followed by two omega 3 supplement periods in a randomized crossover. In these 3-month periods, participants were given a linseed oil supplement equivalent to 35 mg of 18:3 omega 3.kg body weight-1.day-1 or a fish oil supplement equivalent to 35 mg of 20:5 omega 3 + 22:6 omega 3.kg body weight-1. day-1. At the end of each supplement period, a blood sample was drawn from each participant for lipid, lipoprotein, insulin, glucagon and C-peptide analyses. At the end of each 3-month period a 7-day dietary record was completed to calculate dietary fat intake and P/S ratio. Results indicate that fish oil significantly reduced plasma triacylglycerol level (p < 0.05) and increased 20:5 omega 3 and 22:6 omega 3 content of all lipoprotein lipid classes. Linolenic acid supplementation had no effect on plasma triacylglycerol level, but it increased 18:3 omega 3 content of lipoprotein cholesterol ester fractions (p < 0.05). A slight increase in 20:5 omega 3, but not 22:6 omega 3, content was noted in lipoprotein lipid classes as a result of 18:3 omega 3 supplementation. LDL and HDL cholesterol, insulin, glucagon and C-peptide levels were not affected by either omega 3 supplement. It is concluded that a modest intake of omega 3 fatty acids, such as could be obtained from consuming fish regularly, will reduce plasma triglyceride level without affecting LDL or HDL cholesterol levels. Fish oils, containing omega-3 fatty acids (omega 3FAs), favorably influence plasma lipoproteins in nondiabetic humans and prevent the development of insulin resistance induced by fat feeding in rats. We studied the effects of fish oils in 10 subjects (aged 42-65 yr) with mild non-insulin-dependent diabetes mellitus (NIDDM). Subjects were fed a standard diabetic diet plus 1) no supplementation (baseline), 2) 10 g fish oil concentrate (30% omega 3FAs) daily, and 3) 10 g safflower oil daily over separate 3-wk periods, the latter two supplements being given in radom order by use of a double-blind crossover design. At the end of each diet period, fasting blood glucose (FBG), insulin, and lipids were measured, and insulin sensitivity was assessed with a hyperinsulinemic-euglycemic clamp performed with [3-3H]glucose. FBG increased 14% during fish oil and 11% during safflower oil supplementation compared with baseline (P less than .05), whereas body weight, fasting serum insulin levels, and insulin sensitivity were unchanged. The absolute increase in FBG during each supplementation period correlated with the baseline FBG (fish oil, r = .83, P less than .005); safflower oil, r = .75, P = .012). Fasting plasma triglyceride levels decreased during fish oil supplementation in the 4 subjects with baseline hypertriglyceridemia (greater than 2 mM) but were not significantly reduced overall. There was no significant change in fasting plasma total, high-density lipoprotein, and low-density lipoprotein cholesterol levels. In summary, dietary fish oil supplementation adversely affected glycemic control in NIDDM subjects without producing significant beneficial effects on plasma lipids. The effect of safflower oil supplementation was not significantly different from fish oil, suggesting that the negative effects on glucose metabolism may be related to the extra energy or fat intake.(ABSTRACT TRUNCATED AT 250 WORDS) It was investigated the influence of a diet supplemented with PUFA omega-3 ("Eiconol") on dynamic of basal and postprandial glycemia, blood pressure, lipid levels, parameters of lipid peroxidation in 60 patients with non-insulin-dependent diabetes mellitus. Fish oil ("Eiconol") was used as a dietary supplement of PUFA omega-3. The results of investigations indicated that a diet supplemented with "Eiconol" (8 g/day) increased the effect of dietary therapy in correction of essential hypertension and atherogenic lipids. It was not the worsening of the glycemia and activation of lipid peroxidation. The effects on lipoprotein and glucose metabolism of addition of n-3 fatty acids were studied in 14 non-insulin-dependent diabetic patients who were given 10 g of MaxEPA (3 g n-3 fatty acids) or placebo (olive oil) per day in a randomized double-blind cross-over study during two consecutive 8-week periods. After MaxEPA treatment, there was a marked increase in long-chain polyunsaturated fatty acids of the n-3 series in the plasma lipid esters and in the platelet phospholipids, while the n-6 fatty acid content decreased. The very low density lipoprotein (VLDL) triglyceride concentrations decreased significantly (by 22%) on MaxEPA treatment. However, these changes were not significantly different from those observed during the placebo period. The blood glucose concentration tended to increase during MaxEPA treatment, and to decrease during the placebo period, the changes under the two regimes being significantly different (P less than 0.01). In addition, the rate constant for glucose disappearance (k value) for the intravenous insulin-tolerance test, which reflected the peripheral insulin sensitivity, tended to decrease during MaxEPA treatment and increase during administration of the placebo, there being a significant difference (P less than 0.03) between the changes during the two treatments. The reason for the observed changes in blood glucose concentration and peripheral insulin sensitivity is still unclear. Effects of fish oil supplements on metabolic variables are insufficiently clarified in type 2 diabetes.
                We aimed to investigate short-term (1 wk) and longer-term (9 wk) effects of n-3 fatty acids.
                Twenty-six subjects with type 2 diabetes without hypertriacylglycerolemia participated in a double-blind controlled study. Median intake in the intervention group was 17.6 mL fish oil/d (1.8 g 20:5n-3, 3.0 g 22:6n-3, and 5.9 g total n-3 fatty acids). The control group received 17.8 mL corn oil/d (8.5 g 18:2n-6).
                Plasma phospholipid 20:5n-3 and 22:6n-3 increased, whereas 18:2n-6 decreased, in the fish oil group compared with the corn oil group after 1 wk. The two n-3 fatty acids also increased in adipose tissue biopsy samples taken after 9 wk in the fish oil group. Glucose concentrations (home-monitored) were approximately 1 mmol/L higher in the fish oil group than in the corn oil group at the end of the intervention (P = 0.035). Glucose utilization measured by using an isoglycemic clamp was lowered in the fish oil group compared with that in the corn oil group at the end of the intervention (P = 0.049), whereas glucagon-stimulated C-peptide tended to increase (P = 0.078). The fish oil group utilized less fat for oxidation after 1 wk, with a change to more fat and less carbohydrate oxidation after 9 wk (P = 0.040), than did the corn oil group.
                A high intake of fish oil moderately increases blood glucose and decreases insulin sensitivity in persons with type 2 diabetes without hypertriacylglycerolemia and alters carbohydrate and fat utilization in a time-dependent manner. A state of increased oxidative stress has been recognised in type 2 diabetes mellitus (DM). The present study was done to assess the effects of low dose omega-3 fatty acids substitution in patients with type 2 DM with special reference to oxidative stress.
                Sixty-five patients with type 2 DM of body mass index (BMI) < 27 kg/m2 and thirty age and sex matched healthy controls were evaluated for blood glucose, blood pressure and lipid profile and oxidative stress was assessed in them by measuring lipid peroxides (LP), diene conjugates (DC) and reduced glutathione (RG) in the serum. Of the 65, 40 motivated patients were randomly divided into two groups--group 1 comprising of fifteen patients prescribed a diabetic diet along with a placebo and group 2 consisting of twenty-five patients on the same diet with the addition of 0.6 g omega-3 fatty acids as one capsule Maxigard (containing 180 mg eicosapentaenoic acid and 120 mg docosahexaenoic acid) twice daily. All parameters were reassessed after six weeks.
                The levels of lipid peroxides (micromol/L), diene conjugates (OD units) and reduced glutathione (mmol GSH/L) were significantly altered indicating increased oxidative stress in the diabetics compared to the healthy controls: 4.106 +/- 0.889, 2.751 +/- 0.424, 1.344 +/- 0.316 and 1.91 +/- 0.541, 1.735 +/- 0.315, 1.919 +/- 0.310, respectively (p < 0.001 for all the three). Patients in group 1 and 2 were comparable in all respects including oxidative stress at the start of therapy. After six weeks, on comparing the mean % changes in the three parameters of oxidative stress between the two groups, it was seen that the % change was significantly higher in group 2 (Maxigard group) compared to group 1 (Placebo; 5.22 +/- 1.056 (p = 0.05), 3.28 +/- 0.608 (p = 0.01), 5.27 +/- 0.585 (p < 0.001) and 0.82 +/- 0.123, 0.18 +/- 0.017, 0.56 +/- 0.035 (p < 0.001), respectively. The patients in group 2 also exhibited significantly greater improvement in glycemic status, blood pressure and lipid profiles.
                The present study documented the existence of a state of increased oxidative stress in type 2 diabetics. Significant beneficial effects of low dose omega-3 fatty acids substitution for PUFA-6 were observed not only on oxidative stress parameters but also on blood pressure and metabolic profile. To evaluate the effect of a moderate dose of fish oil on glycemic control and in vivo insulin action in type 2 diabetic men with elevated plasma triacylglycerols and to determine the effect of the same treatment on gene expression of GLUT4, lipoprotein lipase (LPL), and hormone-sensitive lipase (HSL) in the abdominal adipose tissue.
                A total of 12 type 2 diabetic men were randomly allocated to 2 months of 6 g daily of either fish oil or sunflower oil, separated by a 2-month washout interval, in a double-blind crossover design.
                For glucose metabolism, 2 months of fish oil supplementation compared with sunflower oil led to similar fasting plasma insulin, glucose, and HbA1c. Basal hepatic glucose production did not increase after fish oil. There was no difference in insulin suppression of hepatic glucose production nor in insulin stimulation of whole-body glucose disposal measured by the euglycemic-hyperinsulinemic clamp. Fish oil did not ameliorate the low mRNA level of GLUT4 in adipose tissue of these patients. For lipid profile, fish oil lowered plasma triacylglycerol more than sunflower oil (P < 0.05) and tended to increase the amount of mRNA of both LPL and HSL in adipose tissue.
                A moderate dose of fish oil did not lead to deleterious effects on glycemic control or whole-body insulin sensitivity in type 2 diabetic men, with preserved triacylglycerol-lowering capacities. To assess the effects of low-dose eicosapentaenoic acid-ethyl-ester on diabetes regulation, lipid metabolism, blood rheology, and platelet reactivity.
                In a double-blind, randomized, placebo-controlled study, 24 NIDDM subjects received 1800 mg of EPA-E, 900 mg of EPA-E, or a placebo (1656 mg olive oil) daily for 8 wk.
                The EPA:arachidonic acid plasma ratio increased over an 8-wk period, then declined after a 4-wk wash-out period in the fish-oil groups in a dose-dependent way. Platelet-activating factor-induced platelet aggregation decreased from 75 +/- 7% at wk 0 to 35 +/- 21% at wk 8 in the 900-mg group (P = 0.016) and from 72 +/- 11 to 40 +/- 30% in the 1800-mg group (P = 0.039), but did not change in the placebo group. No effects on ADP- or collagen-induced aggregation could be attributed to EPA-E. In the 1800-mg group low-density-lipoprotein cholesterol increased significantly, without concomitant rise in apolipoprotein B. Triglycerides, glycemic control, lipoprotein (a), blood and plasma viscosity, erythrocyte deformability, and platelet adhesion to and aggregate formation on extracellular endothelial cell matrix were not significantly influenced.
                Purified EPA-E in doses of 900 and 1800 mg reduces Platelet-activating factor-induced platelet aggregation without negatively affecting glycemic control. Low-density-lipoprotein cholesterol was elevated in the 1800-mg group. Fish-oil supplementation decreases serum triacylglycerols but may worsen hyperglycemia in patients with non-insulin-dependent diabetes mellitus. The reason for the possible deterioration of glycemia is unclear. We examined whether inhibition of triacylglycerol synthesis by n-3 fatty acids changes lipolysis, glycerol gluconeogenesis, or fatty acid oxidation. Nine obese patients with non-insulin-dependent diabetes mellitus participated in a randomized double-blind crossover study in which 6 wk of n-3 fatty acid supplementation (12 g fish oil) was compared with 6 wk of corn plus olive oil. Serum triacylglycerols decreased by 30% during n-3 fatty acid supplementation. Glycerol gluconeogenesis ([U-14C]glycerol) increased by 32%. However, overall glucose production ([3-3H]glucose), glycemic control, and fatty acid oxidation remained unchanged. Thus, 6 wk of n-3 fatty acid supplementation lowers triacylglycerols in patients with non-insulin-dependent diabetes mellitus without worsening glycemic control. However, n-3 fatty acid supplementation increases glycerol gluconeogenesis, which could contribute to deterioration of glycemic control during long-term treatment with high doses of fish-oil supplements. The aim of this study was to evaluate the effects of a fish oil preparation (MaxEPA) on hemostatic function and fasting lipid and glucose levels in non-insulin-dependent diabetic (NIDDM) subjects. Eighty NIDDM outpatients aged 55.9 yr (mean SD 11.5 yr) participated in a prospective double-blind placebo-controlled study of MaxEPA capsules (10 g/day) or olive oil (control) treatment over 6 wk. Patients received either MaxEPA or olive oil in addition to preexisting therapy. Metabolic and hemostatic variables were measured before treatment and after 3 and 6 wk. Platelet membrane eicosapentaenoic acid (EPA) content increased in the treatment group (P less than 0.001). MaxEPA supplementation was associated with a significant fall in total triglycerides (P less than 0.001) but did not affect total cholesterol (P = 0.7) compared with control treatment. Fasting plasma glucose increased after 3 wk (P = 0.01) but not after 6 wk (P = 0.17) treatment with MaxEPA. Spontaneous platelet aggregation in whole blood fell in the MaxEPA group (P less than 0.02) after 6 wk, but there were no changes in agonist-induced platelet aggregation, thromboxane generation in platelet-rich plasma, or plasma beta-thromboglobulin and platelet factor IV levels. An increase in clotting factor VII (P = 0.02), without changes in fibrinogen or factor X levels, occurred in the MaxEPA group. Similar reductions in blood pressure were observed in both groups. Dietary supplementation with MaxEPA capsules (10 g/day) in NIDDM subjects is associated with improvement in hypertriglyceridemia but with deleterious effects in factor VII and blood glucose levels. Most indices of platelet function are unaffected by this therapy.
Omega-3 PUFA supplementation in type 2 diabetes lowers triglycerides and VLDL cholesterol, but may raise LDL cholesterol (although results were non-significant in subgroups) and has no statistically significant effect on glycemic control or fasting insulin. Trials with vascular events or mortality defined endpoints are needed.