Periodontal Disease Is Associated with Insomnia among Victims of the Great East Japan Earthquake: A Panel Study Initiated Three Months after the Disaster

In March 2011, the Great East Japan Earthquake (GEJE), which was followed by a devastating tsunami, destroyed the societal and the public hygiene systems in Japanese coastal areas. Insomnia, the greatest issue among disaster victims, has detrimental effects on both physical and psychological health. Periodontitis causes chronic discomfort and inflammation, and little is known about its impact on insomnia. Three months after the earthquake, a health panel survey was conducted over four surveys, till September 2013, in which information regarding 8,015 adults was collected and used. In addition to the heath-related questionnaire, other variables including subjective symptoms of oral diseases were recorded, and the Athens Insomnia Scale was used to evaluate the severity of insomnia. The association between insomnia and periodontal disease was examined using multilevel logistic models on the panel data, after adjusting for sex, age, economic status, comorbidities, body mass index, post-traumatic stress reactions, habitual smoking and alcohol drinking, and the Kessler Psychological Distress Scale score. In addition to the higher prevalence of insomnia among GEJE victims, significant association was revealed between insomnia and gum problems (OR = 2.16, 95% CI = 1.43-3.26), and difficulty chewing (OR = 2.22, 95% CI = 1.40-3.51), after adjusting for all covariates. The present study revealed significant association between insomnia and periodontal disease among GEJE victims. This indicated that together, integrated oral health care for disaster victims would contribute not only to prevention of oral infectious diseases, but may also help alleviate other problems caused by these harmful events.

Dietary Patterns and Incident Dementia in Elderly Japanese: The Ohsaki Cohort 2006 Study

BACKGROUND

Although it has been speculated that the Japanese dietary pattern has a preventive effect against incident dementia, no reported study has yet investigated this issue. The present prospective cohort study investigated the association between dietary patterns and incident dementia in elderly Japanese subjects.

METHODS

We analyzed follow-up data covering a 5.7-year period for 14,402 older adults (≥65 years) participating in a community-based, prospective cohort study. Three dietary patterns (Japanese pattern, animal food pattern, and high-dairy pattern) were derived using principal component analysis of the consumption of 39 food and beverage items assessed using a food frequency questionnaire. Data on incident dementia were retrieved from the public Long-term Care Insurance database.

RESULTS

With 71,043 person-years of follow-up, incidence of dementia was 9.0%. The score for the Japanese dietary pattern was associated with a lower risk of incident dementia (hazard ratio of the highest quartile vs the lowest, 0.80; 95% confidence interval: 0.66-0.97; p-trend = .016). The animal food pattern and the high-dairy pattern showed no significant association with incident dementia.

CONCLUSIONS

In this population of elderly Japanese individuals, the Japanese dietary pattern was associated with a decreased risk of incident dementia.

[Health effects of interventions to promote physical activity in survivors of the 2011 Great East Japan Earthquake. A longitudinal study]

OBJECTIVES

Interventions that promote physical activity to prevent psychological distress and disuse syndromes were carried out in disaster-stricken areas. However, the effect of these interventions to promote physical activity in disaster-stricken areas has not yet been fully clarified. The purpose of this study was to examine the health effects of promoting physical activity in a disaster-stricken area.

METHODS

We conducted an exercise intervention as part of a health survey project among residents of Ishinomaki-city, Miyagi, Japan in 2012. To determine if changes in health condition differed between intervention participants and nonparticipants, health condition data from 81 participants were compared with data from 81 nonparticipants selected by propensity score matching. Factors including sex, age, original address (pre-quake), and six outcome variables (psychological distress [K6 score], subjective health status, sleep duration, sleep quality, frequency of outings, and time spent walking) were used for matching. A linear mixed model was used for statistical analysis.

RESULTS

There were no significant differences in K6 score between participants and nonparticipants (P=0.913). Significant improvements were observed in subjective health status (P=0.011) and outing frequency (P=0.002), but not in other outcome variables.

CONCLUSION

Subjective health status and outing frequency were significantly improved among participants of the exercise intervention. Exercise intervention may be an effective public health strategy in disaster-stricken areas.

Characteristics of pneumonia deaths after an earthquake and tsunami: an ecological study of 5.7 million participants in 131 municipalities, Japan

OBJECTIVE

On 11 March 2011, the Great East Japan Earthquake struck off Japan. Although some studies showed that the earthquake increased the risk of pneumonia death, no study reported whether and how much a tsunami increased the risk. We examined the risk for pneumonia death after the earthquake/tsunami.

DESIGN

This is an ecological study.

SETTING

Data on population and pneumonia deaths obtained from the Vital Statistics 2010 and 2012, National Census 2010 and Basic Resident Register 2010 and 2012 in Japan.

PARTICIPANTS

About 5.7 million participants residing in Miyagi, Iwate and Fukushima Prefectures during 1 year after the disaster were targeted. All municipalities (n=131) were categorised into inland (n=93), that is, the earthquake-impacted area, and coastal types (n=38), that is, the earthquake-impacted and tsunami-impacted area.

OUTCOME MEASURES

The number of pneumonia deaths per week was totalled from 12 March 2010 to 9 March 2012. The number of observed pneumonia deaths (O) and the sum of the sex and age classes in the observed population multiplied by the sex and age classes of expected pneumonia mortality (E) were calculated. Expected pneumonia mortality was the pneumonia mortality during the year before. Standardised mortality ratios (SMRs) were calculated for pneumonia deaths (O/E), adjusting for sex and age using the indirect method. SMRs were then calculated by coastal and inland municipalities.

RESULTS

6603 participants died of pneumonia during 1 year after the earthquake. SMRs increased significantly during the 1st-12th weeks. In the 2nd week, SMRs in coastal and inland municipalities were 2.49 (95% CI 2.02 to 7.64) and 1.48 (95% CI 1.24 to 2.61), respectively. SMRs of coastal municipalities were higher than those of inland municipalities.

CONCLUSIONS

An earthquake increased the risk of pneumonia death and tsunamis additionally increased the risk.

Defecation frequency and cardiovascular disease mortality in Japan: The Ohsaki cohort study

BACKGROUND

It has been suggested that constipation is associated with cardiovascular disease (CVD). The association between defecation frequency and CVD mortality in a large population has not been reported hitherto. The aim of this study was to examine whether defecation frequency is related to CVD mortality.

METHODS AND RESULTS

A total of 45,112 eligible Japanese men and women aged 40-79 years participated in the Ohsaki Cohort study. Defecation frequency was evaluated at the baseline using a self-administered questionnaire. Hazard ratios (HRs) and 95% confidence intervals (CIs) for cardiovascular disease mortality were calculated according to defecation frequency (≥ 1 time/day, 1 time/2-3 days, ≤ 1 time/4 days) by the Cox proportional hazards model. During 13.3 years of follow-up, 2028 participants died due to CVD. Compared with those in the ≥ 1 time/day group, the risk of overall CVD mortality was significantly higher in the 1 time/2-3 days and ≤ 1 time/4 days groups; the multivariate HR (95%CI) for 1 time/2-3 days and ≤ 1 time/4 days was 1.21 (95% CI: 1.08-1.35) and 1.39 (95% CI: 1.06-1.81), respectively.

CONCLUSION

A lower defecation frequency was associated with risk of CVD mortality in this Japanese population. Future studies, aiming at elucidating the mechanisms underlying the associations between chronic constipation and risk of CVD mortality, may be facilitated by our findings.

Associations of body mass index, smoking, and alcohol consumption with prostate cancer mortality in the Asia Cohort Consortium

Many potentially modifiable risk factors for prostate cancer are also associated with prostate cancer screening, which may induce a bias in epidemiologic studies. We investigated the associations of body mass index (weight (kg)/height (m)(2)), smoking, and alcohol consumption with risk of fatal prostate cancer in Asian countries where prostate cancer screening is not widely utilized. Analysis included 18 prospective cohort studies conducted during 1963-2006 across 6 countries in southern and eastern Asia that are part of the Asia Cohort Consortium. Body mass index, smoking, and alcohol intake were determined by questionnaire at baseline, and cause of death was ascertained through death certificates. Analysis included 522,736 men aged 54 years, on average, at baseline. During 4.8 million person-years of follow-up, there were 634 prostate cancer deaths (367 prostate cancer deaths across the 11 cohorts with alcohol data). In Cox proportional hazards analyses of all cohorts in the Asia Cohort Consortium, prostate cancer mortality was not significantly associated with obesity (body mass index >25: hazard ratio (HR) = 1.08, 95% confidence interval (CI): 0.85, 1.36), ever smoking (HR = 1.00, 95% CI: 0.84, 1.21), or heavy alcohol intake (HR = 1.00, 95% CI: 0.74, 1.35). Differences in prostate cancer screening and detection probably contribute to differences in the association of obesity, smoking, or alcohol intake with prostate cancer risk and mortality between Asian and Western populations and thus require further investigation.

High circulating adiponectin levels predict decreased muscle strength among older adults aged 70 years and over: A prospective cohort study

BACKGROUND AND AIMS

Population-based researches indicate that circulating adiponectin is inversely associated with muscle strength. However, interpretation of the findings has been limited by the use of a cross-sectional design. This study aimed to examine the prospective relationship between baseline circulating adiponectin concentration and change in muscular function-related physical performance in older adults.

METHODS AND RESULTS

A 1-year prospective cohort study of Japanese community-dwelling elderly was conducted between 2002 and 2003. Four hundred thirty-four older persons participated in the measurements of physical function, including leg extension power, functional reach, timed up-and-go test, and 10-m maximum walking speed, at baseline and follow-up. After adjustment for potential covariates, higher serum adiponectin concentration was found to be significantly associated with poorer physical performance at baseline (leg extension power [watt], P < 0.001; functional reach [cm], P < 0.001; log timed up-and-go test, P = 0.007; log 10-m maximum walking speed, P < 0.001). The results of the prospective analysis by analysis of covariance indicated that the elderly with higher serum adiponectin concentrations (tertiles) at baseline tended to have a decreased performance in leg extension power (means [95% confidence interval]: lowest, -105 [-125, -85.7]; middle, -117 [-135, -97.8]; highest, -140 [-160, -120], watt, P for trend = 0.021) and timed up-and-go test (lowest, -0.08 [-0.28, -0.12]; middle, -0.10 [-0.29, 0.10]; highest, 0.28 [0.07, 0.48], s, P for trend = 0.019), but not two other functioning.

CONCLUSION

High circulating adiponectin concentration may be an indicator of decreased physical performance, especially muscle strength, in older adults.

Association between the disability prevention program "Secondary Preventive Services" and disability incidence among the elderly population: A nationwide longitudinal comparison of Japanese municipalities

AIM

The aim of the present ecological study was to evaluate the relationship between the rate of participation in Secondary Preventive Services (SPS) and the incidence of disability in Japanese municipalities.

METHODS

We used the national statistics data for Long-term Care Insurance (LTCI), because all Japanese people aged ≥65 years are eligible for LTCI services depending on their functional status assessed by a national uniform standard in all municipalities. The disability incidence rate for the 2-year period in 2009-2010 was compared among five different levels of SPS participation in 2006-2008. The primary outcome was the sum total disability incidence rate in LTCI from 2009 to 2010. The outcome was divided according to disability level into three patterns: "all levels (Support Level 1 - Care Level 5)", "mild disability (Care Level ≤1)" and "moderate to severe disability (Care Level ≥2)".

RESULTS

There was a significant inverse association between the SPS participation rate and disability incidence rate. Among 1541 municipalities, those in the highest SPS participation rate quintile (≥9.79 per 1000 elderly population) had a lower disability incidence rate for all levels than those in the lowest quintile (<1.86 per 1000 elderly population; absolute rate difference 0.6%; age-adjusted incident rate ratio 0.94; 95% CI 0.89-0.99). This inverse association was observed for mild disability and not for moderate to severe disability.

CONCLUSIONS

Municipalities with a higher SPS participation rate have a lower incidence rate of mild disability. SPS could be an effective health policy for containing mild disability incidence among the elderly.

Effects of extracranial-intracranial bypass for patients with hemorrhagic moyamoya disease: results of the Japan Adult Moyamoya Trial

BACKGROUND AND PURPOSE

About one half of those who develop adult-onset moyamoya disease experience intracranial hemorrhage. Despite the extremely high frequency of rebleeding attacks and poor prognosis, measures to prevent rebleeding have not been established. The purpose of this study is to determine whether extracranial-intracranial bypass can reduce incidence of rebleeding and improve patient prognosis.

METHODS

This study was a multicentered, prospective, randomized, controlled trial conducted by 22 institutes in Japan. Adult patients with moyamoya disease who had experienced intracranial hemorrhage within the preceding year were given either conservative care or bilateral extracranial-intracranial direct bypass and were observed for 5 years. Primary and secondary end points were defined as all adverse events and rebleeding attacks, respectively.

RESULTS

Eighty patients were enrolled (surgical, 42; nonsurgical, 38). Adverse events causing significant morbidity were observed in 6 patients in the surgical group (14.3%) and 13 patients in the nonsurgical group (34.2%). Kaplan-Meier survival analysis revealed significant differences between the 2 groups (3.2%/y versus 8.2%/y; P=0.048). The hazard ratio of the surgical group calculated by Cox regression analysis was 0.391 (95% confidence interval, 0.148-1.029). Rebleeding attacks were observed in 5 patients in the surgical group (11.9%) and 12 in the nonsurgical group (31.6%), significantly different in the Kaplan-Meier survival analysis (2.7%/y versus 7.6%/y; P=0.042). The hazard ratio of the surgical group was 0.355 (95% confidence interval, 0.125-1.009).

CONCLUSIONS

Although statistically marginal, Kaplan-Meier analysis revealed the significant difference between surgical and nonsurgical group, suggesting the preventive effect of direct bypass against rebleeding.

CLINICAL TRIAL REGISTRATION URL

http://www.umin.ac.jp/ctr/index.htm. Unique identifier: C000000166.

Relationships between changes in time spent walking since middle age and incident functional disability

OBJECTIVE

To examine the relationship between changes in time spent walking since middle age and incident functional disability.

METHOD

In 2006, we conducted a prospective cohort study of 7177 disability-free Japanese individuals aged ≥65years who lived in Ohsaki City, Miyagi Prefecture, Japan. Participants were categorized into four groups according to changes in time spent walking based on two questionnaire surveys conducted in 1994 and in 2006. Incident functional disability was retrieved from the public Long-term Care Insurance database, and the subjects were followed up for 5years. The Cox proportional hazards model was used to investigate the association between changes in time spent walking and the risk of incident functional disability.

RESULTS

Compared with subjects who remained sedentary, the multivariate-adjusted hazard ratios (95% confidence intervals) were 0.69 (0.49-0.98) among those who became active and 0.64 (0.50-0.82) among those who remained active. These results did not alter when analyses were stratified by gender, age and motor function status.

CONCLUSION

An increase in time spent walking among sedentary adults is significantly associated with a lower risk of incident functional disability.

[Prediction of future cost savings in long-term care and medical care if Japan achieves the health expectancy target of Health Japan 21 (second term)]

OBJECTIVES

An earlier study using the data from the Japanese Long-term Care Insurance (LTCI) system reported a scenario for achieving the target of Health Japan 21 (the second term): future gains in health expectancy from 2011 to 2020 must be larger than gains in expectancy. According to this scenario (the Healthy Life Expectancy Extension Scenario), the proportion of disability (cases≥Care Level 2 in LTCI disability certification) will gradually decrease by 1% per year from 2011. The purpose of this study was to estimate the cost savings in long-term care and medical care if the Healthy Life Expectancy Extension Scenario is achieved.

METHODS

We used data from Japanese national statistics and a survey conducted in Osaki city, Miyagi. The natural course of disability cases (≥Care Level 2) was estimated under the assumption that the future population composition would be equal to the population projections for Japan and the future proportion of disabilities for each age grade would be equal to that of 2010. Then, the decrease in the number of disabilities based on the Healthy Life Expectancy Extension Scenario was calculated. Finally, the cost savings in long-term care and medical care associated with the assumed decrease in the number of disability cases was calculated.

RESULTS

When the disability cases (≥Care Level 2) were shifted to "no disability certification (not requiring care)," a total estimated cost reduction of 5,291 billion yen was achieved from 2011 to 2020. Furthermore, a total estimated reduction of 2,491 billion yen was achieved for the same period when all disability shifts to "Care Level 1" were accounted for.

CONCLUSION

As a rough calculation, if the Health Japan 21 (second term) target is achieved, approximately 2,500-5,300 billion yen will be saved in the cost of long-term care and medical care.

[Serum total cholesterol levels and eligibility for long-term care insurance: a prospective cohort study of the Tsurugaya project]

OBJECTIVES

The purpose of this study was to examine the relationship between serum total cholesterol levels and certification eligibility for long-term care insurance in elderly Japanese individuals.

METHODS

The Tsurugaya Project was a comprehensive geriatric assessment conducted for community-dwelling elderly individuals aged ≥70 years in the Tsurugaya area, Sendai, Japan. Of the 2,925 inhabitants, 958 subjects participated in the Tsurugaya Project. For this analysis, we used 827 subjects who gave informed consent and were not qualified for long-term care insurance at the time of the baseline survey. Subjects were followed up for 6 years. We classified the subjects into 4 quintiles and used the fourth quintile (212-230 mg/dL) as a reference for statistical analysis. We used Cox proportional hazards model to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of certification eligibility for long-term care insurance according to total cholesterol levels in serum.

RESULTS

During 6 years of follow-up, a total of 214 subjects were qualified for long-term care insurance certification. The lowest serum total cholesterol level (<177 mg/dL) was significantly associated with increased eligibility for long-term care insurance certification. Compared with the fourth quintile, multivariate HRs (95%CIs) of long-term care insurance certification were 1.91 (1.23-2.98), 1.36 (0.85-2.18), 0.99 (0.62-1.56), 1.38 (0.88-2.17), for <177 mg/dL, 177-194 mg/dL, 195-211 mg/dL, and ≤231 mg/dL, respectively. Moreover, the association was statistically significant even after excluding subjects with a history of liver disease or cancer, an abnormality in the liver function test, or high levels of high-sensitivity C-reactive protein.

CONCLUSION

Low serum total cholesterol levels were significantly associated with increased eligibility for long-term care insurance certification even after adjusting for a variety of confounding factors.

[Prognostic prediction of the functional capacity and effectiveness of functional improvement program of the musculoskeletal system among users of preventive care service under long-term care insurance]

OBJECTIVE

The purpose of this study was to examine the effectiveness of the Functional Improvement Program of the Musculoskeletal System among users of Preventive Care Service under Long-Term Care Insurance.

METHODS

A total of 3,073 subjects were analyzed. We used the prediction formula to estimate the predicted value of the Kihon Checklist after one year, and calculated the measured value minus the predicted value. The subjects were divided into two groups according to the measured value minus predicted value tertiles: the lowest and middle tertile (good-to-fair measured value) and the highest tertile (poor measured value). We used a multiple logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of the good-to-fair measured values of the Kihon Checklist after one year, according to the Functional Improvement Program of the Musculoskeletal System.

RESULTS

In potentially dependent elderly, the multivariate adjusted ORs (95% CI) of the good-to-fair measured values were 2.4 (1.3-4.4) for those who attended the program eight times or more in a month (vs those who attended it three times or less in a month), 1.3 (1.0-1.8) for those who engaged in strength training using machines (vs those who did not train), and 1.4 (1.0-1.9) for those who engaged in endurance training.

CONCLUSIONS

In this study, among potentially dependent elderly, those who attended the program eight times or more in a month and those who engaged in strength training using machines or endurance training showed a significant improvement of their functional capacity.

[Future prediction of health expectancy considering the target of Health Japan 21 (the second term)]

OBJECTIVES

We attempted to predict health expectancy in Japan for the period between 2011 and 2020, considering the target of Health Japan 21 (the second term) that future gains in health expectancy be larger than in life expectancy.

METHODS

We used data from Japanese national statistics. Health expectancy between 2011 and 2020 was predicted using the Sullivan method under the assumption that future mortality was equal to the estimate in Population Projections for Japan (January 2012), and under three scenarios of future prevalence of bad health status.

RESULTS

The numbers of expected years without activity limitation at birth for males and females in 2020 were predicted as 71.2 and 74.3, respectively, under the scenario that prevalence of activity limitation was constant since 2010; 71.4 and 74.5 under the scenario that the prevalence followed the recent trend; and 71.7 and 74.9 under the scenario that the prevalence decreased with such a rate that future gains in health expectancy were equal to in life expectancy. The rate of decrease in the prevalence in 2010-2020 in the last scenario was estimated to be 0.95 in males and 0.96 in females. The numbers of expected years with subjective well-being at birth in 2020 predicted under above three scenarios were between 69.5 and 71.2 in males and between 72.9 and 74.6 in females. The rate of decrease in the last scenario was estimated to be 0.96 in males and 0.97 in females. The numbers of expected years without care needs at age 65 in 2020 predicted under above three scenarios were between 18.0-18.2 in males and between 21.2-21.5 in females. The rate of decrease in the last scenario was estimated to be 0.90 in males and 0.91 in females.

CONCLUSION

The health expectancy in 2011-2020 was predicted under some scenarios of future prevalence of bad health status. The rate of decrease in the future prevalence of bad health status was estimated with a view to the accomplishment of the target of Health Japan 21 (the second term).

Association between sleep duration, weight gain, and obesity for long period

BACKGROUND

Although previous studies showed the long-term effects of sleep duration on risk of weight gain, Western tends to gain weight irrespective of sleep duration over a long period. Conversely, it is showed that body mass index (BMI) decreases during a long period in Japanese and thus, the long-term effect of sleep duration on weight gain and obesity is still unclear in Asia.

METHODS

We followed up 13,629 participants aged 40-79years and prospectively collected data from 1995 to 2006. We divided the participants into five groups according to their self-reported sleep duration: ⩽5h (short sleep), 6h, 7h (reference), 8h, and ⩾9h (long sleep). The main outcome was ⩾5kg weight gain or BMI⩾25kg/m(2) (obesity). We used logistic regression analyses to derive odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for several confounding factors.

RESULTS

We observed no association between sleep duration and risk of ⩾5kg weight gain and obesity. After stratification by BMI, long sleepers had a significantly increased risk of ⩾5kg weight gain (OR: 1.36, 95%CI: 1.09-1.70) in obese participants.

CONCLUSIONS

Among community-dwelling Japanese, only obese long sleepers have a significantly increased long-term risk of ⩾5kg weight gain.

[Activities in daily life and changes in care level among users of Preventive Care Service under Long-Term Care Insurance]

OBJECTIVES

The aim of this study was to investigate the association between social roles (engaged in working outside or house work) or hobbies and changes in care level among users of Preventive Care Service under Long-Term Care Insurance.

METHODS

A total of 8,734 Preventive Care Service users were analyzed. The assessment was conducted between February 2007 and December 2008. The improvement, maintenance, and aggravation in care level were defined by changes in care level from the beginning to the end. To assess their activities in daily life, the participants were asked, "Which is the major activity in your daily life? Please select one from the following: working outside, house work, hobbies, watching television, others, or none." We used the multiple logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of the maintenance or improvement in care level according to the category of activity.

RESULTS

As compared with subjects who answered none, the multivariate adjusted ORs (95% CI) of the maintenance or improvement in care level were 2.0 (1.4-2.9) for those who answered working outside, 1.5 (1.2-1.8) for those who answered house work, and 1.5 (1.2-1.9) for those who answered hobbies. However, those who answered watching television or others did not show a significant association with the maintenance or improvement in care level.

CONCLUSIONS

In this study, compared with subjects who answered none, those who answered that they were engaged in working outside, house work, or hobbies were associated with having significantly higher ORs of the maintenance or improvement in care level.

Green tea consumption and the risk of incident functional disability in elderly Japanese: the Ohsaki Cohort 2006 Study

BACKGROUND

Previous studies have reported that green tea consumption is associated with a lower risk of diseases that cause functional disability, such as stroke, cognitive impairment, and osteoporosis. Although it is expected that green tea consumption would lower the risk of incident functional disability, this has never been investigated directly.

OBJECTIVE

The objective was to determine the association between green tea consumption and incident functional disability in elderly individuals.

DESIGN

We conducted a prospective cohort study in 13,988 Japanese individuals aged ≥65 y. Information on daily green tea consumption and other lifestyle factors was collected via questionnaire in 2006. Data on functional disability were retrieved from the public Long-term Care Insurance database, in which subjects were followed up for 3 y. We used Cox proportional hazards regression analysis to investigate the association between green tea consumption and functional disability.

RESULTS

The 3-y incidence of functional disability was 9.4% (1316 cases). The multiple-adjusted HR (95% CI) of incident functional disability was 0.90 (0.77, 1.06) among respondents who consumed 1-2 cups green tea/d, 0.75 (0.64, 0.88) for those who consumed 3-4 cups/d, and 0.67 (0.57, 0.79) for those who consumed ≥5 cups/d in comparison with those who consumed <1 cup/d (P-trend < 0.001).

CONCLUSION

Green tea consumption is significantly associated with a lower risk of incident functional disability, even after adjustment for possible confounding factors.

[Perceived stress and cardiovascular disease mortality. The Ohsaki Cohort Study]

OBJECTIVES

Previous studies have indicated that stress can affect the circulatory system. Although prospective studies have examined the association between perceived stress and cardiovascular disease (CVD) mortality, the results are still controversial. The purpose of the present study was to elucidate the relationship with stratified analyses by alcohol intake category and smoking status.

METHODS

The prospective Ohsaki Cohort Study covered all National Health Insurance beneficiaries aged 40 to 79 years living in the precinct of Ohsaki Public Health Center, Miyagi, Japan. A total of 45,293 Japanese (21,552 men and 23,741 women), without a history of cancer, ischemic heart disease or stroke, and who answered all items related to stress level at the baseline in 1994, were followed prospectively. Over 12 years of follow-up, 1,751 deaths from CVD occurred (994 men and 757 women). We used Cox proportional hazards models to calculate the hazard ratios (HR) and 95% confidence intervals (CI) for CVD mortality according to the perceived stress categories. The low stress category was used as the reference in all analyses.

RESULTS

Perceived stress demonstrated a significant positive association with CVD mortality for men; the multivariate adjusted HR for high versus low stress was 1.43 (95% CI: 1.19, 1.87, P = 0.006). No significant relationship was noted for women. With current smokers, perceived high stress versus low had a pronounced association for both men (HR = 1.76, 95% CI: 1.28, 2.41, P = 0.001) and women (HR = 1.61, 95% CI: 1.20, 2.16, P = 0.004), and a similar tendency was noted for current drinking (HR = 1.56, 95% CI: 1.16, 2.09, P = 0.006, HR = 1.42, 95% CI: 1.08, 1.87, P = 0.001). Additionally, for both smoking and drinking men, those reporting high stress had 2 times the risk of CVD mortality of their low stress counterparts (P for trend < 0.001). The interaction of perceived stress with smoking for CVD mortality was of borderline statistical significance only for men (P for interaction = 0.04).

CONCLUSION

The results suggest that the percentage of current smoking and drinking are factors that distinguish between sexes with regard to the effects of perceived stress on the incidence of CVD mortality. Furthermore our present findings indicate that smoking and drinking habit are not the way to relieve one's stress. A review of these should be conducted and we need to enhance support for stress management as well as control over smoking and drinking habits.

Gamma-glutamyltransferase and cancer incidence: the Ohsaki cohort study

Background

Although experimental studies have shown that gamma-glutamyltransferase (GGT) has a role in tumor progression, epidemiologic evidence for a relationship between GGT and cancer incidence is limited. The present study investigated the association between GGT and cancer incidence and assessed the role of alcohol consumption in this association.

Methods

We examined a cohort of 15 031 Japanese adults aged 40 to 79 years who attended a health checkup in 1995 and were free of cancer at that time. GGT was measured using the Szasz method. The participants were then followed from 1 January 1996 until 31 December 2005, and cancer incidence was recorded by using the Miyagi Regional Cancer Registry. Hazard ratios (HRs) and 95% confidence intervals (CIs) were computed for each quartile of GGT and compared. The lowest quartile (GGT <13.0 IU/ml) was used as the reference category.

Results

We documented 1505 cancers. Among participants in the highest quartile (GGT ≥31.0 IU/ml), the multivariate HR for any cancer was 1.28 (95% CI, 1.08–1.53; P for trend, <0.001), the HR for colorectal cancer was significantly greater than unity, and the HRs for esophageal, pancreatic, and breast cancers were greater than unity but not significantly so. This positive trend was observed only in current drinkers.

Conclusions

Our findings suggest that there is a positive relationship between GGT and cancer incidence only for alcohol-related cancers in current drinkers and that the positive association of GGT with cancer incidence largely reflects alcohol consumption.

Relationship between serum adiponectin levels and disability-free survival among community-dwelling elderly individuals: The Tsurugaya Project

BACKGROUND

Mortality risk tends to be higher among elderly individuals with higher serum adiponectin levels. The objective of this study was to clarify whether the relationship between adiponectin and a higher risk of disability or death can be explained by physical function, bone mineral density, depression, and malnutrition.

METHODS

We analyzed 505 individuals who underwent comprehensive geriatric assessment and who agreed to provide information on long-term care insurance. The endpoint was the composite outcome of death and incident disability defined as a first certification for any level of care need. Relationships between adiponectin and incident disability or death were estimated using the Cox proportional hazards model.

RESULTS

During 6 years of follow-up, 179 incident disabilities or deaths occurred. Among them, 20 and 23 died with and without disability, respectively. The risk of incident disability or death was significantly higher among participants with adiponectin greater than or equal to 22.4 (90%) than 8.0 or less (25%) mg/L (Hazard ratio: 95% confidence interval, 1.92: 1.01-3.64) in the model adjusted for age, sex, and metabolic risk factors. Adjustment for N-terminal pro-B-type natriuretic peptide and nutritional status did not substantially alter this risk estimate, although the association ceased to be statistically significant. Adjustment for physical function did attenuate the relationship, however, which ceased to be apparent upon exclusion of disability or death occurring within 3 years of follow-up.

CONCLUSION

The relationship between adiponectin and the composite outcome of incident disability and death was at least partly explained by reduced physical function and wasting in participants with higher adiponectin levels.

[Validation of the Kihon Checklist for predicting the risk of 1-year incident long-term care insurance certification: the Ohsaki Cohort 2006 Study]

OBJECTIVE

The "Kihon Checklist" (a frailty checklist), consisting of 25 items, is used for screening frail elderly, based on the Japanese long-term care insurance system. However, few reports have investigated predictive ability of incident long-term care insurance certification in the Kihon Checklist. The purpose of this study was to investigate inter-relationships and accuracy as a screening test of individual items and criteria in the Kihon Checklist for incident long-term care insurance certification.

METHODS

In December 2006, we distributed a questionnaire including the Kihon Checklist to individuals older than 65 years living in Ohsaki City, Japan. Among the valid respondents, we followed those who gave informed consent to follow-up, had more than 1 item of response on the Kihon Checklist, and were not qualified for long-term care insurance certification at the baseline. We further excluded individuals who died or moved away in the one year follow-up, analyzing 14,636 elderly. The age- and sex-adjusted odds ratio (OR) and 95% confidence interval (95%CI) for newly incident long-term care insurance certification were estimated by logistic regression analysis. Independent variables were each of the items and criteria in the Kihon Checklist used for screening of "frail elderly". In addition, we estimated the sensitivity and specificity, and conducted receiver operating characteristic (ROC) analysis for each criteria domain.

RESULTS

5,560 (38.0%) matched the criteria of "frail elderly". During the one year of follow-up, 483 (3.3%) required newly incident long-term care insurance certification. All of the items in the Kihon Checklist were significantly associated with incident long-term care insurance certification (range of ORs: 1.45-4.67). In addition, all of the criteria also significantly predicted the risk of incident long-term care insurance certification (range of OR: 1.93-6.54). The OR (95%CI) for "frail elderly" was 3.80 (3.02-4.78). Among the various domains, "20 items other than five related to prevention and support for depression" had the largest area under the ROC curve.

CONCLUSION

All items and criteria used for screening frail elderly in the Kihon Checklist are useful for predicting the risk of incident long-term care insurance certification during a one-year period. However, the strength of the relation and accuracy for screening test were variable among items or domains, and criteria values could be improved.

The Ohsaki Cohort 2006 Study: design of study and profile of participants at baseline

BACKGROUND

Large-scale cohort studies conducted in Japan do not always include psychosocial factors as exposures. In addition, such studies sometimes fail to satisfactorily evaluate disability status as an outcome.

METHODS

This prospective cohort study comprised 49 603 (22 438 men and 27 165 women) community-dwelling adults aged 40 years or older who were included in the Residential Registry for Ohsaki City, Miyagi Prefecture, in northeastern Japan. The baseline survey, which included psychosocial factors, was conducted in December 2006. Follow-up of death, immigration, cause of death, cancer incidence, and long-term care insurance certification was started on 1 January 2007.

RESULTS

The response rate was 64.2%. In general, lifestyle-related conditions in the study population were similar to those of the general Japanese population; however, the proportion of male current smokers was higher in the cohort. The association between age and the proportion of those reporting psychological distress showed a clear U-shaped curve, with a nadir at age 60 to 69 years in both men and women, although more women were affected by such distress than men. The proportion of those who reported a lack of social support was highest among those aged 40 to 49 years. Most men and women surveyed did not participate in community activities. Among participants aged 65 years or older, 10.9% of participants were certified beneficiaries of the long-term care insurance system at baseline.

CONCLUSIONS

The Ohsaki Cohort 2006 Study is a novel population-based prospective cohort study that focuses on psychosocial factors and long-term care insurance certification.

Green tea consumption is associated with lower psychological distress in a general population: the Ohsaki Cohort 2006 Study

BACKGROUND

Although green tea or its constituents might reduce psychological stress, the relation between green tea consumption and psychological distress has not been investigated in a large-scale study.

OBJECTIVE

Our aim was to clarify whether green tea consumption is associated with lower psychological distress.

DESIGN

We analyzed cross-sectional data for 42,093 Japanese individuals aged > or =40 y from the general population. Information on daily green tea consumption, psychological distress as assessed by the Kessler 6-item psychological distress scale, and other lifestyle factors was collected by using a questionnaire. We used multiple logistic regression analyses adjusted for age, sex, history of disease, body mass index, cigarette smoking, alcohol consumption, time spent walking, dietary factors, social support, and participation in community activities to investigate the relation between green tea consumption and psychological distress.

RESULTS

We classified 2774 (6.6%) of the respondents as having psychological distress (Kessler 6-item psychological distress scale > or =13/24). There was an inverse association between green tea consumption and psychological distress in a model adjusted for age and sex. Although the relation was largely attenuated when possible confounding factors were adjusted for, a statistically significant inverse association remained. The odds ratio (with 95% CI) of developing psychological distress among respondents who consumed >/=5 cups of green tea/d was 0.80 (0.70, 0.91) compared with those who consumed <1 cup/d. These relations persisted when respondents were stratified by social support subgroups or by activities in communities.

CONCLUSION

Green tea consumption was inversely associated with psychological distress even after adjustment for possible confounding factors.