Objective:To investigate the assoication of amino acid metabolism levels with severity of diabetic peripheral neuropathy(DPN) in patients with type 2 diabetes mellitus.Methods:A retrospective analysis was conducted on 118 patients with type 2 diabetes mellitus who were admitted to Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from January to April 2021. Patients were divided into groups according to the Toronto Clinical Scoring System(TCSS), and amino acid profiling was performed. General demographics and biochemical indicators of each group were collected to analyze the relationship between DPN severity and amino acid metabolism.Results:As TCSS scores increased, patients were older and had a longer duration of diabetes. Statistically significant differences in leucine, isoleucine, tryptophan, and phenylalanine levels were observed among the four groups. After adjusting for confounding variables using covariance analysis, when the TCSS score was≥13, the serum phenylalanine level was significantly elevated, and the difference was statistically significant( P<0.05). Multivariate linear regression analysis indicated that TCSS score was an influencing factor for phenylalanine levels( P=0.010). Multivariate logistic regression analysis demonstrated that higher serum phenylalanine levels correlated with higher TCSS scores( OR=1.047, 95% CI 1.011-1.083, P=0.010). Receiver operating characteristic(ROC) curve analysis revealed that serum phenylalanine and the difference between phenylalanine and tryptophan had diagnostic value for severe DPN patients, with areas under the ROC curve of 0.673(95% CI 0.553-0.793, P=0.006) and 0.746(95% CI 0.641-0.852, P<0.001) respectively. Conclusions:The levels of phenylalanine and tryptophan in the serum of patients with type 2 diabetes mellitus are correlated with the severity of DPN. These findings suggest that serum phenylalanine, tryptophan, or their metabolic products may be involved in the pathogenesis and progression of DPN.

Objective:To investigate the assoication of amino acid metabolism levels with severity of diabetic peripheral neuropathy(DPN) in patients with type 2 diabetes mellitus.Methods:A retrospective analysis was conducted on 118 patients with type 2 diabetes mellitus who were admitted to Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from January to April 2021. Patients were divided into groups according to the Toronto Clinical Scoring System(TCSS), and amino acid profiling was performed. General demographics and biochemical indicators of each group were collected to analyze the relationship between DPN severity and amino acid metabolism.Results:As TCSS scores increased, patients were older and had a longer duration of diabetes. Statistically significant differences in leucine, isoleucine, tryptophan, and phenylalanine levels were observed among the four groups. After adjusting for confounding variables using covariance analysis, when the TCSS score was≥13, the serum phenylalanine level was significantly elevated, and the difference was statistically significant( P<0.05). Multivariate linear regression analysis indicated that TCSS score was an influencing factor for phenylalanine levels( P=0.010). Multivariate logistic regression analysis demonstrated that higher serum phenylalanine levels correlated with higher TCSS scores( OR=1.047, 95% CI 1.011-1.083, P=0.010). Receiver operating characteristic(ROC) curve analysis revealed that serum phenylalanine and the difference between phenylalanine and tryptophan had diagnostic value for severe DPN patients, with areas under the ROC curve of 0.673(95% CI 0.553-0.793, P=0.006) and 0.746(95% CI 0.641-0.852, P<0.001) respectively. Conclusions:The levels of phenylalanine and tryptophan in the serum of patients with type 2 diabetes mellitus are correlated with the severity of DPN. These findings suggest that serum phenylalanine, tryptophan, or their metabolic products may be involved in the pathogenesis and progression of DPN.