Objective: To evaluate mechanisms underlying diabetic neuropathy (DN) progression using indices of sural nerve morphometry obtained from two identical randomized placebo-controlled clinical trials.
Research Design and Methods: Sural nerve myelinated fiber density (MFD), nerve conduction velocities, vibration perception thresholds, clinical symptom scores and a visual analogue scale for pain were analyzed in participants with DN. A loss of ≥ 500 fibers/mm2 in sural nerve MFD over 52 weeks was defined as progressing DN and a MFD loss of ≤ 100 fibers/mm2 during the same time interval as non-progressing DN. The progressing and non-progressing cohorts were matched for baseline characteristics using an O’Brien rank sum and baseline MFD.
Results: At 52 weeks, the progressing cohort demonstrated a 25% decrease (p < p="0.87)," p="0.48)," p="0.11)" p="0.30)." p="0.04).
Conclusions: In this cohort of participants with mild/moderate DN, elevated triglycerides correlated with MFD loss independent of disease duration, age, diabetes control or other variables. These data support the evolving concept that hyperlipidemia is instrumental in the progression of DN.