Effects of Walking-Only Intervention on Physical Function, Fall-Related Outcomes, and Health-Related Quality of Life in Community-Dwelling Older Adults: A Systematic Review and Meta-Analysis.

This study aimed to determine the effects of walking-only intervention (walking was the only exercise in which people participated) on physical function, fall-related outcomes, and health-related quality of life in community-dwelling older adults. We conducted a systematic search across five electronic databases, assessing risk of bias using Minds Manual for Guideline Development. Meta-analyses were performed, and pooled standardized mean differences were calculated. Nine studies (a total of 1,309 participants) were included, showing that walking-only interventions improved walking endurance (standardized mean difference: 1.11, 95% confidence interval: [0.08, 2.15]) and health-related quality of life (standardized mean difference: 0.71, 95% confidence interval: [0.18, 1.25]). However, there were no significant improvements in other outcomes. The certainty of the evidence based on the Grading of Recommendations, Assessment, Development, and Evaluation approach for all outcomes was graded as very low, primarily due to significant inconsistency and imprecision. Our results suggest that walking-only intervention can be effective for enhancing walking endurance and health-related quality of life for community-dwelling older adults. Further studies are required to investigate the effects of walking-only intervention. This need stems from the limited number of randomized controlled trials, heterogeneous intervention settings and results, and the very low certainty of the evidence.

Development of the Self-Assessment Self-Disclosure Questionnaire to Examine the Association between Self-Disclosure and Frailty among Community-Dwelling Older Adults in Japan.

Self-disclosure is the attitude of communicating one's experiences and condition to others and is an indicator of mental health and an open personality. Frailty, characterized by reduced physical and psychological resistance, predicts the incidence of dependency and mortality. Although low self-disclosure may be associated with frailty, there is no scale to measure older adults' self-disclosure. This cross-sectional study assessed the validity of a self-assessment self-disclosure questionnaire and examined the association between the content of self-disclosures to friends and acquaintances and frailty among community-dwelling older adults. A total of 237 adults aged ≥65 in Japan were surveyed using a mailed self-administered questionnaire in 2021. The self-disclosure scale consisted of 10 items and showed adequate validity. Participants were classified into a robust group (n = 117, women 57.3%) and a frailty group (n = 120, women 73.3%) using the Kihon Checklist. After adjusting for covariates, multivariate-adjusted logistic regression models revealed frailty was associated with lower self-disclosure of recent positive events, motivation and strengths (indicating strong points) in life, relationships with family and relatives, experiences of work and social activities, and financial status. The proposed questionnaire must still be further tested in other populations, but our initial results may contribute to preventing frailty and improving mental health among community-dwelling older adults.

Association Between Oral Malodor and Dementia: An 11-Year Follow-Up Study in Japan.

Background: As infrequent social interaction is a potential risk of dementia, oral malodor may increase the risk of dementia, including Alzheimer's disease. Objective: This study investigated the association between malodor and dementia. Methods: We used the Japan Public Health Center-based Prospective Study data obtained at Yokote City. A total of 1,493 individuals aged 56 to 75 years underwent a dental examination and self-reported survey from May 2005 to January 2006. Follow-up for the onset of dementia was conducted using long-term care insurance data from 2006 to 2016. Hazard ratios of oral malodor on dementia were estimated by the Cox proportional hazards model. The inverse probability-weighted Cox model was used as a sensitivity analysis. Results: The study comprised 1493 participants (53.6% women) with a mean age of 65.6 (SD = 5.8) years old; at the end of the follow-up, 6.4% (n = 96) developed dementia, and the percentage was 20.7 in severe malodor group. Throughout 15274.133 person-years of follow-up, the average incidence rate for the onset of dementia per 1000 person-years was 6.29. The highest incidence rate was seen in participants with severe malodor (22.4 per 1000 person-years). After adjusting for confounders, compared to those with no malodor, there was a 3.8 (95% confidence interval: 1.5 to 9.4) times greater hazard of developing dementia in participants with severe malodor. The inverse probability weighted Cox model confirmed the same trend with an adjusted marginal hazard ratio of 4.4 (1.2 to 16.4). CONCLUSIONS: A significant association between oral malodor and the onset of dementia exists.

Plasma Albumin, Bilirubin, and Uric Acid and the Subsequent Risk of Cancer: A Case-Cohort Study in the Japan Public Health Center-based Prospective Study.

Several epidemiological studies have investigated the circulating levels of albumin, bilirubin, and uric acid (UA) in relation to cancer risk; however, they have provided equivocal evidence. In this prospective case-cohort study, we aimed to explore the association of plasma albumin, bilirubin, and UA levels with cancer incidence. We measured the plasma levels of albumin, bilirubin, and UA and investigated their association with cancer incidence in 3,584 cases and 4,270 randomly selected participants with a median follow-up of 15.8 years. The adjusted hazard ratios (HR) and 95% confidence intervals (CI) of total cancer for the highest (Q4) versus lowest quartile (Q1) was 0.77 (95% CI: 0.67-0.90, P for trend: <0.001) for albumin. This association was attenuated after excluding liver cancer cases with lower plasma albumin levels. Plasma bilirubin levels were positively related to liver cancer but inversely to total cancer after excluding liver cancer with adjusted HR Q4 vs. Q1 of 0.86 (95% CI: 0.74-0.99, P for trend = 0.015). Plasma UA levels were not dose-responsively associated with total cancer risk. Higher plasma bilirubin levels were associated with a decreased risk of total cancer after excluding liver cancer, which is likely attributed to the antioxidant properties of bilirubin.

Validity of self-reported Helicobacter pylori eradication treatment from questionnaire and interview surveys of the JPHC-NEXT study: comparison with prescription history from insurance claims data.

BACKGROUND: We aimed to evaluate the validity of self-administered questionnaire surveys and face-to-face interview surveys for the detection of Helicobacter pylori eradication therapy. METHODS: Participants were a cohort, aged 40-74 years, living in three different locations of Japan, who took part in the baseline survey (2011-2012) of the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT). Five years after the baseline survey, a questionnaire and interview survey were independently conducted to determine the history of Helicobacter pylori eradication treatment over the 5-year period. Prescription of Helicobacter pylori eradication medications in national insurance claims data from the baseline survey to the 5-year survey was used as a reference standard. RESULTS: In total, 15,760 questionnaire surveys and 8,006 interview surveys were included in the analysis. There were 3,471 respondents to the questionnaire and 2,398 respondents to the interview who reported having received Helicobacter pylori eradication treatment within the past five years. Comparison of the questionnaire survey to national insurance claims data showed a sensitivity of 95.1% (2213/2328), specificity of 90.6% (12174/13432), positive predictive value of 63.8% (2213/3471), negative predictive value of 99.1% (12174/12289), and Cohen's Kappa value of 0.71. Respective values of the interview survey were 94.4% (1694/1795), 88.7% (5507/6211), 70.6% (1694/2398), 98.2% (5507/5608), and 0.74. CONCLUSION: Both the questionnaire and the interview showed high sensitivity, high specificity, and good agreement with the insurance claim prescriptions data. Some participants may have received eradication treatment without going through the public insurance claim database, resulting in a low positive predictive value.

Relationships of Total and Domain-Specific Moderate-to-Vigorous Physical Activity with All-Cause and Disease-Specific Mortality.

PURPOSE: This study aimed to investigate the relationships of moderate-to-vigorous physical activity (MVPA) with all-cause and disease-specific mortality. We also investigated how the association between MVPA at leisure time (LT-MVPA) and health outcomes differs at different MVPA at work (WT-MVPA) levels. METHODS: The 81,601 community-dwelling Japanese persons age 50-79 yr who responded to a questionnaire in 2000-2003 were followed until 2018. Cox proportional hazard model was used to examine the association of total MVPA with risks of all-cause, cancer, heart disease, stroke, and respiratory disease mortality. Then, we compared the mortality risk according to the tertile of LT-MVPA, stratified by the tertile of WT-MVPA. RESULTS: During the 15.1 yr of average follow-up, 16,951 deaths were identified. Even total MVPA below the recommended volume (i.e., 0.1-1.49 MET·h·d -1 ) was associated with 11% to 24% reductions in all-cause (hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.82-0.96) and heart disease mortality (HR, 0.76; 95% CI, 0.61-0.94), compared with no MVPA at all. The further reduced risks were seen in MVPA up to 10 MET·h·d -1 . The inverse association between LT-MVPA and mortality risks was more evident at lower WT-MVPA, which was also inversely associated with the risks. CONCLUSIONS: Health benefits were observed at low levels of MVPA and up to 10 MET·h·d -1 , although the fine threshold for excessive MVPA was not clear. LT-MVPA had distinct health benefits especially for persons with lower WT-MVPA.

Dietary diversity and risk of late-life disabling dementia in middle-aged and older adults.

BACKGROUND & AIMS: A balanced diet integrating several foods and nutrients may promote the maintenance of brain function. Previous studies have substantiated the above hypothesis in the regional population in Japan. This study aimed to investigate the potential effect of dietary diversity on the risk of disabling dementia in a nationwide large-scale cohort of the Japanese population. METHODS: A total of 38,797 participants (17,708 men and 21,089 women) aged 45-74 years were followed up for a median of 11.0 years. The daily frequencies of the consumption of each of the 133 food and beverage items listed on a food frequency questionnaire (excluding five alcoholic beverages) were measured. The dietary diversity score was calculated as the number of food items consumed per day. Multivariable adjusted Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of the dietary diversity score quintile groups. RESULTS: We documented 4302 participants with disabling dementia (11.1%) during the follow-up period. Among women, the dietary diversity score was inversely associated with disabling dementia (highest quintile HR [with the lowest quintile as the reference]: 0.67; 95% CI: 0.56-0.78; Q1-Q5 p for trend <0.001), but this was not true among men (highest quintile HR: 1.06; 95% CI: 0.87-1.29; Q1-Q5 p for trend = 0.415). These results did not change substantially when using disabling dementia with stroke as the outcome; the association remained significant among women but was absent among men. CONCLUSIONS: Our findings indicate that eating a variety of foods may prevent disabling dementia only among women. Thus, the habit of consuming a variety of food items has important public health implications for women.

Alcohol consumption from midlife and risk of disabling dementia in a large population-based cohort study in Japan.

OBJECTIVES: The association between alcohol consumption and dementia in Japanese is poorly understood, and use of single-point alcohol assessment may cause measurement error. We explored this association in Japanese using repeated alcohol assessments. METHODS: Participants in the Japan Public Health Center-based Prospective Study (JPHC Study) since 1990 and who were alive in 2006 were followed from 2006 until 2016 for dementia ascertainment. Disabling dementia was identified through long-term care insurance records. Alcohol consumption was assessed at the 5-year questionnaire survey (1995-1999) and drinking patterns were assessed on repeated follow-up (2000-2003). We performed Cox proportional hazards models with age as the time-scale with adjustment for various lifestyle factors and medical history using light consumption (<75 g ethanol/week, hereinafter "g") as reference. Analysis considering death as a competing risk was also conducted. RESULTS: Among 42,870 participants aged 54-84 years, 4802 cases of disabling dementia were newly diagnosed. Average years from alcohol assessment until dementia incidence was 14.9 years. Non-drinkers and regular drinkers with ≥450 g at 5 years had adjusted HRs (95% CI) of 1.29 (1.12-1.47) and 1.34 (1.12-1.60). Patterns of long-term abstinence, former drinking, and regular heavy weekly consumption of ≥450 g showed increased adjusted HRs of 1.61 (1.28-2.03), 2.54 (1.93-3.35), and 1.96 (1.49-2.59), respectively. Competing risk analysis yielded similar results. CONCLUSIONS: In Japanese, non-drinking and regular weekly consumption of ≥450 g from midlife were associated with high risk of disabling dementia compared with light drinking.

Prevalence of family history of cancer in the NC-CCAPH consortium of Japan.

The objective of this study was to identify the prevalence of family history of cancer using cohorts participating in the Japanese National Center Cohort Collaborative for Advancing Population Health (NC-CCAPH). We pooled data from seven eligible cohorts of the Collaborative with available data on family history of cancer. Prevalence of family history of cancer and corresponding 95% confidence intervals are presented for all cancers and selected site-specific cancers for the total population and stratified by sex, age, and birth cohort. Prevalence of family history of cancer increased with age ranging from 10.51% in the 15 to 39 year age category to 47.11% in 70-year-olds. Overall prevalence increased in birth cohorts from ≤ 1929 until 1960 and decreased for the next two decades. Gastric cancer (11.97%) was the most common site recorded for family members, followed by colorectal and lung (5.75%), prostate (4.37%), breast (3.43%) and liver (3.05%) cancer. Women consistently had a higher prevalence of family history of cancer (34.32%) versus men (28.75%). Almost one in three participants had a family history of cancer in this Japanese consortium study highlighting the importance of early and targeted cancer screening services.

A cross-sectional study of the association between periodontitis and physical activity in the Japanese population.

OBJECTIVE: The aim of this study was to determine whether physical activity (PA) is associated with periodontitis in the Japanese population. BACKGROUND: The potential association between PA and periodontitis has not been thoroughly investigated in the Japanese population. METHODS: We used cross-sectional data from the Japan Public Health Center-based Prospective Study for the Next-Generation Oral Health Study. Periodontitis was determined by a full-mouth periodontal examination. PA was assessed using a validated questionnaire. We performed multivariable ordinal logistic regression analyses to assess the association of total PA (the first quintile was set as the reference category) with periodontitis (three categories: no/mild, moderate, and severe), stratified by sex. The associations of periodontitis with domain- and intensity-specific PA were also studied in separate logistic regression models. RESULTS: This study included 2160 Japanese adults [1414 women and 746 men; mean (standard deviation) age 58.1 (9.6) years]. After adjusting for potential confounders, total PA was inversely associated with the presence and severity of periodontitis in women. The multivariable-adjusted odds ratios (95% confidence intervals) for periodontitis in the second to fifth quintiles (compared with the first quintile) of total PA were 0.81 (0.59-1.12), 0.74 (0.53-1.02), 0.77 (0.55-1.06), and 0.64 (0.46-0.89), respectively (p for trend = .01). We did not find different results when we further investigated the associations of periodontitis with domain- and intensity-specific PA. By contrast, PA was not associated with periodontitis in men. CONCLUSION: Total PA had an inverse, linear association with the presence and severity of periodontitis in Japanese women but not in Japanese men. Further prospective studies are required to determine the association between PA and periodontitis.

Efficacy of Therapeutic Exercise on Activities of Daily Living and Cognitive Function Among Older Residents in Long-term Care Facilities: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVES: This study aimed to systematically analyze the efficacy of therapeutic exercise on activities of daily living (ADL) and cognitive function among older residents in long-term care facilities. DATA SOURCES: PubMed, Cochrane Central of Register Trials, Physiotherapy Evidence Database, OTseeker, and Ichushi-Web were searched from inception until December 2018. STUDY SELECTION: Databases were searched to identify randomized controlled trials (RCTs) of therapeutic exercise for long-term care facility residents aged 60 years and older, focusing on ADL and cognitive function as outcomes. DATA EXTRACTION: Two independent reviewers extracted the key information from each eligible study. Two reviewers independently screened and assessed all studies for eligibility, extracting information on study participants, details of interventions, outcome characteristics, and significant outcomes. Any discrepancies were resolved by a third reviewer. DATA SYNTHESIS: A total of 11 RCTs with 1280 participants were eligible for analyses. Therapeutic exercise had a significant benefit on ADL (standard mean difference [SMD]=0. 22, 95% confidence interval [CI]: 0.02, 0.42, P=.03). Subgroup analyses indicated that interventions conducted ≥3 days per week [SMD=0.42, 95% CI 0.02, 0.82, P=.04] had a significant benefit on ADL. For cognitive function, group exercise and ≥3 days/week of intervention had a significant benefit (group exercise: mean difference [MD]=3.36, 95% CI 0.91, 5.80, P=.007; ≥3 days/week of intervention: MD=2.28, 95% CI 0.07, 4.49, P=.04). CONCLUSIONS: Therapeutic exercise conducted 3 or more days per week may be effective for improving ADL and cognitive function among older residents in long-term care facilities. This meta-analysis suggested that group exercise for cognitive functions was effective. However, the effective method of intervention delivery for ADL was unclear.

Low-intensity resistance training to improve knee extension strength in community-dwelling older adults: Systematic review and meta-analysis of randomized controlled studies.

AIM: The purpose of this systematic review and meta-analysis was to investigate the effects of low-intensity resistance training on knee extension strength with respect to intensity, frequency, duration and training site in community-dwelling older adults. METHODS: A literature search was conducted for articles published up to December 2018 on PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Physiotherapy Evidence Database (PEDro), OTseeker and Ichushi-Web. Randomized controlled trials involving resistance training with <60 % one repetition maximum (1RM) in community-dwelling older adults aged 60 years and older were eligible. RESULTS: In total, 7 studies involving 275 participants were included in the meta-analysis. The results showed significant improvements in knee extension strength with low-intensity resistance training [standardized mean difference (SMD) 0.62, 95 % confidence interval (CI) 0.32 to 0.91]. In subgroup analyses, significant improvements were observed in the group with intensity at 50-60 % 1RM (0.83, 0.46 to 1.19), but not in the group at 40 % or less 1RM (0.30, 95%CI: -0.08 to 0.68). Concerning frequency, there were significant improvements in knee strength for those receiving training three times (0.90, 0.52 to 1.27) and two times (0.36, 0.03 to 0.69) per week, with a significant difference between the groups (p = 0.04). CONCLUSIONS: Low-intensity resistance training should be considered as an effective intervention to improve knee extension strength in community-dwelling older adults. Older adults may show more improvement in knee extension strength if intensity of the training is set at 50-60 % 1RM and frequency of training is three times per week.

Validation Study of Diabetes Definitions Using Japanese Diagnosis Procedure Combination Data Among Hospitalized Patients.

BACKGROUND: Validation studies of diabetes definitions using nationwide healthcare databases are scarce. We evaluated the validity of diabetes definitions using disease codes and antidiabetic drug prescriptions in the Japanese Diagnosis Procedure Combination (DPC) data via medical chart review. METHODS: We randomly selected 500 records among 15,334 patients who participated in the Japan Public Health Center-Based Prospective Study for the Next Generation in Yokote City and who had visited a general hospital in Akita between October 2011 and August 2018. Of the 500 patients, 98 were linked to DPC data; however, only 72 had sufficient information in the medical chart. Gold standard confirmation was performed by board-certified diabetologists. DPC-based diabetes definitions were based on the International Classification of Diseases, 10th Revision codes and antidiabetic prescriptions. Sensitivity, specificity, and the positive and negative predictive values (PPV and NPV, respectively) of DPC-based diabetes definitions were evaluated. RESULTS: Of 72 patients, 23 were diagnosed with diabetes using chart review; 19 had a diabetes code, and 13 had both a diabetes code and antidiabetic prescriptions. The sensitivity, specificity, PPV, and NPV were 89.5% (95% confidence interval [CI], 66.9-98.7%), 96.2% (95% CI, 87.0-99.5%), 89.5% (95% CI, 66.9-98.7%), and 96.2% (95% CI, 87.0-99.5%), respectively, for (i) diabetes codes alone; 89.5% (95% CI, 66.9-98.7%), 94.3% (95% CI, 84.3-98.8%), 85.0% (95% CI, 62.1-96.8%), and 96.2% (95% CI, 86.8-99.5%) for (ii) diabetes codes and/or prescriptions; 68.4% (95% CI, 43.4-87.4%), 100% (95% CI, 93.3-100%), 100% (95% CI, 75.3-100%), and 89.8% (95% CI, 79.2-96.2%) for (iii) both diabetes codes and prescriptions. CONCLUSION: Our results suggest that DPC data can accurately identify diabetes among inpatients using (i) diabetes codes alone or (ii) diabetes codes and/or prescriptions.

Association between Productive Roles and Frailty Factors among Community-Dwelling Older Adults: A Cross-Sectional Analysis.

The employment rate of older people in Japan is expected to increase in the future owing to the increase in the retirement age. Preventing frailty is imperative to maintaining productive roles of older adults. Therefore, this study aimed to examine the association between productive roles and frailty factors among community-dwelling older adults. A total of 135 older adults, enrolled in 2017, participated in the study. Productive roles and domains related to frailty were measured. We measured usual gait speed and grip strength for the physical domain; Mini-Mental State Examination (MMSE) and Geriatric Depression Scale (GDS-15) scores for the cognitive and mental domains; and social role and group activity for the social domain. Multivariate-adjusted logistic regression models revealed that having productive roles was associated with faster usual gait speed (odds ratios [OR] = 1.05; 95% confidence interval [CI], 1.01-1.08; p = 0.005) and lower GDS-15 score (OR = 0.79; 95% CI, 0.64-0.97; p = 0.023). These results suggest that health promotion to maintain gait speed and prevent depressive symptoms may contribute to maintaining productivity in community-dwelling older adults.

Association of Plasma Iron Status with Subsequent Risk of Total and Site-Specific Cancer: A Large Case-Cohort Study within JPHC Study.

It is unclear whether prediagnostic iron-related biomarkers in circulation are associated with cancer risk. We constructed a case-cohort of participants who had plasma samples available from the Japan Public Health Center-based Prospective Study and determined the incidence of cancer in these participants. We measured plasma concentrations of iron, ferritin, and hepcidin, and assessed the association between each biomarker and cancer incidence using a weighted Cox regression model. There were 4,253 participants in the sub-cohort (the randomly selected participants from an eligible, at-risk population) and 3,596 incident cancer cases (499 cases occurred in the sub-cohort). Median follow-up was for 16.5 years. In the multivariable adjusted analysis, iron deficiency (plasma ferritin <30 ng/mL) was associated with a higher risk of total cancer [adjusted HR, 1.23; 95% confidence interval (CI), 1.07-1.42] and the association was weaker after excluding those followed-up for <3 years. Iron overload was not significantly associated with total cancer (HR, 1.04; 95% CI, 0.82-1.33), but was associated with liver cancer (HR, 4.49; 95% CI, 2.71-7.43). Lower plasma levels of hepcidin and ferritin are associated with an increased gastrointestinal cancer risk. Meanwhile, lower plasma hepcidin and higher plasma ferritin levels were associated with an increased liver cancer risk. In conclusion, there was no association between iron overload and cancer risk, besides liver cancer. PREVENTION RELEVANCE: High ferritin and low hepcidin levels in the plasma were associated with increased liver cancer risk. Evaluating iron metabolism including hepcidin levels may help identify people with high liver cancer risk.

Validity of claims data for identifying cancer incidence in the Japan public health center-based prospective study for the next generation.

PURPOSE: This study determined the validity of claims-based definitions for identifying the incidence of total and site-specific cancers in a population-based cohort study. METHODS: Claims data were obtained for 21 946 participants aged 40-74 years enrolled in the Japan Public Health Center-based Prospective Study for the Next Generation. We defined total and site-specific cancer incidence using combinations of codes from claims data, including diagnosis and procedure codes for cancer therapy. Data from the cancer registry were used as the gold standard to evaluate validity. RESULTS: Among 21 946 participants, 454 total, 89 stomach, 67 colorectal, 51 lung, 39 breast and 99 prostate invasive cancer cases were newly diagnosed in the cancer registry. For invasive cancer, the sensitivity and specificity of the definition that combined codes for diagnosis and procedures for cancer therapy were 87.0% and 99.4% for total, 88.8% and 99.9% for stomach, 80.6% and 99.9% for colorectal, 86.3% and 99.9% for lung, 100% and 99.9% for breast and 91.9% and 99.9% for prostate cancer, respectively. Furthermore, for invasive and/or in situ cancer, the sensitivity and specificity of the definition were 84.5% and 99.5% for total, 66.7% and 99.9% for colorectal and 100% and 99.9% for breast cancer. CONCLUSIONS: Our findings suggest that claims-based definitions using diagnosis and procedure codes generally have high validity for total, stomach, lung, breast and prostate cancer incidence, but may underestimate colorectal cancer incidence.

Association Between Physical Activity and Risk of Disabling Dementia in Japan.

Importance: The associations of daily total physical activity and total moderate to vigorous physical activity (MVPA) with dementia are still unclear. Objective: To investigate the association between daily total physical activity and subsequent risk of disabling dementia in large-scale, extended follow-up prospective study. Design, Setting, and Participants: This prospective cohort study used data from questionnaires collected between 2000 and 2003 from 8 areas from the Japan Public Health Center-based Prospective Disabling Dementia Study. Participants included adults aged 50 to 79 years in with available follow-up data on disabling dementia. Data analysis was performed from February 1, 2019, to July 31, 2021. Exposures: Daily total physical activity, total MVPA, and leisure-time MVPA. Main Outcomes and Measures: The main outcome was incidence of disabling dementia during the dementia ascertainment period between 2006 and 2016, based on the national long-term care insurance system. Risks of dementia in association with daily total physical activity, total MVPA, and leisure time MVPA were calculated using multivariable adjusted hazard ratios (aHRs). Results: Among 43 896 participants (mean [SD] age, 61.0 [7.5] years; 23 659 [53.9%] women), 5010 participants were newly diagnosed with disabling dementia during a mean (SD) of 9.5 (2.8) years in the dementia ascertainment period. In the highest daily total physical activity group, compared with the lowest activity group, risk of dementia was lower in men (aHR, 0.75 [95% CI, 0.66-0.85]; P for trend < .001) and women (aHR, 0.75 [95% CI, 0.67-0.84]; P for trend < .001). Similar inverse associations were observed in men and women for total MVPA (men: aHR, 0.74 [95% CI, 0.65-0.84]; P for trend < .001; women: aHR, 0.74 [95% CI, 0.66-0.83]; P for trend < .001) and leisure-time MVPA (men: aHR, 0.59 [95% CI, 0.53-0.67]; P for trend < .001; women: aHR, 0.70 [95% CI, 0.63-0.78]; P for trend < .001). However, these inverse associations disappeared when participants diagnosed with disabling dementia within 7 years of the starting point were excluded in men (aHR, 0.93 [95%CI, 0.77-1.12]) and within 8 years were excluded in women (aHR, 0.86 [95%CI, 0.71-1.04]). The association remained significant among men in the highest vs lowest group of leisure-time MVPA, after excluding participants diagnosed within the first 9 years (aHR, 0.72 [95% CI, 0.56-0.92]; P for trend = .004). Conclusions and Relevance: This cohort study examined associations of daily total physical activity and total MVPA with risk of disabling dementia. The findings suggest that a high level of leisure-time MVPA was associated with decreased risk of disabling dementia in men.

Association between C-reactive protein and risk of overall and 18 site-specific cancers in a Japanese case-cohort.

BACKGROUND: Evidence of the association between chronic low-grade inflammation, as reflected by C-reactive protein (CRP) measurements, and cancer risk is equivocal. Specifically, few studies have examined this in uncommon cancers and Asian populations. METHODS: We utilised a case-cohort design consisting of multi-types of cancer (N = 3608), and a random subcohort (N = 4432) in a Japanese large population-based study, with a median follow-up time of 15.6 years, and measured baseline plasma CRP using high sensitivity assay. The hazard ratios (HRs) were estimated using weighted Cox proportional hazards methods. RESULTS: The multivariable-adjusted HR (95% confidence interval) for the top quartile of CRP was 1.28 (1.11‒1.48) (Ptrend < 0.001) for overall cancer compared to the bottom quartile of CRP. Among site-specific cancers, higher CRP levels were associated with an increased risk of colorectal, lung, breast, biliary tract, and kidney cancer, and leukaemia. These positive associations remained among participants after >3 years' follow-up. Furthermore, subgroup analyses for overall cancer robustly showed a positive association with CRP levels, regardless of sex and obesity. CONCLUSION: Our consistent findings suggested that chronic low-grade inflammation measured by CRP is associated with the risk of cancer.

Smoking and colorectal cancer: A pooled analysis of 10 population-based cohort studies in Japan.

Smoking has been consistently associated with the risk of colorectal cancer (CRC) in Western populations; however, evidence is limited and inconsistent in Asian people. To assess the association of smoking status, smoking intensity and smoking cessation with colorectal risk in the Japanese population, we performed a pooled analysis of 10 population-based cohort studies. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox's proportional hazards model and then pooled using a random-effects model. Among 363 409 participants followed up for 2 666 004 person-years, 9232 incident CRCs were identified. In men, compared with never smokers, ever smokers showed higher risk of CRC. The HRs (95% CI) were 1.19 (1.10-1.29) for CRC, 1.19 (1.09-1.30) for colon cancer, 1.28 (1.13-1.46) for distal colon cancer and 1.21 (1.07-1.36) for rectal cancer. Smoking was associated with risk of CRC in a dose-response manner. In women, compared with never smokers, ever smokers showed increased risk of distal colon cancer (1.47 [1.19-1.82]). There was no evidence of a significant gender difference in the association of smoking and CRC risk. Our results confirm that smoking is associated with an increased risk of CRC, both overall and subsites, in Japanese men and distal colon cancer in Japanese women.

Intensity-specific validity and reliability of the Japan Public Health Center-based prospective study-physical activity questionnaire.

The Japan Public Health Center-based prospective study- physical activity questionnaire (JPHC-PAQ) was originally developed and validated for total physical activity (total PA). However, it is uncertain whether JPHC-PAQ could also estimate intensity-specific physical activity. The present study aims to evaluate the validity and reliability of intensity-specific physical activity by the JPHC-PAQ against 24-hour activity records (24 h-R). One-hundred and ten participants were chosen from those who had enrolled in the JPHC cohort. Time spent for total PA and intensity-specific physical activity, i.e. moderate (MPA), vigorous (VPA) and moderate-to-vigorous physical activity (MVPA) was estimated by JPHC-PAQ. In addition, the volume of PA was calculated by time of each activity multiplied by intensity of activity. For validity assessment, estimated physical activities were compared with 24 h-R. For reliability evaluation, a retest was conducted 3-6 months after the first survey was answered. Moderately strong correlation between JPHC-PAQ and 24 h-R was observed for total PA estimations (Spearman's rho = 0.672). In addition, moderate correlations were found for MPA (activity time: rho = 0.345, activity volume: rho = 0.300) and MVPA (activity time: rho = 0.563, activity volume: rho = 0.672). Whereas, little association was found for VPA time and volume. As for reliability, moderately strong correlation was found for both total and intensity-specific physical activity in the test-retest (rho = 0.482-0.745). In addition to total PA, the JPHC-PAQ showed acceptable validity and reliability for intensity-specific physical activity, especially in estimating MVPA and MPA.