Cardiorespiratory fitness and body mass index on metabolic syndrome in middle-aged Japanese adults under national health guidance: a cross-sectional study.

OBJECTIVES: Poor cardiorespiratory fitness (CRF) and high body mass index (BMI) increased the risk of developing metabolic Syndrome (MetS) mostly in Caucasians. However, the sex-specific combined association of CRF and BMI on MetS considering health-related behaviors has yet to be thoroughly examined in Japanese. This study aims to investigate the sex-specific independent and combined associations of CRF and BMI with MetS in middle-aged Japanese adults. METHODS: 421 participants were included in this cross-sectional study. CRF was estimated using a submaximal cycle ergometer. CRF and BMI were respectively divided into three categories according to tertile distribution. MetS was diagnosed based on five risk factors: waist circumference, triglycerides, high-density lipoprotein cholesterol, blood pressure, and fasting glucose. Multivariable logistic regression models were used to estimate independent and combined association of CRF and BMI with MetS. RESULTS: Results showed that 154 (57.5%) and 70 (45.8%) of men and women had MetS, respectively. Compared to men with lower CRF or higher BMI, men with middle and higher CRF or middle and lower BMI were less likely to have MetS. Compared with 'unfit and higher BMI' group, 'unfit and lower BMI', 'fit and higher BMI', and 'fit and lower BMI' groups in men showed statistically significant decreased prevalences of MetS. However, no significant associations were found in women. CONCLUSIONS: This study found significant independent and combined associations of CRF and BMI with MetS only in men, but not in women. However, prospective studies are warranted to confirm sex-specific associations of CRF and BMI with MetS.

Does health literacy moderate the psychological pathways of physical activity from guideline awareness to behavior? A multi-group structural equation modeling.

BACKGROUND: Awareness, knowledge, beliefs, and behavioral intentions of physical activity (PA) guidelines may be important mediating factors for promoting PA. However, these pathways of the psychological process to PA behavior have not been examined. These pathways may differ depending on health literacy levels. This study investigated the pathways to PA, from guideline awareness to behavior, and further examined whether they differed by health literacy. METHODS: A cross-sectional study was conducted with 7,000 Japanese participants aged 20-69 years. The participants were registered with an Internet survey company. Participants' awareness, knowledge, beliefs, and behavioral intentions regarding the PA guidelines of Japan, the volume of moderate-to-vigorous intensity PA, activity level, and health literacy were examined through a questionnaire. The PA pathways, from guideline awareness to behavior, were examined by structural equation modeling (SEM), with PA behavior as the dependent variable. Multi-group SEM was conducted to examine the moderating effect of health literacy on PA pathways. Health literacy scores were dichotomized into high and low groups in multi-group modeling by the median split. RESULTS: SEM revealed that PA guideline awareness directly affects PA behavior and has certain indirect effects through the mediation of knowledge, beliefs, and behavioral intentions. Furthermore, the multi-group SEM showed that the proportion of indirect effects (path coefficient [PC]: 0.11, 95% confidence interval [CI]: 0.10-0.13) was higher than direct effects (PC: 0.07, 95%CI: 0.03-0.11) in the high-health literacy group. In contrast, the proportion of direct effects (PC: 0.22, 95%CI: 0.15-0.30) was higher than indirect effects (PC: 0.06, 95%CI: 0.05-0.07) in the low-health literacy group. CONCLUSIONS: PA guideline awareness is both directly and indirectly associated with PA behavior, mediated by psychological pathways of knowledge, beliefs, and behavioral intentions, and influenced by health literacy. These results suggest that health literacy should be considered when implementing PA guideline-based interventions.

Leisure-time physical activity and incidence of objectively assessed hearing loss: The Niigata Wellness Study.

Previous cohort study reported that high physical activity was associated with a low risk of self-reported hearing loss in women. However, no studies have examined the association between physical activity and the development of hearing loss as measured using an objective assessment of hearing loss in men and women. Here, we used cohort data to examine the association between leisure-time physical activity and incidence of objectively assessed hearing loss in men and women. Participants included 27 537 Japanese adults aged 20-80 years without hearing loss, who completed a self-administered physical activity questionnaire between April 2001 and March 2002. The participants were followed up for the development of hearing loss as measured by audiometry between April 2002 and March 2008. During follow-up, 3691 participants developed hearing loss. Compared with the none physical activity group, multivariable adjusted hazard ratios (HRs) for developing hearing loss were 0.93 (95% confidence interval (CI), 0.86-1.01) and 0.87 (0.81-0.95) for the medium (<525 MET-min/week) and high (≥525 MET-min/week) physical activity groups, respectively (p for trend = 0.001). The magnitude of risk reduction was slightly greater in vigorous-intensity activity than in moderate-intensity activity (p for interaction = 0.01). Analysis by sound frequency showed that the amount of physical activity was inversely associated with high frequency hearing loss development (p for trend <0.001), but not with low frequency hearing loss development (p for trend = 0.19). Higher level of leisure-time physical activity was associated with lower incidence of hearing loss, particularly for vigorous-intensity activities and high sound frequencies.

The combination of cardiorespiratory fitness and muscular fitness, and prevalence of diabetes mellitus in middle-aged and older men: WASEDA'S Health Study.

BACKGROUND: Although the negative relationship between cardiorespiratory fitness (CRF) or muscular fitness and diabetes mellitus were respectively observed in many previous studies, there is still a lack of studies that include CRF and muscular fitness simultaneously. Therefore, this study aimed to investigate the relationship between the combination of CRF and muscular fitness and diabetes through a cross-sectional study.  METHODS: This study was part of WASEDA'S Health Study, a cohort study launched in 2014. We used a part of the baseline data collected for this study. Maximal exercise test using a cycle ergometer and leg extension power (LEP) test were respectively used to evaluate CRF and muscular fitness. Since LEP is affected by body weight, relative LEP (rLEP) which is LEP per body weight, was used as an index of muscular fitness. 796 men (56.5 ± 10.4 years old) who completed a medical examination and fitness tests, were divided into two groups based on CRF and rLEP, respectively. The prevalence of diabetes was collected based on a self-reported questionnaire or blood test. Odds ratios and 95% confidence intervals (CIs) for the prevalence of diabetes were obtained using logistic regression models while adjusting for age, body mass index, exercise habits, family history of diabetes, smoking habits, and drinking habits. RESULTS: 55 (7%) participants had diabetes. Compared to participants with lower CRF or rLEP, the odds ratio (95% CIs) of diabetes in those with higher CRF or rLEP was 0.46 (0.21-0.98) or 0.34 (0.16-0.74), respectively. Furthermore, using the lower CRF and lower rLEP group as the reference, the odds ratio (95% CIs) for the lower CRF and higher rLEP group was 0.32 (0.12-0.88), and higher CRF and higher rLEP group was 0.21 (0.07-0.63), after adjusting for potential confounding factors. CONCLUSIONS: CRF and rLEP have independent and joint inverse associations with diabetes prevalence. In addition, participants with high CRF and high rLEP had a lower prevalence of diabetes compared to those with only high CRF or only high rLEP.

Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: a systematic review and meta-analysis of cohort studies.

OBJECTIVE: To quantify the associations between muscle-strengthening activities and the risk of non-communicable diseases and mortality in adults independent of aerobic activities. DESIGN: Systematic review and meta-analysis of prospective cohort studies. DATA SOURCES: MEDLINE and Embase were searched from inception to June 2021 and the reference lists of all related articles were reviewed. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Prospective cohort studies that examined the association between muscle-strengthening activities and health outcomes in adults aged ≥18 years without severe health conditions. RESULTS: Sixteen studies met the eligibility criteria. Muscle-strengthening activities were associated with a 10-17% lower risk of all-cause mortality, cardiovascular disease (CVD), total cancer, diabetes and lung cancer. No association was found between muscle-strengthening activities and the risk of some site-specific cancers (colon, kidney, bladder and pancreatic cancers). J-shaped associations with the maximum risk reduction (approximately 10-20%) at approximately 30-60 min/week of muscle-strengthening activities were found for all-cause mortality, CVD and total cancer, whereas an L-shaped association showing a large risk reduction at up to 60 min/week of muscle-strengthening activities was observed for diabetes. Combined muscle-strengthening and aerobic activities (versus none) were associated with a lower risk of all-cause, CVD and total cancer mortality. CONCLUSION: Muscle-strengthening activities were inversely associated with the risk of all-cause mortality and major non-communicable diseases including CVD, total cancer, diabetes and lung cancer; however, the influence of a higher volume of muscle-strengthening activities on all-cause mortality, CVD and total cancer is unclear when considering the observed J-shaped associations. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020219808.

[Current status of awareness, knowledge, beliefs, and behavioral intentions regarding the Japanese physical activity guidelines and their relationship with physical activity and sedentary behavior].

Objective　This study clarified the current status of awareness, knowledge, beliefs, and behavioral intentions regarding the Japanese physical activity guidelines (Active Guide) and their relationship with physical activity, sedentary behavior, and the participants' characteristics.Methods　A cross-sectional study was conducted with 7,000 participants aged 20-69 years registered with an online survey company. Awareness, knowledge, beliefs, and behavioral intentions regarding the Active Guide were examined. Awareness was assessed by unprompted and prompted recall. Knowledge was assessed by numerical responses to "the recommended daily activity time (18-64 years/65 years and older)" and "physical activity time to be increased (plus-ten)," respectively. To survey the beliefs and behavioral intentions, we created a 5-point scale for the Active Guide. For physical activity, the amount of moderate-to-vigorous intensity physical activity was calculated from the Japan Public Health Center-based prospective Study (JPHC study) questionnaire. Physical activity level was calculated from the standard specific medical checkup and health guidance questionnaire. For sedentary behavior, the Japanese version of the International Physical Activity Questionnaire (IPAQ) was used. The dependent variables were awareness, knowledge, beliefs, and behavioral intentions. The independent variables were physical activity, sedentary behavior, and the participants' characteristics (gender, age, body mass index, marital status, educational background, work status, and household income). After descriptive statistics were measured, a logistic regression analysis was performed to examine the associations.Results　Unprompted and prompted recall of the Active Guide were 1.7% and 5.3-13.4%, respectively. Those with knowledge of it scored 37.2%, 7.0%, 24.8%, and 2.6% for recommended daily activity time (18-64 years), daily physical activity time (65 years and older), plus-ten, and all three items answered correctly, respectively. The median (interquartile range) score of the beliefs was 21 (16-25) points (32-point scale). Those with behavioral intentions scored 51.4% for "recommended daily activity" and 66.9% for "plus-ten." Logistic regression analysis showed that awareness, knowledge, beliefs, and behavioral intentions were positively associated with moderate-to-vigorous intensity physical activity and level. The results were inconsistent for sedentary behavior. Although personal characteristics differed based on assessment item, they were mainly associated with age, education level, employment, and household income.Conclusions　This study revealed that the number of people who had awareness and knowledge of the Active Guide remained low. Those with awareness, knowledge, beliefs, and behavioral intentions were more physically active. However, the results for sedentary behavior were not consistent. Hence, further research is required to understand this tendency. A future longitudinal study is also required.

The association of fitness and fatness with intermediate hyperglycemia incidence in women: A cohort study.

The purpose of this study was to examine the associations of cardiorespiratory fitness, general adiposity, and central adiposity with incident intermediate hyperglycemia (IH) in women. We conducted a prospective cohort study of 1534 women aged 20-79 years old who had an annual health check-up with no history of major chronic diseases. At baseline, fitness was assessed by a Balke graded exercise test, and the estimated metabolic equivalents were used to create quartile groups. Women were also grouped based on their body mass index (<25 kg/m2, 25-29.9 kg/m2, and ≥ 30 kg/m2) and waist-to-height ratio (≥0.50 or < 0.50). Cox proportional hazards models were conducted to assess the association of fitness and fatness variables with incident IH defined as fasting glucose of 5.6-6.9 mmol/L. Overall, 18.1% (n = 277) of the women developed IH during an average follow-up of 5.06 years. Fitness, body mass index, and waist-to-height ratio at baseline were the independent predictors of the IH incidence in separate age-adjusted models; yet when all three variables were included in the same model along with confounding variables, only fitness remained significant and demonstrated a clear inverse association with incident IH (P-for-trend <0.001). Health promotion efforts should focus on improving fitness for the prevention of IH in women.

Physical Fitness and Dyslipidemia Among Japanese: A Cohort Study From the Niigata Wellness Study.

BACKGROUND: Grip strength reflects systemic muscle strength and mass and is reportedly associated with various metabolic variables. However, its prognostic association with dyslipidemia is unknown. We examined the association of grip strength and other physical fitness markers with the incidence of dyslipidemia among Japanese adults. METHODS: A total of 16,149 Japanese (6,208 women) individuals aged 20-92 years who underwent a physical fitness test between April 2001 and March 2002 were included in this cohort study. Grip strength, vertical jump, single-leg balance with eyes closed, forward bending, and whole-body reaction time were evaluated at baseline. Dyslipidemia was annually determined based on fasting serum lipid profiles and self-reported dyslipidemia from April 2001 to March 2008. RESULTS: During the follow-up period, 4,458 (44.9%) men and 2,461 (39.6%) women developed dyslipidemia. A higher relative grip strength (grip strength/body mass index) was associated with a lower incidence of dyslipidemia among both men and women (P for trend <0.001). Compared with those for the first septile, the hazards ratios and 95% confidence intervals (CIs) for the seventh septile were 0.56 (95% CI, 0.50-0.63) for men and 0.69 (95% CI, 0.58-0.81) for women. Moreover, relative vertical jump (vertical jump strength/body mass index) was also inversely associated with the incidence of dyslipidemia among both men and women (P for trend <0.001). There was no association between other physical fitness and dyslipidemia among both men and women. CONCLUSION: Relative grip strength and vertical jump may be useful risk markers of the incidence of dyslipidemia.

Body flexibility and incident hypertension: The Niigata wellness study.

A high level of physical fitness, especially cardiorespiratory fitness, is associated with lower incidence of hypertension. However, the relationship between flexibility, which is a component of physical fitness, and the incidence of hypertension is unknown. The purpose of this study was to investigate the relationship between flexibility and the incidence of hypertension in a cohort study. A total of 22,972 (14,805 men and 8167 women; median age 49 years) normotensive participants were included in this study. Between April 2001 and March 2002, flexibility (standing forward bending) was measured using a standing trunk flexion meter. The participants were divided into quartiles of flexibility by sex and age group. Hypertension was defined as systolic blood pressure ≥ 140 mm Hg, diastolic blood pressure ≥ 90 mm Hg, or a self-reported history of previously diagnosed hypertension or current medication for hypertension at a health examination between April 2002 and March 2008. Hazard ratios and 95% confidence intervals (95% CI) for the incidence of hypertension were estimated using Cox proportional hazards models after adjusting for age, sex, body mass index, exercise habits, smoking status, and drinking status. During 102,948 person years of follow-up (median 5.6 years), 4235 participants developed hypertension. Compared with the lowest flexibility (quartile 1), hazard ratios and 95% CI were 0.96 (0.88 - 1.04) for quartile 2, 0.94 (0.86 - 1.03) for quartile 3, and 0.83 (0.76 - 0.91) for quartile 4. A high level of flexibility was associated with lower incidence of hypertension, independent of other confounding factors.

[Associations between psychological attitudes toward exercise and fitness club membership resignation among new members: A cohort study].

Objectives　Approximately 40% of new fitness club (FC) members drop out within the first six months; however, the factors associated with FC membership resignation are largely unknown. This study aimed to identify the association between psychological attitudes toward exercise and FC membership resignation.Methods　We conducted a cohort study enrolling participants from 17 FCs. All individuals who became members at FCs between April 1st, 2015 and March 31st, 2016 (n=5,421) were invited to participate in the study, and those who agreed to participate completed a self-administered baseline questionnaire (n=2,934). We excluded participants aged <20 years (n=167) and those with missing values (n=702). Psychological factors were evaluated using the short version of the perceived benefit and barriers to exercise scale. Participants were followed until September 30th, 2016, at which time we assessed the FC membership drop-out rate. Cox proportional-hazards models were used to evaluate the association between perceived benefits/barriers of exercise and FC membership resignation. Sub-analyses were then conducted, stratifying by gender and age group.Results　A total of 2,065 participants were included in the analyses. The mean (standard deviation) age was 39.0 (15.0) years and 28.8% were male. Over 10.1 (4.4) months of newly-joined member follow-up, the FC membership drop-out rate was 24.6 instances per 1000 person-months. Multivariable analyses revealed no significant factors associated with FC membership drop-out. However, men aged 40-59 years who had a high physical benefit score and who perceived improving physical fitness as a benefit, were less likely to resign their memberships (hazard ratio [HR], 95% confidence interval [CI], 0.72 [0.52-1.00]). However, women aged <40 years with a high discomfort score and who saw discomfort as a barrier were more likely to resign membership (HR, 1.10 [1.01-1.19]). Women aged 40-59 years with high social benefit scores and who perceived social interaction as a benefit were less likely to resign their memberships, as were women with higher lack of motivation to exercise scores and who perceived lack of motivation as a barrier to exercise (HR for social benefit, 0.84 [0.74-0.97]; HR for lack of motivation, 0.85 [0.73-0.99]). Among both male and female participants aged ≥60 years, higher self-improvement scores, indicating that peer recognition was perceived as a benefit of exercise, was associated with higher HR for drop-out (men, 2.52 [1.10-5.81]; women, 1.31 [1.00-1.72]).Conclusions　The results revealed gender and age differences in the association between the perceived benefits/barriers of exercise and FC membership dropout. Implementing programs based on enrollees' characteristics and psychological factors may contribute to preventing FC dropout in the future.

[Effect of an exercise program targeting knee pain on medical costs of elderly community-dwelling adults].

Objectives　The aim of this study was to examine the effect of an exercise program targeting knee pain on longitudinal medical costs (MC) of elderly community-dwelling adults.Methods　A community-based health program using specific exercises for improving knee pain was held from January to February, 2015. Twenty-eight individuals participated in the program (intervention group) and seventy individuals were selected from the respondents of a health and lifestyle survey by matching age, sex, and baseline value of severity of knee pain as a control group. Twenty individuals from the intervention group and twenty-nine from the control group were included in the final analysis. The changes in MC from 2014 to 2018 were compared between the two groups using a linear mixed-effects model.Results　The effect of the program on MC, estimated as a change from the baseline in 2014, showed a reduction of -5.6×103 yen/person (95% CI: -39.2-28.0) for the entire four-year period after the intervention. However, this difference was not significant. The changes in MC each year after the intervention were 9.3×103 yen/person (95% CI: -39.6-58.3) in 2015, -2.0×103 yen/person (95% CI: -44.4-40.5) in 2016, -10.3×103 yen/person (95% CI: -42.5-21.9) in 2017, and 8.2×103 yen/person (95% CI: -39.1-55.4) in 2018.Conclusion　The exercise program did not show a clear benefit in reducing the MC of elderly community-dwellers during the four years after the intervention. Further research with longer study durations and larger sample populations would be necessary to determine the effect of such intervention programs on MC.

Simple-measured leg muscle strength and the prevalence of diabetes among Japanese males: a cross-sectional analysis of data from the Kameda health study.

[Purpose] The aim of this study was to investigate the relationship between leg muscle strength, measured by a very simple one-leg stand-up test, and the prevalence of diabetes among Japanese males to raise awareness of diabetes prevention. [Participants and Methods] This cross-sectional analysis was conducted in 1,800 Japanese males (median [interquartile range] age, 61 [56-67] years) who completed health examinations and a one-leg stand-up test. The prevalence of diabetes was defined if any of the following conditions applied: 1) fasting blood glucose level more than 126 mg/dl, 2) two-hour blood glucose level more than 200 mg/dl (75-g oral glucose tolerance test), 3) HbA1c more than 6.5%, 4) diagnosed with diabetes by a physician, and/or 5) treated for diabetes. [Results] There were 490 participants with diabetes, and 517 participants were unable to complete the sit-to-stand task. When males, who could stand up, were used as a reference, the odds ratio for the prevalence of diabetes was significantly higher among those who were unable to stand up on neither leg than those who successfully stood up on both right and left legs after adjustment for covariates. [Conclusion] Low leg muscle strength, as measured by the one-leg stand-up test, was associated with a higher prevalence of diabetes among Japanese males. Because of its simplicity, this test could be useful detecting individuals who are at increased risk of developing diabetes.

Physical Fitness Tests and Type 2 Diabetes Among Japanese: A Longitudinal Study From the Niigata Wellness Study.

BACKGROUND: Simple physical fitness test can be a useful potential predictor of type 2 diabetes (T2DM). We examined the association between performances on simple physical fitness tests and the incidence of T2DM. METHODS: This longitudinal study was conducted in 21,802 nondiabetic Japanese (6,649 women) aged 20 to 92 years, who underwent all physical fitness tests at baseline (April 2001 to March 2002). From April 2001 to March 2008, physical fitness tests, including grip strength, vertical jump, single-leg balance with eyes closed, forward bending, whole-body reaction time, and supine legs-up, were performed every year. Participants had physical fitness tests at least two times during the period. T2DM was also annually determined based on fasting blood glucose, glycated hemoglobin, and self-reported diabetes during the period. Discrete-time logit models were used to examine the influence of the serial level of each physical fitness test on the incidence of T2DM. RESULTS: During the entire study period, 972 participants developed diabetes. Lower relative grip strength (grip strength/body weight) and single-leg balance performance were associated with a higher incidence of T2DM. For relative grip strength, as compared with the fourth quartile group, the odds ratios for other groups ranged from 1.16 to 1.56 (P for trend < 0.001). For single-leg balance, the odds ratios ranged from 1.03 to 1.49 (P for trend < 0.001). CONCLUSION: The performance of a simple single-leg balance test as well as that of a grip strength test were negatively associated with the risk of T2DM among Japanese.

Stand-up test overestimates the decline of locomotor function in taller people: a cross-sectional analysis of data from the Kameda Health Study.

[Purpose] The purpose of this study was to identify which physical attribute could influence each outcome in the Stand-up test and the Two-step test and the degree of their involvement. [Participants and Methods] The participants were 2,476 people (1,674 males and 802 females), who underwent a two-day health checkup and were requested to take the Locomotive Syndrome Risk Test (Locomo Test). Participants were divided into groups under the Locomo level based on the result of Locomo Test by gender. Furthermore, the relationship between each physical attributes (quartile) based on the result of Locomo Test and the Locomo level was evaluated. [Results] According to the relationship between each physical attributes and Locomo level 1 in the Stand-up test, height showed a positive relationship and the multivariable adjusted odds ratio significantly increased with taller height in both genders. Body weight and BMI showed a negative relationship, although rather weak positive relationship, it was identified in waist circumference. On the other hand, there was no clear correlation between each physical attribute and Locomo level 1 in the Two-step test. [Conclusion] The findings indicate The Stand-up test would overestimate the decline of locomotor function in taller people and would underestimate it in shorter individuals.

Importance of Achieving a "Fit" Cardiorespiratory Fitness Level for Several Years on the Incidence of Type 2 Diabetes Mellitus: A Japanese Cohort Study.

BACKGROUND: The "Physical Activity Reference for Health Promotion 2013" provides "fit" reference values for cardiorespiratory fitness (CRF) for good health. The importance of achieving a fit CRF level for several years on the subsequent prevention of type 2 diabetes mellitus (T2DM) remains to be clarified. METHODS: This cohort study was conducted in 2,235 nondiabetic males aged 21 to 59 years, enrolled in April 1986 through March 1987. We calculated the ratio of the area under the curve (AUCratio) for actual measured values and the AUC for the reference values of CRF in each individual during an 8-year measurement period before the baseline. According to whether they met a fit CRF level or not, participants were categorized into groups based on the AUCratio (FitAUC or UnfitAUC) and initial CRF (Fitinitial or Unfitinitial), respectively. T2DM was evaluated on health checkups until March 2010. RESULTS: During the follow-up period, 400 men developed T2DM. After adjustment for confounders, as compared with those in the FitAUC group, the hazard ratio (HR) for those in the UnfitAUC group was 1.33 (95% confidence interval [CI], 1.06-1.65). A combined analysis with the categories of initial value and AUCratio showed that, compared with the Fitinitial and FitAUC group, the HRs of Fitinitial and UnfitAUC, Unfitinitial and FitAUC, and Unfitinitial and UnfitAUC groups were 1.41 (95% CI, 0.99-2.00), 1.18 (95% CI, 0.81-1.70), and 1.40 (95% CI, 1.08-1.83), respectively. CONCLUSION: Achievement of a fit CRF level established in the Japan physical activity guideline for several years was associated with lower subsequent risk of T2DM.

Long-term Impact of Cardiorespiratory Fitness on Type 2 Diabetes Incidence: A Cohort Study of Japanese Men.

BACKGROUND: We sought to examine the association between cardiorespiratory fitness (CRF) and incidence of type 2 diabetes considering the follow-up period in a cohort of Japanese men with a maximum follow-up period of 23 years. METHODS: This study enrolled 7,804 male workers free of diabetes in 1986. CRF was measured using a cycle ergometer, and maximal oxygen uptake was estimated. During 1986-2009, participants were followed for development of type 2 diabetes, which was diagnosed using fasting blood tests, self-administered questionnaires, or oral glucose tolerance tests after urinary tests from annual health checkups. Hazard ratios for the incidence of type 2 diabetes were estimated using Cox proportional hazards models. RESULTS: During the follow-up period, 1,047 men developed type 2 diabetes. In analyses by follow-up periods (1986-1993, 1994-2001, and 2002-2009), there was an inverse dose-response relationship between CRF and the development of type 2 diabetes for all three follow-up periods (P for trend 0.019, <0.001, and 0.001, respectively), and the association between CRF at baseline and the incidence of type 2 diabetes did not weaken with longer follow-up period. Compared with the lowest CRF group, hazard ratios of developing type 2 diabetes were 0.69 (95% confidence interval [CI], 0.49-0.97) for the highest CRF group in 1986-1993, 0.57 (95% CI, 0.42-0.79) for the highest CRF in 1994-2001, and 0.47 (95% CI, 0.30-0.74) for the highest CRF in 2002-2009. CONCLUSION: High CRF is associated with a lower risk of the incidence of type 2 diabetes over an extended period of >20 years among men.

Daily step count and all-cause mortality in a sample of Japanese elderly people: a cohort study.

BACKGROUND: This study aimed to examine the relationship between pedometer-assessed daily step count and all-cause mortality in a sample of elderly Japanese people. METHODS: Participants included 419 (228 males and 191 females) physically independent, community-dwelling 71-year-old Japanese people. The number of steps per day was measured by a waist-mounted pedometer for seven consecutive days at baseline. Participants were divided into quartiles based on their average number of steps/day (first quartile, < 4503 steps/day; second quartile, 4503-6110 steps/day; third quartile, 6111-7971 steps/day; fourth quartile, > 7972 steps/day) and were followed up over a mean period of 9.8 years (1999-2010) for mortality. RESULTS: Seventy-six participants (18.1%) died during the follow-up period. The hazard ratios (adjusted for sex, body mass index, cigarette smoking, alcohol intake, and medication use) for mortality across the quartiles of daily step count (lowest to highest) were 1.00 (reference), 0.81 (95%CI, 0.43-1.54), 1.26 (95%CI, 0.70-2.26), and 0.46 (95%CI, 0.22-0.96) (P for trend = 0.149). Participants in the highest quartile had a significantly lower risk of death compared with participants in the lowest quartile. CONCLUSION: This study suggested that a high daily step count is associated with a lower risk of all-cause mortality in physically independent Japanese elderly people.

Association between objectively measured physical activity and body mass index with low back pain: a large-scale cross-sectional study of Japanese men.

BACKGROUND: The relationship between the combination of physical activity (PA) and body mass index (BMI) with low back pain (LBP) is unclear. The present study offers a cross-sectional assessment of how combinations of PA and BMI are related to LBP in Japanese men. METHODS: Participants were 4022 Japanese men (mean age = 47) who underwent regular clinical examinations. PA was measured using a uniaxial accelerometer and divided into tertiles (PAhigh, PAmiddle, PAlow). A self-administered questionnaire was used to report on persistent LBP experience, drinking and smoking habits, and any existing lifestyle diseases. After covariance adjustment, a logistic regression model was used to assess how combinations of PA and BMI are related to persistent LBP. RESULTS: 428 of the participants had persistent LBP. A clear negative dose-response relationship was found between PA levels and persistent LBP (P for linearity = 0.012). Regarding BMI, odd ratios were shown to be higher in the overweight/obese category (BMI ≥ 25 kg/m2) than for the normal weight category (BMI < 25 kg/m2). When the PAhigh was taken as the reference in the normal weight category, odds ratios for PAlow and PAmiddle in the normal weight category were shown to be high. Moreover, in the overweight/obese category, odd ratios for every fitness level were also high as for the normal weight category. CONCLUSION: The present study showed that both PA and BMI are related to persistent LBP. Also, the prevalence of persistent LBP became higher when PAlow and high BMI are combined rather than the group of PAhigh and low BMI combination.

Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association.

Mounting evidence has firmly established that low levels of cardiorespiratory fitness (CRF) are associated with a high risk of cardiovascular disease, all-cause mortality, and mortality rates attributable to various cancers. A growing body of epidemiological and clinical evidence demonstrates not only that CRF is a potentially stronger predictor of mortality than established risk factors such as smoking, hypertension, high cholesterol, and type 2 diabetes mellitus, but that the addition of CRF to traditional risk factors significantly improves the reclassification of risk for adverse outcomes. The purpose of this statement is to review current knowledge related to the association between CRF and health outcomes, increase awareness of the added value of CRF to improve risk prediction, and suggest future directions in research. Although the statement is not intended to be a comprehensive review, critical references that address important advances in the field are highlighted. The underlying premise of this statement is that the addition of CRF for risk classification presents health professionals with unique opportunities to improve patient management and to encourage lifestyle-based strategies designed to reduce cardiovascular risk. These opportunities must be realized to optimize the prevention and treatment of cardiovascular disease and hence meet the American Heart Association's 2020 goals.

Obesity and low back pain: a retrospective cohort study of Japanese males.

[Purpose] This study evaluated whether obesity is a risk factor for low back pain, by using body fat percentage (%FAT) and body mass index (BMI) as indices of obesity among Japanese males. [Subjects and Methods] This study included 1,152 males (average age: 28.0 ± 4.6 years). BMI was calculated from subject's height and weight, and %FAT was estimated by the thickness of two parts of skin. Low back pain, drinking and smoking were surveyed using a self-administered questionnaire, and maximal oxygen uptake was measured by a submaximal exercise test using a cycle ergometer. [Results] A significant positive dose-response relationship was shown between %FAT and persistent low back pain prevalence. Similarly, a significant positive dose-response relationship was confirmed between BMI and persistent low back pain. [Conclusion] This study suggests that both high %FAT and BMI are risk factors for persistent low back pain.