“…There were several methods for DPN diagnosis, we classified in four groups: a) >2 clinical signs, including nine studies [48,49,54,56,58,64,71,72,75]; b) >2 clinical signs and symptoms, including 14 studies [50, 52, 53, 57, 59-61, 63, 65, 66, 68-70]; c) >2 clinical signs + nerve conduction test (NCT), including one study [55]; and d) only NCT or sudomotor disfunction test, including four studies [51,62,67,74]…”