Effect of Anaemia on Sensory Nerve Conduction in Diabetic Peripheral Neuropathy: A Cross-sectional Study

Abstract

Introduction: Diabetic Peripheral Neuropathy (DPN) occurs in more than 50% of patients with Type 2 Diabetes Mellitus (T2DM). Though multi-factorial pathogenesis has been claimed for the occurrence of DPN, the exact mechanism is unclear. Recently, it was found that the prevalence of anaemia is two to three times higher in diabetic patients even with preserved renal function. Aim: To compare the sensory nerve conduction study variables such as latency (ms), amplitude (μV) and Nerve Conduction Velocity (NCV) (m/s) of the median, ulnar and sural nerves in DPN patients with anaemia to those without anaemia. Materials and Methods: This cross-sectional study was conducted in the Department of Neurology, PSG Hospital, Coimbatore, Tamil Nadu, India, December 2017 to December 2018 with 80 DPN subjects, included both males and females of age group from 35 to 70 years, grouped into those without anaemia (n=40) and those with anaemia (n=40). Subjects were considered to have anaemia based on the World Health Organisation (WHO) classification of haemoglobin. Sensory nerve conduction studies were performed on right and left median, ulnar and sural nerves. Logistic regression was performed in DPN without and with anaemia to rule out confounding variables. Independent t-test and Mann-Whitney U test were used to compare the variables between the groups with normal and skewed distribution, respectively. The p-value <0.05 was considered to be statistically significant. Results: Among 80 study participants, 38 (47.50%) were male and 42 (52.50%) were female. About 20 (50%) were male and 20 (50%) were female in group A (DPN without anaemia). Seventeen (42.50%) were male and 23 (57.50%) were female in group B (DPN with anaemia). Among DPN subjects with anaemia, 57.50% had mild anaemia and 42.50% had moderate anaemia. In the present study, normocytic normochromic anaemia was the predominant form of anaemia seen. NCV of right median nerve, right ulnar nerve, right sural nerve and left sural nerve were significantly reduced in DPN with anaemia when compared to DPN without anaemia with values <0.001, <0.001, 0.001 and <0.001, respectively. The amplitude of right sural nerve and left sural nerve were significantly reduced in DPN with anaemia, compared to DPN without anaemia with p-values <0.001 and 0.017, respectively. Conclusion: DPN patients with anaemia had lower NCV and amplitude of sensory nerves, when compared to those without anaemia. Hence, even mild to moderate anaemia could be a possible risk factor that exacerbates the severity of DPN.