Offspring of patients with type 2 diabetes (OPDs) exhibits endothelial dysfunction (ED) associated with a chronic inflammatory state. N-3 polyunsaturated fatty acids (n-3 PUFA) may have antioxidant and anti-inflammatory properties that are beneficial for cardiovascular and metabolic health. Therefore, in the present study, we tested the hypothesis that dietary supplementation with fish oil rich in n-3 PUFA may improve ED in otherwise healthy OPDs.
Methods and design
A double-blind, placebo-controlled trial was conducted with 50 OPDs. Participants were randomized to treatment with either placebo or n-3 PUFA (2 g/day) for 12 weeks. Before and after treatment we evaluated endothelial function (using flow-mediated dilation (FMD) of the brachial artery), circulating inflammatory markers (adiponectin, TNF-α, and high sensitivity-CRP), and insulin resistance (QUICKI).
No significant changes were observed in study outcomes in subjects treated with placebo. By contrast, when compared with baseline values, subjects treated with n-3 PUFA had significant improvement in FMD (9.1 ± 5.8% vs. 11.7 ± 4.4%, p = 0.02) that was accompanied by decreased plasma triglycerides (117 ± 73 mg/dl vs. 86 ± 44 mg/dl, p = 0.001) and TNF-α levels (8.9 ± 2.3 pg/ml vs. 6.8 ± 2.7 pg/ml, p = 0.001), and a trend towards increased plasma adiponectin levels (7.8 ± 4.5 μg/ml vs. 9.5 ± 5.1 μg/ml, p = 0.09). When data were analyzed by multiple regression analysis, decreased TNF-α after treatment with n-3 PUFA predicted increased FMD.
Dietary supplementation with n-3 PUFA significantly improved endothelial function and reduced pro-inflammatory markers in OPDs. Thus, fish oil consumption may have beneficial cardiovascular and metabolic health effects in otherwise healthy subjects predisposed to diabetes and its vascular complications.