Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
  • Users Online: 2686
  • Home
  • Print this page
  • Email this page

 Table of Contents  
Year : 2023  |  Volume : 20  |  Issue : 1  |  Page : 73

Periodic acid–Schiff staining in oral exfoliative cytology of diabetic patients: The odyssey for noninvasive screening – A systematic review and meta-analysis

Department of Oral Medicine and Radiology, SRM Dental College, SRM University, Chennai, Tamil Nadu, India

Date of Submission21-Nov-2022
Date of Acceptance03-May-2023
Date of Web Publication27-Jun-2023

Correspondence Address:
Dr. K Yesoda Aniyan
Department of Oral Medicine and Radiology, SRM Dental College, Ramapuram, Chennai - 600 093, Tamil Nadu
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1735-3327.379630

Rights and Permissions

Background: Diabetes mellitus is a dominant metabolic disorder in the current fast paced culture; its prevalence is escalating worldwide and among all age groups. Guidelines recommend universal screening for diabetes; however, the uptake of these tests in individuals suggests challenges owing to invasive nature of blood collection. Thus, there arises the need for a noninvasive investigation for diabetes screening with a minimum paraphilia and for all medical settings.
Materials and Methods: We have thus conducted a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, to quantify the association between diabetes and effectiveness of periodic acid–Schiff staining of exfoliative cytology as a screening method. MEDLINE, EMBASE, Cochrane, Scopus, Web of science, CINAHL, and Google Scholar were searched systematically for publications dated till July 20, 2022. Six studies (case–control cross-sectional) were selected and evaluated in depth. The statistical evaluation was done with a forest plot with odds ratio and weightage examined.
Results: It was proved that exfoliative cytology with periodic acid–Schiff (PAS) staining can be used as a screening test for diabetic status evaluation. The findings suggest that the aforesaid noninvasive test is a conclusive screening practice for diabetics.
Conclusion: This systematic review and meta-analysis suggest that PAS staining in exfoliative cytology can be used as a noninvasive screening in diabetic individuals to assess the current level of blood glucose. Given the increased risk of diabetes worldwide, higher quality prospective evidence is suggested in larger sample sizes with other metabolic disorders, ethnicity, and oral disorders to further evaluate the plausibility of the results.

Keywords: Cytology, diabetes mellitus, diagnosis, exfoliative cytology, noninvasive, periodic acid–Schiff staining

How to cite this article:
Aniyan K Y, Lakshmi KC, Ganesan A. Periodic acid–Schiff staining in oral exfoliative cytology of diabetic patients: The odyssey for noninvasive screening – A systematic review and meta-analysis. Dent Res J 2023;20:73

How to cite this URL:
Aniyan K Y, Lakshmi KC, Ganesan A. Periodic acid–Schiff staining in oral exfoliative cytology of diabetic patients: The odyssey for noninvasive screening – A systematic review and meta-analysis. Dent Res J [serial online] 2023 [cited 2023 Sep 24];20:73. Available from: https://www.drjjournal.net/text.asp?2023/20/1/73/379630

  Introduction Top

Diabetes mellitus (DM) is a global health problem and one of the fastest-growing chronic conditions. It is adjudged that one in two diabetics is unaware of their condition. In the current fast paced and stress fueled culture, this metabolic disorder's prevalence is escalating worldwide and among all age groups.[1] The WHO has predicted that this disorder will prevail as the 7th primary cause of fatality by 2030.[2]

For the development of diabetes, the etiological factors are inclusive of obesity, physical inactivity, smoking, and older age. Furthermore, it targets certain ethnic population groups. However, one cause of concern is that it progresses slowly and silently despite microvascular disease resulting in vascular damage during the subclinical phase.[3],[4],[5]

Exfoliative cytology, a simple, quick, and inexpensive procedure, is used to study exfoliated desquamated cells. A study by Jajram et al. reported the use of exfoliative cytology as a point of differentiation between diabetic and controls. The changes referred to the nuclear area and cytoplasmic area of oral mucosal epithelial cells, N/C ratio, hyperplasia, and an elevation in glycogen deposits in cells of oral epithelium.[6] These reports prompted the authors to use the assessment of this investigation and periodic acid–Schiff (PAS) staining that detects the glycogen deposits as a manner of assessment in diabetes.[7],[8],[9]

Diabetes screening is recommended and mandated in health care, enabling an ideal environment for early diabetes diagnosis and management.[4] Considering the tranquil nature of the disorder and the systemic complications, screening tests that are noninvasive and encourage compliance are the need of the hour. The authors also observed that a routine screening for this disorder must be done for all age groups in all medical and dental centers to facilitate early diagnosis, disease control, and minimum of organ damage. The search for an optimum investigation led the way to PAS staining in exfoliative cytology of oral mucosa. With this objective in the forefront, a systematic review and meta-analysis of PAS staining of exfoliative cytology in oral mucosa in cross-sectional observational studies was done. This assessment aimed to derive upon the utility of using this noninvasive methodology as a screening test for diagnosis of diabetes.

  Methodology Top

Search strategy

The authors systematically searched Scopus, MEDLINE (PubMed), Embase, Google Scholar, Web of Science, CINAHL, and Cochrane Library up to July 20, 2022, for published clinical studies examining the use of PAS staining in exfoliated cells of oral mucosa of diabetic patients in glycogen assessment [Figure 1]. The systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement guideline with study selection following population, intervention, control, and outcomes criteria.[10],[11] The search terms or text terms were: (Periodic acid Schiff staining OR Exfoliative cytology OR oral mucosa OR diabetes mellitus OR Cytomorphometric analysis). The searches were filtered to include only studies written in English, on human subjects. In addition, relevant articles from references were manually searched. Two independent reviewers screened the abstracts and titles for eligibility and to eliminate duplication. The full text of the articles was assessed when the two reviewers ascertained that the abstract or title represented a potentially relevant study. The reviewers critically evaluated the methodology and results of the included studies. The data were extracted independently and discrepancies were adjudicated by consensus.
Figure 1: Flowchart on selection strategy.

Click here to view

Eligibility criteria

The studies were screened according to the following inclusion criteria: (a) human subjects; (b) evaluation of PAS staining for exfoliated oral mucosal cells; (c) independent data from the original papers and sufficient information to calculate the outcomes; (d) the population comprised if individuals diagnosed with DM treated with an oral hypoglycemic agent; (e) the selected population was free of additional systemic diseases; and (f) the selected population suffered from medical disorders. Studies were excluded if they (a) were not original articles (e.g., review, case report, or comments); (b) were not human studies (e.g., animal study or in vitro study); (c) were duplicate publications; (d) were articles without the necessary information; or (e) were not published in English.

Data abstraction and quality assessment

The data were appraised by one reviewer and the critical evaluation by another reviewer. In the event of disagreements, it was resolved by in depth discussion in the presence of a third reviewer. The Cochrane Handbook for Systematic Reviews-recommended Newcastle–Ottawa Scale (NOS) was referred to assess the selected study quality.[11] The NOS allocates up to 9 points to studies according to three quality domains: selection of the study groups; comparability of the groups; and ascertainment of the outcome.

  Results Top

Characteristics of the included studies

The study search produced 47 studies, of which 6 met with the inclusion criteria. Individual study characteristics are given in [Table 1]. All the six studies evaluated PAS staining in oral mucosa cells obtained by exfoliative cytology. One of the studies had done PAS staining,[10] while two of the others supplemented with Papanicolaou staining[12],[17] and one with PAS diastase staining, respectively.[13] The remaining study additionally estimated the correlation with salivary glucose and blood serum glucose.[14] All the studies were cross-sectional and observational. All the studies were conducted in India, except two which were undertaken in Saudi Arabia and Iran, respectively. The sample sizes ranged from 45 to 150.
Table 1: Aggregate data of selected studies

Click here to view

Assessment of methodological quality

The core methodological process was quite similar among the studies. All the five studies were rated as high quality (>6 points) and design. The studies comprised high to moderate sample sizes and were conducted in large population-based samples. In addition, the studies had the recorded history of the said medical condition for a minimum time period of 1 year before sample selection. The age was controlled in all the studies, whereas among the gender, it was matched with the controls. The case groups had look back periods with detailed prescriptions and recorded medical histories. In addition, laboratory examinations performed at the time of the study initiation as well.

Screening for diabetes by exfoliative cytology with periodic acid–Schiff staining

A detailed case history and glycemic control reports were evaluated at the start of each of these studies.[7],[12],[13],[14],[15],[16],[17] At the study outset, a confirmatory test of blood evaluation was conducted in each of the studies. Further, exfoliative cytology was performed on the oral buccal mucosa and devoid of lesions.[16] The collected cells were fixed on a glass slide with alcohol and then stained with PAS reagent. The sensitivity and specificity were noted to be 100% in all the studies,[7],[13],[14],[15],[16],[17] except one.[12] A forest plot demonstrated the statistical evaluation; PAS staining was effective among case groups,[7],[13],[14],[15],[16],[17] except in one study.[12]

[Graph 1] shows the forest plot of PAS staining of exfoliative cytology from oral mucosa in case and control groups. The line demonstrates that of the six studies included in meta-analysis five studies demonstrate Case groups to be more effective than the Control groups. Thus it was corroborated that the elevated serum glucose level was in correlation with the glycogen demonstrated in staining. The only study in which an exception was noted being that by Asemi-Rad et al.[12] where the Case group failed to demonstrate enhanced glycogen storage in diabetic subjects.

The middle line is indicative of the odds ratio (OR) and dot detail entails the 95% Confidence Interval with upper and lower limit. The OR is the strength of association between the exposure and the outcome. The OR and the weightage highlighted the study by Salih et al.[17] to have a strong relationship than the other studies. In addition, Salih et al.'s[17] study had a highest weightage of the selected studies in terms of association of the serum glucose level and glycogen staining in the selected study sample.

  Discussion Top

This systematic review and meta-analysis of six studies suggested that PAS staining in exfoliative cytology is recommended for screening in diabetic patients. The findings were particularly favorable for diabetic screening, with low heterogeneity across studies.

To our knowledge, this is the first systematic review and meta-analysis, evaluating the use of PAS staining techniques for diabetic screening. The robustness of this study includes quantifying the specific correlation between the glycogen storage in oral mucosal cells and the serum blood sugar and thus the staining methodology is corroborative for the evaluation. Compared with prior research, our review resulted in a pool of eligible studies for the purpose of comparison, as no reviews were available on the subject during the course of this manuscript writing. In addition, the methodology quality was high, no loss to follow–up, or nonresponse bias among the selected studies.

It is brought to attention that this systematic review focused on studies reported in English alone. However, as per a prior comprehensive review by evidence synthesis experts,[18],[19],[20] restrictions in language do not influence systematic biases that could affect the result interpretation.[21],[22],[23]

The main advantages of this diagnostic methodology were the noninvasive, relatively painless, inexpensive, and require a minimum of technical skill. This was in accordance with the findings by Latti et al.[24] Studies by Ahmed et al. and Acha et al. attest to the use of the oral cytologic analysis as a useful early diagnostic method.[25],[26] The use of PAS staining in the selected studies maintain that the cells in all the study groups displayed binucleation, decreased cytoplasmic/nuclear ratio, nuclear enlargement, enucleation and inflammation as compared to the control groups. This was in tandem with the reporting of Shareef et al. and Alberti et al. It was further affirmed that DM alters the oral epithelial cells, detectable by microscopy and cytomorphometry.[27],[28] The limitations of this methodology from the author standpoint was that the glycogen deposits indicative of diabetes could not be quantified or standardized unlike serum blood glucose. In the same vein, this diagnostic methodology is not indicative of long-term glucose control evaluation, attributed to the increased turnover of oral epithelial cells.

  Conclusion Top

This systematic review and meta-analysis suggest that PAS staining in exfoliative cytology can be used as a noninvasive screening in diabetic individuals to assess the current level of blood glucose. The procedure demonstrated active patient compliance owing the ease of procedure and because it can be performed both in a medical as well as dental clinics. Caution is warranted in interpreting these findings due to the fact that this investigative method does not indicate long-term glucose levels. Given the increased risk of diabetics in this population, future studies should consider using higher population quantity and diversity to assess the quality of this investigative method.

Ethical statement

The study did not require consent from patients or from the institution.

Financial support and sponsorship


Conflicts of interest

The authors of this manuscript declare that they have no conflicts of interest, real or perceived, financial or non-financial in this article.

  References Top

Zheng M, Bernardo CO, Stocks N, Gonzalez-Chica D. Diabetes mellitus diagnosis and screening in Australian general practice: A national study. J Diabetes Res 2022;2022:1566408.  Back to cited text no. 1
World Health Organization (WHO). Global Report on Diabetes. Geneva, Switzerland: World Health Organization; 2017. Available from: http://www.who.int/diabetes/global-report/en/. [Last accessed on 2021 Sep 22].  Back to cited text no. 2
Selph S, Dana T, Blazina I, Bougatsos C, Patel H, Chou R. Screening for type 2 diabetes mellitus: A systematic review for the U.S. Preventive services task force. Ann Intern Med 2015;162:765-76.  Back to cited text no. 3
Rafiee Z, Orazizadeh M, Nejad Dehbashi F, Neisi N, Babaahmadi-Rezaei H, Mansouri E. Mesenchymal stem cells derived from the kidney can ameliorate diabetic nephropathy through the TGF-β/Smad signaling pathway. Environ Sci Pollut Res Int 2022;29:53212-24.  Back to cited text no. 4
Huang SJ, Zhang Y, Wang GH, Lu J, Chen PP, Zhang JX, et al. Deposition of platelet-derived microparticles in podocytes contributes to diabetic nephropathy. Int Urol Nephrol 2023;55:355-66.  Back to cited text no. 5
Ogura Y, Fukatsu A. Exfoliative cytology of oral mucosa epithelium: Cytochemical study and morphologic analysis of patients with type 2 diabetes. Open J Stomatol 2019;9:281-94.  Back to cited text no. 6
Ravindran R, Gopinathan DM, Sukumaran S. Estimation of salivary glucose and glycogen content in exfoliated buccal mucosal cells of patients with type II diabetes mellitus. J Clin Diagn Res 2015;9:C89-93.  Back to cited text no. 7
Australian Bureau of Statistics. Patient Experiences in Australia: Summary of Findings. Australian Bureau of Statistics; 2020. Available from: https://www.abs.gov.au/statistics/health/health-services/patient-experiences-australia-summary-findings/latest-release. [Last accessed on 2021 Sep 22].  Back to cited text no. 8
Ma X, Wang Q. Short-chain fatty acids attenuate renal fibrosis and enhance autophagy of renal tubular cells in diabetic mice through the HDAC2/ULK1 axis. Endocrinol Metab (Seoul) 2022;37:432-43.  Back to cited text no. 9
Moher D, Liberati A, Tetzlaff J, Altman DG, PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. BMJ 2009;339:b2535.  Back to cited text no. 10
Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: Explanation and elaboration. BMJ 2009;339:b2700.  Back to cited text no. 11
Asemi-Rad A, Heidari Z, Mahmoudzadeh-Sagheb H. The relationship between the staining intensity of oral exfoliative cells with periodic acid Schiff and cytomorphometric indices with fasting blood sugar in type 2 diabetic patients. Interdiscip J Contemp Res Bus 2013;4:375-81.  Back to cited text no. 12
Ravikumar SS, Menaka TR, Vasupradha G, Dhivya K, Dinakaran J, Saranya V. Cytological intracellular glycogen evaluation using PAS and PAS-D stains to correlate plasma glucose in diabetics. Indian J Dent Res 2019;30:703-7.  Back to cited text no. 13
  [Full text]  
Hallikerimath S, Sapra G, Kale A, Malur PR. Cytomorphometric analysis and assessment of periodic acid Schiff positivity of exfoliated cells from apparently normal buccal mucosa of type 2 diabetic patients. Acta Cytol 2011;55:197-202.  Back to cited text no. 14
Imran A, Parakh MK, Kumar SM, Nachiammai N, Sriram K. Periodontal health status and implication of periodic acid-Schiff diastase – A key in exfoliative cytology among diabetics mellitus patients: A case-control study. Eur J Dent 2016;10:475-9.  Back to cited text no. 15
[PUBMED]  [Full text]  
Madhusudhan R, Govindraj K N, Ravikanth M, Swetha P, Naga Supriya A, Sreenivasa BT, et al. Comparison of glycogen positive cells in oral smears with random blood sugar levels of type 2 diabetes patients. Ann Med Health Sci Res 2018;8:1-5.  Back to cited text no. 16
Salih MM, El-Esawy BH, Abd El Hafez A, Abd El-Hafez A. 2018. Cytomorphologic patterns of Pap and PAS-stained oral exfoliative cytology smears in adult Saudi diabetic patients as compared to healthy controls. Diagn Cytopathol. 46:501-506.  Back to cited text no. 17
Broadwater DR, Messersmith LM, Bishop BN, Tomkovich AM, Salinas JR, Lynch DT. Development and validation of ultra-rapid periodic acid-Schiff stain for use in identifying fungus on frozen section. Arch Pathol Lab Med 2022; 146:1268-72.  Back to cited text no. 18
Singh V, Varma K, Bhargava M, Misra V, Singh M, Singh R. Evaluation of role of visual inspection using acetic acid (VIA) and exfoliative cytology in screening and early detection of oral premalignant lesions and oral cancer. Asian Pac J Cancer Prev 2021; 22:2273-8.  Back to cited text no. 19
Magkana M, Mentzelopoulou P, Magkana E, Pampanos A, Vrachnis N, Kalafati E, et al. p16/Ki-67 dual staining is a reliable biomarker for risk stratification for patients with borderline/mild cytology in cervical cancer screening. Anticancer Res 2022; 42:2599-606.  Back to cited text no. 20
Morrison A, Polisena J, Husereau D, Moulton K, Clark M, Fiander M, et al. The effect of English-language restriction on systematic review-based meta-analyses: A systematic review of empirical studies. Int J Technol Assess Health Care 2012; 28:138-44.  Back to cited text no. 21
Balaji S, Cholan PK, Victor DJ. Evaluation of “soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), interleukin-1β, and matrix metalloproteinase-8” as a short panel of salivary biomarkers in patients with and without stage III/IV periodontitis and type 2 diabetes mellitus. J Oral Biol Craniofac Res 2022; 12:33-7.  Back to cited text no. 22
Radhika BN, Appukuttan DP, Prakash PS, Subramanian S, Victor DJ, Balasundaram A. Estimation of periostin and tumour necrosis factor-α in type II diabetics with chronic periodontitis: A case-control study. J Indian Soc Periodontol 2019; 23:106-12.  Back to cited text no. 23
[PUBMED]  [Full text]  
Latti BR, Birajdar SB, Latti RG. Periodic acid Schiff-diastase as a key in exfoliative cytology in diabetics: A pilot study. J Oral Maxillofac Pathol 2015; 19:188-91.  Back to cited text no. 24
[PUBMED]  [Full text]  
Acha A, Ruesga MT, Rodríguez MJ, Martínez de Pancorbo MA, Aguirre JM. Applications of the oral scraped (exfoliative) cytology in oral cancer and precancer. Med Oral Patol Oral Cir Bucal 2005; 10:95-102.  Back to cited text no. 25
Ahmed HG, Idris AM, Ibrahim SO. Study of oral epithelial atypia among Sudanese tobacco users by exfoliative cytology. Anticancer Res 2003; 23:1943-9.  Back to cited text no. 26
Shareef BT, Ang KT, Naik VR. Qualitative and quantitative exfoliative cytology of normal oral mucosa in type 2 diabetic patients. Med Oral Patol Oral Cir Bucal 2008;13: E693-6.  Back to cited text no. 27
Alberti S, Spadella CT, Francischone TR, Assis GF, Cestari TM, Taveira LA. Exfoliative cytology of the oral mucosa in type II diabetic patients: Morphology and cytomorphometry. J Oral Pathol Med 2003; 32:538-43.  Back to cited text no. 28


  [Figure 1]

  [Table 1]


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

  In this article
Article Figures
Article Tables

 Article Access Statistics
    PDF Downloaded63    
    Comments [Add]    

Recommend this journal