Evan J.H. Lewis, PhD, Bruce A. Perkins, MD, Leif E. Lovblom, MSc, Richard P. Bazinet, PhD, Thomas M.S. Wolever, DM, PhD Vera Bril, MD
Objective: To test the hypothesis that 12 months of seal oil omega-3 polyunsaturated fatty acids (v-3 PUFA) supplementation will stop the known progression of diabetic sensorimotor polyneuropathy (DSP) in type 1 diabetes mellitus (T1DM).
Methods: Individuals with T1DM and evidence of DSP as determined by a Toronto Clinical Neuropathy Score $1 were recruited to participate in a single-arm, open-label trial of seal oil v-3 PUFA supplementation (10 mL.d21; 750 mg eicosapentaenoic acid, 560 mg docosapentaenoic acid, and 1,020 mg docosahexaenoic acid) for 1 year. The primary outcome was the 1-year change in corneal nerve fiber length (CNFL) measured by in vivo corneal confocal microscopy, with sensory and nerve conduction measures as secondary outcomes.
Results: Forty participants (53% female), aged 48 6 14 years, body mass index 28.1 6 5.8 with diabetes duration of 27 6 18 years, were enrolled. At baseline, 23 participants had clinical DSP and 17 did not. Baseline CNFL was 8.3 6 2.9 mm/mm2 and increased 29% to 10.1 6 3.7 mm/mm2 (p 5 0.002) after 12 months of supplementation. There was no change in nerve conduction or sensory function.
Conclusions: Twelve months of v-3 supplementation was associated with increase in CNFL in T1DM.
Classification of evidence: This study provides Class IV evidence that for patients with T1DM and
evidence of DSP, 12 months of seal oil omega-3 supplementation increases CNFL. Neurology®