Older Patients on Hemodiafiltration: Behavior of Uremic Toxins, Inflammation, Endothelium, and Bone Mineral Disorder

Round 1

Reviewer 1 Report

This is a very interesting paper on "Older patients on hemodiafiltration: behavior of uremic toxins, inflammation, endothelium, and bone mineral disorder" However I have few important comments 

Introduction

-Introduction is clear and well presented 

Patients and Methods Section

-Patients and Methods Section should follow Introduction. Please correct this

-The paragraph of exclusion criteria should be rephrased as it is not grammatically correct

-Study design is clear and simple and figure 5 has nothing to add

-On patients section should be added HD vintage and possibly on results section this parameter should to be evaluated statistically

Results Section

-Table 1 and 2 are not even mentioned in the text. Not to report the all data but to clarify what in these tables is presented

-Please mention in text the important results of table 2 (urea and creatine were both significantly increased after 6 months of OL-HDF-discuss these results)

-Statistical analysis is weak. Please perform regression analysis to make your results stronger 

Discussion section

-Enrich Discussion section in accordance with remarks on results section 

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This is an interesting study about using online HDF for older patients ( age>65) for 6 months and check the serum parameters before and after the intervention (n=31)

Several question may be addressed.

1. Are those patients all initially under regular hemodialysis (HD)?

If so, they are very prone to disease due to their old age and  uremic status. 

How many of them are included and how many of them drop out due to inflammation or infection? How do you deal with the patients who is stable at recruitment but suffered from disease during the 6 months follow up? 

Drop out rate is the most important issue when dealing with uremic patients, especially for eldely.  This might also explain why inflammation marker are not changed during the study because those who had infection are always excluded.

 

2. The study number is small, only 31 patients. 

How the researchers design their study to reach an endpoint and set the recruitment numner 31 for this study? And why set 6 months as the study period? Maybe previous study which composed of youger people may help to answer the question. 

3. Why the researcher set to recruit older patients who are age over 65? Is there a reasonable explanation for this age at population who is under regular HD? 

For example, the mean age of HD patients at Taiwan is about 60. What 

is the clinical importance of studing those whose mean age is about 

77? What is the difference between younger patients and older 

patients during online hemodiafiltration (OL HDF)? 

4. Is there any contraindication for HDF? or does it applied to anyone for people under hemodialysis? The duration of each session for HDF and the heparin dose used, are they the same compared to previous HD sessions? These factors may affect the final result as well.

5. How do you explain the significant increase of serum Cr and urea after shifting to 6 months of HDF? How about the URR ( urea reduction rate) for each session of HD and HDF? 

And more importantly, how is the appetite or protein intake for each  patient under HDF? Do they intake more and hence have a higher predialysis serum urea and creatinine? or is that simply the URR is lower in HDF compared with HD? The author may provide the BMI change after the intervention.

6.What is the clinical importance of the population who had reduction of IS and IAA during online HDF, as shown in Fig 3 & 4? Why are these patients mentioned separately? Why online HDF seems to be more effective on those patients? Are they youger?  More explanation is needed for these 2 figures.

7. minor issue: 

a. The word size should be consistent over the manuscript. 

b. Abbreviation (such as AP for alk-p) should be mentioned with full name mentioned at that the first time. (Due to method section is moved to the last part of the manuscript, the author should check it carefully.)

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I have no further comments

Reviewer 2 Report

I  am happy with the response.

No further question ny now.