Progressive loss of corneal nerve fibers is associated with physical inactivity and glucose lowering medication associated with weight gain in type 2 diabetes.
Academic Article
Overview
abstract
AIMS/INTRODUCTION: Limited studies have identified risk factors linked to progression of diabetic peripheral neuropathy (DPN) in type 2 diabetes (T2D). This study examined the association of risk factors with change in neuropathy measures over 2-years. MATERIALS AND METHODS: Participants with T2D (n=78) and controls (n=26) underwent assessments of clinical, metabolic and neuropathy using corneal confocal microscopy (CCM), vibration perception threshold (VPT) and the DN4 questionnaire at baseline and 2-year follow-up. RESULTS: Participants with T2D had a lower corneal nerve fiber density (CNFD), branch density (CNBD) and fiber length (CNFL) (P≤0.0001) and higher VPT (P≤0.01) compared to controls. Over 2-years, despite a modest reduction in HbA1c (P≤0.001), body weight (P≤0.05) and LDL (P≤0.05) the prevalence of DPN (P=0.28) and painful DPN (P=0.21) did not change, but there was a significant further reduction in CNBD (P≤0.0001) and CNFL (P≤0.05). CNFD, CNBD, and CNFL decreased significantly in physically inactive subjects (P<0.05-0.0001), whilst there was no change in CNFD (P=0.07) or CNFL (P=0.85) in physically active subjects. Furthermore, there was no change in CNFD (P=0.82), CNBD (P=0.08) or CNFL (P=0.66) in patients treated with glucose lowering medication associated with weight loss, whilst CNBD (P=0.001) decreased in patients on glucose lowering medication associated with weight gain. CONCLUSIONS: In participants with T2D, despite a modest improvement in HbA1c, body weight and LDL there was a progressive loss of corneal nerve fibers; except in those who were physically active or on glucose lowering medication associated with weight loss.
