Neutrophil-to-Lymphocyte Ratio as a Marker for Cardiac Autonomic Neuropathy in Egyptian Patients With Type 2 Diabetes: A Cross-Sectional Study

Objective: Cardiac autonomic neuropathy (CAN) is one of the most serious complications of diabetes. This study aimed to analyze the correlation between neutrophil-to-lymphocyte ratio (NLR) and CAN in patients with type 2 diabetes (T2D) using 24-hour Holter ECG and to assess the relationship between NLR and severity of diabetic peripheral neuropathy (DPN).

Subjects & methods: This cross-sectional study included 90 T2D patients with DPN confirmed by nerve conduction study (NCS). A 24-hour Holter ECG was done to detect the decrease in heart rate variability (HRV). Laboratory parameters, including fasting blood glucose, creatinine, cholesterol, triglyceride, and glycosylated hemoglobin (HbA1c) levels, as well as CBC, neutrophils, lymphocytes, NLR, and platelet-to-lymphocyte ratio (PLR), were calculated accordingly. An albumin-to-creatinine ratio (ACR) test was done and the estimated glomerular filtration rate (eGFR) was calculated. Chronic kidney disease was diagnosed by the presence of albuminuria (≥30 mg/g creatinine) and/or eGFR less than 60.

Results: Based on the 24-hour Holter ECG, 25 patients out of 90 (27.7%) had CAN. On comparing both the CAN and non-CAN groups, the CAN group had higher HbA1C (p = 0.005), higher NLR (p = 0.014), and higher neutrophils (p = 0.10). Also, PLR was higher in the CAN group than in the non-CAN group, but this was not statistically significant (p = 0.180). Receiver operator characteristic curve analysis revealed that NLR with a cutoff of 1.7 succeeded in detecting patients with CAN.

Conclusion: NLR can be used as an inexpensive and accessible marker to detect patients with diabetes at risk for developing CAN.