Progressive damage to peripheral nerves (particularly small unmyelinated C-fibers and thinly myelinated A-delta fibers) resulting from chronic hyperglycemia, advanced glycation end-products (AGEs), oxidative stress, and microvascular ischemia in diabetes. Presents as burning pain, numbness, allodynia, and loss of protective sensation, typically in a 'stocking-glove' distribution.
Multiple pathogenic pathways converge: (1) Hyperglycemia drives polyol pathway activation (glucose β sorbitol via aldose reductase), depleting NADPH needed for glutathione regeneration and creating oxidative stress, (2) AGE formation from glucose-protein crosslinking activates RAGE receptors, triggering NFΞΊB and inflammatory cascades, (3) Protein kinase C (PKC) activation alters nerve blood flow and vascular permeability, (4) Microvascular damage causes nerve ischemia (loss of vasa nervorum), (5) Mitochondrial dysfunction and reduced ATP impair axonal transport, (6) Loss of neurotrophic support (reduced NGF, BDNF). The result is length-dependent axonal degeneration starting distally (feet) and progressing proximally. Small fiber loss causes neuropathic pain; large fiber loss causes proprioceptive deficits and falls.
Diabetic neuropathy represents a preventable and partially reversible complication if interventions address root metabolic dysfunction early. Pain presents with characteristic temporal patterns (worse at night, unpredictable intensity fluctuations) and requires neuropathic pain pharmacotherapy (not NSAIDs). cPNI interventions focus on: glycemic control via time-restricted eating and metabolic flexibility, antioxidant support (alpha-lipoic acid, acetyl-L-carnitine), anti-inflammatory nutrients (omega-3s), PEA for neuroprotection, and movement to restore neurotrophic signaling.
- Affects 50% of people with diabetes; prevalence increases with disease duration
- Small fiber damage (C-fibers, A-delta) causes burning pain, allodynia
- Large fiber damage causes proprioceptive loss, falls, Charcot joints
- Length-dependent: starts in feet, progresses proximally in 'stocking-glove' pattern
- Pain worse at night due to reduced descending inhibition during sleep
- NRS pain scores fluctuate unpredictably (2-8/10 across hours)
- Alpha-lipoic acid (600-1200 mg/day) improves neuropathy symptoms
- PEA (300-1200 mg/day) provides neuroprotection and analgesia
- Prevented/reversed by strict glycemic control and metabolic flexibility
- Type 2 Diabetes β primary metabolic disease causing diabetic neuropathy
- neuropathic pain β diabetic neuropathy is a major cause of chronic neuropathic pain
- small fiber neuropathy β diabetic neuropathy preferentially damages small fibers
- C-fibers β unmyelinated nociceptive fibers damaged in diabetic neuropathy
- A-delta fibers β thinly myelinated pain fibers affected in diabetic neuropathy
- hyperglycaemia β chronic elevation drives neuropathy via multiple mechanisms
- AGEs β advanced glycation end-products accumulate and trigger nerve damage
- oxidative stress β generated by polyol pathway and AGE formation in neuropathy
- PEA β palmitoylethanolamide used therapeutically for neuropathic pain
- alpha-lipoic acid β antioxidant that improves diabetic neuropathy symptoms
- acetyl-L-carnitine β supports mitochondrial function and nerve regeneration
- NGF β nerve growth factor reduced in diabetic neuropathy
- BDNF β neurotrophic factor depleted in diabetic nerve damage
- allodynia β painful response to non-noxious stimuli in diabetic neuropathy
- insulin resistance β underlying metabolic dysfunction driving neuropathy
- metabolic flexibility β restoration prevents and reverses diabetic neuropathy
- time-restricted eating β improves glycemic control to prevent neuropathy
- mitochondrial dysfunction β impairs axonal transport and contributes to nerve death
- physical exercise β supports neurotrophic signaling and nerve regeneration
- omega-3 fatty acids β reduce inflammation and support nerve membrane integrity