Baseline omega-3 level is associated with nerve regeneration following 12-months of omega-3 nutrition therapy in patients with type 1 diabetes

Aim: Omega-3 (n-3) polyunsaturated fatty-acids are essential for the development and maintenance of nerve function, but the relationship of plasma n-3 to the presence of diabetic distal-symmetric-polyneuropathy (DSP) and the effect of n-3 therapy on plasma levels and small nerve fibre morphology in T1D are unknown. Methods: Participants with T1D (n 40, 53% female, aged (mean +/- SD) 48 +/- 14 years, BMI 28.1 +/- 5.8 kg/m(2), diabetes duration 27 +/- 18 years), 23 of whom had DSP, took seal-oil (10 mL/day; 750 mg eicosapentaenoic acid (EPA), 560 mg docosapentaenoic acid (DPAn -3), and 1020 mg docosahexaenoic acid (DHA)) for 12-months in a single-arm open-label study. The improvement in corneal nerve fibre length (CNFL) (primary outcome) was previously reported. In this secondary analysis, plasma n -3s were measured at baseline, 4, 8 and 12-months. Results: At baseline, participants with DSP had lower DHA than those without (1.73 +/- 0.89 vs. 227 +/- 0.70%, p = 0.049). Twelve-months seal-oil therapy increased mean plasma EPA by 185%, DPA by 29%, DHA by 79% (p < 0.001) and CNFL by 29% (p = 0.001). Change in CNFL was positively associated with higher baseline total n-3 (Spearman's correlation coefficient r = 0.41, p = 0.013). DPA (r = 0.33, p = 0.047) and DHA (r = 0.42, p = 0.012). Conclusion: In conclusion, low plasma DHA was associated with prevalent DSP, n-3 therapy increased blood n-3 levels and higher baseline n-3s were associated with greater nerve regeneration. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

This study found an association between low plasma DHA and prevalent DSP in patients with T1D, while n-3 therapy increased blood n-3 levels and promoted nerve regeneration, with higher baseline n-3 levels correlating with greater nerve regeneration.