Research Report
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World J Gastroenterol. Apr 7, 2014; 20(13): 3635-3639
Published online Apr 7, 2014. doi: 10.3748/wjg.v20.i13.3635
Seroepidemiology of Helicobacter pylori infection in elderly people in the Beijing region, China
Mei Zhang, Ying-Zhi Zhou, Xiao-Ying Li, Zhe Tang, Hong-Ming Zhu, Yan Yang, Jagadish K Chhetri
Mei Zhang, Ying-Zhi Zhou, Xiao-Ying Li, Zhe Tang, Hong-Ming Zhu, Yan Yang, Jagadish K Chhetri, Department of Gastroenterology, XuanWu Hospital, Capital Medical University, Beijing 100053, China
Author contributions: Zhang M conceived the study and drafted the paper; Li XY approved and supervised the paper; Zhou YZ and Chhetri JK critically reviewed and revised the paper; Tang Z collected source material and analyzed the preliminary data; Zhu HM and Yang Y analyzed the data and performed the statistics.
Correspondence to: Mei Zhang, Professor, Department of Gastroenterology, Xuanwu Hospital, Capital Medical University, No. 45 Changchun Street, Xuanwu District, Beijing100053, China. zhang2955@sina.com
Telephone: +86-10-83198899 Fax: +86-10-83198899
Received: February 13, 2014
Revised: February 25, 2014
Accepted: March 5, 2014
Published online: April 7, 2014
Abstract

AIM: To investigate seroepidemiology of cagA+ and vacA+ strains of Helicobacter pylori (H. pylori) in an elderly population in Beijing and to determine risk factors for seropositivity.

METHODS: A total of 2006 elderly persons (> 60 years) were selected using a random cluster sampling method in different parts of the Beijing area (urban, suburban and mountainous districts). Structured questionnaires were completed during home visits, including history of H. pylori infection, history of gastrointestinal diseases, diet types, hygiene habits, occupation and economic status. Blood samples (2 mL) were collected from each participant, and serum IgG antibodies to cagA, vacA and H. pylori urease antigens were measured by immunodetection.

RESULTS: The prevalence of H. pylori infection in elderly subjects was 83.4% and the type I H. pylori strain infection rate was 56%. The seroprevalence for type I H. pylori strain infection in urban and suburban districts was higher than that in the mountainous areas (P < 0.001). Elderly subjects who had previously performed manual labor or were in the young-old age group (age < 75 years) had a higher seroprevalence of H. pylori infection than those who had previously performed mental labor or were in the oldest-old age group (age ≥ 75 year) (P < 0.05). The type I H. pylori strain infection rate in the elderly with vegetarian diets was higher than in those eating high-protein foods (P < 0.001). There was no significant difference in the prevalence of H. pylori strains between male and female elderly participants (P > 0.05).

CONCLUSION: Type I H. pylori seroprevalence is higher in elderly people. The distribution of strains of H. pylori is significantly affected by age, area and dietary habits.

Keywords: Elderly, Epidemiology, Helicobacter pylori, Virulence factors, Immunoblotting

Core tip: As society ages, a considerable proportion of the elderly population will suffer from digestive diseases combined with Helicobacter pylori (H. pylori) infection. In Beijing, there are no data regarding the pattern of H. pylori genotypes in the elderly. Our study investigated the seroepidemiology of the cytotoxin-associated gene product cagA+ and vacuolating cytotoxin vacA+ strains of H. pylori in elderly people in Beijing, and risk factors for seropositivity. Interesting associations between H. pylori seropositivity and subjects’ habits were found in this population. This is the first prospective study conducted in China to investigate the genotype profiles of H. pylori.