Salivary Flow Rate, ph, Buffering Capacity and Esophageal ph metry Results in Gastro Esophageal Reflux Disease Patients

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1 ORIGINAL PAPERS Dent. Med. Probl. 2007, 44, 4, ISSN X Copyright by Silesian Piasts University of Medicine in Wrocław and Polish Stomatological Association URSZULA KACZMAREK 1, ELŻBIETA SOŁTAN 1, DOROTA WAŚKO CZOPNIK 2, LESZEK PARADOWSKI 2 Salivary Flow Rate, ph, Buffering Capacity and Esophageal ph metry Results in Gastro Esophageal Reflux Disease Patients Szybkość wydzielania, ph i pojemność buforowa śliny a wyniki ph metrii u pacjentów z chorobą refluksową przełyku 1 Department of Conservative Dentistry and Pedodontics, Silesian Piasts University of Medicine in Wrocław, Poland 2 Department of Gastroenterology and Hepatology, Silesian Piasts University of Medicine in Wrocław, Poland Abstract Background. Gastro esophageal reflux disease (GERD) is a common disease of the contemporary society. Saliva with its organic and inorganic components is responsible for the integrity of oral mucosa and contributes to the pro tection of upper digestive tract. Objectives. The goal of the study was to evaluate a relationship between the salivary flow rate, ph, buffering ca pacity, bicarbonate and phosphates content, and esophageal ph metry results in GERD patients. Material and Methods. 36 subjects were examined, out of which 18 with newly diagnosed gastro esophageal re flux disease by 24 hour ph metry and 18 generally healthy. The GERD patients were subdivided in relation to nor mal and abnormal exposure onto acid in distal and proximal part of esophagus. In unstimulated mixed saliva ph, buffering capacity, bicarbonate and inorganic phosphate content were measured as well as salivary flow rate was calculated. Results. In GERD patients significantly higher (p < 0.05) salivary flow rate than in the control was found (0.66 ± ± 0.46 ml/min vs ± 0.22 ml/min). Taking into consideration mean values of the studied salivary variables in relation to severity of proximal and distal reflux significantly (p < 0.05) lower salivary flow rate in abnormal di stal reflux compared to normal one was found (0.53 ± 0.16 ml/min vs ± 0.61 ml/min). Moreover, positive correlation between salivary flow rate and percentage of the time ph < 4 in upright position (r = 0.517, p = 0.040) for proximal reflux was noticed. Conclusions. The newly diagnosed GERD patients showed increase of salivary secretion probably due to the eso phago salivary reflex evoking by acidification of esophagus (Dent. Med. Probl. 2007, 44, 4, ). Key words: salivary secretion, ph, buffering capacity, GERD. Streszczenie Wprowadzenie. Choroba refluksowa przełyku (GERD gastro esophageal reflux disease) występuje często we współ czesnym społeczeństwie. Ślina wraz ze swoimi składnikami organicznymi i nieorganicznymi jest odpowiedzialna za integralność błony śluzowej jamy ustnej i uczestniczy w ochronie górnego odcinka przewodu pokarmowego. Cel pracy. Ocena zależności między szybkością wydzielania śliny, ph, pojemnością buforową, stężeniami dwu węglanów i fosforanów a wynikami ph metrii przełyku u pacjentów chorych na chorobę refluksową przełyku. Materiał i metody. Zbadano 36 osób, w tym 18 z nowo zdiagnozowaną chorobą refluksową na podstawie 24 go dzinnej ph metrii i 18 ogólnie zdrowych. Pacjentów z GERD podzielono na podgrupy w odniesieniu do prawidło wej i nieprawidłowej ekspozycji na kwas w dystalnej i proksymalnej części przełyku. W niestymulowanej ślinie mieszanej oznaczano ph, pojemność buforową, stężenia dwuwęglanów i fosforanów oraz określano szybkość wy dzielania śliny. Wyniki. U chorych na chorobę refluksową stwierdzono istotnie (p < 0,05) większą szybkość wydzielania śliny niż u osób zdrowych (0,66 ± 0,46 ml/min vs. 0,37 ± 0,22 ml/min). Rozpatrując średnie wartości analizowanych zmien * Supported by KBN 2PO5E10627.

2 440 U. KACZMAREK et al. nych w odniesieniu do nasilenia refluksu proksymalnego i distalnego, zaobserwowano istotnie (p < 0,05) mniejszą szybkość wydzielania śliny przy refluksie nieprawidłowym, w porównaniu z prawidłową ekspozycja w części dy stalnej przełyku (0,53 ± 0,16 ml/min vs. 0,77 ± 0,61 ml/min). Stwierdzono ponadto pozytywną korelację między sekrecją śliny a odsetkiem czasu z ph < 4 w pozycji pionowej dla refluksu proksymalnego (r = 0,517, p = 0,040). Wnioski. Pacjenci z nowo zdiagnozowaną chorobą refluksową wykazują wzrost szybkości wydzielania śliny prawdopodobnie spowodowanym refleksem przełykowo ślinowym wywołanym zakwaszeniem przełyku (Dent. Med. Probl. 2007, 44, 4, ). Słowa kluczowe: wydzielanie śliny, ph, pojemność buforowa, choroba refluksowa przełyku. Gastro esophageal reflux (GER) is the sponta neous movement of the gastric content to the eso phagus. This reflux may occur daily without dama ge of the esophageal mucosa thus considered phy siological. However, GER may cause symptoms and lesions, and then is named gastroesophageal reflux disease (GERD). Nowadays, it is the most prevalent gastrointestinal disease. Reflux related symptoms are reported daily by 7 to 10% of adult population and monthly by 40% [1]. The presence of acid and pepsin in the lumen of esophagus in pa tients with GER is reported as a main factor in the pathology development of esophageal mucosa. Frequent and severe reflux episodes occurring in gastroesophageal reflux disease affect the pa tient s quality of life and cause a damage to the esophageal tissue leading to the esophageal (eso phagitis, esophageal ulcer, strictures, Barrett s eso phagus) and extraesophageal complications (asth ma, chronic cough, laryngitis, pulmonary fibrosis, dental erosion) [2]. Injuring factors acting within the esophageal lumen during the episode of gastro esophageal reflux can balance by suitably mobili zed protective agents. Protection of esophageal mucosa is based on three complementary mechani sms pre epithelial, epithelial and post epithelial. The first line defense is pre epithelial barrier as in juring factors mainly operate within the esophage al lumen. It is enhanced by salivary components. The esophageal exposure to reflux content evokes the esophago salivary reflex causing increase of sa liva secretion and changes in its content of organic and inorganic components [3 6]. The swallowed volume of saliva dilutes acidic reflux and its buffe ring capacity counteracts lowering intraluminal ph within esophagus. Submucosal glands of esopha gus secrete mucous secretion rich in buffers, mu cin, prostaglandin E, epidermal growth factor and transforming growth factor alpha. This esophageal secretion together with similar protective factors occurring in swallowed saliva, forms a mucus buf fer layer, which covers the esophageal mucosa and retards the diffusion of hydrogen ions [4]. The goal of the study was to evaluate a rela tionship between the salivary flow rate, ph and buffering capacity, and esophageal ph metry re sults in GERD patients. Material and Methods The study comprised 36 subjects aged from 21 to 63 years (mean 41.9), out of which 18 with a newly diagnosed gastro esophageal reflux disea se (GERD) and 18 healthy volunteers as control. Esophageal manometry and ph metry was done in Department of Gastroenterology and Hepatology Silesian Piasts University of Medicine in Wro cław. Always, before ph metry manometric stu dies were done to estimate lower esophageal sphincter pressure (LESP), corpus manometry, upper esophageal sphincter pressure (UESP), and upper border of LES (neccessary for precision ph catheter fixation). Esophageal manometry was do ne with the use of water filled catheter (Medtronic, Synecpol) with Upper Polygraph Software. ph metry was done with the use of dual antimony ph electrodes containing spacing 10 cm between them and with one electrode located at the tip. The data in the recorder were transferred to a computer with special program for analysis following com pletion of the ph study (Medtronic, Synecpol). ph catheter was placed transnasally into the esopha gus in position 5 cm above LES. During the study, the patient marked changes in body position and meal time, because it is necessary to estimate cor relation of symptom index. GERD was diagnosed when total time ph < 4 was 3.4% (upper border for our labolatory) and DeMeester score was above 14.75, total number of refluxes over 20 and patho logical, long refluxes were confirm (longer than 5 min). Twelve components for proximal and distal acid refluxes were measured: numbers of total re fluxes and long refluxes lasting longer than 5 min, the percentage time of ph below 4 for total refluxes, and in upright and supine positions, and Johnson & DeMeester score (Table 1). The GERD patients (group I) were subdivided accor ding to abnormal and normal the distal and proxi mal esophageal 24 hour acid exposure. Abnor mal distal reflux was defined as upright ph < 4 lasting above 8.8% or supine ph < 4 lasting abo ve 3.0%. Proximal esophageal ph data were con sidered abnormal if time of ph < 4 in upright and supine position exceeded 1.7% and 0.6%, respec tively [5].

3 Salivary Parameters and Esophaegal ph metry in GERD 441 Table 1. Severity of reflux in GERD patients Tabela 1. Ciężkość refluksu u pacjentów z GERD Proximal reflux (Proksymalny refluks) Number of total Number of % time ph below 4 Johnson & refluxes long reflux (% czasu ph poniżej 4) DeMeester index (Liczba wszystkich > 5 min total upright supine (wskaźnik Johnsona refluksów) (Liczba długich i DeMeestera) refluksów > 5 min) x ± SD x ± SD x ± SD x ± SD x ± SD x ± SD ± ± ± ± ± ± Distal reflux (Dystalny refluks) ± ± ± ± ± ± Samples of resting mixed saliva were collec ted in GERD patients (group I) and in matched he althy controls (group II). In the salivary superna tants obtained after samples centrifugation for 10 minutes at room temperature at speed rpm ph (by a pehameter), buffering capacity Bc (by potentiometric titration method), bicarbonate Bi (by titration method), inorganic phosphate Pi (by Alpha Diagnostic Kit based on the formation of a complex of phosphate ion using a molybdate compound). The protocol of the study has been approved by Bioethics Committee at the Wroclaw Medical Uni versity (protocol KB 27/2004) and informed, writ ten consent from all the subjects was obtained. The obtained data were analyzed by Student t, U Mann Whitney, Levene and paired tests at p < Pe arson s correlation coefficients were calculated to investigate the association between variables. Results Comparing GERD patients (group I) to the control (group II) significantly higher salivary flow rate was found (p < 0.05). The remaining sa livary variables did not reveal any significant dif ferences (Table 2). Analysis of correlation betwe en salivary variables showed negative correlation between inorganic phosphate and bicarbonate con tent (r = , p = 0.003) in GERD patients and positive correlation between ph and buffering ca pacity (r = , p = 0.035) in the control group (Table 3). Taking into consideration mean values of the studied salivary variables in relation to severity of proximal and distal reflux significantly lower sali vary flow rate in abnormal distal reflux compared to normal one, was found (Table 4). Table 2. Salivary parameters in GERD patients and heal thy control Tabela 2. Parametry śliny u pacjentów z GERD i zdro wych w grupie kontrolnej Analysis of interrelationship between salivary variables and parameters of reflux severity showed positive correlation between salivary flow rate and percentage of the time ph below 4 in upright po sition (r = 0.517, p = 0.040) for proximal reflux (Table 5). Discussion Group I (Grupa I) Group II control (Grupa II kontrolna) V ml/min) 0.66 ± ± 0.22 (Szybkość wydzie lania śliny ml/min) ph 6.83 ± ± 0.20 Bc mmol/l) 5.44 ± ± 2.41 (Pojemność bufo rowa mmol/l) Bi meq/l) ± ± 1.34 (Dwuwęglany meq/l) Pi mg/l ± ± (Fosforany nieorga niczne mg/l) Significant difference at p < Istotność różnic na poziomie p < 0,05. It has been found that saliva plays a role in the clearance of acid in the esophagus in healthy and GERD subjects. Organic and inorganic compo nents of saliva enhance the pre epithelial defense

4 442 U. KACZMAREK et al. Table 3. Values of Pearson s correlation coefficient between salivary variables in GERD and control patients Tabela 3. Wartości współczynnika korelacji Pearsona między zmiennymi śliny u pacjentów z GERD i w grupie kontrolnej Group II control (Grupa II kontrolna) Group I V ph Bc Bi Pi (Grupa I) (Szybkość (Pojemność (Dwuwęglany) (Fosforany wydzielania buforowa) nieorganiczne) śliny) V r = r = r = r = (Szybkość p = p = p = p = wydzielania śliny) ph r = r = r = r = p = p = p = p = Bc r = r = r = r = (Pojemność p = p = 0.65 p = p = buforowa) Bi r = r = r = r = (Dwuwęglany) p = p = p = p = Pi r = r = r = r= (Fosforany p = p = p = p = nieorganiczne) Table 4. Salivary parameters in subgroups of GERD patients according to severity of proximal and distal reflux Tabela 4. Parametry śliny w podgrupach pacjentów z GERD w odniesieniu do proksymalnego i dystalnego refluksu Subgroups Proximal reflux Distal reflux (Podgrupy) (Proksymalny refluks) (Dystalny refluks) abnormal normal abnormal normal Salivary parameters x ± SD x ± SD x ± SD x ± SD (Parametry śliny) V ml/min 0.64 ± ± ± ± 0.61 (Szybkość wydzielania śliny ml/min) ph 7.19 ± ± ± ± 0.28 Bc mmol/l 5.65 ± ± ± ± 2.68 (Pojemność buforowa mmol/l) Bi meq/l ± ± ± ± 1.58 (Dwuwęglany meq/l) Pi mg/l ± ± ± ± (Fosforany nieorganiczne mg/l) Significant difference at p < Istotność różnic na poziomie p < 0,05. barrier of esophagus [4, 6, 7]. Acid clearance of esophagus occurs in two step mechanisms, eso phageal peristalsis which clearing down the reflu xat volume and saliva neutralizing the acid [8]. The esophageal clearance form acid is an impor tant defense against the development of reflux eso phagitis. The salivary glands in response to eso phageal acidification secrete more saliva, which is named esophago salivary reflex [3, 9]. The incre ase of swallowed saliva shortens the contact time of acid with esophageal mucosa. It was reported diminishing salivary glands function in GERD pa tients [10, 11]. However, other authors did not find any difference in salivary flow rate between GERD patients and healthy control [5, 12 14]. Our data showed higher salivary flow rate in new diagnosed GERD patients compared to the control (Table 2) as well as positive correlation between

5 Salivary Parameters and Esophaegal ph metry in GERD 443 Table 5. Values of Pearson s correlation coefficient between salivary variables and severity of reflux in GERD patients Tabela 5. Wartości współczynnika korelacji Pearsona między zmiennymi śliny a ciężkością refluksu u pacjentów z GERD Proximal reflux (Proksymalny refluks) Number of Number of % time ph below 4 Johnson & total refluxes long reflux (% czasu ph poniżej 4) DeMeester index (Liczba > 5 min total upright supine (Wskaźnik wszystkich (Liczba Johnsona refluksów) długich i DeMeestera) refluksów < 5 min) V r = 0.44 r = r = r = r = r = (Szybkość wy p = p = p = p = p = p = dzielania śliny) ph r = r = r = r = r = r = p = p = p = p = p = p = Bc r = 0.74 r = r = r = r = r = (pojemność p = p = p = p = p = p = buforowa) Bi r = r = r = r = r = r = (Dwuwęglany) p = p = p = p = p = p = Pi r = r = r = r = r = r = (Fosforany p = p = p = p = p = p = nieorganiczne) Distal reflux (Dystalny refluks) V r = r = r = r = r = r = Szybkość wy p = p = p = p = p = p = dzielania śliny) ph r = r = r = r = r = r = p = p = p = p = p = p = Bc r = r = r = r = r = r = (Pojemność p = p = p = p = p = p = buforowa) Bi r = r = r = r = r = r = (Dwuwęglany) p = p = p = p = p = p = Pi r = r = r = r = 0.04 r = r = (Fosforany p = p = p = p = p = p = nieorganiczne) salivary flow rate and the percentage of time with ph below 4 at proximal reflux (Table 5). It was probably caused by esophageal acidification evo king salivary secretion via esophago salivary re flex. In model of esophageal perfusion in humans the chemical stimuli mimicking the reflux episode resulted in increase of volume of saliva, salivary ph and viscosity as well as mucin concentration over the baseline value [3, 9, 15]. Similarly to the results obtained by the other authors [13, 14], we did not find significant difference in salivary ph value between GERD patients and healthy sub jects, however slightly lower ph value in the pa tients was noticed. Costa et al. [16] presented a re lationship between ph and volume of saliva and esophageal ph metry results in GERD patients with laryngo phageal manifestation, which were divided into four groups according to the number of distal reflux episodes and two groups according to the presence or absence of proximal reflux. They observed correlation between salivary volu me alone and salivary ph x volume with the number of distal and proximal episodes of reflux on the esophageal ph metry. The salivary buffering capacity is supplied by three main buffer systems the bicarbonate, the phosphate and the protein. These systems differ in their ph ranged of maximal buffering capacity; the pk value of bicarbonate is and phosphate [17, 18], the increase of salivary flow re sults in higher bicarbonate concentration and acid neutralization. The phosphate and protein buffers

6 444 U. KACZMAREK et al. have a minor contribution in the total salivary buf fering capacity in relation to bicarbonate system. Moreover, the phosphate system is relatively inde pendent of salivary secretion rate [18]. We did not observe any significant difference in buffering ca pacity, bicarbonate and inorganic phosphate con tents between the GERD patients and the healthy control (Table 2). These findings are in agreement with results of the other authors [5, 12, 13]. Howe ver, Bouchoucha et al [14] found significantly hi gher phosphate concentration in saliva of patients with clinical symptoms of GER and abnormal acid exposure of esophagus confirmed by 24 hour ph metry in comparison to the control. Finally, among the studied salivary variables the only salivary flow rate seems to be a marker for the presence and intensity of gastro esophage al reflux at newly diagnosed GERD patients in cli nical setting. The authors concluded that the newly diagno sed GERD patients showed the increase of saliva ry secretion. References [1] NEBEL O., FORNES M., CASTELL D.: Symptomatic gastroesophageal reflux: incidence and precipitating factors. Am. J. Dig. Dis. 1976, 21, [2] BERNARDI R.R., PETERSON W.L., REED K.L., WEART C.W.: Gastroesophageal reflux disease: simple heartburn or serious disease. APhA [3] NAMIOT Z., ROURK R.M., PIASCIK R., HETZEL D.P., SAROSIEK J., MACCALLUM R.W.: Interrelationship between eso phageal challenge with mechanical and chemical stimuli and salivary protective mechanisms. Am. J. Gastroente rol. 1994, 89, [4] SAROSIEK J., MCCALLUM R.W.: Mechanisms of oesophageal mucosal defence. Baillieres Best Pract. Res. Clin. Ga stroenterol. 2000, 14, [5] SCHRODER P.L., FILLER S.J., RAMIREZ B., LAZARCHIK D.A., VAEZI M.F., RICHTER J.E.: Dental erosion and acid re flux disease. Ann. Int. Med. 1995, 122, [6] SAROSIEK J. MCCALLUM R.W.: What role do salivary inorganic components play in health and disease of the eso phageal mucosa? Digestion 1995, 56, Suppl. 1, [7] SAROSIEK J. MCCALLUM R.W.: Do salivary organic components play a protective role in health and disease of the esophageal mucosa? Digestion 1995, 56, Suppl. 1, [8] HELM J.F.: Role of saliva in esophageal function and disease. Dysphagia 1989, 4, [9] SHAFIK A., EL SIBAI O., SHAFIK A.A., MOSTAFA R. Effect of topical esophageal acidification on salivary secretion: Identification of the mechanism of action. J. Gastroenterol. Hepatol. 2005, 20, [10] URITA Y., DOMON K., YANAGISAWA T., ISHIKARA S., HOSHINA M., AKIMOTO T., KATO H., HARA N., HONDA Y., NAGAI Y., NAKANISHI N., TAKANO M., WATANABE T., SUGIMOTO M., MIKI K.: Salivary glands scintigraphy in gastro esopha geal reflux disease. Inflammopharmacology 2007, 15, [11] KAO C.H., HO Y.J., CHANGLAI S.P., LIAO K.K.: Evidence for decreased salivary function in patients with reflux esophagitis. Digestion 1999, 60, [12] SAXENA R., BARTLETT D.W., SMITH B.G.: The role of saliva in regurgitation erosion. Eur. J. Prostheodont. Resto rative Dent. 1999, 7, [13] SAROSIEK J., SCHEURICH C.J., MARCINKIEWICZ M., MCCALLUM R.W.: Enhancement of salivary esophagoprotection: rationale for a physiological approach to gastroesophageal reflux disease. Gastroenterology 1996, 110, [14] BOUCHOUCHA M., CALLAIS F., RENARD P., EKINDIJAN O.G., CUGNENC P.H., BARBIER J.P.: Relationship between acid neutralization capacity of saliva and gastro oesophageal reflux. Arch. Physiol. Viochem. 1997, 105, [15] SAROSIEK J., ROURK R.M., PIASCIK R., NAMIOT Z., HETZEL D.P., MCCALLUM R.W.: The effect of esophageal mechani cal and chemical stimuli on salivary mucin secretion in healthy individuals. Am. J. Med. Sci. 1994, 308, 1, [16] COSTA H.O., NETO O.M., ECKLEY C.A.: Is there a relationship between the ph and volume of saliva and esopha geal ph metry results? Dysphagia 2005, 20, [17] BARDOW A., MOE D., NYVAD B., NAUNTOFTE B.: The buffer capacity and buffer systems of human whole saliva measured without loss of CO 2. Arch. Oral Biol. 2000, 45, [18] LENANDER LUMIKARI M., LOIMARANTA V.: Saliva and dental caries. Adv. Dent. Res. 2000, 14, Address for correspondence Urszula Kaczmarek Department of Conservative Dentistry and Pedodontics Silesian Piasts University of Medicine Krakowska Wrocław Poland Tel.: E mail: ukaczm@stom.am.wroc.pl Received: Revised: Accepted: Praca wpłynęła do Redakcji: r. Po recenzji: r. Zaakceptowano do druku: r.