Clinical and Morphofunctional Characteristics of Gastroesophageal Reflux Disease in the Conditions of Yakutia

The dissertation is devoted to the study of the clinical, endoscopic, and morphofunctional characteristics of gastroesophageal reflux disease (GERD) among the population of Yakutia, taking into account ethnicity. It examines the prevalence and structure of the disease in the northern region, the peculiarities of the combination of GERD with thyroid pathology under conditions of iodine deficiency, and the role of Helicobacter pylori infection. A comprehensive clinical-endoscopic and morphological examination of patients was carried out, and the capabilities of 24-hour intraesophageal pH monitoring were assessed for the diagnosis of endoscopically negative and atypical forms of the disease. The data obtained were compared between the indigenous and incoming populations and are aimed at optimizing the diagnosis and treatment of GERD in the specific climatic and geographic conditions of Yakutia.

RELEVANCE OF THE STUDY

The study of gastroesophageal reflux disease (GERD) is one of the priority areas of modern gastroenterology. The relevance of its investigation is determined by the wide prevalence of the disease, including in northern conditions (V.Kh. Vasilenko, A.L. Grebenev et al., 1971; A.V. Kalinin, 1999; E.S. Ryss, 2002; V.T. Ivashkin, A.S. Trukhmanov, 2003; Ya.S. Tsimmerman, 2009; R.S. Fisher et al., 1994; T.R. DeMeester et al., 1995).

By its frequency, temporary disability, and presence of complications, GERD constitutes a socio-medical problem of contemporary society (P.Ya. Grigor'ev, A.V. Yakovenko, 2001). The prevalence of GERD among the adult population of developed countries reaches 20–40%, while in Asian countries it is around 5% (S.J. Spechler, 1992; H. Petersen, 1995; J. Dent et al., 2005; K.-L. Goh, 2007). Comparable findings are provided by epidemiological studies conducted in Russia in recent years: in Novosibirsk, GERD symptoms are reported weekly by 17% of the population (O.V. Reshetnikov, S.A. Kurilovich, 2008), in Moscow the prevalence of GERD is 23.6% (S. Bor et al., 2006), and in other Russian cities it is 13.3% (D.S. Bordin, A.A. Masharova, 2008).

Over the past 15–20 years, the relative frequency of detection of gastric and duodenal ulcers has decreased from 15.9 to 4.6% and from 39.1 to 9.3%, respectively, whereas the detection rate of the erosive form of GERD has, on the contrary, increased from 3.1 to 16% (N.B. El-Serag, A. Sonnenberg, 1998; S.F. Assimakopoulos et al., 2007). Leading gastroenterologists (A.A. Sheptulin, 2008; M.J. Blaser, 1999) believe that the dynamics of the increase in GERD morbidity and the decrease in peptic ulcer morbidity will be so intense that in the twenty-first century GERD will become the dominant gastroenterological disease.

The relevance of the GERD problem is determined by the presence of serious complications—erosions, peptic ulcers, hemorrhages, strictures, the development of Barrett's esophagus as a precancerous condition, and esophageal adenocarcinoma. Over the past 20 years, the number of patients with adenocarcinoma of the distal esophagus has increased threefold (Yu.V. Vasil'ev, 2005).

In Yakutia, GERD has been studied by many surgical researchers (Ivanov A.I., 1996; Tobokhov A.V., 2003; Pavlova Z.V., 2006, et al.). At the same time, the manifestations of GERD in different ethnic groups of the Yakutia population remain insufficiently studied.

A turning point in the understanding and diagnosis of GERD was the introduction of intraesophageal pH monitoring, when Johnson and DeMeester first studied the normal parameters and qualitative indicators of acid exposure of the esophagus in patients with reflux disease, presenting the concept of physiological reflux (L.F. Johnson, T.F. DeMeester, 1974).

The combination of GERD with thyroid diseases is of definite interest, given that Yakutia is among the territories with a high prevalence of iodine-deficiency disorders.

Among diseases of the endocrine system, thyroid diseases occupy the leading place by prevalence (I.I. Dedov, 1999). Over the last decade, thyroid diseases have shown a marked tendency toward further growth. This is facilitated by the influence of adverse environmental factors (an increase in the radioactive background in a number of localities, a deterioration of the overall ecological situation), which reduce the immunological defense of the body, as well as the discontinuation of planned iodine prophylaxis in endemic zones, deterioration of the population's nutrition, and a large number of causes of stressful situations (G.S. Zefirova, 1999).

The frequency of gastrointestinal disorders is so high that it suggests a certain interrelation between the thyroid gland and the digestive tract (Shereshevskii N.A., 1957; Sakharchuk I.I., 1969; Miesowicz E., 1904; Derblom H., 1963; Miller L.I. et al., 1978). Various dyspeptic phenomena, such as heartburn, nausea, vomiting, and a feeling of pressure in the epigastric region, occur in patients regardless of the severity of thyrotoxicosis and may be the sole manifestation of this disease (Kurbatova L.I., 1962; Miller L.I. et al., 1978), whereas primary hypothyroidism is characterized by functional changes in esophageal motility and the tone of the lower esophageal sphincter that promote the development of hiatal hernia and reflux esophagitis (Savina L.V., Semenikhina T.M. et al., 2006). Investigation of the functional and morphological changes in the stomach and duodenum reveals that the majority of patients have gastroduodenitis, with the damage to the glands correlating with the severity and duration of the underlying disease (S.M. Kotova, 1975). However, the abdominal symptoms of thyroid diseases are recognized as the least studied.

There are no data on the nature and peculiarities of the course of GERD with concomitant Helicobacter pylori-associated gastritis in patients with impaired thyroid function. It appears important to study the effect of HP on the processes of epithelial cell regeneration and the development of atrophy and metaplasia of the esophageal mucosa in this group of patients. Equally relevant is the assessment of the relationship between functional disorders of the esophagus and stomach, acid-peptic aggression, and the degree of microbial expansion in the upper digestive tract.

At the present stage of GERD research, the effectiveness of its treatment cannot be considered satisfactory—the cure of this disease remains an unsolved task (Tsimmerman Ya.S., 2009).

The development of megaprojects in Yakutia implies an increase in the number of incoming population, which may be associated with issues of timely prevention, diagnosis, and treatment of many diseases, including GERD.

In view of the above, it appears that the study of the clinical-endoscopic, functional, and morphological manifestations of GERD will make it possible to determine the peculiarities of the course of this disease in different ethnic groups of the Yakutia population, including in combination with functional thyroid disorders.

AIM OF THE STUDY

To investigate the clinical-endoscopic and morphofunctional characteristics of GERD in different ethnic groups living in the conditions of Yakutia.

OBJECTIVES OF THE STUDY

1. To identify the peculiarities of the clinical manifestations of GERD in different ethnic groups living in the conditions of Yakutia.

2. To study the character of the endoscopic and morphological manifestations of GERD in different ethnic groups living in the conditions of Yakutia.

3. To identify the peculiarities of the course of GERD in combination with thyroid diseases in the conditions of Yakutia.

4. To establish the frequency and degree of Helicobacter pylori colonization in patients with GERD in the conditions of Yakutia.

5. To evaluate the capabilities of 24-hour intraesophageal pH monitoring in the diagnosis and optimization of GERD treatment.

KEY FINDINGS SUBMITTED FOR DEFENSE

1. The clinical picture of GERD in different ethnic groups living in the conditions of Yakutia is characterized by polymorphism of symptoms and depends on the severity of the course and the concomitant pathology.

2. The histomorphological criteria of GERD in the conditions of Yakutia are signs of hypertrophic esophagitis with hyperkeratosis, parakeratosis, and acanthosis in the majority of patients. More severe endoscopic signs of esophageal damage are characteristic of patients from the incoming (non-indigenous) population.

3. GERD in combination with hypo- and hyperfunction of the thyroid gland has specific features of its course.

4. Helicobacter pylori infection in GERD patients in the study is higher among incoming patients.

5. The use of 24-hour pH monitoring makes it possible to evaluate the course of endoscopically negative forms and atypical clinical manifestations of GERD in the conditions of Yakutia, as well as to optimize treatment costs.

SCIENTIFIC NOVELTY

The peculiarities of the clinical, endoscopic, and morphological manifestations of GERD in different ethnic groups living in the conditions of Yakutia have been studied and identified, including in combination with thyroid hyper- and hypofunction. It has been shown that Helicobacter pylori infection among GERD patients from the indigenous population is lower than among the incoming population, and the indices of Helicobacter pylori contamination have been compared with the severity of esophageal mucosal changes.

PRACTICAL SIGNIFICANCE

The studies performed on the peculiarities of the clinical, endoscopic, and morphofunctional manifestations of GERD in the conditions of Yakutia, taking into account the severity of the disease and the character of the concomitant pathology, have made it possible to optimize the diagnosis and treatment of patients.

The identified peculiarities of the course of GERD in patients with thyroid pathology can improve the quality of treatment in this category of patients.

The broad use of 24-hour esophageal pH monitoring in the conditions of Yakutia has been proposed for the individual assessment of the effectiveness of pharmacological drugs, given the high cost of modern acid-suppressive agents, as well as for the diagnosis of endoscopically negative and atypical manifestations of this disease.

APPROVAL of the dissertation took place at the joint scientific and practical conference of the Departments of Propaedeutics of Internal Medicine and Faculty Therapy of the Medical Institute of the Yakutsk State University, the Yakutsk Scientific Center of Complex Medical Problems of the Siberian Branch of the Russian Academy of Medical Sciences, and the departments of the Municipal Institution «Yakutsk Municipal Clinical Hospital» on 26 May 2009. The main provisions of the dissertation were reported at the 11th Russian-Japanese International Medical Symposium (Niigata, 2004), at the 2nd Interregional Scientific and Practical Conference Dedicated to the 50th Anniversary of Higher Medical Education of the Republic of Sakha (Yakutia) «Ecology and Human Health in the North» (Yakutsk, 2007), at the Conference Dedicated to the 165th Anniversary of the Municipal Institution «Yakutsk Municipal Hospital» (Yakutsk, 2008), at the All-Russian Scientific and Practical Conference with International Participation Dedicated to the Third International Polar Year «International Polar Year: Achievements and Prospects for the Development of Circumpolar Medicine» (Arkhangelsk, 2009), and at the Interregional Scientific and Practical Conference with International Participation «Current Issues of Precancerogenesis and Malignant Tumors in Different Climatic and Geographic Zones» (Yakutsk, 2009).

VOLUME AND STRUCTURE OF THE WORK

The dissertation is set out on 123 pages of typewritten text and consists of an introduction, a review of the literature, a description of the materials and methods of the study, a chapter of original observations, a conclusion, conclusions, practical recommendations, and a bibliography. The work is illustrated with 39 tables and 6 figures. The bibliography includes 237 sources, of which 92 are Russian and 145 are by foreign authors.