Skin autofluorescence: Correlation with measures of diabetic sensorimotor neuropathy.

OBJECTIVE: Advanced glycation end products (AGE) contribute to the development of diabetes complications. Their accumulation in skin can be non-invasively assessed by measurement of skin autofluorescence (SAF). Our study investigated whether SAF correlates with measures of diabetic peripheral neuropathy (DPN).

METHODS: In a multi-center study (8 centers), 497 consecutive individuals with diabetes mellitus were investigated. Forearm SAF was measured using the AGE Reader (Groningen, The Netherlands). DPN was assessed using the Toronto Clinical Neuropathy Score (TCNS), the Neuropathy Symptoms Score (NSS) and the Neuropathy Disability Score (NDS). RESULTS (MEAN ± SD): According to the TCNS, SAF (arbitrary units - AU) was increased in individuals with DPN (TCNS > 5): 2.59 ± 0.56 AU compared with those without DPN (TCNS ≤ 5): 2.45 ± 0.53 AU, (p = 0.04) and significantly increased with the severity of DPN (p = 0.028). Higher SAF was detected in individuals with neuropathic deficits (NDS > 2): 2.58 ± 0.56 AU vs. those without deficits (NDS ≤ 2): 2.45 ± 0.53 AU, (p = 0.009) as well as in individuals with symptoms (NSS > 2): 2.54 ± 0.56 AU vs. those without symptoms (NSS ≤ 2): 2.40 ± 0.47 AU, (p = 0.022).

CONCLUSIONS: Accumulation of AGE in skin is increased in individuals with DPN and progresses with the severity of DPN. Therefore, SAF measurement, an easy-to-use, quick and non-invasive method, might help in identifying subjects at high risk for having DPN.