Relationship between chronic stress, nutritional status, neutrophil-lymphocyte ratio, and heart rate variability among active military police officers in a metropolitan region

Introduction: Chronic stress, sociodemographic characteristics, and nutritional status can negatively affect heart rate variability (HRV), especially in active-duty military personnel, resulting in altered cardiac autonomic modulation. Objective: The aim of this study was to relate cardiac autonomic modulation in active-duty military personnel with chronic stress, sociodemographic characteristics, and nutritional status. Methods: A cross-sectional study was conducted in military personnel from the state of Espírito Santo with 71 participants over 18 years of age from August to November 2022. The analysis of autonomic modulation of heart rate was performed using the Kubios® software. For this analysis, individuals remained in the supine position for 25 minutes. HRV indices were calculated using linear methods in the time and frequency domains. Statistical differences were found between men and women in the variable SDNN (standard deviation of the mean of all normal RR intervals) (p=0.006), RMSSD (square root of the mean of the squares of the differences between successive normal RR intervals) (p=0.028). Between the different BMI (body mass index) ranges mean RR (mean of consecutive RR intervals) (p=0.007) and mean HR (mean heart rate) (p=0.015) and in the different age groups SI (Baevsky stress index) (p=0.001), SDNN (p=0.003), RMSSD (p=0.004). Results: There was an association between body mass index (BMI) and mean RR interval (Mean RR). People with obesity tend to have a higher mean heart rate, while those with overweight generally have a longer mean RR interval. These differences indicate distinct patterns in cardiac autonomic regulation according to nutritional status. Conclusion: There was an influence of nutritional status on cardiac autonomic modulation in active military public agents, but there is no relationship with chronic stress suffered by this population.