Sleep and sleep-disordered breathing in commercial long-haul truck drivers

We have performed a study assessing the prevalence of sleep-disordered breathing in a large US trucking company using a validated portable monitor (MESAM-4) and a validated symptom questionnaire. Three hundred eighty-eight drivers with a mean age of 36 years filled out the questionnaire. One hundred fifty-nine drivers with a mean age of 35 years spent the night at the terminal hub where they underwent monitoring for identification of sleep-disordered breathing. The drivers also had blood pressure recorded while awake, seated, and after 15 min of quiet rest. Seventy-eight percent of the drivers had an oxygen desaturation index (ODI) > or = 5 per hour of sleep; 10% had an ODI > or = 30 per hour of sleep. There was a significant difference in the body mass index (BMI) between drivers with ODI < 5 and drivers with ODI > or = 5 (25.7 +/- 6.0 kg/m2 in drivers with ODI < 5 vs 29.0 +/- 6.3 kg/m2 in drivers with ODI > or = 5, p < 0.001). Sixteen percent of all drivers tested were hypertensive. Twelve percent were unaware of their hypertension. Hypertensive drivers were significantly more overweight (p < 0.0001), slept more restlessly (p < 0.04), took more naps (p < 0.03), and woke up more frequently during the night (p < 0.005). About 20% of drivers presented symptoms indicating very regular sleep disturbances. Drivers who had been with the company for more than 1 year were more likely to present daytime fatigue, daytime tiredness, unrestorative sleep, hypertension, and higher BMI. Long-haul truck drivers have very irregular sleep/wake schedules and a high prevalence of sleep-disordered breathing. Chronic sleep/wake disruption and partial, prolonged sleep deprivation may worsen sleep-disordered breathing. This combination of problems may impact significantly on the daytime alertness of truckers.

Prevalence of Frailty Assessed by Fried and Kihon Checklist Indexes in a Prospective Cohort Study: Design and Demographics of the Kyoto-Kameoka Longitudinal Study

OBJECTIVE

The Kyoto-Kameoka Study was launched in 2011-2012 to identify the associations among food intake, nutritional status, physical activity, oral function, quality of life or social capital, the use of long-term care insurance (LTCI) system, and healthy lifespan in community-dwelling older people as a part of the World Health Organization Safe Community program.

DESIGN

A prospective cohort study, reporting baseline demographics (cross-sectional data).

SETTING AND PARTICIPANTS

We conducted 2 mailed self-administered questionnaire surveys; one is a complete population survey with a comprehensive survey of needs in the sphere of daily life (NSDL) that included 2 different frailty indexes, the Kihon Checklist (KCL) and the Fried phenotype, socioeconomic status, general and psychological health, and social relationships; followed by the more detailed Health and Nutrition Survey. A slightly modified NSDL survey was conducted again in 2013. Survival time, LTCI certification, and medical and long-term care costs after the baseline survey will be followed.

RESULTS

Of 18,231 NSDL questionnaires distributed, 13,294 people responded (response rate: 72.92%; mean age 73.7 ± 6.4 and 75.1 ± 7.2 years for men and women, respectively; 12,054 people without and 1240 with LTCI certification). In people without LTCI, the proportion of robust, prefrail, and frail were 30.3%, 59.8%, and 9.9% in men and 25.3%, 64.7%, and 10.0% in women, according to the Fried index. The proportion of frail people as defined by KCL ≥7 was 30.8% in men and 33.3% in women.

CONCLUSIONS

The study is the first to document frailty prevalence using both Fried and KCL measures with a complete city population survey among older Japanese in the community as a part of World Health Organization Safe Community program. The study is expected to provide valuable evidence of the effects of lifestyle habits on long-term care prevention and healthy life span.

Difference of pharyngeal morphology and mechanical property between OSAHS patients and normal subjects

OBJECTIVE

The intrinsic properties such as baseline caliber and compliance of upper airway are thought to be important in the pathogenesis of obstructive sleep apnea hypopnea syndrome (OSAHS). Our study was designed to detect the difference of baseline caliber (morphological property) of pharynx during both wakefulness and sleep, and difference of pharyngeal compliance (mechanical property) between OSAHS patients and normal subjects.

METHODS

CT scan was performed on 7 normal subjects and 13 OSAHS patients when they are awake, during drug-induced sleep with minimally effective therapeutic pressure (P(eff)), 0 cmH2O, and critical pressure (P(crit)) being given via a nose mask system, respectively. 3D images of pharyngeal airway were reconstructed, and volume of each subdivision of pharynx was measured. Volume, average area and compliance of each subdivision and in total were compared between the two groups.

RESULTS

The OSAHS group was shown to have a smaller average area at upper (1.20+/-0.26 cm2 versus 1.57+/-0.17 cm2, p<0.05) and middle part of pharynx (1.89+/-0.52 cm2 versus 2.58+/-0.27 cm2, p<0.05) during wakefulness. During sleep, this difference was shown to be even more obvious at upper part (0.77+/-0.30 cm2 versus 1.45+/-0.18 cm2, p<0.01); and middle part, (1.15+/-0.47 cm2 versus 2.44+/-0.26 cm2, p<0.01). The average area during wakefulness and sleep was also shown to be highly correlated. OSAHS group had a higher compliance at middle part (0.28+/-0.15 cmH2O(-1) versus 0.13+/-0.07 cmH2O(-1), p<0.05) of pharynx.

CONCLUSION

We conclude that OSAHS patients have a narrower and more collapsible upper airway than normal subjects do, the caliber data obtained during wakefulness could reflect the baseline caliber during sleep, and our method is valid to evaluate both morphology and function of upper airway.

Association Between the Prevalence of Frailty and Doubly Labeled Water-Calibrated Energy Intake Among Community-Dwelling Older Adults

BACKGROUND

Appropriate energy intake (EI) is essential to prevent frailty. Because self-reported EI is inaccurate and has systematic errors, adequate biomarker calibration is required. This study examined the association between doubly labeled water (DLW)-calibrated EI and the prevalence of frailty among community-dwelling older adults.

METHOD

A cross-sectional study was performed using baseline data of 7,022 older adults aged ≥65 years in the Kyoto-Kameoka Study. EI was evaluated using a validated food frequency questionnaire (FFQ), and calibrated EI was obtained from a previously established equation using the DLW method. Physical and comprehensive frailty were defined by the Fried phenotype (FP) model and the Kihon Checklist (KCL), respectively. We used multivariable-adjusted restricted cubic spline logistic regression analysis.

RESULTS

The prevalence of physical frailty was 14.8% and 13.6% in women and men, respectively. The spline models showed significant reverse J-shaped or U-shaped relationships between the prevalence of physical or comprehensive frailty against the DLW-calibrated EI, respectively. The lowest prevalence of both types of frailty was found at 1,900-2,000 kcal/d in women and 2,400-2,500 kcal/d in men, which corresponded to approximately 40 kcal/d/kg IBW (ideal body weight = 22 × height2) with DLW-calibrated EI. Uncalibrated EI underestimated approximately 20% compared with calibrated EI; underestimated EI were attenuated by calibration approach.

CONCLUSIONS

This study suggests that low EI has a greater detrimental effect compared with excessive EI, particularly on physical frailty. Using biomarkers to calibrate EI holds promise for providing accurate energy requirements to establish guidelines used in public health and clinical nutrition.

Association of bioelectrical phase angle with aerobic capacity, complex gait ability and total fitness score in older adults

PURPOSE

This study aimed to examine the association between whole-body or segmental phase angle (PhA) based on bioelectrical impedance analysis (BIA) and aerobic capacity (endurance), complex gait ability, and total fitness age score (FAS).

METHODS

A total of 426 community-dwelling older adults (332 women and 94 men) aged 60 to 93 years participated in this study. PhA and appendicular skeletal mass index (ASMI) were obtained by an eight-electrode standing BIA. Aerobic capacity was assessed using the shuttle stamina walk test (SSTw); complex gait ability, using the timed-up-and-go test (TUG). FAS was obtained using the previously validated multi-dimensional equations based on 7-year longitudinal data. SSTw, TUG, and FAS were compared between the low PhA (<4.4° for women and <5.2° for men) and normal PhA groups. Pearson's correlation between PhA and SSTw, TUG, and FAS was determined. Multiple linear regression analysis was conducted using SSTw, TUG, and FAS as dependent variables. Age, sex, height, body mass index (BMI), ASMI, and PhA were entered into the linear model.

RESULTS

SSTw and TUG results and FAS were significantly lower in the low PhA group (P < 0.05). PhA was significantly correlated with SSTw, TUG, and FAS (P < 0.001), and leg PhA showed a stronger correlation than whole-body or arm PhA. PhA at 50 kHz had higher correlation coefficients with SSTw, TUG, or FAS compared with PhA at 5 or 250 kHz. Multiple regression analyses indicated that leg PhA at 50 kHz was a significant predictor of SSTw, TUG, and FAS, independent of age, sex, height, BMI, and ASMI.

CONCLUSION

Our results indicate that leg PhA is associated with multi-dimensional physical fitness in community-dwelling older adults. PhA is a highly informative biomarker of skeletal muscle and exercise physiology in clinical settings.

Estimation of Energy Intake by a Food Frequency Questionnaire: Calibration and Validation with the Doubly Labeled Water Method in Japanese Older People

Accurate assessments of a target population’s energy intake (EI) are essential to prevent poor nutritional status. However, self-reported dietary records (DRs) or food frequency questionnaires (FFQs) are not always accurate, thereby requiring validation and calibration studies. This study aimed to validate the EI estimated by a FFQ using the doubly labeled water (DLW) method. Participants were 109 Japanese older adults (50 women and 59 men) aged 65–88 years. The EI was obtained by a DR and 47-item FFQ over 1 year. The total energy expenditure (TEE) was measured by DLW for ~2 weeks. EI was significantly lower than TEE (p < 0.01); ratios of EI assessed by DR and FFQ against TEE were 0.91 ± 0.17 and 0.82 ± 0.22, respectively. TEE was significantly and moderately correlated with the EI estimated by the DR (r = 0.45, p < 0.01) and FFQ (r = 0.37, p < 0.01). Furthermore, the EI correlation coefficients estimated by DR and the FFQ in this study were not significantly different (p = 0.46). The EI/TEE ratio was significantly and negatively correlated with the body mass index (BMI). In conclusion, EI estimated with a DR or FFQ modestly correlated with TEE, and calibrating EI with a developed equation in this study can attenuate the underestimation of EI.

Sociodemographic and physical predictors of non-participation in community based physical checkup among older neighbors: a case-control study from the Kyoto-Kameoka longitudinal study, Japan

Background

It is difficult to obtain detailed information on non-participants in physical and health examination checkups in community-based epidemiological studies. We investigated the characteristics of non-participants in a physical and health examination checkup for older adults in a nested study from the Japanese Kyoto-Kameoka Longitudinal Study.

Methods

We approached a total of 4831 people aged ≥65 years in 10 randomly selected intervention regions. Participants responded to a mail-based population survey on needs in the sphere of daily life to encourage participation in a free face-to-face physical checkup examination; 1463 participants (706 men, 757 women) participated in the physical checkup. A multiple logistic regression model was performed to investigate the adjusted odds ratios (aOR) of non-participation based on sociodemographic status apart from psychological and physiological frailty as assessed by the validated Kihon Checklist.

Results

There was a significant, inverse relationship between non-participation and frequently spending time alone among individuals who lived with someone or other family structure (aOR = 0.53, standard error [SE] 0.08 in men, aOR = 0.66, SE 0.09 in women). Very elderly (over 80 years old) women, poorer health consciousness and current smoking in both sexes and poor self-rated health in men, were significantly related to higher non-participation rates. In both sexes, individuals who did not participate in community activities were significantly more likely to be non-participants than individuals who did (aOR = 1.94, SE 0.23 in men, aOR = 3.29, SE 0.39 in women). Having low IADL and physical functioning scores were also associated with higher rates of non-participation.

Conclusion

Health consciousness and lack of community activity participation were predictors of non-participation in a physical checkup examination among older adults. In addition, lower IADL and physical functioning/strength were also predictors of non-participation.

On the contrary, older inhabitants living with someone tended to participate in the physical checkup examination for social interchange when they were frequently alone in the household. This study suggests the importance of considering aging especially for women and poor sociodemographic background and physical frailty for both sexes so that older people can access health programs without difficulty.

Trial registration

UMIN000008105. Registered 26 April 2012. Retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5426-5) contains supplementary material, which is available to authorized users.

Frequency of Fruit and Vegetable Consumption and the Oral Health-Related Quality of Life among Japanese Elderly: A Cross-Sectional Study from the Kyoto-Kameoka Study

OBJECTIVE

Many previous studies have reported that fruit and vegetable consumption is associated with a reduced risk of various disease, but whether or not their consumption is associated with the oral health-related quality of life (OHRQoL) is unclear. The objective of this study was to examine the association between the frequency of fruit and vegetable consumption and the OHRQoL in elderly subjects by sex.

METHODS

We analyzed cross-sectional data from a population-based Kyoto-Kameoka Study in 2012 of 3112 men and 3439 women (age ≥ 65 years). The frequencies of fruit and vegetable consumption were assessed using a validated food frequency questionnaire. We evaluated the OHRQoL using the General Oral Health Assessment Index (GOHAI), a self-reported measure designed to assess the oral health problems in old adults.

RESULTS

After adjusting for age, body mass index, alcohol, smoking, education, socioeconomic status, history of disease, medication use, mobility disability, and total energy intake, a higher frequency of combined fruit and vegetable consumption showed a significant positive association with the GOHAI score in both men and women (p-trend < 0.001 in both sexes). These associations remained significant after adjustment for poor mastication and denture use (p-trend all < 0.05 in both sexes). We observed a significant positive association even when the frequencies of fruit or vegetable consumption were analyzed separately (all p-trend < 0.05 in both sexes).

CONCLUSIONS

A higher frequency of fruit and/or vegetable consumption independently showed a strong positive association with the OHRQoL in both men and women. Further prospective studies are needed to confirm these findings.

Physical activity, energy intake, and obesity prevalence among urban and rural schoolchildren aged 11–12 years in Japan

The prevalence of childhood overweight and obesity has been shown to differ among regions, including rural–urban regional differences within nations. This study obtained simultaneous accelerometry-derived physical activity, 24 h activity, and food records to clarify the potential contributing factors to rural–urban differences in childhood overweight and obesity in Japan. Sixth-grade children (n = 227, 11–12 years old) from two urban elementary schools in Kyoto and four rural elementary schools in Tohoku participated in the study. The children were instructed to wear a pedometer that included a uniaxial accelerometer and, assisted by their parents, keep minute-by-minute 24 h activity and food records. For 12 children, the total energy expenditure was measured by the doubly labeled water method that was used to correct the Lifecorder-predicted activity energy expenditure and physical activity level. The overweight and obesity prevalence was significantly higher in rural than in urban children. The number of steps per day, activity energy expenditure, physical activity level, and duration of walking to school were significantly lower in rural than in urban children. In contrast, the reported energy intake did not differ significantly between the regions. The physical activity and duration of the walk to school were significantly correlated with body mass index. Rural children had a higher prevalence of overweight and obesity, and this may be at least partly caused by lower physical activity, especially less time spent walking to school, than urban children.

Diet quality and physical or comprehensive frailty among older adults

PURPOSE

While the association between diet quality and mortality has been previously demonstrated, the association between frailty and diet quality has not been evaluated well. This study aimed to investigate the association between diet quality and prevalence of both physical and comprehensive frailty, using two validated tools, in a community-based cohort of older adults.

METHODS

We conducted cross-sectional analyses using baseline data of 7022 participants aged ≥ 65 years in the Kyoto-Kameoka study. Diet quality was assessed by calculating the adherence scores to the Japanese Food Guide Spinning Top using a validated questionnaire; the participants were stratified into quartile groups based on these scores. Physical and comprehensive frailty was assessed using the Fried phenotype model-based Frailty Screening Index and the Kihon Checklist, respectively. Multivariable logistic regression and the restricted cubic spline model were used to calculate odds ratios (ORs) and their 95% confidence intervals (CIs) for associations between adherence scores and frailty prevalence.

RESULTS

Higher adherence scores signified a higher intake of vitamin C, vegetables, dairy products, and fruits. Physical and comprehensive frailty prevalence was 14.2 and 35.8%, respectively. In a multivariable adjusted model, compared with the bottom adherence score quartile, the top quartile was associated with lower ORs of physical (OR 0.64; 95% CI 0.52-0.80) and comprehensive frailty (OR 0.60; 95% CI 0.51-0.71). These relationships were similar to results in the spline model.

CONCLUSIONS

This study shows an inverse dose-response relationship between diet quality and prevalence of both physical and comprehensive frailty in older adults.

Decline in objective physical activity over a 10-year period in a Japanese elementary school

Background

The purpose of this study was to examine the change in accelerometer-derived daily physical activity (PA) and activity record-derived daily activities over a 10-year period in urban elementary schoolchildren in Japan.

Methods

A total of 233 sixth-grade children (11–12 years old) in a same elementary school in Kyoto participated in the study (n = 125 and 108 in 1999 and 2009, respectively). The participant rate is 91.9 and 98.2 % in 1999 and 2009, respectively. The size and shape of the school district was not changed. The children were instructed to wear an accelerometer for 5 consecutive days of weekday and to keep minute-by-minute 24-h activity records with the assistance of their parents. The school-day scheduling was similar between 1999 and 2009 (29 and 27 sessions of 45-min class per week, respectively).

Results

From 1999 to 2009, step counts considerably decreased (20,832 vs. 12,237 steps per day in boys and 16,087 vs. 10,748 steps per day in girls; P < 0.001) with concomitant significant decreases in total energy expenditure (P = 0.011), activity energy expenditure (P < 0.001), and physical activity level (P < 0.001). Time spent playing outdoors and walking to school were also significantly less in 2009 than 1999 (P < 0.001). Accelerometer-measured PA was significantly associated with the amount of time spent playing outdoors and walking to school.

Conclusions

These results indicate that elementary schoolchildren in 2009 spend less time playing outdoors and walking to school, perform less PA, and take fewer steps than children of a decade ago.

Comprehensive geriatric intervention program with and without weekly class-style exercise: research protocol of a cluster randomized controlled trial in Kyoto-Kameoka Study

Objective

The number of long-term care (LTC) users and the associated expenditures in Japan are increasing dramatically. The national government recommends LTC prevention through activation of communities. However, there is no clear evidence of the effect of population-based comprehensive geriatric intervention program (CGIP) for restraints of LTC users and the associated expenditures in the future. The aims of the current paper are to describe the study protocol and progress of a cluster randomized controlled trial (RCT) with a CGIP in Kameoka City.

Methods

The cluster RCT involved random allocation of regions as intervention (n=4,859) and nonintervention (n=7,195). Participants were elderly persons aged ≥65 years without LTC certification who had responded to a mailing survey. The residents living in intervention regions were invited to a physical check-up, and 1,463 people participated (30.3%). These individuals were invited to the CGIP, and 526 accepted. The CGIP comprised instructions on: 1) low-load resistance training using bodyweight, ankle weights, and elastic bands; 2) increasing daily physical activity; 3) oral motor exercise and care; and 4) a well-balanced diet based on a program from Ministry of Health, Labour and Welfare. We allocated the intervention regions randomly into home-based self-care program alone (HB group, 5 regions, n=275) and home-based program+weekly class-style session (CS group, 5 regions, n=251). We evaluated the effects of the CGIP at 12 weeks and at 12 or 15 months on physical function, and are conducting follow-up data collection for an indefinite period regarding LTC certification, medical costs, and mortality.

Results and discussion

The study was launched with good response rates in each phase. Participants of both groups significantly increased their step counts by ~1,000 per day from the baseline during the CGIP. This RCT will provide valuable information and evidence about effectiveness of a community-based CGIP.

Anti-obesity effects of α-cyclodextrin-stabilized 4-methylthio-3-butenyl isothiocyanate from daikon (Raphanus sativus var. longipinnatus) in mice

4-Methylthio-3-butenyl isothiocyanate (MTBI) is a pungent bioactive constituent found in daikon. However, MTBI is immediately hydrolyzed to 3-hydroxy-methylene-2-thioxopyrrolidine in grated daikon. In this study, we evaluated whether MTBI in grated daikon complexed with α-cyclodextrin (αCD) has anti-obesity effects in mice. C57BL/6J mice were fed a normal diet (normal group), high-fat diet (HFD, control group), HFD with αCD (αCD group), or HFD with MTBI-αCD (MTBI-αCD group) for 16 weeks. The results showed that the final body weight, epididymal white adipose tissue weight, and plasma triglyceride and total cholesterol levels were significantly lower in the MTBI-αCD group than in the control group. The cell size in epididymal adipose tissue was significantly smaller and the accumulation of lipids in the liver was significantly lower in the MTBI-αCD group than in the control group. Furthermore, real-time polymerase chain reaction showed that the mRNA expression level of tumor necrosis factor-alpha was suppressed in the MTBI-αCD group. We also observed low superoxide dismutase activity in the MTBI-αCD group, possibly because MTBI-αCD has the potential to resist HFD-induced oxidative injury. In conclusion, MTBI-αCD exerted anti-inflammation and antioxidant effects to suppress lipid accumulation in epididymal adipose tissue and the liver. These effects then prevented HFD-induced obesity in mice.

Adherence to the food-based Japanese dietary guidelines and prevalence of poor oral health-related quality of life among older Japanese adults in the Kyoto-Kameoka study

Although better diet quality is inversely related to the risk of geriatric disorders, the association of adherence to dietary guidelines with oral health-related quality of life (OHRQoL) is unclear. We aimed to investigate this association in older Japanese adults. This cross-sectional study included 7984 Japanese participants aged ≥ 65 years from the population-based Kyoto-Kameoka study. Dietary intake was estimated using a validated self-administered FFQ. The scores for adherence to the Japanese Food Guide Spinning Top (range: 0 (worst) to 80 (best)) were calculated. These scores were stratified into quartiles (Qs). Poor OHRQoL was defined as a score ≤ 50 using a 12-item Geriatric Oral Health Assessment Index. The OR and 95 % CI were calculated using multivariable logistic regression and the spline model. Higher adherence score was associated with a lower prevalence of poor OHRQoL (Q1-Q4:36·0 %, 32·1 %, 27·9 % and 25·1 %, respectively). An inverse association was found between the score for adherence to the food-based Japanese dietary guidelines and the OR of poor OHRQoL among all the participants (Q1: reference; Q2: OR, 0·87 (95 % CI: 0·75, 1·00); Q3: OR, 0·77 (95 % CI: 0·66, 0·90); Q4: OR, 0·72 (95 % CI: 0·62, 0·85); Pfor trend < 0·001). These relationships were similar to the results in the spline model. Higher adherence to the food-based Japanese dietary guidelines is inversely associated with the prevalence of poor OHRQoL in older adults. Our results may provide useful insights to improve and maintain oral health.

[Adjuvant chemotherapy with TS-1 for head and neck cancer--side effect of two-week application followed by one-week rest regimen]

Multimodality therapy incorporated with radiotherapy, surgery and chemotherapy are used in the treatment of head and neck cancer in order to improve the local control and survival rate. TS-1, a newly developed oral antitumor agent which could achieve the same therapeutic concentration as that of 5-FU under continuous and intravenous treatment, has been used as adjuvant therapy for carcinomas in recent years. We presented our experience applying a new regimen of TS-1 and its side effects. TS-1 has been applied for head and neck carcinomas since 2001. The oral application of TS-1 has been used in 32 cases of head and neck cancer in our department since 2003, and the agent has been applied in 22 of 32 cases as adjuvant therapy. The primary sites of malignancy included hypopharyngx (7 cases), larynx (6 cases), maxillary sinus (2 cases), oropharynx (2 cases), oral cavity (4 cases), submandibular gland (1 case) and one case in which the primary site was unknown. A regimen of four-week application followed by two-week rest had been used in 6 cases in the first part of this trial. However, a high frequency of blood toxicity was found from the third week, requiring alteration of the protocol. Thus, a new regimen of two-week application followed by one week rest was thereafter used in the other 16 cases. Blood toxicity was found in 66.7% of those cases receiving a four-week application followed by two-week rest regimen. In the 16 cases receiving the two-week application followed by one-week rest regimen, only one case showed grade 2 leucopenia while continuous application for more than eight weeks was possible in 9 cases. Mild macrocytic anemia was found in some of these cases, however none of which required any necessary interruption of the treatment. Side effects other than blood toxicity, such as edema or pigmentation of lower limbs, erythema of skin and diarrhea, were found in the other cases, requiring suspension of the treatment. But the subsequent application was possible after a break or decreasing the dosage. We concluded that the new regimen of two-week application followed by one-week rest is less likely to be interrupted by the side effects and is safer to be used outpatiently, compared with the four-week application followed by two-week rest.

Determinant of factors associated with water requirement measured using the doubly labelled water method among older Japanese adults

OBJECTIVE

Water is an essential nutrient for all organisms and is important for maintaining life and health. We aimed to develop a biomarker-calibrated equation for predicting water turnover (WT) and pre-formed water (PW) using the doubly labelled water (DLW) method.

DESIGN

Cross-sectional study.

SETTING

General older population from the Kyoto-Kameoka Study, Japan.

PARTICIPANTS

The 141 participants aged ≥ 65 years were divided into a model developing (n 71) and a validation cohort group (n 70) using a random number generation. WT and PW was measured using the DLW method in May-June of 2012. In developing the cohort, equations for predicting WT and PW were developed by multivariate stepwise regression using all data from the questionnaires in the Kyoto-Kameoka study (including factors such as dietary intake and personal characteristics). WT and PW measured using the DLW method were compared with the estimates from the regression equations developed using the Wilcoxon signed-rank test and correlation analysis in validation cohort.

RESULTS

The median WT and PW for 141 participants were 2·81 and 2·28 l/d, respectively. In the multivariate model, WT (R2 = 0·652) and PW (R2 = 0·623) were moderately predicted using variables, such as height, weight and fluid intake from beverages based on questionnaire data. WT (r = 0·527) and PW (r = 0·477) predicted that using this model was positively correlated with the values measured by the DLW method.

CONCLUSIONS

Our results showed factors associated with water requirement and indicated a methodological approach of calibrating the self-reported dietary intake data using biomarkers of water consumption.

Dose-Response Relationships between Diet Quality and Mortality among Frail and Non-Frail Older Adults: A Population-Based Kyoto-Kameoka Prospective Cohort Study

OBJECTIVES

Although better diet quality is inversely associated with mortality risk, the association between diet quality and mortality remains unclear in frail and non-frail older adults. Thus, we aimed to examine this association in older Japanese adults.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

We used the data of 8,051 Japanese older adults aged ≥65 years in the Kyoto-Kameoka study.

MESUREMENTS

Dietary intake was estimated using a validated food frequency questionnaire. Diet quality was evaluated by calculating the adherence scores to the Japanese Food Guide Spinning Top (range, 0 [worst] to 80 [best]), which were stratified into quartiles. Frailty status was assessed using the validated self-administered Kihon Checklist (KCL) and the Fried phenotype (FP) model. Survival data were collected between February 15, 2012 and November 30, 2016. Statistical analysis was performed using the multivariate Cox proportional hazard analysis and the spline model.

RESULTS

During the median 4.75-year follow-up (36,552 person-years), we recorded 661 deaths. After adjusting for confounders, compared with the bottom adherence score quartile, the top quartile was associated with lower hazard ratio (HR) of mortality in frailty (HR, 0.73; 95% confidence interval [CI], 0.54-1.00) and non-frailty, as defined by the KCL (HR, 0.72; 95% CI, 0.52-1.01). In the spline model, regardless of frailty status defined by the KCL and FP model, adherence score showed a strongly dose-dependent inverse association with mortality up to approximately 55 points; however, no significant differences were observed thereafter. This association was similar to the results obtained in individuals with physical, cognitive, and depression as domains of KCL in the spline model.

CONCLUSIONS

Our findings demonstrate an L-shaped association between diet quality and mortality in both frail and non-frail individuals. This study may provide important knowledge for improving poor diet quality in older individuals with frailty or domains of frailty.