Better Islet Function and Cardiovascular Autonomic Function in Chinese Type 2 Diabetic Patients with Pure Small Fiber...

Area of Science:

• Neurology
• Endocrinology
• Diabetology

Background:

• Small fiber neuropathy (SFN) in Chinese patients with type 2 diabetes mellitus (T2DM) is not well-characterized.
• This study investigates metabolic and neurological profiles and prognosis in T2DM patients using skin biopsy.

Purpose of the Study:

• To describe clinical characteristics and outcomes of SFN in Chinese T2DM patients.
• To compare metabolic and neurological indexes between pure SFN and mixed diabetic polyneuropathy (DPN).

Main Methods:

• Skin biopsy was performed on 34 healthy volunteers to establish intra-epidermal nerve fiber density (IENFD) reference ranges.
• 89 T2DM patients were evaluated, with 17 pure SFN and 9 mixed DPN patients reassessed at follow-up.

Main Results:

• Pure SFN patients had lower HbA1c and postprandial glucose, but higher C-peptide and insulin levels than mixed DPN patients.
• A negative correlation was found between distal leg IENFD and cardiovascular autonomic reflex test (CART) scores (r = -0.513, P = 0.001).
• Pure SFN patients showed increased vitamin B12 and motor nerve conduction velocity (MCV) of the common peroneal nerve at follow-up, while mixed DPN patients showed decreased MCVs.

Conclusions:

• Patients with pure SFN exhibit superior islet and cardiovascular autonomic function compared to those with mixed DPN.
• Metabolic and neurological indices demonstrated stability in pure SFN patients throughout the follow-up period.