How common is gastritis?

Prevalence of Gastritis

Gastritis is common, with atrophic gastritis affecting up to 15% of the US population, and potentially higher rates in specific populations with increased H. pylori prevalence or gastric cancer risk. 1

Types of Gastritis and Their Prevalence

H. pylori-Associated Gastritis

• H. pylori is the dominant etiology of gastritis globally, with chronic gastritis affecting more than half of people worldwide 2
• H. pylori-associated gastritis (HpAG) is the most common form of atrophic gastritis 1, 3
• The rate ratio of atrophic gastritis incidence in patients with vs. without H. pylori infection is 5.0 (95% CI, 3.1–8.3) 1
• H. pylori infection in childhood is the main cause of chronic gastritis 2

Autoimmune Gastritis

• Autoimmune gastritis (AIG) is significantly less common than H. pylori-associated gastritis 1, 3
• The prevalence of autoimmune gastritis is estimated at 0.5-2% of the population 1, 3
• Prevalence increases with age and presence of other autoimmune diseases 1
• Up to one-third of patients with autoimmune thyroid disease have autoimmune gastritis 1, 4
• Women have a higher prevalence of AIG compared to men 1
• Pernicious anemia, a late-stage complication of AIG, is even rarer with an estimated prevalence of 0.15-1% 1

Age-Related Prevalence

• Atrophic gastritis prevalence increases significantly with age 5
• In an autopsy study of non-hospitalized individuals, the prevalence of atrophic gastritis increased from 7.1% in those under 50 years to 47.8% in those over 70 years 5
• The proportion of healthy gastric mucosa decreased age-dependently from 71.4% among individuals under 50 years to 43.5% among those over 70 years 5

Population-Specific Variations

• Atrophic gastritis may be more prevalent in specific populations with higher baseline H. pylori prevalence 1
• Non-White racial/ethnic minority groups and early-generation immigrants from high-risk countries have higher rates 1
• In contrast to HpAG, racial and ethnic variation is not prominent in autoimmune gastritis 1

Clinical Presentation and Diagnosis Challenges

• Gastritis is typically asymptomatic and may go undiagnosed, or present with nonspecific symptoms that occur later in the disease course 1, 6
• Common symptoms include epigastric pain/discomfort, nausea, vomiting, early satiety, bloating, and heartburn 6
• Inconsistent reporting of atrophic gastritis on histopathology contributes to underdiagnosis 1
• In patients with dyspepsia, H. pylori-negative chronic gastritis is now more common than gastritis with H. pylori infection 7
• Collection of too few biopsy specimens may result in failure to detect inflammatory changes and/or H. pylori infection 7

Complications and Risk Factors

• Atrophic gastritis is associated with increased risk of gastric adenocarcinoma (0.1-0.3% per year) 1, 3
• Patients with chronic atrophic gastritis, particularly AIG, are at increased risk of type I gastric neuroendocrine tumors (0.4-0.7% per year) 1, 3
• Risk factors for non-autoimmune atrophic gastritis include age, tobacco use, high-salt diet, and possibly chronic bile acid reflux 1
• Severe atrophic gastritis can lead to malabsorption of essential vitamins and micronutrients (vitamin B12, iron, calcium, magnesium, and zinc) 2

In summary, gastritis is a common condition with varying prevalence based on type, age, and population characteristics. Atrophic gastritis affects up to 15% of the US population, with higher rates in older individuals and specific high-risk groups. The condition is often underdiagnosed due to its asymptomatic nature and inconsistent reporting on histopathology.