Abstract
Background: High blood pressure, commonly termed hypertension, is becoming more common in both developing and industrialized nations, making it a worldwide health concern. An increase in blood pressure is broadly categorized into prehypertension and hypertension based on JNC VIII criteria. Prehypertension is a state in between normal blood pressure and high blood pressure, and it is linked with injury to target organs and subclinical atherosclerosis an easy and non-invasive way to look into autonomic dysfunction in those who are pre-hypertensive is to measure heart rate variability (HRV). Neutrophil-to-lymphocyte ratio (NLR) is a cheap, simple, and novel hematological parameter of oxidative stress and pro-inflammatory marker and has recently emerged as a useful indicator to predict cardiovascular risk and adverse outcomes in patients with hypertension.

Aims and Objectives: The aim of the study is to assess the correlation between cardiovascular autonomic function using HRV and NLR in pre-hypertensive individuals and to find out if NLR can be used as a marker to detect autonomic dysfunction.

Materials and Methods: HRV is recorded in a supine position with eyes closed in the study population. About 2 mL of venous blood was collected from the individuals to measure NLR using an automated hematology analyzer.

Results: The mean values of time domain indices showed significant reduction and frequency domain indices low frequency (LF) values were significantly higher and high frequency (HF) values were significantly lower in pre-hypertensive. The mean NLR was significantly higher in pre-hypertensive individuals. Time domain indices showed a negative correlation with NLR. HF values were negatively correlated and LF values were positively correlated with NLR.

Conclusion: NLR was increased in pre-hypertensive individuals which suggest that people in pre-hypertensive state are also at risk of developing cardiovascular and cerebrovascular complications. This study showed a positive association between NLR and sympathetic activity and a negative association between NLR and parasympathetic activity. This concludes that NLR could be used as a marker to assess autonomic dysfunction in them.

Key words: Prehypertension; Hypertension; Heart Rate Variability; Time Domain Methods Frequency Domain Methods; Neutrophil–Lymphocyte Ratio; Autonomic Dysfunction