RESUMO
AIMS: The nailfold microcirculation index (MI) is a non-invasive, objective, and highly sensitive blood capillary detection method. This study evaluated the diagnostic efficiency of the nailfold MI relative to the more subjective vibration perception threshold (VPT) examination for early diagnostic screening of diabetic peripheral neuropathy (DPN). METHODS: From February 2015 to February 2016, 227 diabetes mellitus patients and 39 healthy individuals were enrolled. Each subject underwent the MI test and the VPT examination. RESULTS: MI was more closely associated with DPN than age, diabetic duration, smoking, drinking, systolic pressure, serum creatinine, 24-h urinary protein, hypoxia-inducible factor-1α (HIF1A), vascular endothelial growth factor (VEGF), the VEGF receptors Flt-1 and Flt-4, ankle branchial index (ABI), DPN, or DPN stage (OR=11.819). Both the MI and VPT closely correlated with age, diabetic duration, serum creatinine, 24-h urinary protein, HIF1A, VEGF, Flt-1, Flt-4, ABI, DPN, and DPN stage. By the receiver operating characteristic (ROC) curve, the MI diagnostic cutoff point was 2.56, where the corresponding Youden's index was maximum and the area under ROC curve was 0.943. The diagnostic efficiency of MI and VPT were similar. MI and VPT indicated similar percentages of diabetic patients with DPN at the most severe stage, while MI achieved a higher diagnostic rate for the earliest stages. CONCLUSIONS: The nailfold MI is a feasible method for clinical early diagnostic screening of DPN in diabetic patients, and is more objective and reliable than VPT.
