## 5 Conclusions  
In summary, we have demonstrated the significant association between salivary conductivity and CTR and the validity of salivary conductivity on the diagnosis of cardiomegaly. Although CTR is routinely used to define cardiomegaly, it is usually measured by chest X-ray, computed tomography, or echocardiography. These diagnostic tools are ionizing radiation or relatively expensive and inconvenient when compared with the salivary examination. The real-time, radiation-free, and non-invasive properties of salivary measurement make it a promising tool for monitoring fluid status and cardiac sizes among dialysis patients. However, the current results are not enough to confirm that salivary conductivity is a good biomarker of cardiovascular prognosis. Therefore, we nonetheless need to conduct a well-designed prospective cohort study to further clarify the ability of salivary conductivity for predicting cardiovascular risk.  
The following are available online at [[https://www.mdpi.com/article/10.3390/app11167405/s1](https://www.mdpi.com/article/10.3390/app11167405/s1)]([https://www.mdpi.com/article/10.3390/app11167405/s1](https://www.mdpi.com/article/10.3390/app11167405/s1)), [PERSON], [PERSON], and [PERSON], et al. The Association of Salivary Conductivity with Cardiomegaly in Hemodialysis Patients. Table S1: Values of all three measurements of salivary conductivity, Table S2: Baseline demographics of cardiomegaly patients, and age- and sex-matched controls (\(n=84\)).  
Conceptualization, A.-T.L., Y.-H.T., C.-H.C. ([PERSON]), and C.-W.T.; methodology, A.-T.L., C.-H.C. ([PERSON]), C.-W.T., and J.-T.Y.; software, Y.-P.L. and Y.-H.T.; validation, A.-T.L. and J.-T.Y.; formal analysis, A.-T.L., C.-H.C. ([PERSON]) and C.-W.T.; investigation, A.-T.L., Y.-P.L. and J.-T.Y.; resources, A.-T.L., Y.-P.L., C.-H.C. ([PERSON]), C.-H.C. ([PERSON]), Y.-H.T., C.-W.T. and J.-T.Y.; data curation, A.-T.L., Y.-P.L., C.-H.C. ([PERSON]), C.-H.C.([PERSON]), C.-W.T. and J.-T.Y.; writing--original draft preparation, A.-T.L. and C.-H.C. ([PERSON]); writing--review and editing, J.-T.Y.; visualization, J.-T.Y.; supervision, C.-W.T.; project administration, C.-W.T.; funding acquisition, J.-T.Y. All authors have read and agreed to the published version of the manuscript.  
This research was supported by grants from the Chang Gung Medical Research Project to [PERSON] and [PERSON] (CORPG6G0183, CORPG6G0211, CORPG6G0212, CORPG6G0213 and CORPG6G0233).  
The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics Committee of Chang Gung Memorial Hospital (institutional review board number: 201801708B0).  
Written informed consent has been obtained from the patient(s) to publish this paper.  
Datasets in this study are available from the corresponding author upon reasonable request.  
The authors would like to thank [PERSON] (the Department of Diagnostic Radiology, Chang Gung Memorial Hospital,) for the image consultation.  
All authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.