Booster vaccination and post COVID-19 condition during the Omicron variant-dominant wave: A large population-based study.

Objectives: The effect of the COVID-19 booster vaccination and the long-term consequences concerning preventing post COVID-19 condition (PCC) remain unclear. We aimed to investigate the association of COVID-19 booster vaccination dose and vaccination timing before infection with the risk of PCC during the Omicron variant-dominant wave.

Methods: This population-based study included confirmed COVID-19 patients (extracted from the Health Center Real-time Information-sharing System) aged 20-69 years, who were infected between July 1 and August 31, 2022.

Mortality from Aortic Disease in Relation with Sleep Duration at Night and Daytime Napping: The Japan Collaborative Cohort Study.

Aims: Few studies have investigated the impact of sleep duration at night and daytime napping on mortality from aortic disease. In this study, we examined the associations of sleep duration at night with daytime napping and mortality from aortic disease.

Methods: We followed 67,269 participants (26,826 men and 40,443 women, aged 40-79 years) who were not night shift workers and had no history of stroke, heart disease, or cancer.

Social Relationships and Tooth Loss in Adults Aged 60 Years and Older: A Systematic Review and Meta-Analysis.

Objective: To systematically assess current evidence on the extent to which social relationships are associated with tooth loss in adults aged 60 years and older.

Methods: A systematic literature search was conducted on PubMed, Embase, Web of Science, CINAHL and The Cochrane Library databases to identify relevant studies published from 1966 up to March 2024. Cross-sectional or cohort studies investigating the association between structural, functional and/or combined (structural and functional) components of social relationships and the number of remaining teeth or edentulism among community-dwelling or institutionalised older adults were included.

Particulate Matter and Incident Chronic Kidney Disease in Japan: The Ibaraki Prefectural Health Study (IPHS).

Introduction: Global health hazards caused by air pollution, such as chronic kidney disease (CKD), have been gaining attention; however, air pollution-associated CKD has not been explored in Japan.

Methods: We examined 77,770 men and women with estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m in the Ibaraki Prefecture who participated in annual community-based health checkups from 1993 at 40-75 years old and were followed up through December 2020.

Fruit and Vegetable Intake and Risk of Disabling Dementia: Japan Public Health Center Disabling Dementia Study.

Background: Fruits and vegetables contain abundant amounts of antioxidant vitamins such as vitamin C, α-carotene, and β-carotene. Few prospective observational studies have investigated the effects of fruit and vegetable intake on the risk of dementia, and the results are inconsistent.

Objectives: Our aim was to examine associations between fruit and vegetable intake and the risk of disabling dementia.

Prevention of cardiovascular disease, a major non-communicable disease, in a super-aging society: Health success and unsolved issues in Japan.

As far as non-communicable disease is concerned, Japan is unique in showing a substantial decline in stroke mortality and the lowest and declining mortality from ischemic heart disease during the past half century, which contributed to the elongation of a 4-year average life expectancy, leading to top longevity in the world. However, several issues have remained in the prevention of cardiovascular disease with super-aging: ) how to manage the screening and lifestyle modification for both individuals with metabolic syndrome and those with non-overweight/ obesity plus metabolic risk factors, and ) how to enhance the referral of very high-risk individuals screened at health checks to physicians for seeking treatment and examine whether an early clinical visit was associated with a lower risk of cardiovascular disease and total mortality. Health counseling is needed for both persons with metabolic syndrome and high-risk individuals with non-obese/overweight because the population attributable risk fraction of ischemic cardiovascular disease was similar for both high-risk individuals.

Risk of herpes zoster according to past history in the general population: The Japanese Shozu herpes zoster study.

Immunity is known to persist after vaccination for varicella zoster virus, but the duration of immunity in patients who develop herpes zoster (HZ) remains unknown. To investigate the association between a past history of HZ and its occurrence in the general population. The Shozu HZ (SHEZ) cohort study included data for 12 299 individuals aged ≥50 years with information on their HZ history.

Serum folate and risk of disabling dementia: a community-based nested case-control study.

Purpose: The aim of this study was to examine associations between serum folate levels and risk of disabling dementia that required care under the national insurance (disabling dementia).

Methods: We performed a nested case-control study in a community-based cohort, the Circulatory Risk in Communities Study, involving 13,934 Japanese individuals aged 40-84 years at the baseline period of 1984-2005. Serum folate was measured in 578 cases of incident disabling dementia, and in 1,156 controls whose age (±1 years), sex, area of residence, and baseline year were matched with the cases.

Economic effects of healthy ageing: functional limitation, forgone wages, and medical and long-term care costs.

This study aims to estimate the potential economic benefits of healthy ageing by obtaining estimates of the economic losses generated by functional limitations among middle-aged and older people. Utilising two data sources retrieved from nationally representative samples of the Japanese people, we analysed the association between functional limitation and economic indicators, including labour market outcomes, savings, investment, consumption, and unpaid activities among individuals aged ≥ 60. Using the estimated parameters from our micro-econometric analyses and the official statistics by the Japanese government and a previous study, we calculated the financial costs that can be averted if healthy ageing is achieved as foregone wages and formal medical/long-term care costs incurred by functional limitations.

Sex- and age-specific impacts of smoking, overweight/obesity, hypertension, and diabetes mellitus in the development of disabling dementia in a Japanese population.

Background: Sex- and age-specific impacts of cardiovascular risk factors on the development of dementia have not been well evaluated. We investigated these impacts of smoking, overweight/obesity, hypertension, and diabetes mellitus on the risk of disabling dementia.

Methods: The study participants were 25,029 (10,134 men and 14,895 women) Japanese aged 40-74 years without disabling dementia at baseline (2008-2013).

Longitudinal changes in cell-mediated immunity after varicella-zoster virus skin test in the general population; Shozu Herpes Zoster Study: SHEZ study.

Varicella-zoster virus-specific cell-mediated immunity has been associated with the onset and severity of herpes zoster (HZ), and the administration of the HZ vaccine enhanced the immunity. However, limited data is available on the duration of cell-mediated immunity enhancement by soluble antigen of varicella-zoster virus (VZV) skin test. A prospective, community-based cohort study was conducted in Shozu County, Kagawa Prefecture, Japan.

Dietary Manganese Intake and Risk of Liver Cancer in Japanese Men and Women: The JACC Study.

We explored the association between dietary manganese intake and the risk of liver cancer in 14,517 men and 21,583 women who participated in the Japan Collaborative Cohort Study for Cancer Risk Assessment. We assessed dietary manganese intake using a food frequency questionnaire and incident liver cancer by reviewing cancer registries. According to manganese intake, we estimated the liver cancer risk by Cox regression analyses.

Cardiovascular disease, a major global burden: Epidemiology of stroke and ischemic heart disease in Japan.

Japan ranks the highest globally, in terms of longevity. The average life expectancy was 81.4 years for men and 87.

Loss of Working Life Years Due to Mortality, Sickness Absence, or Ill-health Retirement: A Comprehensive Approach to Estimating Disease Burden in the Workplace.

Background: While much effort has focused on quantifying disease burden in occupational health, no study has simultaneously assessed disease burden in terms of mortality and morbidity. We aimed to propose a new comprehensive method of quantifying the disease burden in the workplace.

Methods: The data were obtained from the Japan Epidemiology Collaboration on Occupational Health (J-ECOH) Study, a large-scale prospective study of approximately 80,000 workers.

Contributions of information and communications technology to future health systems and Universal Health Coverage: application of Japan's experiences.

Background: Demographic changes in the pattern of disease burden, escalating health expenditures and inequitable access to healthcare are global challenges. Irrespective of their level of development, all countries need to reform their health systems to prepare for the future emerging health needs, in order to meet their commitments of health systems strengthening, universal health coverage (UHC) and explicit targets in the Sustainable Development Goals (SDGs). We propose three core principles for the future health system as described herein.