Mushroom intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study (CIRCS).

It is uncertain whether dietary intake of mushrooms rich in dietary fibre and several antioxidants is associated with a lower risk of dementia. We sought to examine prospectively the association between mushroom intake and the risk of disabling dementia. We performed a prospective study involving 3750 people aged 40 to 64 years residing in three communities who participated in an annual cardiovascular risk survey from 1985 to 1999. Cases of incident disabling dementia were surveyed from 1999 to 2020. We calculated the hazard ratios (HR) and 95 % CI for incident total dementia according to mushroom intake among participants with or without a history of stroke. During a mean 16·0 years' follow-up in 3739 eligible participants, 670 people developed disabling dementia. For women, mushroom intake was inversely associated with the risk of total dementia and the association was confined to dementia without a history of stroke. The multivariable HR (95 % CI) for total dementia in women were 0·81 (0·62, 1·06) for mushroom intake of 0·1-14·9 g/d and 0·56 (0·42, 0·75) for mushroom intake above 15·0 g/d (Pfor trend = 0·003) compared with no intake. The corresponding HR (95 % CI) for dementia without a history of stroke were 0·66 (0·47, 0·93) and 0·55 (0·38, 0·79) (Pfor trend = 0·01). In men, no associations were observed between mushroom intake and the risk of disabling dementia. Among Japanese women, dietary mushroom intake was associated with a lower risk of disabling dementia.

Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study.

OBJECTIVES: It has been hypothesized that dietary fiber intake has a beneficial impact on prevention of dementia, but the epidemiological evidence is scant. We sought to examine whether dietary fiber intake is inversely associated with risk of dementia requiring care under the national insurance (disabling dementia). METHODS: The study setting was the Circulatory Risk in Communities Study, involving 3739 Japanese individuals aged 40-64 years at the dietary surveys (1985-99). Dietary fiber intake was estimated using the 24-hour dietary recall method. Incident disabling dementia was followed up from 1999 through 2020. Disabling dementia was further classified into that with or without a history of stroke. Hazard ratios of disabling dementia according to quartiles of total, soluble, and insoluble fiber intake were calculated using the Cox proportional hazards model. RESULTS: During a median 19.7-year follow-up, a total of 670 cases of disabling dementia developed. Dietary fiber intake was inversely associated with risk of dementia: the multivariate hazards ratios (95% confidence intervals) were 0.83 (0.67-1.04), 0.81 (0.65-1.02), and 0.74 (0.57-0.96) for individuals with the second, third, and highest quartiles of dietary fiber intake, respectively, as compared with the lowest quartile (P for trend = 0.03). The inverse association was more evident for soluble fiber intake and was confined to dementia without a history of stroke. As for fiber-containing foods, potatoes, but not vegetables or fruits, showed a similar association. CONCLUSIONS: Dietary fiber intake, especially soluble fiber, was inversely associated with risk of disabling dementia in a general Japanese population.

Determination of dietary essential fatty acids in a deep-sea fish, the splendid alfonsino Beryx splendens: functional characterization of enzymes involved in long-chain polyunsaturated fatty acid biosynthesis.

The splendid alfonsino Beryx splendens is a commercially important deep-sea fish in East Asian countries. Because the wild stock of this species has been declining, there is an urgent need to develop aquaculture systems. In the present study, we investigated the long-chain polyunsaturated fatty acid (LC-PUFA) requirements of B. splendens, which are known as essential dietary components in many carnivorous marine fish species. The fatty acid profiles of the muscles, liver, and stomach contents of B. splendens suggested that it acquires substantial levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from its natural diet. The functional characterization of a fatty acid desaturase (Fads2) and three elongases (Elovl5, Elovl4a, and Elovl4b) from B. splendens confirmed their enzymatic capabilities in LC-PUFA biosynthesis. Fads2 showed Δ6 and Δ8 bifunctional desaturase activities. Elovl5 showed preferential elongase activities toward C18 and C20 PUFA substrates, whereas Elovl4a and Elovl4b showed activities toward various C18-22 substrates. Given that Fads2 showed no Δ5 desaturase activity and no other fads-like sequence was found in the B. splendens genome, EPA and arachidonic acid cannot be synthesized from C18 precursors; hence, they can be categorized as dietary essential fatty acids in B. splendens. EPA can be converted into DHA in B. splendens via the so-called Sprecher pathway. However, given that fads2 is only expressed in the brain, it is unlikely that the capacity of B. splendens to biosynthesize DHA from EPA can fulfill its physiological requirements. These results will be useful to researchers developing B. splendens aquaculture methods.

Total protein intake and subsequent risk of chronic kidney disease: the Circulatory Risk in Communities Study.

BACKGROUND: Whether dietary protein intake worsens renal function in the general population has been discussed but not yet determined. We aimed to examine the longitudinal association between dietary protein intake and risk of incident chronic kidney disease (CKD). METHODS: We conducted a 12-year follow-up study with 3,277 Japanese adults (1,150 men and 2,127 women) aged 40-74 years, initially free from CKD, who participated in cardiovascular risk surveys from two Japanese communities under the Circulatory Risk in Communities Study. The development of CKD was defined by the estimated glomerular filtration rate (eGFR) during the follow-up period. Protein intake was measured at baseline by using the brief-type self-administered diet history questionnaire. We estimated sex-, age-, community- and multivariate-adjusted hazard ratios (HR) for incident CKD were calculated using the Cox proportional hazards regression models according to quartiles of percentage of energy (%energy) from protein intake. RESULTS: During 26,422 person-years of follow-up, 300 participants developed CKD (137 men and 163 women). The sex-, age-, and community-adjusted HR (95% confidence interval, CI) for the highest (≥16.9%energy) versus lowest (≤13.4%energy) quartiles of total protein intake was 0.66 (0.48-0.90), p for trend = 0.007. The multivariable HR (95%CI) was 0.72 (0.52-0.99), p for trend = 0.016 after further adjustment for body mass index, smoking status, alcohol drinking status, diastolic blood pressure, antihypertensive medication use, diabetes mellitus, serum total cholesterol levels, cholesterol-lowering medication use, total energy intake, and baseline eGFR. The association did not vary by sex, age, and baseline eGFR. When examining animal and vegetable protein intake separately, the respective multivariable HRs (95%CIs) were 0.77 (0.56-1.08), p for trend = 0.036, and 1.24 (0.89-1.75), p for trend = 0.270. CONCLUSIONS: Higher protein intake, more specifically animal protein intake was associated with a lower risk of CKD.

Walking time, sports activity, job type, and body posture during work in relation to incident colorectal cancer: the JACC prospective cohort study.

PURPOSE: An inverse association between physical activity and colorectal cancer (CRC) has been suggested. We aimed to assess the specific and combined effects of leisure-time and occupational physical activities on CRC risk among Japanese adults. METHODS: Using Cox proportional hazard models, we tested whether walking time, sports activity, body posture during work, and job type-or the combination of these variables-were associated with CRC incidence in a prospective cohort of 26,897 Japanese adults aged 40-79 years. RESULTS: During a median 17-year follow-up (1990-2009) period, we ascertained 423 incident cases of CRC (267 colon and 156 rectum cancer). Time spent walking suggested a dose-response inverse relationship with CRC risk (p-trend = 0.051). Manual labor was associated with lower CRC risk when compared to office work with HRs (95% CIs) of 0.74 (0.56-0.97) for CRC and 0.68 (0.48-0.96) for colon cancer. Compared to sitting, moving during work tended to be inversely associated with rectal cancer risk, especially after censoring early incident cases within 3 years after baseline; HR (95% CI) = 0.63 (0.40-0.99). Combining walking and job type suggested mutual and synergistic benefits on the risk of colon cancer (p-interaction = 0.03). Compared to office workers walking < 1 h/day, the HR (95% CI) of colon cancer was 0.48 (0.23-0.98), 0.61 (0.42-0.89), and 0.59 (0.41-0.87) in office workers walking ≥ 1 h/day, non-office workers walking < 1 h/day, and non-office workers walking ≥ 1 h/day, respectively. CONCLUSION: The time spent walking, job type, and posture during work were independently associated with the reduced incident CRC risk among Japanese men and women.

Simple method to measure rheological properties of soft surfaces by a micro-needle contact.

We developed a simple method to investigate rheological properties of soft surfaces, such as polymeric liquids and colloidal suspensions, by capturing the images of a metal micro-needle inserted into the surface. At contact, a meniscus-like deformation is formed on the surface. By relating the shape of the deformation to the balance of applied forces, local elasticity and viscosity just inside the surface are obtained. With a facile setup and rapid measurement process, the present method can be implemented to variety of systems, for instance, drying sessile drops and small volume of liquid confined in a capillary.

Progress of public health policy regarding global infectious diseases over the past decade in Japan.

This article aims to examine progress of public health policy regarding global infectious diseases over the past decade in Japan. A narrative review was conducted, overviewing items of the Infectious Disease Committee and the Tuberculosis Committee of the Ministry of Health, Labour and Welfare between 2010 and 2019. The mean value of items discussed in each meeting were 9.7 items. Among these items, these committees have discussed about countermeasures in terms of reduced burden of indigenous infectious diseases such as measles, rubella and pertussis, and increased risk of imported infectious diseases such as Ebola virus disease, Middle East Respiratory Syndrome, plague, avian influenza, pandemic influenza and tuberculosis. These changes regarding infectious diseases lead to loss of target population, difficulty of early detection, and market failure in old and new antibiotics and others, which requires challenge to scattered at-risk targets, effort to training and awareness, and creation of novel public health policy for research and development as well as production and supply. Over the past decade, public health policy regarding global infectious diseases have been one of the key targets under the triangle of global infectious disease, and recent experience of Coronavirus disease 2019 will further prioritize it in Japan. However, the principles of public health policy are globally vulnerable in the Post-Corona era, which can lead to the collapse of democratic way. To combat global infectious diseases without going off the road, we need to learn about the past history of public health policy.

Stable creeping fault segments can become destructive as a result of dynamic weakening.

Faults in Earth's crust accommodate slow relative motion between tectonic plates through either similarly slow slip or fast, seismic-wave-producing rupture events perceived as earthquakes. These types of behaviour are often assumed to be separated in space and to occur on two different types of fault segment: one with stable, rate-strengthening friction and the other with rate-weakening friction that leads to stick-slip. The 2011 Tohoku-Oki earthquake with moment magnitude M(w) = 9.0 challenged such assumptions by accumulating its largest seismic slip in the area that had been assumed to be creeping. Here we propose a model in which stable, rate-strengthening behaviour at low slip rates is combined with coseismic weakening due to rapid shear heating of pore fluids, allowing unstable slip to occur in segments that can creep between events. The model parameters are based on laboratory measurements on samples from the fault of the M(w) 7.6 1999 Chi-Chi earthquake. The long-term slip behaviour of the model, which we examine using a unique numerical approach that includes all wave effects, reproduces and explains a number of both long-term and coseismic observations-some of them seemingly contradictory-about the faults at which the Tohoku-Oki and Chi-Chi earthquakes occurred, including there being more high-frequency radiation from areas of lower slip, the largest seismic slip in the Tohoku-Oki earthquake having occurred in a potentially creeping segment, the overall pattern of previous events in the area and the complexity of the Tohoku-Oki rupture. The implication that earthquake rupture may break through large portions of creeping segments, which are at present considered to be barriers, requires a re-evaluation of seismic hazard in many areas.

The relationship between sodium concentrations in spot urine and blood pressure increases: a prospective study of Japanese general population: the Circulatory Risk in Communities Study (CIRCS).

BACKGROUND: Although several cross-sectional and intervention studies showed that sodium intake or excretion was associated with blood pressure levels, no prospective study has examined the long-term association between sodium excretion in spot urine and blood pressure changes. METHODS: We conducted a prospective study of 889 normotensive subjects (295 men and 594 women, mean age 57.3 years) who underwent the baseline survey including spot urine test in 2005 and the follow-up survey in 2009 to 2011 (mean follow-up period: 5.8 years). We examined the association between sodium concentration in spot urine, a validated index of sodium excretion occurring over 24-h, and blood pressure changes between baseline and follow-up survey in all, non-overweight (body mass index(BMI) ≤ 25 kg/m(2)) and overweight normotensives. RESULTS: For all subjects, sodium concentrations in spot urine were not associated with either systolic or diastolic blood pressure changes. When stratified by BMI at baseline survey, sodium concentrations were positively associated with systolic blood pressure changes in non-overweight subjects, but not in overweight subjects. After adjustment for age, sex, BMI, alcohol intake status, current smoking and estimated glomerular filtration rate, the multivariable-adjusted mean values of the systolic blood pressure change among non-overweight subjects was +7.3 mmHg in the highest quartiles of sodium concentrations, while it was +3.9 mmHg in the lowest quartile (P for difference = 0.021, P for trend = 0.040). After further adjustment of baseline blood pressure levels, the association was slightly weakened; the multivariable-adjusted mean values of the systolic blood pressure changes were +7.0 mmHg and +4.2 mmHg (P for difference = 0.047, P for trend = 0.071). CONCLUSIONS: High sodium concentrations in spot urine were associated with subsequent systolic blood pressure increases among non-overweight normotensive individuals. (272 words).

Health Disparities in Ischaemic Heart Disease Mortality in Hungary From 1970 to 2010: An Age-Period-Cohort Analysis.

BACKGROUND: The objective of this study was to examine long-term trends in rates of ischaemic heart disease (IHD) mortality, a leading cause of mortality in Hungary. The study examined the effects of age, period, and cohort on IHD mortality rates and compared mortality rates between the capital (Budapest) and non-capital counties. METHODS: Data on IHD deaths and population censuses were obtained from the Hungarian Central Statistical Office. Age-period-cohort analysis utilized nine age-group classes for ages 40 to 84 years, eight time periods from 1970 to 2009, and 16 birth cohorts from 1886 to 1969. RESULTS: Age-adjusted IHD mortality rates for men and for women generally increased from 1970 to 1993 and from 1980 to 1999, respectively, decreasing thereafter for both sexes. IHD mortality rates for men and for women from Budapest were lower from 1991 and from 1970, respectively, than corresponding rates in non-capital counties, with the difference increasing after 1999. Age had a more significant influence on mortality rates for women than for men. The period effect increased from 1972 to 1982 and decreased thereafter for men, while the period effect decreased consistently for women from 1972 to 2007. The decline in period effect for both sexes was larger for individuals from the capital than for those from non-capital counties. The cohort effect for both sexes declined from birth years 1890 to 1965, with a steeper decline for individuals from the capital than for those from non-capital counties. CONCLUSIONS: The findings indicate a need for programs in Hungary for IHD prevention, especially for non-capital counties.

The Scabbard of Excalibur: An Allegory on the Role of an Efficient and Effective Healthcare System under Universal Health Coverage during the Pandemic Response.

During the COVID-19 pandemic, while some countries succeeded in reducing their rate of death after SARS-CoV-2 infection via vaccination by the end of 2021, some of them also faced hospital capacity strain, leading to social anxiety about delays in the diagnosis and treatment of patients with other diseases. This essay presents an allegory to explain the situation during the COVID-19 pandemic. Through an allegory and Le Morte d'Arthur (Arthur's Death), this essay indicates that "the scabbard of Excalibur" that we are looking for is an efficient and effective healthcare system that can diagnose patients who might become severely ill due to COVID-19 and to treat them without hospital capacity strain. In Le Morte d'Arthur, the scabbard of Excalibur was lost, and we have not been able to find any alternatives to end the COVID-19 pandemic. We can choose a future in which "the scabbard of Excalibur" exists, providing a different ending for the next pandemic.

Prospective cohort study on television viewing time and incidence of lung cancer: findings from the Japan Collaborative Cohort Study.

PURPOSE: To ascertain whether prolonged television viewing time was associated with lung cancer incidence in Japanese adults aged 40-79 years from a nationwide large-scale cohort study. METHODS: A total of 54,258 adults (23,090 men and 31,168 women) without a history of cancer at baseline (1988-1990) were enrolled and followed for a median of 15.6 years. The Cox proportional hazard model was used to calculate hazard ratios (HRs) and 95 % confidence interval (CI) for lung cancer according to television viewing time adjusted for age and other possible confounding factors. RESULTS: During the study period, 798 participants were diagnosed with lung cancer. The HR of male participants who watched television for more than 4 h daily was 1.36 (95 % CI 1.04-1.80) compared with <2 h/day. CONCLUSION: Our findings suggest that reducing the amount of time spent watching television may be beneficial for preventing lung cancer.

Revised system to evaluate measurement of blood chemistry data from the Japanese National Health and Nutrition Survey and Prefectural Health and Nutrition Surveys.

BACKGROUND: We developed a monitoring system that uses total errors (TEs) to evaluate measurement of blood chemistry data from the National Health and Nutrition Survey (NHNS) and Prefectural Health and Nutrition Surveys (PHNS). METHODS: Blood chemistry data from the NHNS and PHNS were analyzed by SRL, Inc., a commercial laboratory in Tokyo, Japan. Using accuracy and precision from external and internal quality controls, TEs were calculated for 14 blood chemistry items during the period 1999-2010. The acceptable range was defined as less than the upper 80% confidence limit for the median, the unacceptable range as more than twice the cut-off value of the acceptable range, and the borderline range as the interval between the acceptable and unacceptable ranges. RESULTS: The TE upper limit for the acceptable and borderline ranges was 5.7% for total cholesterol (mg/dL), 9.9% for high-density lipoprotein cholesterol (mg/dL), 10.0% for low-density lipoprotein cholesterol (mg/dL), 10.4% for triglycerides (mg/dL), 6.6% for total protein (g/dL), 7.6% for albumin (g/dL), 10.8% for creatinine (mg/dL), 6.5% for glucose (mg/dL), 9.7% for γ-glutamyl transpeptidase (U/L), 7.7% for uric acid (mg/dL), 8.7% for urea nitrogen (mg/dL), 9.2% for aspartate aminotransferase (U/L), 9.5% for alanine aminotransferase (U/L), and 6.5% for hemoglobin A1c (%). CONCLUSIONS: This monitoring system was established to assist health professionals in evaluating the continuity and comparability of NHNS and PHNS blood chemistry data among survey years and areas and to prevent biased or incorrect conclusions.

Risk Factors for Mortality From Aortic Aneurysm and Dissection: Results From a 26-Year Follow-Up of a Community-Based Population.

Background Aortic aneurysm rupture and acute aortic dissection are life-threatening conditions and represent an ever-growing public health challenge. Comprehensive epidemiologic investigations for their risk factors are scant. We aimed to investigate risk factors associated with mortality from aortic diseases through analysis of a community-based Japanese cohort. Methods and Results IPHS (Ibaraki Prefectural Health Study) comprises 95 723 participants who took part in municipal health checkups in 1993. Factors considered for analysis included age, sex, body mass index, blood pressure, serum lipids (high-density lipoprotein [HDL] cholesterol, non-HDL cholesterol, and triglycerides), diabetes, antihypertensive and lipid-lowering drug use, and smoking and drinking habits. Cox proportional hazards models were applied to evaluate the associations between these variables and mortality from aortic diseases. During the median 26-year follow-up, 190 participants died of aortic aneurysm rupture, and 188 died of aortic dissection. An increased multivariable hazard ratio (HR) for mortality from total aortic diseases was observed for high systolic blood pressure (1.61 [1.00-2.59]), diastolic blood pressure (2.95 [1.95-4.48]), high non-HDL cholesterol (1.63 [1.19-2.24]), low HDL cholesterol (1.86 [1.29-2.68]), and heavy (>20 cigarettes/day) smoking habit (2.46 [1.66-3.63]). A lower multivariable HR was observed for diabetes (0.50 [0.28-0.89]). Conclusions Smoking habit, higher systolic blood pressure and diastolic blood pressure levels, higher non-HDL, and lower HDL cholesterol levels were positively associated with mortality from total aortic diseases, whereas diabetes was inversely associated.

Trends in stroke, cardiovascular disease, and medical expenditure under a community-based long-term stroke prevention program.

BACKGROUND: Evidence on the effects of preventive measures for noncommunicable disease is urgently needed for low-income and middle-income countries suffering from stroke epidemics along with population aging. OBJECTIVES: We sought to examine the impact of a community-based stroke prevention program on incidences of stroke and ischemic heart disease, mortality from cardiovascular disease, and medical expenditure. METHODS: Trends in the incidences of stroke and ischemic heart disease were documented in a Japanese rural community, Kyowa, from 1981 through 2015. Trends in mortality from cardiovascular disease and in medical expenditures were compared between Kyowa and its surrounding municipalities from 1981 through 2004. RESULTS: In Kyowa, the age-and-sex-adjusted incidences of stroke and of ischemic heart disease decreased by half (from 4.1 to 1.9 and from 1.5 to 0.7 per year/1000 persons, respectively) over the past 35 years. A similar decreasing trend was observed for the age-and-sex-adjusted mortality from cardiovascular disease, and this decreasing trend occurred earlier than that in the surrounding municipalities. The medical expenditures for cardiovascular disease became lower in Kyowa than in the surrounding municipalities over time. CONCLUSION: Our study's findings suggest that a community-based stroke prevention program augmented the decline in the incidences of stroke and ischemic heart disease, mortality from cardiovascular disease, and attenuated the increase in medical expenditures for cardiovascular disease.

Non-fasting blood glucose and risk of incident coronary heart disease in middle-aged general population: the Circulatory Risk in Communities Study (CIRCS).

OBJECTIVE: The objective was to determine whether non-fasting glucose concentration is a predictor for incident coronary heart disease. METHODS: We investigated a cohort data of 9,900 40- to 69-year-old residents in four Japanese communities for 1975-1986 baseline surveys of the Circulatory Risk in Communities Study (CIRCS). Non-fasting blood glucose concentrations were available for 7,332 participants. Diabetic type was defined as a glucose level of ≥ 11.1 mmol/L and/or the use of medication for diabetes mellitus. RESULTS: A total of 170 coronary heart disease including 113 myocardial infarctions occurred in non-fasting participants within the median 22-year follow-up period. Multivariable hazard ratios (HRs) of incident coronary heart disease for the participants with diabetic type compared with the normal type were 1.98 (0.84-4.68) for men, 3.39 (1.47-7.81) for women, and 2.47 (1.37-4.46) for total subjects. Corresponding HRs for myocardial infarction were 2.14 (0.83-5.55), 5.70 (2.21-14.67) and 3.17 (1.65-6.10), respectively. Multivariable HRs of incident coronary heart disease per one standard deviation of serum glucose levels were 1.17 (1.02-1.36), 1.19 (1.03-1.38), and 1.19 (1.08-1.32), respectively. The corresponding HRs for myocardial infarction were 1.18 (1.00-1.38), 1.27 (1.07-1.49) and 1.23 (1.10-1.37). CONCLUSION: Non-fasting glucose concentration, either as diagnosis of diabetic type or as continuous variable, proved to be an independent predictor for incident coronary heart disease in middle-aged general population.

A Model to Estimate the Effect of International Traffic on Malaria Cases: The Case of Japan from 1999 to 2021.

Aiming to identify the potentially reduced malaria cases by stagnation of international traffic after the COVID-19 pandemic, a longitudinal analysis of malaria cases as well as entries of Japanese and foreigners was conducted using data from 5 April 1999 to 30 September 2021 in Japan. Multivariable risk ratios were calculated with the Poison regression model as a predictive model of malaria cases by the number of entries for Japanese and foreigners. A generalized regression model was used to examine an association of time trend with entries for Japanese and foreigners using data before 2019, to estimate the potentially reduced number of entries after 2020. The potentially reduced number of malaria cases was estimated by the potentially reduced number of entries for Japanese and foreigners after 2020 using a multivariable Poison regression model. The multivariable risk ratio (95% confidence intervals) of malaria case numbers per 100,000 persons increment of entries per day was 3.41 (1.50-7.77) for Japanese and 1.47 (0.92-2.35) for foreigners. During 2020, a potential reduction of 28 (95% confidence limit: 22-34) malaria cases was estimated, which accounted for 58% (52-63%) of malaria cases in Japan. These finding suggest that the stagnation of international traffic during the COVID-19 pandemic reduced the number of malaria cases in Japan. This model may be helpful for countries without indigenous malaria to predict future trends of imported malaria cases.

A Macro-Level Association of Vaccination Rate with the Number of Confirmed COVID-19 Cases in the United States and Japan.

Aiming to evaluate a macro-level association of vaccination rate as well as booster vaccination rate with the number of confirmed COVID-19 cases in the United States and Japan, a cross-sectional study was conducted using data in each jurisdiction. Data on the total number of people who were fully vaccinated as of the end of December 2021, data on the total number of people who have received a booster dose as of the end of March 2022 and data on the cumulative number of confirmed COVID-19 cases were obtained from the website of the national governments. A generalized regression model was used to examine the association. This study showed that a higher vaccination rate was associated with a lower number of confirmed COVID-19 cases per year in 2021 for both the United States and Japan. The number of confirmed COVID-19 cases per 1000 population per year (95% confidence intervals) as a 1% increment of the vaccination rate was −0.74 (−1.29, −0.20), p = 0.007 for the United States and −1.48 (−1.95, −1.00), p < 0.0001 for Japan. A similar association was observed for the booster vaccination rate in 2022, although the association was attenuated in a multivariable model, particularly for the United States. This study provided macro-level evidence that vaccination may reduce the number of confirmed COVID-19 cases.

Risk factors of early spontaneous abortions among Japanese: a matched case-control study.

BACKGROUND: No epidemiological studies have examined risk factors for early spontaneous abortions among Japanese women. In this matched case-control study, we investigated the associations of reproductive, physical, and lifestyle characteristics of women and their husbands with early spontaneous abortion <12 weeks of gestation. METHODS: Information was collected through medical records for 430 cases of early spontaneous abortion and 860 controls of term delivery. Two controls were individual-matched to one case according to maternal age (± 3 years) and calendar year of events (either early spontaneous abortion or delivery). Multivariable conditional odds ratios (ORs) and 95% confidence interval (CI) were calculated with conditional logistic-regression. RESULTS: The risk of early spontaneous abortions was higher for women with a past history of early spontaneous abortions; OR was 1.98 (95% CI: 1.35, 2.89) for one previous spontaneous abortion, 2.36 (95% CI: 1.47, 3.79) for two, and 8.73 (95% CI: 5.22, 14.62) for three or more. Other factors also influence risk; an OR of 2.39 (95% CI: 1.26, 4.25) was found for women who smoked, and 1.65 (95%CI: 1.17, 2.35) for women working outside the home. CONCLUSIONS: Our finding suggests that for Japanese women, smoking and working may be important public health issue targets for the prevention of early spontaneous abortions.