Prevalence of Helicobacter pylori infection in the general population evaluated by a resident-register-based epidemiological study.

BACKGROUND: The current status of Helicobacter pylori infection in Japan has not been investigated. We evaluated the status of H. pylori infection in a Japanese general population using large-scale resident-register-based sampling. METHODS: All 6069 adults in a rural town and 6000 adults in two urban cities (3000 each), selected by register-based random sampling, were enrolled in our health check-up program. Antibody titers against Helicobacter pylori (cut-off value was 3 U/mL by Eiken E-plate) were evaluated, and subjects with a positive result were encouraged to undergo further examinations. RESULTS: A total of 1586 subjects participated in serum sampling. The overall prevalence of H. pylori infection was 40.0% (634/1586), and it increased with age both in rural and urban areas. Although the overall positive rate was higher in the rural area (49.4%) than in the urban areas (35.6 and 32.3%), there was no difference in H. pylori status of younger subjects between the two areas. Among 634 patients with a positive titer, 374 (59.0%) underwent further examinations including endoscopic examination, and 180/634 (28.4%) patients received eradication therapy. Gastric neoplasms (three adenocarcinomas and one adenoma) were found in our screening program. CONCLUSION: We clarified population-based random sampling data of H. pylori infection in a Japanese general population. In younger subjects, a decrease in the prevalence of H. pylori infection was confirmed both in rural and urban areas. This provides basic information for establishing a strategy to reduce gastric cancer deaths.

Distribution of FIB-4 index in the general population: analysis of 75,666 residents who underwent health checkups.

BACKGROUND: Fatty liver is frequently found in a general population, and it is critical to detect advanced fibrosis. FIB-4 index is considered a useful marker for evaluating liver fibrosis but the distribution of FIB-4 index in the general population remains unknown. METHODS: This cross-sectional study included residents who underwent ultrasonography at health checkups in Hiroshima or Iwate prefectures. The distribution of FIB-4 index in the total study population (N = 75,666) as well as in non-alcoholic fatty liver disease (NAFLD) populations (N = 17,968) and non-drinkers without fatty liver populations (N = 47,222) was evaluated. The distribution of aspartate aminotransferase (AST) levels, alanine aminotransferase (ALT) levels was also evaluated. RESULTS: The mean FIB-4 index in the total study population was 1.20 ± 0.63. FIB-4 index ≥ 2.67, which indicates a high risk of liver fibrosis, was found in 16.4% of those aged ≥ 70 years. In the NAFLD population, 58.1% of those in their 60 s and 88.1% of those ≥ 70 years met the criteria for referral to hepatologists by using the recommended FIB-4 index cutoff value (≥ 1.3). The mean FIB-4 index in the NAFLD population (1.12 ± 0.58) was significantly lower than in the non-drinkers without fatty liver (1.23 ± 0.63, p < 0.0001). The non-drinkers without fatty liver tended to have higher AST relative to ALT levels (60.0% with AST/ALT > 1.0), whereas the results in the NAFLD population were opposite (14.8% with AST/ALT > 1.0). AST > ALT resulted in a higher FIB-4 index in non-drinkers without fatty liver due to the nature of FIB-4 index formula. CONCLUSIONS: The cutoff value of FIB-4 index (≥ 1.3) for triaging the elderly people with fatty liver for referral to hepatologists should be reconsidered to avoid over-referral. Due to the impact of age and characteristics of AST/ALT ratios, there is no prospect of using FIB-4 index for primary screening for liver fibrosis in a general population of unknown presence or absence of liver disease, even though it can be easily calculated using routine clinical indices. It is desired to develop a non-invasive method for picking up cases with advanced fibrosis latent in the general population.

Relationship between drinking frequency and fatty liver prevalence or incidence in Japanese undergoing health checkup in 2008-2019.

BACKGROUND & AIMS: The relationship between the frequency of drinking and fatty liver in the general population is still poorly understood. This study analysed data from a large cohort who underwent health checkups in Japan between 2008 and 2019 to investigate the prevalence and incidence of fatty liver by alcohol consumption and risk factors for fatty liver. METHODS: The prevalence of fatty liver diagnosed with ultrasonography was calculated in 75,670 residents. The incidence of fatty liver in 31,062 residents who underwent ultrasonography at least twice during the period without fatty liver at the first time was calculated using the person-year method. Multivariate logistic analysis was performed to investigate risk factors associated with the prevalence and incidence of fatty liver. RESULTS: The prevalence of fatty liver was 27.6% (95% confidence interval [CI], 27.2-27.9) in non-drinkers, 28.5% (27.5-29.5) in moderate-drinkers and 28.0% (26.0-29.9) in heavy-drinkers. The incidence of fatty liver was 3,084/100,000 person-years (2,997-3,172/100,000) in non-drinkers, 3,754/100,000 person-years (3,481-4,042/100,000) in moderate-drinkers and 3,861/100,000 person-years (3,295-4,497/100,000) in heavy-drinkers. The prevalence and incidence of fatty liver were not associated with drinking status. Obesity was the most important independent risk factor (prevalence: adjusted odds ratio [AOR], 6.3; 95% CI, 6.0-6.5; incidence: AOR, 2.4; 95% CI, 2.3-2.6). CONCLUSIONS: Drinking status does not affect the prevalence or incidence of fatty liver in Japanese residents undergoing health checkups. From a public health perspective, measures for obesity control must be prioritised to reduce the burden of disease of fatty liver in Japan.

Very low prevalence of anti-HAV in Japan: high potential for future outbreak.

Since the early 21st century, almost all developed countries have had a very low hepatitis A virus antibody (anti-HAV) sero-prevalence profile, as sanitation conditions and health care facilities have been optimized to a universal standard. There has not been a report on anti-HAV prevalence among a large scale population in Japan since 2003. Therefore, this study aimed to investigate the current HAV status among the general population in Hiroshima. From each age and sex specific group, a total of 1,200 samples were randomly selected from 7,682 stocked serum samples from residents' and employees' annual health check-ups during 2013-2015. Total anti-HAV was detected using Chemiluminescent Enzyme Immunoassay. The overall anti-HAV sero-prevalence was 16.8%. In both males and females, anti-HAV prevalence among individuals between 20-59 years of age was as low as 0.0-2.0%, whilst that among 70 s was as high as 70.0-71.0%. A large number of residents aged under 60 are now susceptible to HAV infection. The cohort reduction trend of anti-HAV in Japan exposes the high possibility of mass outbreak in the future. HAV vaccine especially to younger generation and high risk population may prevent outbreak in Japan.

Incidence and risk factors of colorectal cancer based on 56 324 health checkups: A 7-year retrospective cohort study.

BACKGROUND AND AIM: Although mortality rates of colorectal cancer (CRC) have been increasing in Japan, its screening rates remain stagnant at 19.2% among Japanese population aged > 40 years in 2014. To evaluate the importance of CRC screening by fecal occult blood test (FOBT), this study estimated the incidence of FOBT-positivity and CRC by sex-age stratification and clarified the risk factors for CRC. METHODS: Between 2007 and 2014, 56 324 residents (21 517 men and 34 807 women) were enrolled in this study. The sex-age-stratified incidence rates of FOBT-positivity and CRC were estimated by records from health checkups and colonoscopy. Regarding CRC incidence rate in particular, positive predictive value was adopted to adjust bias of FOBT-positivity that did not undergo colonoscopy by person-year method. To investigate the risks of CRC onset, a nested case-control study with 1:10 person-matching on sex and age was performed. RESULTS: Incidence rates of FOBT-positivity and CRC are 4183/100 000 person-year (100 Kpy) and 141.3/100 Kpy, respectively. In both cases, men has higher incidence rate than women (1.3 times for FOBT; 4977 vs 3718/100 Kpy and 2.3 times for CRC; 217.0 vs 96.4/100 Kpy). CONCLUSIONS: The records from health checkups were useful to estimate incidence rates of CRC with this procedure. The age-stratified incidence rate indicated the importance of CRC screening by FOBT, especially for men and those aged > 50 years. Additionally, it is strongly recommended to do further investigation if positive for initial FOBT screening especially for those who are > 70 years.