Effect of duration of diabetes mellitus type-2 on electrophysiological indices of sensorimotor nerves in subjects with diabetic polyneuropathy: A cross-sectional study

Abstract

The study investigated the effect of duration of diabetes mellitus type-2 on the electrophysiological characteristics of sensorimotor nerves in patients with clinical diabetic polyneuropathy (DSP). Clinical diagnosis of DSP was assessed with the Michigan Neuropathy Screening Instrument. The diagnosed patients with DMT2 were randomly distributed into 2 groups. Group-I (n= 79) included the patients with DSP having <10 years of duration of DMT2, called short duration, while DSP patients of Group-II (n= 49) had duration of DMT2 for ≥10 years, thereafter called long duration. The patients in both groups were compared with their corresponding duration of DMT2-matched individuals without clinical DSP. Latency, conduction velocity and amplitude of four sensory nerves (median, ulnar, peroneal and sural) and four motor nerves (median, ulnar, peroneal and tibial) were measured. Results demonstrated significant differences in all electrophysiological attributes of motor nerves except tibial nerve of the DSP patients compared to DMT2 patients in the short duration group. Similar results were noticed for sensory nerves except ulnar nerve in DSP patients. For long duration group, DSP nearly affected all 3 electrophysiological characteristics in both sensory and motor nerves. When short and long duration groups were compared with each other for electrophysiological indices for their respective nerves, functional impairment of sensorimotor nerves was more obvious in DSP patients for longer duration compared to the DSP patients for shorter duration. To conclude, long standing DMT2 deteriorates the nerve conduction attributes in the sensorimotor nerves of patients showing clinical DSP.