Effects of neutrophil-to-lymphocyte ratio, serum calcium, and serum albumin on prognosis in patients with diabetic foot

The purpose of this study is to investigate the predictive value of neutrophil-to-lymphocyte ratio (NLR), serum calcium, and serum albumin on the prognosis of patients with diabetic foot. A total of 156 patients who were treated in the Department of Burn and Plastic Surgery of Qilu Hospital of Shandong University from 1 January 2014 to 1 August 2020 were selected. All the patients were randomly divided into a healing group, minor amputation group, major amputation group, and death group according to their treatment outcomes. The levels of NLR, serum calcium and serum albumin in each group were examined and compared. The correlations between NLR, serum calcium, and serum albumin with the prognosis of diabetic foot were analysed to investigate their predictive effects on the prognosis of diabetic foot. The results of one-way ANOVA showed that among the 4 groups of patients, the difference in NLR values between the healing group and the minor amputation group was slightly smaller, but they were significantly different from the major amputation group and the death group, respectively. There was no significant difference in serum calcium levels between the healing group and the minor amputation group, but the serum calcium levels of the major amputation group and the death group gradually decreased. The levels of NLR in the 4 groups gradually increased, while the albumin levels gradually decreased. Spearman's rank correlation test indicated that NLR was significantly related to the prognosis of patients with diabetic foot. The group with higher NLR had a worse prognosis in diabetic foot patients. Serum calcium and serum albumin were strongly correlated with the prognosis of patients with diabetic foot. The group with lower serum calcium and serum albumin values had a worse prognosis in diabetic foot patients. The areas under the receiver operator characteristic curve of NLR, serum calcium and serum albumin were 0.901, 0.803, and 0.816, respectively. NLR, serum calcium and serum albumin can be used as reliable indicators to predict the prognosis of diabetic foot. Preoperative diabetic foot patients with higher NLR values or lower serum calcium and serum albumin have a poorer prognosis.