Longer Ground Contact Time Is Related to a Superior Running Economy in Highly Trained Distance Runners.

ABSTRACT: Tanji, F, Ohnuma, H, Ando, R, Yamanaka, R, Ikeda, T, and Suzuki, Y. Longer ground contact time is related to a superior running economy in highly trained distance runners. J Strength Cond Res 38(5): 985-990, 2024-Running economy is a key component of distance running performance and is associated with gait parameters. However, there is no consensus of the link between the running economy (RE), ground contact time, and footstrike patterns. Thus, this study aimed to clarify the relationship between RE, ground contact time, and thigh muscle cross-sectional area (CSA) in highly trained distance runners and to compare these parameters between 2 habitual footstrike patterns (midfoot vs. rearfoot). Seventeen male distance runners ran on a treadmill to measure RE and gait parameters. We collected the CSAs of the right thigh muscle using a magnetic resonance imaging scanner. The RE had a significant negative relationship with distance running performance ( r = -0.50) and ground contact time ( r = -0.51). The ground contact time had a significant negative relationship with the normalized CSAs of the vastus lateralis muscle ( r = -0.60) and hamstrings ( r = -0.54). No significant differences were found in RE, ground contact time, or normalized CSAs of muscles between midfoot ( n = 10) and rearfoot ( n = 7) strikers. These results suggest that large CSAs of knee extensor muscles results in short ground contact time and worse RE. The effects of the footstrike pattern on the RE appear insignificant, and the preferred footstrike pattern can be recommended for running in highly trained runners.

Preexercise High-Fat Meal Following Carbohydrate Loading Attenuates Glycogen Utilization During Endurance Exercise in Male Recreational Runners.

ABSTRACT: Iwayama, K, Tanabe, Y, Yajima, K, Tanji, F, Onishi, T, and Takahashi, H. Preexercise high-fat meal following carbohydrate loading attenuates glycogen utilization during endurance exercise in male recreational runners. J Strength Cond Res 37(3): 661-668, 2023-This study aimed to investigate whether one preexercise high-fat meal can increase glycogen conservation during endurance exercise, as compared with one preexercise high-carbohydrate meal. Ten young male recreational runners (22.0 ± 0.6 years; 171.3 ± 0.9 cm; 58.3 ± 1.9 kg; maximal oxygen uptake [V̇ o2 max], 62.0 ± 1.6 ml·kg -1 ·min -1 ) completed 2 exercise trials after high-carbohydrate loading: eating a high-carbohydrate (CHO; 7% protein, 13% fat, 80% carbohydrate) meal or eating a high-fat (FAT; 7% protein, 42% fat, 52% carbohydrate) meal 3.5 hours before exercise. The order of the 2 trials was randomized, and the interval between trials was at least 1 week. The experimental exercise consisted of running on a treadmill for 60 minutes at 95% of each subject's lactate threshold. Muscle and liver glycogen content were assessed using noninvasive carbon magnetic resonance spectroscopy before the experimental meal as well as before and after exercise; respiratory gases were measured continuously during exercise. The respiratory exchange ratio during exercise was statistically lower in the FAT trial than in the CHO trial ( p < 0.01). In addition, muscle ( p < 0.05) and liver ( p < 0.05) glycogen utilization during exercise was less in the FAT trial than in the CHO trial. Therefore, one high-fat meal following carbohydrate loading reduced muscle and liver glycogen use during the 60-minute exercise. These results suggest that this dietary approach may be applied as a strategy to optimize energy utilization during endurance exercise.

Augmented muscle glycogen utilization following a single session of sprint training in hypoxia.

PURPOSE: This study determined the effect of a single session of sprint interval training in hypoxia on muscle glycogen content among athletes. METHODS: Ten male college track and field sprinters (mean ± standard error of the mean: age, 21.1 ± 0.2 years; height, 177 ± 2 cm; body weight, 67 ± 2 kg) performed two exercise trials under either hypoxia [HYPO; fraction of inspired oxygen (FiO2), 14.5%] or normoxia (NOR: FiO2, 20.9%). The exercise consisted of 3 × 30 s maximal cycle sprints with 8-min rest periods between sets. Before and immediately after the exercise, the muscle glycogen content was measured using carbon magnetic resonance spectroscopy in vastus lateralis and vastus intermedius muscles. Moreover, power output, blood lactate concentrations, metabolic responses (respiratory oxygen uptake and carbon dioxide output), and muscle oxygenation were evaluated. RESULTS: Exercise significantly decreased muscle glycogen content in both trials (interaction, P = 0.03; main effect for time, P < 0.01). Relative changes in muscle glycogen content following exercise were significantly higher in the HYPO trial (- 43.5 ± 0.4%) than in the NOR trial (- 34.0 ± 0.3%; P < 0.01). The mean power output did not significantly differ between the two trials (P = 0.80). The blood lactate concentration after exercise was not significantly different between trials (P = 0.31). CONCLUSION: A single session of sprint interval training (3 × 30 s sprints) in hypoxia caused a greater decrease in muscle glycogen content compared with the same exercise under normoxia without interfering with the power output.

The Mediating Effect of Life-style Behaviors on the Association Between Personality Traits and Cardiovascular Disease Mortality Among 29,766 Community-Dwelling Japanese.

OBJECTIVE: Personality traits have been associated with an increased risk of cardiovascular disease (CVD) mortality as well as life-style-related cardiovascular risk factors. However, the mediating effects of life-style behaviors in the association between personality factors and CVD mortality remain insufficiently understood. The aim of the present study was to examine the mediating effect of life-style behaviors on the association between personality traits and CVD mortality. METHODS: We conducted a prospective cohort study of 29,766 Japanese adults aged 40 to 64 years at the baseline and followed them up for 20.8 years from 1990 to 2011. Personality was measured using the Japanese version of the Eysenck Personality Questionnaire - Revised Short Form in 1990. We estimated the multivariable hazard ratio and 95% confidence interval for CVD mortality using Cox proportional hazards models, and explored the mediating effects of life-style behaviors (smoking, drinking, body mass index, and time spent walking) on the association between personality traits and CVD mortality. RESULTS: We documented 1033 deaths due to CVD during 562,446 person-years of follow-up. Psychoticism represents tough-mindedness, aggressiveness, coldness, a lack of deliberateness, and egocentricity. After adjusting for confounding variables, higher psychoticism was associated with CVD mortality (base model hazard ratio = 1.36, 95% confidence interval = 1.14-1.61, p trend < .001). All the life-style behaviors together mediated this association by 19.2%, with smoking having the greatest effect at 15.7%. For the other personality traits, no significant associations with CVD mortality were found. CONCLUSION: The present study demonstrated that life-style behaviors, especially smoking, partially mediate the association between psychoticism and CVD mortality.

Dental Status is Associated With Incident Functional Disability in Community-Dwelling Older Japanese: A Prospective Cohort Study Using Propensity Score Matching.

BACKGROUND: A growing number of epidemiology studies have shown that poor oral health is associated with an increased incidence of functional disability. However, there are few studies in which the confounding bias is adjusted appropriately. In this study, we examined whether dental status is associated with functional disability in elderly Japanese using a 13-year prospective cohort study after elimination of confounding factors with propensity score matching. METHODS: Participants were community-dwelling Japanese aged 70 years or older who lived in the Tsurugaya district of Sendai (n = 838). The number of remaining teeth (over 20 teeth vs 0-19 teeth) was defined as the exposure variable. The outcome was the incidence of functional disability, defined as the first certification of long-term care insurance (LTCI) in Japan. The variables that were used to determine propensity score matching were age, sex, body mass index (BMI), medical history (stroke, hypertension, myocardial infarction, cancer, and diabetes), smoking, alcohol consumption, educational attainment, depression symptoms, cognitive impairment, physical function, social support, and marital status. RESULTS: As a result of the propensity score matching, 574 participants were selected. Participants with 0-19 teeth were more likely to develop functional disability than those with 20 or more teeth (hazard ratio 1.33; 95% confidence interval, 1.01-1.75). CONCLUSIONS: In this prospective cohort study targeting community-dwelling older adults in Japan, having less than 20 teeth was confirmed to be an independent risk factor for functional disability even after conducting propensity score matching. This study supports previous publications showing that oral health is associated with functional disability.

The Association between Number of Remaining Teeth and Maintenance of Successful Aging in Japanese Older People: A 9-Year Longitudinal Study.

With population aging, an increasing attention has been paid to quality of life rather than mere longevity. Now, it is urgently needed to clarify predictors of well-being in later life, i.e., "successful aging (SA)." The aim of this study is to investigate whether the number of remaining teeth impacts on maintenance of SA among Japanese older people. The present study was conducted in Tsurugaya district, a suburban area of Sendai, in northern Japan, and included older people aged ≥ 70 years who had met the criteria for SA at a 2003 baseline survey. At the baseline survey, dentists obtained data for the number of remaining teeth. We obtained information about Long-term Care Insurance certification, including the dates of incident functional disability and death between 2003 and 2012. Data pertaining to health-related quality of life (HRQOL) were collected at the 2003 baseline survey and the 2012 follow-up survey. Maintenance of SA was defined in terms of survival, disability-free status and high HRQOL in both 2003 and 2012. Among 450 participants, 108 (24.0%) were considered to have maintained a state of SA. When participants were classified into three groups according to previous studies, in comparison with participants who retained 0-9 teeth, the multivariate prevalence ratios (95% confidence intervals) were 1.39 (0.81-2.36) for those who retained 10-19 teeth and 1.58 (1.002-2.50) for those who retained ≥ 20 teeth (p trend = 0.046). The present results suggest that retaining ≥ 20 teeth is associated with maintenance of SA among Japanese older people.

Contribution of systemic inflammation and nutritional status to the relationship between tooth loss and mortality in a community-dwelling older Japanese population: a mediation analysis of data from the Tsurugaya project.

OBJECTIVES: To assess whether systemic inflammation and nutritional status contribute to a relationship between tooth loss and mortality in community-dwelling older Japanese individuals using mediation analyses. MATERIALS AND METHODS: This longitudinal study targeted community-dwelling older Japanese individuals (N = 891). The exposure variable was the number of teeth (edentulous, 1-9, 10-19, ≥ 20), while the outcome was all-cause mortality from 2003 to 2016. Nutritional status and systemic inflammation were evaluated as mediators and based on serum albumin and high-sensitivity C-reactive protein levels, respectively. Covariates included age, sex, smoking, alcohol consumption, medical history, educational level, depressive symptoms, cognitive impairment, and physical function. The Cox proportional hazards model was applied to calculate hazard ratios (HRs) for the association between tooth loss and mortality and the contributions of systemic inflammation and nutritional status to this association. RESULTS: Edentulous participants (HR, 1.84; 95 % confidence interval [CI], 1.30-2.59) and those with 1-9 teeth (HR, 1.75; 95% CI, 1.28-2.40) groups exhibited a significantly higher risk of mortality than did those with ≥ 20 teeth. Mediation analyses showed that nutritional status contributed to the association between tooth loss and mortality in participants with 1-9 teeth, whereas systemic inflammation played no role in this association. CONCLUSIONS: Nutritional status may contribute to the association between tooth loss and mortality in community-dwelling older Japanese individuals with fewer remaining teeth. CLINICAL RELEVANCE: The data from this prospective cohort study help in elucidating parts of the biological mechanism underlying tooth loss and all-cause mortality in older individuals.

Weight change since age 20 and incident risk of obesity-related cancer in Japan: a pooled analysis of the Miyagi Cohort Study and the Ohsaki Cohort Study.

It is unclear whether weight change during adulthood affects the risk of obesity-related cancers such as those of the esophagus, colorectum, pancreas, breast, endometrium, and kidney among Japanese, where obesity is less frequent and less severe. We examined the association between weight change during adulthood and the risk of obesity-related cancer among Japanese by conducting a pooled analysis of two prospective studies of residents in Miyagi Prefecture, Japan. A total of 78,743 persons (40,422 women and 38,321 men) aged 40-79 years participated in the Miyagi Cohort Study in 1990 and in the Ohsaki Cohort Study in 1994. Weight change since age 20 was divided into four categories (weight loss; stable weight; moderate weight gain; high weight gain). Cox proportional hazards regression analysis was used to estimate the multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for obesity-related cancer incidence. During 1,057,899 person-years of follow up, 4,467 cases of obesity-related cancer (women; 1,916 cases, men; 2,551cases) were identified. In women, compared to the stable weight, weight gain was associated with an increased risk of obesity-related cancer (moderate weight gain; HRs = 1.10, 95%CIs: 0.97-1.26, high weight gain; HRs = 1.29, 95%CIs: 1.14-1.47). The results indicate that weight gain since age 20 was associated with a significantly increased risk of obesity-related cancer among Japanese women. By contrast, in men, our study found that weight change is not associated with the incidence of obesity-related cancer.

The relationship between body mass index and disability-free survival in elderly Japanese: the Ohsaki Cohort 2006 Study.

BACKGROUND: The relationship between body mass index (BMI) and disability-free survival (DFS) remains unclear. METHODS: We conducted a 10-year prospective cohort study of 12,666 Japanese individuals aged ≥ 65 y. Information on BMI and lifestyle factors was collected via a questionnaire in 2006. Functional disability data were retrieved from the public Long-term Care Insurance database. Subjects were divided into seven groups according to BMI (<19, 19-21, 21-23, 23-25, 25-27, 27-29 and ≥29). Fiftieth percentile differences (PDs) and 95% confidence intervals (CIs) in the DFS period (differences of period until the first 50% of the composite outcome (disability or death) occurred in each of the BMI groups) were calculated using the Laplace regression model. RESULTS: There was a U-shaped relationship between BMI and the risk of incident composite outcome, with a BMI nadir of 25-27. Based on BMI 25-27 as a reference, the 50th PDs (95% CIs) (in months) in age at disability or death (median DFS) were -20.8 (-26.4, -15.2) (P < 0.001) months for BMI <19, -13.5 (-18.2, -8.7) (P < 0.001) months for BMI 19-21, -9.8 (-14.2, -5.4) (P < 0.001) months for BMI 21-23, -2.9 (-7.5, 1.7) (P = 0.21) months for BMI 23-25, -2.7 (-8.4, 2.9) (P = 0.34) months for BMI 27-29, and -11.5 (-19.6, -3.5) (P = 0.005) months for BMI ≥ 29. These relationships did not differ by sex. CONCLUSION: Older individuals with a BMI of <23 or ≥29 have a significantly shorter DFS period than those with a BMI of 25-27. It is suggested that the optimal BMI range for maximization of disability-free life expectancy in the elderly population is 23-29.

Combined Healthy Lifestyle Behaviors and Disability-Free Survival: the Ohsaki Cohort 2006 Study.

BACKGROUND: Previous studies have suggested that a healthy lifestyle (HL) may prolong the years of life spent in good health. However, the impact of HL on disability-free survival (DFS) among the elderly is still uncertain. OBJECTIVE: To investigate the relationship between HL and DFS in the general elderly population. DESIGN: Prospective cohort study with a 10-year follow-up (2006-2016). PARTICIPANTS: 9910 community-dwelling elderly people (≥ 65 years). MAIN MEASURES: A HL index derived by summing the number of HL behaviors. Data on incident disability were retrieved from the public Long-term Care Insurance database. Multivariate-adjusted 50th percentile differences (PDs) in age at disability or death (months) and their 95% CIs were estimated with the Laplace regression model. KEY RESULTS: During the 10 years, 4562 disability or death events occurred. Participants who adhered to all three HL behaviors lived 17.1 (95% CI 12.7, 21.5) months longer without disability than those who adhered to zero or one. Each 1-point increase of the index score conferred 8.8 months additional life without disability. The tendency for the 50th PDs to increase with a higher HL index score did not differ according to age (< 75 or ≥ 75 years), sex, or the presence of chronic conditions (none, or ≥ 1 chronic condition). CONCLUSIONS: A combination of HL behaviors may substantially increase DFS, even for late-elderly (≥ 75 years), or elderly people with chronic conditions.

A multicenter trial of extracorporeal cardiac shock wave therapy for refractory angina pectoris: report of the highly advanced medical treatment in Japan.

We have previously demonstrated that cardiac shock wave therapy (CSWT) effectively improves myocardial ischemia through coronary neovascularization both in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris (AP). In this study, we further addressed the efficacy and safety of CSWT in a single-arm multicenter study approved as a highly advanced medical treatment by the Japanese Ministry of Health, Labour and Welfare. Fifty patients with refractory AP [mean age 70.9 ± 12.6 (SD) years, M/F 38/12] without the indications of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were enrolled in 4 institutes in Japan. Ischemic myocardial regions in the left ventricle (LV) were identified by drug-induced stress myocardial perfusion imaging (MPI). Shock waves (200 shots/spot at 0.09 mJ/mm2) were applied to 40-60 spots in the ischemic myocardium 3 times in the first week. The patients were followed up for 3 months thereafter. Forty-one patients underwent CSWT and completed the follow-up at 3 months. CSWT markedly improved weekly nitroglycerin use [from 3.5 (IQR 2 to 6) to 0 (IQR 0 to 1)] and the symptoms [Canadian Cardiovascular Society functional class score, from 2 (IQR 2 to 3) to 1 (IQR 1 to 2)] (both P < 0.001). CSWT also significantly improved 6-min walking distance (from 384 ± 91 to 435 ± 122 m, P < 0.05). There were no significant changes in LV ejection fraction evaluated by echocardiography and LV stroke volume evaluated by cardiac magnetic resonance imaging (from 56.3 ± 14.7 to 58.8 ± 12.8%, P = 0.10, and from 52.3 ± 17.4 to 55.6 ± 15.7 mL, P = 0.15, respectively). Percent myocardium ischemia assessed by drug-induced stress MPI tended to be improved only in the treated segments (from 16.0 ± 11.1 to 12.1 ± 16.2%, P = 0.06), although no change was noted in the whole LV. No procedural complications or adverse effects related to the CSWT were noted. These results of the multicenter trial further indicate that CSWT is a useful and safe non-invasive strategy for patients with refractory AP with no options of PCI or CABG.

Preventive Effect of Oral Self-Care on Pneumonia Death among the Elderly with Tooth Loss: The Ohsaki Cohort 2006 Study.

Tooth loss is a risk factor for pneumonia mortality, but it is unclear whether oral care negates excess mortality due to pneumonia among community-dwelling elderly with tooth loss. The purpose of this study was to examine the influence of oral care on the association between the number of remaining teeth and the risk of pneumonia death. We analyzed for 18,098 individuals (aged ≥ 65 years) participating in a prospective cohort study. In a 2006 baseline survey, the following data were collected: the number of remaining teeth, oral care, history of disease, smoking, alcohol drinking, education level and so forth. We also obtained data on dates and causes of death between 2006 and 2014. The primary outcome was mortality due to pneumonia. Compared with those having ≥ 20 teeth, the risk of pneumonia mortality was increased among participants having 10-19 or 0-9 teeth; the multivariate hazard ratios (HRs) (95% confidence intervals [CI]) were 1.45 (1.03-2.04) and 1.38 (1.01-1.87), respectively. Among those having 0-9 teeth, a significantly increased risk of mortality due to pneumonia was disappeared for those who brushed their teeth ≥ 2 times per day, for those with visiting a dentist, and for those with use of denture, whereas the risk persisted among those who brushed their teeth ≤ 2 times per day, for those without visiting a dentist, and for those without use of denture. Tooth-brushing, visiting a dentist or use of denture may negate the increased risk of pneumonia death among the elderly with tooth loss.

Psychological distress and completed suicide in Japan: A comparison of the impact of moderate and severe psychological distress.

It has already been established that severe psychological distress is a major risk factor for completed suicide. However, the impact (population attributable fraction; PAF) of moderate psychological distress on completed suicide has not been clarified. The present study investigated the association between various severities of psychological distress and completed suicide. We analyzed follow-up data covering a 7.3-year period (2006-2014) for 43,473 adults (aged ≥ 40 years) participating in a community-based, prospective cohort study. Psychological distress was measured using the K6 psychological distress scale at the baseline. Participants were classified into three groups according to their K6 score (low: 0-4; moderate: 5-12; severe: 13-24). Completed suicide was determined from a Japanese national database. The Cox model was used to estimate hazard ratios (HRs) for completed suicide. The PAFs of moderate and severe psychological distress for completed suicide were also estimated. The multivariate-adjusted HRs (95% confidence interval) for completed suicide were 2.37 (1.49-3.78) among participants with moderate psychological distress, and 4.16 (2.13-8.15) among those with severe psychological distress, relative to those with low psychological distress (P for trend < 0.001). The PAF of the moderate group for completed suicide was 26.8%, whereas that of the severe group was 10.9%. Not only severe but also moderate psychological distress was significantly associated with an increased risk of completed suicide. The PAF of moderate psychological distress for completed suicide was larger than that of severe psychological distress. Public health actions for suicide prevention should focus on moderate as well as severe psychological distress.

Influence of subjective economic hardship on new onset of neck pain (so-called: katakori) in the chronic phase of the Great East Japan Earthquake: A prospective cohort study.

BACKGROUND: Studies have suggested that musculoskeletal symptoms increase after natural disasters. The Great East Japan Earthquake (GEJE) and accompanying tsunami placed a huge financial burden on the local population. This study determined whether subjective economic hardship influenced the new onset of neck pain (katakori) in the chronic phase after the GEJE. METHODS: This study used longitudinal data from 1359 adults who had responded to the self-report questionnaire at 2 and 3 years after the GEJE. New-onset neck pain was defined as neck pain absent at 2 years and present at 3 years. Subjective economic hardship at 2 years after the GEJE was categorized into 4 groups: "normal," "a little bit hard," "hard," and "very hard." Multiple logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI) in order to examine the association between subjective economic hardship and new-onset neck pain. RESULTS: Among the participants, 12.9% (n = 175) reported new-onset neck pain. A significantly higher rate of new-onset neck pain was observed in participants who considered their subjective economic hardship to be "hard" (OR = 2.10, 95% CI = 1.34-3.30) or "very hard" (OR = 3.26, 95% CI = 1.83-5.46; p for trend <0.001) compared with those who considered their hardship to be "normal." CONCLUSIONS: Subjective economic hardship was significantly associated with new-onset neck pain in the chronic phase of the GEJE. (228/300).

Association of Suicidal Ideation With Physical Health Conditions, Mental Health Conditions, and Multimorbidity and the Modifying Role of Emotional Social Support: A Cross-Sectional Study in Japan.

INTRODUCTION: It is unclear whether the risk of suicide differs among individuals with only physical health condition, those with only mental health conditions, and those with both types of conditions (multimorbidity) and how emotional social support modifies these associations. This study aimed to examine differences in the association of suicidal ideation with the presence of only physical health conditions, only mental health conditions, and multimorbidity and the modifying role of emotional social support in these associations. METHODS: A cross-sectional survey was conducted between August and September 2023 in a Japanese rural town to collect data. The exposure variable was the health condition, and it was classified into 4 groups: disease-free, only physical health conditions, only mental health conditions, and multimorbidity. The outcome variable was suicidal ideation. The data collected were analyzed using multivariate logistic regression analysis and stratified analysis. RESULTS: Suicidal ideation was found to have a significant positive association with the presence of only mental health conditions and multimorbidity. These associations remained unchanged in the absence of emotional social support. However, the odds ratio for the only mental health conditions group decreased in the presence of emotional social support, while the odds ratio for the multimorbidity group remained significantly higher. CONCLUSIONS: Suicidal ideation is positively associated with the presence of only mental health conditions and multimorbidity, but emotional social support modifies only the association between suicidal ideation and the presence of only mental health conditions. These results suggest that it may be important to identify the type of social support one needs based on one's health condition to prevent suicide.

Dementia knowledge and attitudes of nursing undergraduate students-association between lifestyle background and practical training experience.

Objective: To clarify the association between dementia knowledge and attitudes, lifestyle backgrounds, and practical training experiences of nursing students, and examine the basic nursing education for dementia. Participants and Methods: A total of 412 first-to-fourth-year students at Nursing College A participated in the study. A cross-sectional survey was conducted regarding knowledge (15 questions) and attitudes (15 questions) related to dementia. Results: Consent was obtained from 158 individuals (The response rate was 38.3%). Significant items regarding dementia attitudes and cohabitation experiences were identified. Additionally, significant items regarding attitude toward dementia and care providing experiences were identified. Conclusion: Associations among attitude toward dementia, cohabitation experiences, and care providing experiences were determined. Knowledge and attitudes regarding dementia improved with practical training experience.

Cigarette smoking and lung cancer risk according to histologic type in Japanese men and women.

Although cigarette smoking is a well-known risk factor for lung cancer, histology-specific risk has not been fully clarified in Japan. This case-control study evaluated the associations between smoking and lung cancer risk according to sex and histologic type. From among patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2009, 1670 lung cancer cases and 5855 controls were selected. History of smoking, quantity and duration of smoking, and passive smoking from spouses were assessed using a self-administered questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) for each exposure were estimated by unconditional logistic regression. Ever-smoking was significantly associated with a higher risk of squamous cell and small cell carcinoma. The OR for these two histologic types combined was larger in women (OR = 24.98, 95% CI: 13.50-46.23) than in men (OR = 9.43, 95% CI: 5.73-15.51). Analysis of the quantity and duration of smoking showed that the OR for each exposure level tended to be larger in women than in men. For adenocarcinoma, clear positive associations with quantity and duration-related factors were observed among men, and a significant positive association with passive smoking from spouses was found among non-smoking women (OR = 1.44, 95% CI: 1.06-1.95). These results suggest sex- and histologic type- differences in the association of smoking with lung cancer risk. Although smoking control should be continued to prevent lung cancers, further studies are required to better clarify differences in smoking-related lung cancer risk between the sexes and histologic types.

Association Between History of Psychiatric Disorder and Degree of Physical Injury Among Suicide Attempters: Secondary Data Analysis in a Japanese Rural Area.

INTRODUCTION: While there may be differences in the choice of suicide methods between attempters with and those without a history of psychiatric disorders, it is not clear whether these differences predict the actual degree of physical injury. The present study aimed to investigate the association between the history of psychiatric disorder and the degree of physical injury among suicide attempters in a Japanese rural area. METHODS: We conducted a cross-sectional study analyzing secondary data of 806 suicide attempters from April 2012 to March 2022 obtained from a Japanese rural city. The exposure variable was a history of psychiatric disorders. The primary outcome was the degree of physical injury of suicide attempters: moderate and severe. We conducted a multivariate Poisson regression analysis to estimate the prevalence ratios (PRs) and 95% confidence intervals (CIs). RESULTS: Among 806 suicide attempters, a significant negative association between the history of psychiatric disorder and the degree of physical injury was observed (PR = 0.40; 95% CI, 0.28-0.59). Those with and without psychiatric disorders were more likely to choose low- and severe-lethality suicide methods such as drug or psychotropic overdoses and hanging or deep wrist injuries, respectively (P < .001). CONCLUSIONS: The present study highlights the importance of considering suicide attempters, both with and without psychiatric disorders, while formulating targeted suicide prevention strategies.

Association between number of remaining teeth and healthy aging in Japanese older people: The Ohsaki Cohort 2006 Study.

AIM: Maintaining ≥20 teeth is a public health goal worldwide. Healthy aging, which includes psychological and social well-being, as well as physical indicators, has attracted a great deal of attention with the progression of aging societies. However, no studies have examined the association between the number of remaining teeth and healthy aging. This study aimed to investigate the association between the number of remaining teeth and healthy aging. METHODS: This community-based longitudinal cohort study included 8300 Japanese people aged ≥65 years who were free of disability and depression in the baseline survey in 2006. The participants were categorized into four groups according to the number of remaining teeth at baseline: 0-9, 10-19, 20-24 and ≥25. The primary outcome was healthy aging (defined as meeting all four of the following criteria: free of disability, free of depression, high health-related quality of life and high life satisfaction), as assessed by a questionnaire survey carried out in 2017. Multiple logistic regression was used to calculate the corresponding odds ratios and 95% confidence intervals. RESULTS: During about 11 years of follow-up, 621 (7.5%) participants attained healthy aging. Participants with ≥20 remaining teeth showed a higher healthy aging rate. Compared with participants with 0-9 teeth, the multivariate-adjusted odds ratios (95% confidence intervals) for 10-19, 20-24 and ≥25 teeth were 0.98 (0.77-1.26), 1.28 (1.01-1.63) and 1.59 (1.24-2.03), respectively. CONCLUSIONS: These findings suggest that maintaining ≥20 teeth was associated with healthy aging. Geriatr Gerontol Int 2022; 22: 68-74.

Thigh Muscularity and Sprinting Performance of National-Level Long-Distance Runners.

Long-distance runners require aerobic capacity as well as sprinting ability for superior performance; however, the factors which determine the sprinting ability of long-distance runners remain undetermined. Therefore, the purpose of our study was to examine the association between thigh muscle size and sprinting ability in national-level male long-distance runners. Nineteen male long-distance runners with 5000 m personal-best times of 13:12.63-14:14.87 participated in this study, and transaxial images of their right thighs were collected using magnetic resonance imaging. The cross-sectional areas of the quadriceps femoris, hamstrings, and adductor muscles were calculated from the transaxial images at 30%, 50%, and 70% of the distance from the greater trochanter to the lower edge of the femur; these areas were normalized by body mass. Sprint times for 100 m and 400 m were recorded on an all-weather track. The results revealed positive correlations between the normalized cross-sectional areas of the quadriceps femoris at 50% and 70% of the thigh length and the 100 m (r = 0.666, p = 0.002 and r = 0.531, p = 0.019, respectively) and 400 m sprint times (r = 0.769, p < 0.001 and r = 0.580, p = 0.009, respectively); hence, the larger the quadriceps, the slower the sprint speed. However, no association was found between the normalized cross-sectional areas of the hamstrings or adductor muscles and sprinting performance. Therefore, running motions which activate the quadriceps femoris much more than the hamstrings and adductor muscles should be avoided by national-level long-distance runners.