Elevated triglycerides correlate with progression of diabetic neuropathy.
OBJECTIVE
To evaluate mechanisms underlying diabetic neuropathy progression using indexes of sural nerve morphometry obtained from two identical randomized, placebo-controlled clinical trials.


METHODS
Sural nerve myelinated fiber density (MFD), nerve conduction velocities (NCVs), vibration perception thresholds, clinical symptom scores, and a visual analog scale for pain were analyzed in participants with diabetic neuropathy. A loss of > or =500 fibers/mm(2) in sural nerve MFD over 52 weeks was defined as progressing diabetic neuropathy, and a MFD loss of < or =100 fibers/mm(2) during the same time interval as nonprogressing diabetic neuropathy. The progressing and nonprogressing 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 < 0.0001) from baseline in MFD, while the nonprogressing cohort remained unchanged. MFD was not affected by active drug treatment (P = 0.87), diabetes duration (P = 0.48), age (P = 0.11), or BMI (P = 0.30). Among all variables tested, elevated triglycerides and decreased peroneal motor NCV at baseline significantly correlated with loss of MFD at 52 weeks (P = 0.04).


CONCLUSIONS
In this cohort of participants with mild to moderate diabetic neuropathy, 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 diabetic neuropathy.
Wiggin
Timothy D
TD
Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
Sullivan
Kelli A
KA
Pop-Busui
Rodica
R
Amato
Antonino
A
Sima
Anders A F
AA
Feldman
Eva L
EL
D000328:Adult; D000368:Aged; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology; D003929:Diabetic Neuropathies / Q000097:blood / Q000473:pathology / Q000503:physiopathology*; D018450:Disease Progression; D004594:Electrophysiology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009413:Nerve Fibers, Myelinated / Q000473:pathology / Q000502:physiology; D013497:Sural Nerve / Q000473:pathology / Q000503:physiopathology; D014280:Triglycerides / Q000097:blood*; D014732:Vibration
D006442:Glycated Hemoglobin; D014280:Triglycerides