## 1 Introduction
The authors concluded there was a need to further understand the complex mechanisms related to why this association existed, and therefore recommended the need for further research. Moreover, a point that needs to be noted is that [PERSON] et al. [19] included in their meta-analysis any human study that assessed HRV and inflammatory biomarkers. However, a great number of the studies that were included in this meta-analysis focused on the relationship between HRV and inflammatory biomarkers, either in healthy subjects or in cardiovascular disease and depression. Only three studies [20; 21; 22] explored the association between HRV and a suite of inflammatory makers in sepsis (C-reactive protein, IL6 and IL10). [PERSON] et al. [20] carried out a study to explore whether CAD was associated with increased levels of CRP and IL6. They assessed, during 6 days, the HRV of 45 critically ill septic patients, while being sedated and intubated in an ICU, and they measured their IL6 and CRP levels. [PERSON] et al. [20] agreed with what has previously been discussed, as they found that autonomic dysfunction as assessed by HRV was associated with a higher inflammatory response in septic patients. In addition to this, [PERSON] et al. [21; 22] conducted similar studies to [PERSON] et al. [20], as they evaluated the association between the HRV of patients admitted to an ICU with sepsis and their levels of IL6. These authors concurred with the previous authors, as they concluded that an inverse correlation appeared to exist between the levels of IL6 and HRV. However, it needs to be highlighted that all the latter studies [20; 21; 22] used a sample of critically ill septic patients who had been admitted to an ICU and, as [PERSON] et al. [20] state, factors, such as sedation time, medications used and breathing patterns when on mechanical support, need to be considered as they can all affect the HRV values. Furthermore, as the patients in those studies were critically ill, the HRV was assessed while resting and no other stimuli could be applied to further evaluate the integrity of the ANS, as suggested by [PERSON] [23]. Lastly, it needs to be considered that, in these studies, patients were not followed-up for a long period of time, and therefore it can be argued that the recovery pattern of both the HRV and inflammatory markers was not able to be fully evaluated. It is for these reasons that further research is needed to explore the relationship between HRV and inflammatory markers in the context of an infection. The current study is therefore designed to provide further knowledge of the association between CAD and inflammatory biomarkers in a sample of individuals with community-acquired bacterial infections, which did not required ICU admission and that were hemodynamically stable to undertake the HRV assessment as developed by [PERSON] [23]. Cardiovascular autonomic dysfunction is the alteration of the normal ANS function that has an adverse effect on an individual's health [24]. The heart rate variability (HRV), which is the measurement of the temporal variability in between heart beats in relation to the mean HR [25; 26; 27], appears to be one of the best markers to assess cardiac autonomic function [28; 29; 30]. Cardiovascular autonomic dysfunction is associated with infectious processes [31; 32]. Furthermore, [PERSON] et al. [33], [PERSON] et al. [34] and [PERSON] et al. [35] concluded that abnormalities in autonomic cardiovascular reflexes as measured by the heart rate variability (HRV) are associated with a higher risk of death. In this observational longitudinal study of patients with an acute bacterial infection and healthy-control participants, the serum inflammatory biomarker concentrations are measured (CRP, IL1, IL4, IL6, IL10 and TNFa), and the cardiovascular autonomic function assessed. It is hypothesized that, during the recovery period from an acute bacterial infection, some inflammatory markers may be a useful biomarker to promptly identify cardiovascular autonomic dysfunction.