Home Print this page Email this page Small font size Default font size Increase font size
Users Online: 6195
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents 
ORIGINAL ARTICLE
Year : 2020  |  Volume : 9  |  Issue : 6  |  Page : 2985-2989  

Evaluation of salivary flow rate, pH, and buffer capacities in end-stage renal disease patients versus control – A prospective comparative study


1 Department of Oral Pathology and Microbiology, Patna Dental College and Hospital, Patna, Bihar, India
2 Dentist, Oral Pathology and Microbiology, Bihar Government, Primary Health Centre, Sahdei Buzurg, Vaishali, Bihar, India
3 Public Health Dentistry, Patna Dental College and Hospital, Patna, Bihar, India
4 Orthodontics, Patna Dental College and Hospital, Patna, Bihar, India
5 Department of Oral and Maxillofacial Surgery, Buddha Institute of Dental Sciences and Hospital, Kankarbagh, Patna, Bihar, India
6 Reader, Department of Oral Pathology and Microbiology, Sarjug Dental College and Hospital, Darbhanga, Bihar, India

Date of Submission10-Feb-2020
Date of Decision13-Mar-2020
Date of Acceptance26-Mar-2020
Date of Web Publication30-Jun-2020

Correspondence Address:
Dr. Jay Kishore
Dentist, Oral Pathology and Microbiology, Bihar Government, Primary Health Centre, Sahdei Buzurg, Vaishali-844 509, Bihar
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jfmpc.jfmpc_242_20

Rights and Permissions
  Abstract 


Background: Saliva plays a major role in preserving the integrity of oral tissues. Chronic renal failure patient undergoes many oral and salivary changes for which they require special oral health care. The patient undergoing hemodialysis session has altered salivary composition. Many changes occur during hemodialysis that severely affect the flow rate and the biochemical composition of saliva. Methods: A total of 50 patients of end-stage renal disease undergoing hemodialysis for renal insufficiency were selected based on inclusion and exclusion criteria set prior to the study. These patients were compared with the control group who had already undergone hemodialysis. A total of 30 patients were selected as a control group. In this study, unstimulated whole saliva was collected by the spitting method before and after the dialysis session. Salivary flow rate, pH, and buffering capacities were measured. Results: Hemodialysis had a significant effect on the salivary flow rate. The mean pH of unstimulated whole saliva showed no significant changes before and after dialysis. The concentrations of urea, creatinine, chloride, and potassium in the whole saliva changed markedly before and after a hemodialysis session, whereas no significant difference was seen in the concentration of sodium and calcium. Conclusion: Through this study, we came into a conclusion that hemodialysis had a significant effect on salivary secretion and the biochemical composition of saliva. We conclude that the observed changes in salivary concentrations and the flow rate are mainly due to an increased watery secretion from the salivary glands and also saliva can be used as a tool for monitoring hemodialysis.

Keywords: End-stage renal disease (ESRD), hemodialysis, saliva


How to cite this article:
Kumar T, Kishore J, Kumari M, Rai A, Rai S, Jha A. Evaluation of salivary flow rate, pH, and buffer capacities in end-stage renal disease patients versus control – A prospective comparative study. J Family Med Prim Care 2020;9:2985-9

How to cite this URL:
Kumar T, Kishore J, Kumari M, Rai A, Rai S, Jha A. Evaluation of salivary flow rate, pH, and buffer capacities in end-stage renal disease patients versus control – A prospective comparative study. J Family Med Prim Care [serial online] 2020 [cited 2020 Sep 19];9:2985-9. Available from: http://www.jfmpc.com/text.asp?2020/9/6/2985/287854




  Introduction Top


Among all the systemic disorders, renal system diseases play a major cause of morbidity and mortality worldwide as the kidney maintains the internal environment of a body, i.e. homeostasis.[1] As a result, many people suffering from renal diseases require more oral health care often. Chronic renal failure and its treatment have systemic and oral manifestation.[2],[3] Saliva is known as a soldier of oral cavity. Saliva plays a significant diagnostic marker to rule out oral diseases at an early stage. Saliva monitors the health and disease state of an individual that is a highly desirable goal for health promotion and health care research. Over the last decades, the prevalence and incidence of end-stage renal disease (ESRD) have increased. It has been observed that with age male individuals are more commonly affected than females. The most common causes of ESRD are chronic hypertension, glomerulonephritis, polycystic kidney disease, and endovascular disease and diabetes mellitus.[4]

The management of chronic kidney disease (CKD) requires a clear understanding of its definition as proposed by the National Kidney Foundation (NKF). For this, the exact interpretation of the estimated glomerular filtration rate (eGFR) is required, because GFR is still considered as the best overall index of kidney function in stable, non-hospitalized patients. Kidney damage is defined by anyone of the following findings:[5]

  • pathologic kidney abnormalities;
  • persistent proteinuria;
  • other urine abnormalities, e.g. renal hematuria;
  • imaging abnormalities; and
  • estimated glomerular filtration rate (eGFR).


Classification of CKD stage estimated GFR (mL/min/1.73 m2)[5]

Stage 1 – ≥90 – Normal GFR w/proteinuria

Stage 2 – 60-89 – Age-related decline in GFR w/proteinuria

Stage 3-A-3B – 30-59 – Low risk of progression to kidney failure

Stages 4-15-29 – High risk of progression to kidney failure

Stage 5-5D – (chronic dialysis) 5T (kidney transplant) – <15 kidney failure

The above-mentioned literature regarding the ease of collection and performance of various tests on saliva makes it helpful in the primary care of the early detection of ESRD cases. Moreover, salivary changes also indicate the minor to major alterations in any systemic, endocrinal, and exocrine changes.

Therefore, the present study was performed to assess oral and salivary change, i.e. salivary flow rate, pH, and buffering capacities in ESRD undergoing hemodialysis in comparison with healthy controls.


  Materials and Methods Top


After obtaining Institutional Ethical Committee Clearance, the study was conducted in the Department of Oral Pathology and Microbiology, Patna Dental College and Hospital, Patna (Bihar) in the time period of 18 months from March 2018 to September 2019. The date of approval is 25 November 2018.

A total of 50 patients of either sex having ESRD undergoing hemodialysis for renal insufficiency who visited the college outpatient department were selected [Table 1]. The patients' age ranges from 15 to 60 years with the mean age of 34 years. Among this, 32 patients were male and 18 were female. Before the sample collection complete history was taken from patients regarding dry mouth, tongue and/or mucosal pain, and taste change, complete oral examination was done such as uremic odor, tongue coating, candidiasis, petechiae, ecchymosis, oral ulcer, enamel hypoplasia, and gingival bleeding.
Table 1: Demographic data of patients included in the study group

Click here to view


Inclusion criteria

Patients of either sex in the age group of 15-60 years, with ESRD having a glomerular filtration rate of <15 ml/min, undergoing hemodialysis were included in the study.

Exclusion criteria

Patients with any of the following features were excluded from the study:

  • Diseases affecting water and electrolyte balance like diabetes insipidus, thyroid disorders, etc.
  • Patients under medication (other than insulin and antihypertensive drugs) who could affect saliva production.
  • Patients with salivary gland disorders.
  • Patients who already underwent a hemodialysis procedure (at least not for 3 days).


Thirty patients were randomly selected as a control group who recently underwent hemodialysis (at least within 24 h) with no history of serious illness rather than kidney disease and who were not under any medication that can alter pH and the buffer of saliva. The control group age ranges from 18 to 59 years with the mean age of 34.7 years. Among these patients, 14 patients were female and 16 were male. The mean time of treatment on hemodialysis was 22 months with a range being 1 month to 8 years.

The patients were explained about the procedure, and the written informed consent was obtained. Unstimulated whole saliva was collected by the spitting method. Samples from the patients (a day after dialysis visit) and the control group were collected between 8:00 AM and 11:00 AM. Samples were collected before meals or at least 2 h after meals. During the time of collection, smoking and eating were prohibited. Unstimulated whole saliva was collected for 10 min by the spitting method, and the subjects were instructed to spit out into the sterile calibrated container every 30 s. Each saliva collection period was 5 min, and after the sample collection, the flow rate (ml/min) was calculated.

After this, pH was measured using the pH indicator strip (Merck). One drop of the collected saliva sample was placed on the test strip, and its color change indicated the pH of saliva.

The remaining samples were stored in an icebox at -20°C and sent to a laboratory within the 30 min of sample collection. The saliva samples were then centrifuged at 4000 rpm for 10 min, to eliminate cellular debris. Then, the concentrations of salivary urea, creatinine, sodium, chloride, potassium, and calcium were determined using an autoanalyzer.

Statistics

Statistical analysis was done using Descriptive statistics, Chi-square test, and Paired sample 't' test. The statistical analysis was done using the SPSS version 16 statistical software package. Data were collected, tabulated, and then subjected to the statistical analysis. The qualitative data were presented as numbers and percentages, and the Chi-square test was used to examine the significance of the differences in mean and distribution of categorical variables between groups. The data were presented as mean ± standard deviation, and the paired sample t-test was used for comparison of values before and after hemodialysis.


  Results Top


This study was conducted on prediagnosed nephritis patients who regularly undergo hemodialysis and compared with normal healthy controls.

Salivary flow rate

To compare the salivary flow rate before and after hemodialysis paired samples, statistics was applied. The mean flow rate before was 0.42 ± 0.27 mL/min, and the mean flow rate after hemodialysis was 0.81 ± 0.34 mL/min. There was a statistically significant difference between the salivary flow rate before and after hemodialysis, as a P value of 0.000 was obtained.

Salivary pH

The mean pH before hemodialysis was 6.49 ± 1.1, and the mean pH after hemodialysis was 6.65 ± 0.60. There was no statistically significant difference between the salivary pH before and after hemodialysis, as the P value was 0.231.

Saliva composition

Biochemical parameters measured in saliva are shown in [Table 2].
Table 2: Mean concentration of the salivary flow rate in ml/min, pH, and biochemical constituents urea in mg/dl, creatinine in mg/dl, sodium in mmol/L, chloride in mmol/L, potassium in mmol/L, calcium in mg/dl, before and after hemodialysis

Click here to view


The salivary composition of CKD patients differed before and after a dialysis session. The concentrations of urea, creatinine, potassium, and chloride were found to be significantly lower in patients after hemodialysis than it was before hemodialysis. There were no statistically significant changes seen in the concentrations of sodium and calcium, before and after hemodialysis.

The mean concentration of urea before hemodialysis was 162.80 ± 90.21 mg/dl, and the mean urea concentration after hemodialysis was 100.1 ± 62.87 mg/dl, with a P value of 0.000, which is statistically significant. The mean concentration of creatinine before hemodialysis was 1.68 ± 0.6 mg/dl, and the mean creatinine concentration after hemodialysis was 1.13 ± 0.56 mg/dl, which was also statistically significant.

The mean sodium concentration before hemodialysis was 12.96 ± 8.07 mmol/L, and the mean sodium concentration after hemodialysis was 13.89 ± 6.95 mmol/L. The mean calcium concentration before hemodialysis was 8.77 ± 0.53 mg/dl, and the mean calcium concentration after hemodialysis was 8.79 ± 0.52 mg/dl, which was not significant statistically with a P value of 0.112 and 0.791, respectively [Table 3].
Table 3: Paired samples' t-test of difference in salivary constituents before and after hemodialysis

Click here to view


The mean concentration of chloride before hemodialysis was 38.01 ± 13.63 mmol/L, and the mean chloride concentration after hemodialysis was 26.44 ± 11.85 mmol/L. The mean potassium concentration before hemodialysis was 28.56 ± 9.51 mmol/L, and the mean potassium concentration after hemodialysis was 21.90 ± 7.58 mmol/L, which was statistically significant with a P value of 0.000 and 0.002, respectively [Table 3].


  Discussion Top


Some of the most frequent and important many pathological conditions of the teeth and the oral cavity are strongly dependent on pH changes. Till now, limited literature is available about the salivary composition and oral manifestation of patients with ESRD. About 60,000 persons annually lose their lives due to kidney-related diseases. Glomerulonephritis constitutes 54.7% of the kidney diseases, pyelonephritis accounts for 12.3% of renal failures and others about 33%. Therefore, patients with end-stage kidney disease, especially those on hemodialysis show a wide range of clinical symptoms and signs including biochemical changes such as hyperkalemia, hyperphosphatemia, hypocalcemia, and hormonal disturbances like secondary hyperparathyroidism, low activity of 1,25(OH) 2 Vitamin D.[6]

CKD is a life-threatening disorder for which a patient will require either a kidney transplant or hemodialysis. CKD patients exhibit oral manifestations, recognition of which is important since they may be the indicators of the presence or extent of the disease.[6]

Saliva is a unique fluid and its significance as a diagnostic medium has advanced exponentially in the past decade. In the present study, the whole saliva collected which is noninvasive, cost effective, and with no training of patient required. No special equipment is needed for the collection of the fluid. Diagnosis of the disease via the analysis of saliva is a potentially valuable tool for children and older adults because the collection of the fluid is associated with fewer compliance problems compared with the collection of blood.[6]

Therefore, this study was designed to rule out changes in the composition of saliva in CKD patients. The saliva samples were analyzed for sodium, potassium, calcium, phosphorous, bicarbonate, and urea.

More than 30 oral signs and symptoms of patients with ESRD have been reported.[7] Several cases each of gingival hemorrhage, uremic stomatitis, change of taste acuity, enamel hypoplasia, pallor of oral mucosa, xerostomia, uremic odor have been presented.[8],[9],[10],[11],[12]

With respect to pH and Ericsson's buffer capacity of stimulated parotid saliva, there was no significant difference between the patients with ESRD and the healthy controls. This is because urea is converted to ammonia by oral bacteria.[4],[13] The stimulation itself increases pH and buffer capacity as well as the flow rate. This effect might mask the changes that are due to the disease condition.[3]

Oral manifestations generally observed in patients with CRF include enamel hypoplasia, pallor of the oral mucosa, xerostomia, uremic odor, low caries prevalence in both primary and permanent dentitions, as well as a large amount of calculus.[4],[13]

Dialysis leads to systemic alterations, oral complications, and variations in the flow and composition of saliva. Salivary functions including lubrication, buffering action, maintenance of tooth integrity, antibacterial activity, and taste and digestion may by disturbed by altered salivary flow and composition.[14] It is considered that the determination of some biomarkers in saliva can be an effective alternative method for monitoring the efficacy of the treatment with dialysis in CKD patients.

Salivary flow rate and pH: in our study, the salivary flow rate before and after a dialysis session (Before dialysis: – 0.4 ± 0.2 ml/min and after dialysis: – 0.8 ± 0.3 ml/min) was found to be statistically significant (P < 0.005). Salivary pH before and after dialysis was almost similar, no significant difference in pH was found. A similar result was found in the study of Martins et al.,[15] who also found a statistically significant difference between the salivary flow rate before and after a hemodialysis session, and also between patients on hemodialysis and healthy controls. Similar results were obtained by Kaushik et al.,[16] who found a statistically significant lower stimulated and unstimulated salivary flow rate in patients on dialysis when compared to healthy controls. Khanum et al. also found similar results.[4]

Bayraktar et al.[17] reported the stimulated salivary flow rate to be significantly lower in patients on hemodialysis when compared to patients on peritoneal dialysis and healthy controls. They also found a statistically significant higher salivary pH and buffer capacity in patients on peritoneal and hemodialysis when compared to controls.

Dada OT et al. in 2019 mentioned about the salivary creatinine, a reliable diagnostic tool for estimating GFR and previous signaling of renal disease.[18]

Sirma A. et al. in 2020, in his study, also revealed that Salivary IL-6, MMP-8 and GSS mRNA levels in combination with urine test analysis could be a useful diagnostic tool for the evaluation of juvenile pyelonephritis.[19]


  Conclusion Top


The prevalence of chronic renal failure (CRF) is increasing worldwide. ESRD patient requires special oral health care. Many oral and systemic complications occur due to chronic renal failure or due to its treatment. It has been observed that ESRD patient undergoing hemodialysis shows significant oral changes. The increased level of salivary calcium (Ca), phosphorus (P), urea, potassium (K), and sodium (Na) levels in dialysis patient correlated with renal disease severity. The present study was a small effort to prove salivary composition and functional capacities in evaluating the advanced-stage renal disorders. This qualitative analysis gives a promising preventive approach to avoid further damage in a nephritic emergency.

Key message: Salivary flow rate, dental caries prevalence, and calculus deposition may be due to the presence of urea in saliva. Hence, performing some simple tests at primary care settings on the biochemical analysis of saliva can easily detect advanced-stage renal disorders.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand who their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Kuravatti S, David MP, Indira AP. Oral manifestations of chronic kidney disease-an overview. Int J Contemporary Med Res 2016;3.  Back to cited text no. 1
    
2.
Proctor R; Kumar N, Stein A, Moles D, Porter S. Oral and dental aspects of chronic renal failure. J Dent Res 2005;84:199-208.  Back to cited text no. 2
    
3.
Kho HS, Lee SW, Chung SC, Kim YK. Oral manifestations and salivary flow rate, pH, and buffer capacity in patients with end-stage renal disease undergoing hemodialysis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88:316-9.  Back to cited text no. 3
    
4.
Khanum N, Mysore-Shivalingu M, Basappa S, Patil A, Kanwar S. Evaluation of changes in salivary composition in renal failure patients before and after hemodialysis. J Clin Exp Dent 2017;9:e1340-5.  Back to cited text no. 4
    
5.
Clinical Practice Recommendations for Primary Care Physicians and Healthcare Providers. Chronic Kidney Disease by Jerry Ford. edition 6.  Back to cited text no. 5
    
6.
Anuradha BR, Katta S, Kode VS, Praveena C, Sathe N, Sandeep N, et al. Oral and salivary changes in patients with chronic kidney disease: A clinical and biochemical study. J Indian Soc Periodontol 2015;19:297-301.  Back to cited text no. 6
[PUBMED]  [Full text]  
7.
Cohen SG. Renal disease. In: Lynch MA, Brightman VJ, Greenberg MS, editors. Burket's Oral Medicine. 9th ed. Philadelphia: JB Lippincott Co; 1994. p. 487-509.  Back to cited text no. 7
    
8.
Merril A, Peterson LJ. Gingival hemorrhage secondary to uremia. Oral Surg Oral Med Oral Pathology 1970;29:530-35.  Back to cited text no. 8
    
9.
Jaspers MT. Unusual oral lesions in a uremic patient. Oral Surg Oral Med Oral Pathol 1975;39:934-44.  Back to cited text no. 9
    
10.
Larato DC. Uremic stomatitis: Report of a case. J Periodontol 1975;46:731-3.  Back to cited text no. 10
    
11.
Singer DL, Kleinberg I. Ammonia and urea content of human incisor tooth plaque. Arch Oral Biol 1978;23:1083-87.  Back to cited text no. 11
    
12.
Sissons CH, Cutress TW, Pearce EIF. Kinetics and product stoichiometry of ureolysis by human salivary bacteria and artificial mouth plaques. Arch Oral Biol 1985;30:781-90.  Back to cited text no. 12
    
13.
Klassen JT, Krasko BM. The dental health status of dialysis patients. J Can Dent Assoc 2002;68:34-8.  Back to cited text no. 13
    
14.
Tomas I, Marinho JS, Limeres J, Santos MJ, Araujo L, Diz P. Changes in salivary composition in patients with renal failure. Arch Oral Biol 2008;53:528-32.  Back to cited text no. 14
    
15.
Martins C, Siqueria WL, de Oliveira E, de Souza Guimaraes Primo LS, Nicolau J. Salivary analysis of patients with chronic renal failure undergoing hemodialysis. Spec Care Dentist 2006;26:205-8.  Back to cited text no. 15
    
16.
Kaushik A, Reddy SS, Umesh L, Devi BKY, Santana N, Rakesh N. Oral and salivary changes among renal patients undergoing hemodialysis: A cross-sectional study. Indian J Nephrol 2013;23:125-9.  Back to cited text no. 16
[PUBMED]  [Full text]  
17.
Bayraktar G, Kurtulus I, Kazancioglu R, Bayramgurler I, Cintan S, Bural C, et al. Oral health and inflammation in patients with end-stage renal failure. Perit Dial Int 2009;29:472-9.  Back to cited text no. 17
    
18.
Dada OT, Karla B, Rajiv E. Salivary creatinine as a diagnostic tool or evaluating patients with chronic kidney disease. BMC Nephrology 2019;20:387-91.  Back to cited text no. 18
    
19.
Sirma A, Ayshe S, Yoana KK, Diana I, Stefan P. Association of mRNA Levels of IL6, MMP-8, GSS in saliva and pyelonephritis in children. Molecules 2020;25:85-90.  Back to cited text no. 19
    



 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

Top
   
 
  Search
 
Similar in PUBMED
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
   Abstract
  Introduction
   Materials and Me...
  Results
  Discussion
  Conclusion
   References
   Article Tables

 Article Access Statistics
    Viewed198    
    Printed6    
    Emailed0    
    PDF Downloaded40    
    Comments [Add]    

Recommend this journal