General characteristics and epidemiology
Normally, the gastrointestinal wall functions as a reliable mechanical, physico-chemical, and immunogenic barrier. It prevents intestinal microflora, bacterial toxins, and toxic products of food digestion from entering the systemic bloodstream. If this function is impaired, digestive disorders, toxinemia, and systemic infection develop.
Among all nosological forms of digestive system pathology, peptic ulcer disease occupies a prominent place alongside irritable bowel syndrome, malabsorption syndrome, and colitis (chronic and ulcerative colitis). The detection rate of this disease worldwide is steadily increasing.
Key statistical facts:
- Age and gender: The peak incidence occurs in individuals aged 40–60 years. In the age group under 50, men are affected noticeably more often than women.
- Localization: Mucosal destruction of the duodenum predominates over gastric lesions in a 3:1 ratio, and among young patients, this gap reaches 10:1.
- Urbanization: City dwellers are more susceptible to the disease than the rural population.
The pathology is dangerous due to its life-threatening complications: gastrointestinal bleeding occurs in 20–25% of patients, and perforation of the organ wall with subsequent development of peritonitis is also possible.
Infectious factor (Helicobacter pylori)
The role of Helicobacter pylori in the development of recurrent mucosal defects is indisputable. The infection rate among the population is high: even in preschool children (5–7 years old), it is 40–50%. However, it is worth noting that the bacterium is often detected in healthy individuals without clinical symptoms.
The microorganism selectively damages the epithelium and destroys the protective mucus-bicarbonate layer. Mechanisms of aggressive action include:
- Secretion of hydrolytic enzymes (phospholipase, urease, proteases).
- Production of membranotropic and vacuolizing cytotoxic agents.
- Initiation of an inflammatory cascade by stimulating the synthesis of mediators such as tumor necrosis factor alpha (TNF-$\alpha$), various interleukins, and lysosomal hydrolases.
Social and dietary factors
Lifestyle, bad habits, and dietary patterns have a direct impact on the secretory and motor functions of the digestive tract.
Social triggers:
- Chronic stress: High professional workloads and mental exhaustion create a focus of diffuse stagnant excitation in the hypothalamic nuclei. This leads to an increase in the tonic influence of the vagus nerve (n. vagus), which pathologically stimulates motility and secretion.
- Smoking: Nicotine not only triggers pepsinogen hypersecretion but also suppresses the production of protective bicarbonates. In addition, it accelerates the evacuation of low-pH acidic contents into the duodenum.
- Alcohol consumption: Ethanol destroys the mucus-bicarbonate barrier, exerts a direct irritant effect on tissues, and stimulates excessive gastric secretion.
Dietary factor (dietary features): Improper nutrition increases the peptic activity of gastric juice. Regular consumption of large amounts of meat stimulates excessive acid production. Refined foods have low buffering capacity, meaning they are unable to effectively neutralize hydrochloric acid. Finally, infrequent meals and irregular eating schedules lead to the secretion of aggressive digestive juices in the absence of food substrate, damaging the body's own tissues.
Hereditary and iatrogenic (drug-induced) factors
Genetic predisposition plays an important role in etiology. If close relatives suffered from this disease, the risk of its development increases by 10 times. It has also been proven that carriers of blood group 0(I) have a 30–40% higher probability of duodenal ulcer formation. Additionally, an association of the pathology with certain HLA system haplotypes (B5, B12, Bw35) has been identified.
The drug factor is associated with the use of medications that create an imbalance by suppressing the protective mechanisms of the mucosa:
- Nonsteroidal anti-inflammatory drugs (NSAIDs): Drugs like acetylsalicylic acid inhibit the enzyme cyclooxygenase (COX), thereby blocking the production of protective prostaglandins.
- Corticosteroids: Glucocorticoids and mineralocorticoids inhibit gastric epithelial regeneration and significantly reduce mucus secretion.
Briefly: answers to topical questions
What are the complications of peptic ulcer disease?
The main complications of gastric and duodenal ulcers include:
- Bleeding — originates from eroded vessels and is observed in 20–25% of patients (or massive hemorrhage).
- Perforation — rupture of the stomach or duodenal wall with the development of peritonitis.
- Penetration — a variant of perforation where the base of the ulcer becomes the wall of an adjacent organ.
- Pyloric stenosis (pylorostenosis, cicatricial-ulcerative stenosis of the gastric outlet) — in case of decompensation, leads to chlorhydropenic uremia.
- Malignancy — malignant degeneration of the ulcer.
What are the defense factors of the gastric mucosa?
Gastric mucosal defense factors that prevent its damage include:
- Mucus-bicarbonate barrier — the first line of defense, neutralizing acid and creating a pH gradient.
- Prostaglandins — regulate the secretion of mucus and bicarbonates, as well as blood flow.
- Surface epithelium — secretes mucus, bicarbonates, and protective molecules (heat shock proteins, trefoil peptides).
- Phospholipids — create a hydrophobic layer on the epithelial surface.
- Microcirculatory bed — ensures trophic support and adequate blood supply to the mucosa.
- Epithelial regeneration (cellular renewal).
- Sensory nerve bundles.
- Mechanisms of local immunobiological surveillance.
For quick memorization of the five groups of etiological factors, use the mnemonic SIGAL: Social, Infectious, Genetic, Alimentary (Dietary), Drug-induced.
Class and exam questions
Why does the risk of ulcer formation increase during prolonged stress?
Mental exhaustion causes stagnant excitation in the hypothalamus, which increases the tone of the vagus nerve (n. vagus). This leads to excessive stimulation of gastric motor and secretory activity.
Is H. pylori infection the sole cause of the disease?
No. Although the role of this bacterium is indisputable, it can also be detected in completely healthy individuals. The development of mucosal destruction usually requires a combination of several aggressive factors.
How does aspirin intake affect the gastric mucosa?
Acetylsalicylic acid and other NSAIDs suppress cyclooxygenase activity. As a result, the production of prostaglandins, which are necessary to maintain the mucosal protective barrier, ceases.
What else to study on this topic
- Pathogenesis: imbalance of aggressive and defensive factors
- Mechanisms of intestinal barrier dysfunction and the development of toxinemia
- Differences in localization: stomach versus duodenum
- Bleeding and perforation as life-threatening complications
Master the entire topic in the "Pathophysiology" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on the topic «Etiology of Peptic Ulcer Disease» and 4,913 more subject pages
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 135 video lessons on the subject
Other topics in "Chapter 24. Typical Forms of Digestive System Pathology"
Free video lessons: pathophysiologyShort lessons with lecture notes — no registration required.
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.