Abstract
BACKGROUND: The present study aims to review the existing scientific literature on the role of neutrophil to lymphocyte ratio (NLR) in diabetic peripheral neuropathy (DPN) to perform a meta-analysis on the available data. METHODS: The electronic repositories Web of Science, PubMed, and Scopus were systematically explored starting from their establishment up until June 9, 2022. RESULTS: Fifteen articles were included in the meta-analysis after multiple screening according to the PRISMA guidelines. The combined findings indicated that individuals with DPN had higher levels of NLR in comparison to those without DPN (SMD = 0.61; CI 95% = 0.40-0.81, p < 0.001). In the subgroup assessment based on ethnicity, it was observed that diabetic patients with DPN exhibited increased NLR levels in contrast to those without DPN in studies conducted in India (SMD = 1.30; CI 95% = 0.37-2.24, p = 0.006) and East Asia (SMD = 0.53; CI 95% = 0.34-0.73, p < 0.001) but not in studies conducted in Turkey (SMD = 0.30; CI 95% = - 0.06-0.67, p = 0.104) and Egypt (SMD = 0.34; CI 95% = -0.14-0.82, p = 0.165). The pooled sensitivity of NLR was 0.67 (95% CI = 0.49-0.81), and the pooled specificity was 0.70 (95% CI, 0.56-0.81). The pooled positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR) of NLR were 2.30 (95% CI = 1.71-3.09), 0.45 (95%CI = 0.30-0.67), and 5.06 (95% CI = 3.16-8.12), respectively. CONCLUSION: NLR serves as a distinct marker of inflammation, and its rise in cases of DPN suggests an immune system imbalance playing a role in the development of the disease.