Effects of low-dose omega-3 fatty acid substitution in type-2 diabetes mellitus with special reference to oxidative stress--a prospective preliminary study

Abstract

Background: 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.

Method: 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.

Results: 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.

Conclusions: 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.