Analysing food groups and nutrient intake in adults who met and did not meet the daily recommended vegetable intake of 350 g: the 2016 National Health and Nutrition Survey in Japan

This study aimed to compare the differences in the intake of food groups and nutrients between Japanese adults who consumed the recommended daily vegetable intake (350 g/day) and those who did not. Dietary information was obtained from one-day dietary records collected from the 2016 National Health and Nutrition Survey, which was conducted in 46 prefectures in Japan. The participants aged ≥20 years (n = 21,606; 53.8% women) were classified into the < and ≥350 g/day groups. Inter-group differences for 17 food groups and 27 nutrients were assessed as percentages of consumers (food groups only) and energy-adjusted intake (units/MJ/d or % of total energy intake). Overall, 29% of participants consumed ≥350 g/day of vegetables. The ≥350 g/day group had a higher percentage of consumers and energy-adjusted intakes for all vegetable subgroups than the <350 g/day group. For other food groups, the ≥350 g/day group had higher percentages of consumers for all food groups, except for cereals, eggs, and condiments and seasonings, which showed no significant differences. However, the ≥350 g/day group had a significantly higher energy-adjusted intake for potatoes and other tubers, mushrooms, meats, and condiments and seasonings but a significantly lower value for cereals, eggs, savoury snacks and confectionaries, and beverages. The ≥350 g/day group had a significantly higher intake of almost all (25/27) nutrients, including sodium, than the <350 g/day group. Participants with vegetable intake ≥350 g/day might have a more favourable intake of food groups and nutrients; however, watching for salt intake is necessary when promoting vegetable intake.

One-year follow-up of the immunogenicity and safety of a primary series of the NVX-CoV2373 (TAK-019) vaccine in healthy Japanese adults: Final report of a phase I/II randomized controlled trial

BACKGROUND

In the interim report of this phase I/II randomized, placebo-controlled trial in Japanese adults, a two-dose primary series of NVX-CoV2373 (5 µg SARS-CoV-2 recombinant nanoparticle spike protein [rS]; 50 µg Matrix-M) administered 21 days apart induced robust anti-SARS-CoV-2 immune responses up to day 50 and had an acceptable safety profile.

METHODS

Following the double-blind phase of this study (day 1-50), participants were informed about their assignment to NVX-CoV2373 or placebo, and their reconsent was required for continuation in the open-label phase (day 51-387). This final report evaluated immunogenicity on days 202 and 387, and safety findings from the 1-year follow-up.

RESULTS

In total, 131/150 participants in the NVX-CoV2373 arm and 4/50 in the placebo arm completed the study. The most common reason for discontinuation was because the participant requested a publicly available COVID-19 vaccine. At 6 months and 1 year after the second vaccine dose, both the geometric mean titres of anti-SARS-CoV-2 rS serum immunoglobulin G and serum neutralizing antibodies against the SARS-CoV-2 ancestral strain were numerically higher than before the second dose. There were no deaths, adverse events (AEs) leading to participant withdrawal, or AEs of special interest throughout the trial. During follow-up, 2.0 % (1/50) of participants in the placebo arm reported COVID-19 approximately 1 month after the second vaccine dose (serious AE requiring hospitalisation, already presented in the interim report) and 2.7 % (4/150) in the NVX-CoV2373 arm after approximately 10 months (mild [2/4] or moderate [2/4] in severity).

DISCUSSION

A primary series of NVX-CoV2373 induced persistent immune responses up to 1 year after the second dose. The vaccine was well tolerated and had an acceptable safety profile. We believe our findings offer important insights for determining dosing intervals between primary and booster vaccinations.

Insulin Resistance: A Marker for Fat-to-Lean Body Composition in Japanese Adults

We sought to investigate the relationship between insulin resistance (IR) and body composition as assessed by bioelectrical impedance analysis in Japanese health check-up recipients (1186 men and 1441 women). IR was defined as a Homeostasis Model Assessment of IR (HOMA-IR) ≥ 2.5. In body-composition-related parameters, the fat mass index (F index) was defined as fat mass divided by the height squared (kg/m2). The fat-free mass index (FF index) was defined as fat-free mass divided by the height squared (kg/m2). The F index to FF index ratio (F-FF ratio) was defined as the F index divided by the FF index. Factors related to HOMA-IR were examined. The median HOMA-IR was 1.54 in men and 1.30 in women (p < 0.0001). The median F index was 4.9 kg/m2 in men and 6.1 kg/m2 in women (p < 0.0001). The median FF index was 18.2 kg/m2 in men and 15.1 kg/m2 in women (p < 0.0001). The median F-FF ratio was 0.272 in men and 0.405 in women (p < 0.0001). The F-FF ratio was an independent factor associated with HOMA-IR in the multivariate analysis in both genders, while the F index and FF index were not in both genders. In conclusion, fat and skeletal muscle balance can be controlled by IR in Japanese adults.

Immunogenicity and safety of a single booster dose of NVX-CoV2373 (TAK-019) in healthy Japanese adults who had previously received a primary series of COVID-19 mRNA vaccine: Primary analysis report of a phase 3 open-label trial

BACKGROUND

We evaluated the immunogenicity and safety of a booster dose of NVX-CoV2373 in Japanese adults who had completed a primary series of COVID-19 mRNA vaccine 6-12 months previously.

METHODS

This single-arm, open-label, phase 3 study, conducted at two Japanese centres, enrolled healthy adults ≥ 20 years old. Participants received a booster dose of NVX-CoV2373. The primary immunogenicity endpoint was non-inferiority (lower limit of the 95 % confidence interval [CI] ≥ 0.67) of the geometric mean titre (GMT) ratio of titres of serum neutralizing antibodies (nAbs) against the SARS-CoV-2 ancestral strain 14 days after booster vaccination (day 15) in this study, compared with those 14 days after the second primary NVX-CoV2373 vaccination (day 36) in the TAK-019-1501 study (NCT04712110). Primary safety endpoints included local and systemic solicited adverse events (AEs) up to day 7 and unsolicited AEs up to day 28.

RESULTS

Between 15 April 2022 and 10 May 2022, 155 participants were screened and 150, stratified by age (20-64 years old [n = 135] or ≥ 65 years old [n = 15]), received an NVX-CoV2373 booster dose. The GMT ratio between titres of serum nAbs against the SARS-CoV-2 ancestral strain on day 15 in this study and those on day 36 in the TAK-019-1501 study was 1.18 (95 % CI, 0.95-1.47), meeting the non-inferiority criterion. Following vaccination, the proportion of participants who reported local and systemic solicited AEs up to day 7 was 74.0 % and 48.0 %, respectively. The most common local and systemic solicited AEs were tenderness (102 participants [68.0 %]) and malaise (39 participants [26.0 %]), respectively. Seven participants (4.7 %) reported unsolicited AEs between vaccination and day 28; all were severity grade ≤ 2.

DISCUSSION

A single heterologous NVX-CoV2373 booster induced rapid and robust anti-SARS-CoV-2 immune responses, addressing waning immunity in healthy Japanese adults, and had an acceptable safety profile.

CLINICALTRIALS

gov identifier: NCT05299359.

Validity, reliability, and correlates of the Smartphone Addiction Scale-Short Version among Japanese adults

BACKGROUND

The short version of the smartphone addiction scale (SAS-SV) is widely used to measure problematic smartphone use (PSU). This study examined the validity and reliability of the SAS-SV among Japanese adults, as well as cross-sectional and longitudinal associations with relevant mental health traits and problems.

METHODS

Datasets from a larger project on smartphone use and mental health were used to conduct two studies. Participants were adults aged over 20 years who carried a smartphone.

RESULTS

Study 1 (n = 99,156) showed the acceptable internal consistency and structural validity of the SAS-SV with a bifactor model with three factors. For the test-retest reliability of the SAS-SV, the intraclass correlation coefficient (ICC) was .70, 95% CI [.69, 70], when the SAS-SV was measured seven and twelve months apart (n = 20,389). Study 2 (n = 3419) revealed that when measured concurrently, the SAS-SV was strongly positively correlated with another measure of PSU and moderately correlated with smartphone use time, problematic internet use (PIU), depression, the attentional factor of impulsiveness, and symptoms related to attention-deficit hyperactivity disorder and obsessive-compulsive disorder. When measured 12 months apart, the SAS-SV was positively strongly associated with another measure of PSU and PIU and moderately associated with depression.

DISCUSSION

The structural validity of the SAS-SV appeared acceptable among Japanese adults with the bifactor model. The reliability of the SAS-SV was demonstrated in the subsequent seven- and twelve-month associations.

CONCLUSION

The cross-sectional and longitudinal associations of the SAS-SV provided further evidence regarding PSU characteristics.

Pharmacokinetics, Pharmacodynamics, and Tolerability of Olpasiran in Healthy Japanese and Non-Japanese Participants: Results from a Phase I, Single-dose, Open-label Study

PURPOSE

Olpasiran, an N-acetyl galactosamine-conjugated, hepatocyte-targeted, small interfering RNA, is being developed to reduce plasma lipoprotein (Lp)-(a) concentration by directly targeting the LPA gene. This study evaluated the pharmacokinetics, pharmacodynamics, and tolerability of a single SC injection of olpasiran in healthy, Japanese and non-Japanese participants.

METHODS

In this Phase I, open-label, parallel-design study, Japanese participants were randomized in a 1:1:1:1 ratio to receive a single 3, 9, 75, or 225 mg dose of olpasiran. Non-Japanese participants received a single 75 mg dose of olpasiran. The primary end points were pharmacokinetic parameters, including C_max, AUC_inf, t_max, and t_1/2. Tolerability and change in Lp(a) concentration were also assessed.

FINDINGS

A total of 27 enrolled participants had a mean (SD) age of 48.0 (12.5) years. Olpasiran C_max and AUC_inf were increased in an approximately dose-proportional manner in the Japanese groups. Mean (SD) C_max values were 242 (121.0) and 144 (71.3) ng/mL, and mean (SD) AUC_inf values were 3550 (592.0) and 2620 (917.0) h·ng/mL, in the Japanese and non-Japanese groups, respectively, given 75 mg of olpasiran. Median t_max ranged from 3.0 to 9.0 hours and mean (SD) t_1/2 ranged from 4.0 (0.3) to 6.9 (1.6) hours across all groups. The maximal Lp(a) reduction occurred at day 57, with mean (SD) Lp(a) percentage reductions from baseline ranging from 56.0% (21.0%) to 99.0% (0.2%). A reductions in Lp(a) was observed as early as day 4. All adverse events were mild in severity, with no serious or fatal adverse events. No clinically important changes in tolerability-related laboratory analytes or vital signs were observed.

IMPLICATIONS

In this population of healthy Japanese participants, dose-proportional increases in exposure and reduced Lp(a) in a dose-dependent manner were found with single 3, 9, 75, and 225 mg doses of olpasiran. The magnitude and durability of Lp(a) reductions were similar between the Japanese and non-Japanese groups. Olpasiran was well tolerated, with no clinically important adverse events or laboratory or vital sign abnormalities.

[Changes in dietary behaviors and food-related accessibility issues and information needs during the COVID-19 pandemic: comparison based on household economic status]

Objective　This study aimed to assess the household income changes during COVID-19 pandemic among Japanese adults, and to evaluate how this was related to changes in dietary behaviors and food-related accessibility issues and information needs during the emergency period.Method　We conducted an online cross-sectional survey in July, 2020 among residents (aged 20-69 years) of the 13 prefectures under special confinement during the COVID-19 pandemic. Participants were asked about their dietary behaviors before the pandemic (before February 2020) and during the confinement period (April-May 2020), as well as about their food-related accessibility issues and information needs during the confinement period. Data from 2,225 residents were analyzed. Participants were divided into three groups (decreased, unchanged, and increased) based on the household income changes due to COVID-19. Demographics, dietary behaviors, and food-related accessibility issues and information needs were then compared among these three groups. Multiple logistic regression analyses were performed to examine the effect of household income changes on dietary behavior changes, food-related accessibility issues, and food-related information needs, while adjusting for sociodemographic factors. Furthermore, the effect of household income changes and subjective economic status were also analyzed using multiple logistic regression analyses.Result　The participant distribution in each group were as follows: decreased (34.6%), unchanged (63.9%), and increased (1.6%). Higher proportion of those who were employed part-time, self-employed, or unemployed during the confinement period were found among the decreased group. The odds ratios (OR) of the decreased group were significantly higher than the unchanged group for lower frequency of eating out, and for higher frequency of home-cooking, consuming ready-to-eat convenience meals, and eating with children during the confinement period. Furthermore, regardless of the subjective economic status, the decreased group experienced difficulties in accessing required foods because of shortages and congestion in grocery stores, as well as increased prices. Additionally, food-related information needs regarding reduction of food expenses were also high among the decreased group.Conclusion　Participants with a decreased household income were more likely to experience difficulties with food accessibility and desire information about lowering food-related expenses. Furthermore, they reported lower frequency of eating out, and higher frequency of home-cooking and consuming ready-to-eat convenience meals during the confinement period than before the pandemic. Future studies should evaluate the direction (positive or negative) of these changed food consumption patterns.

Adaptation and validation of the main concept analysis of spoken discourse by native Japanese adults

Many people with aphasia demonstrate problems of oral production at the discourse level. The Main Concept Analysis (MCA) for oral discourse production is a published evidence-based battery for quantifying the degree of presence, accuracy, completeness, and efficiency of targeted main concepts in oral discourse. In Japan, such a standardized tool specialized for assessing spoken discourse is currently lacking. The purpose of this study was to adapt the Japanese version of MCA for oral discourse production (the Japanese-MCA) and examine its validity and reliability. Stage 1 of the study involved the establishment of linguistically-specific main concepts (MCs) of the Japanese-MCA. Ten speech-language-hearing therapists and 60 healthy participants who were native monolingual Japanese speakers were recruited to determine MCs. Stage 2 examined the criterion validity and reliability of the Japanese-MCA. Language samples of 20 participants with aphasia, as verified by Standard Language Test of Aphasia (SLTA), and 20 healthy older participants were used. Results of Stage 1 of the study yielded normative data with a set of target MCs that were geographically and linguistically specific for use in Japan. The results also revealed the comparability of the Japanese-MCA and previously reported versions of other languages. Stage 2 findings indicated not only a high correlation of criterion validity, but also good reliability of the test. With established norms and specific scoring criteria of the Japanese-MCA, it is believed that this new tool will become a useful addition to clinical management and research of aphasia in Japan.

Evaluation of occlusal status of Japanese adults based on functional tooth units

OBJECTIVES

Although extensive national oral health data on dental caries and periodontal diseases in Japan are available, few studies have assessed the occlusal status of the Japanese population, and none are based on national survey data. The presence and prosthodontic conditions of the molar region are important for masticatory function, and the functional tooth unit (FTU) approach can be used to evaluate the occlusal status. Thus, using the national oral health survey data, this study investigated the occlusal status of the Japanese population using FTU.

METHODS

Overall, 3,605 adults (aged ≥20 years) who participated in the 2011 Japanese national oral health survey were included. FTUs were used as indices for evaluating the occlusal status. FTUs were calculated according to sex, age group, and the number of teeth present, and their associations were further analysed.

RESULTS

The number of teeth present, posterior teeth, and FTUs decreased with age in both men and women. In the age group of those ≥60 years, all only natural teeth-FTU (n-FTU) and natural teeth and artificial teeth from fixed prostheses or implant-supported FTU (nif-FTU) scores were <8. The total-FTU scores of all age groups, except the 60-69 and 70-79 years age groups, were >10.

CONCLUSION

This is the first study to use FTUs and national oral health survey data to investigate the occlusal status in the Japanese population. People aged ≥60 years who have low n-FTU or natural teeth and artificial teeth from fixed prostheses or implant-supported FTU scores or those aged 60-70 years who have the lowest total-FTU scores require careful evaluation of masticatory performance.

Clinical inertia in patients with type 2 diabetes treated with oral antidiabetic drugs: Results from a Japanese cohort study (JDDM53)

AIMS/INTRODUCTION

Treatment intensification is commonly delayed in people with type 2 diabetes, resulting in poor glycemic control for an unacceptable length of time and increased risk of complications.

MATERIALS AND METHODS

This retrospective study investigated clinical inertia in 33,320 Japanese adults with type 2 diabetes treated with oral antidiabetic drugs (OADs) between 2009 and 2018, using data from the Computerized Diabetes Care (CoDiC® ) database.

RESULTS

The median time from first reported glycated hemoglobin (HbA1c) ≥7.0% (≥53 mmol/mol) to treatment intensification was considerably longer and HbA1c levels were higher the more OADs the patient was exposed to. For patients receiving three OADs, the median times from HbA1c ≥7.0% (53 mmol/mol) to intensification with OAD, glucagon-like peptide-1 receptor agonist or insulin were 8.1, 9.1 and 6.7 months, with a mean HbA1c level at the time of intensification of 8.4%, 8.9% and 9.3%, respectively. The cumulative incidence for time since the first reported HbA1c ≥7.0% (≥53 mmol/mol) to intensification confirmed the existence of clinical inertia, identifying patients whose treatment was not intensified despite poor glycemic control. HbA1c levels ≥7.0% (≥53 mmol/mol) after ≥6 months on one, two or three OADs were observed in 42%, 51% and 58% of patients, respectively, showing that approximately 50% of patients are above HbA1c target regardless of how many OADs they take.

CONCLUSIONS

Real-world data here show clinical inertia in Japanese adults with type 2 diabetes from early diabetes stages when they are receiving OADs, and illustrate a need for earlier, more effective OADs or injectable treatment intensification and better communication around the existence of clinical inertia.

Association Between Chinese Visceral Adiposity Index and Incident Type 2 Diabetes Mellitus in Japanese Adults

BACKGROUND

Obesity is a well-known risk factor for type 2 diabetes mellitus (T2DM). Studies have shown that the Chinese visceral adiposity index (CVAI), a novel visceral adiposity indicator, is positive associated with the risk of T2DM in the Chinese population. This study aimed to investigate the correlation between CVAI and incident T2DM in a Japanese population.

METHODS

We performed a secondary analysis of open-access data from a retrospective cohort study. This study included 15,464 participants who received regular medical examinations at Murakami Memorial Hospital. All participants underwent a questionnaire survey, physical examination, and blood biochemical testing at baseline. The main outcome was new-onset T2DM during follow-up. Cox regression analysis and Kaplan-Meier analysis were used to analyze the risk of CVAI on T2DM, and we conducted smooth curve fitting. Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive value of CVAI, body mass index (BMI), and waist circumference (WC) for incident T2DM.

RESULTS

During a median follow-up time of 5.39 years, 373 new-onset T2DM events were observed. Kaplan-Meier curves showed that the incidence of T2DM increased as the CVAI increased (log-rank χ ² = 187.1076 and 129.6067 in males and females, respectively, both P <0.001). After adjustment for covariates, per 1 increase of CVAI was associated with a 1.0133-fold and 1.0246-fold higher risk of incident T2DM in males and females, respectively (both P <0.001). Those individuals in the top CVAI quartile group had the highest risk of new-onset T2DM (HR = 3.1568 and 5.8415 in males and females, respectively, both P <0.05). A nonlinear relationship was identified by the smooth fitting curve between CVAI and T2DM events in both genders. ROC analysis indicated that CVAI had better predictive power than BMI and WC in both genders.

CONCLUSION

Our results demonstrate that CVAI was significantly associated with an increased risk of new-onset T2DM in Japanese adults.

The development of resilience in Japanese adults: A two-wave latent change model

This study examined the development of resilience in Japanese adults using a two-wave latent change model with 1284 Japanese adults (865 men, aged 20–69 years). The Bidimensional Resilience Scale was administered at both waves over a 2-year interval: January 2017 (Time 1) and January 2019 (Time 2). The results showed no significant mean-level change between Time 1 and Time 2, and relatively high stability. The latent change model indicated that changes in resilience varied significantly among individuals; however, sociodemographic variables were not significantly associated with variations in resilience. Resilience appears relatively stable in Japanese adults, despite individual variation.

Associations between nutritional adequacy and insomnia symptoms in Japanese men and women aged 18-69 years: a cross-sectional study

OBJECTIVES

Sleep and diet are important lifestyle factors for maintaining health. Although previous studies have suggested that sleep quality may be associated with specific nutrient and food intakes, the relationship between nutritional adequacy and sleep quality remains unclear. The purpose of this study was to examine the relationship between sleep quality (insomnia symptoms) and adequate nutrient intake among Japanese adults.

DESIGN

Cross-sectional.

SETTING

Nationwide population survey conducted in 2013.

PARTICIPANTS

1,997 participants (940 men and 1,057 women) aged 18-69 years.

MEASUREMENTS

Insomnia symptoms were assessed using the Athens Insomnia Scale (AIS) and participants were classified into three groups (absent, minor, and moderate-severe) based on the total AIS score. Dietary intake was estimated using a questionnaire and nutrient intake adequacy was evaluated by comparing the self-reported intake with two indices of the Dietary Reference Intakes for Japanese (2015): an estimated average requirement (EAR) and tentative dietary goal for preventing lifestyle-related disease (DG).

RESULTS

A total of 205 men (21.8%) and 266 women (25.2%) were categorized as having moderate-severe insomnia symptoms. Among men, moderate-severe symptoms were associated with higher prevalences of inadequate intakes of total dietary fiber, vitamin C, and zinc. However, there was little association between inadequate nutrient intake and insomnia symptoms among women. The number of inadequate nutrients was significantly associated with insomnia symptoms in men (DG, P=0.004; EAR, P=0.003) but not in women.

CONCLUSIONS

This study suggested that insomnia symptoms may be associated with nutritional inadequacy in Japanese adults, especially among men.

Association Between Second-hand Smoke Exposure and Depressive Symptoms Among Japanese Adults: A Cross-sectional Study

Background

Second-hand smoke exposure has been associated with poor mental health. However, among Japanese adults, little is known about the association between second-hand smoking and depressive symptoms. We examined this association in a cross-sectional study among a Japanese general adult population sample.

Methods

Japanese adults were recruited from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area between 2012 and 2017. Second-hand smoke exposure and smoking status were assessed using a self-administered questionnaire. Based on their frequency of exposure to second-hand smoke, non-smokers and smokers were categorized as “almost never,” “sometimes,” and “almost every day”. Depressive symptoms were defined by a Kessler 6 score ≥5 points. We performed a multivariable Poisson regression analysis to obtain adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for depressive symptoms.

Results

Overall, 5,121 participants (4,547 non-smokers and 574 smokers) were included whose mean age was 63.6 (standard deviation [SD], 10.3) years for non-smokers and 59.33 (SD, 10.2) years for smokers. The association between second-hand smoking and depressive symptoms was significant among non-smokers, but not among smokers. Among non-smokers, PRs compared with “almost never” were 1.25 (95% CI, 1.09–1.42) for “sometimes” and 1.41 (95% CI, 1.09–1.84) for “almost every day” (P for trend <0.001); among smokers, PRs compared with “almost never” were 1.30 (95% CI, 0.82–2.06) for “sometimes” and 1.44 (95% CI, 0.90–2.33) for “almost every day” (P for trend = 0.144).

Conclusions

Second-hand smoking and depressive symptoms were associated among non-smokers. Our findings indicate the importance of tobacco smoke control for mental health.

[Subjective happiness among Japanese adults: An upward tendency associated with age]

Objectives　The present study investigated subjective happiness in Japanese adults and offers basic knowledge for future studies. In addition, how subjective happiness varies in relation to certain demographic variables, such as gender and age, as well as factors that influence this variability, are examined.Methods　A total of 2,000 Japanese people (1,000 females and 1,000 males) over the age of 20 completed an anonymous self-report internet survey. There were approximately the same number of participants in each of six age groups ranging from the 20s to 70s. How Subjective Happiness Scale (SHS) scores were related to various demographic variables, including gender and age, as well as happiness, life satisfaction, and stress response, were analyzed.Results　The validity of the SHS was supported by positive correlations with happiness and life satisfaction scores and negative correlation with stress response scores. The results also showed that females had higher SHS scores than males, and this gender difference was distinctive, especially among young adults. In addition, there was a U-shaped change in SHS score by age. That is, subjective happiness dropped with age, but started increasing again after the 50s. The same findings were reconfirmed by an additional survey one year later. Moreover, those with a spouse showed higher SHS scores than unmarried participants. Lastly, SHS scores were low among those whose highest education was junior high school and those who lived alone, although the limitations of sampling bias should be considered.Conclusion　The SHS is an internationally accepted measure of subjective happiness consisting of only four items and can easily be used in public health research and practice. The current study offers basic information regarding SHS scores as well as subjective happiness in Japanese adults of different age groups and genders. The findings of the present study clearly indicate higher levels of subjective happiness among older age groups than younger ones, those with a spouse than those without a spouse, and females than males. As many studies conducted in other cultures have shown no such gender difference, further cross-cultural comparison studies are needed to clarify this discrepancy. The SHS as an indicator of personal well-being can be strongly expected to show extended utility in the future.

Validity and Reliability of a General Nutrition Knowledge Questionnaire for Japanese Adults

Nutrition knowledge is necessary for individuals to adopt appropriate dietary habits, and needs to be evaluated before nutrition education is provided. However, there is no tool to assess general nutrition knowledge of adults in Japan. Our aims were to determine the validity and reliability of a general nutrition knowledge questionnaire for Japanese adults. We developed the pilot version of the Japanese general nutrition knowledge questionnaire (JGNKQ) and administered the pilot study to assess content validity and internal reliability to 1,182 Japanese adults aged 18-64 y. The JGNKQ was further modified based on the pilot study and the final version consisted of 5 sections and 147 items. The JGNKQ was administered to female undergraduate Japanese students in their senior year twice in 2015 to assess construct validity and test-retest reliability. Ninety-six students majoring in nutrition and 44 students in other majors who studied at the same university completed the first questionnaire. Seventy-five students completed the questionnaire twice. The responses from the first questionnaire and both questionnaires were used to assess construct validity and test-retest reliability, respectively. The students in nutrition major had significantly higher scores than the students in other majors on all sections of the questionnaire (p=0.000); therefore, the questionnaire had good construct validity. The test-retest reliability correlation coefficient value of overall and each section except "The use of dietary information to make dietary choices" were 0.75, 0.67, 0.67, 0.68 and 0.61, respectively. We suggest that the JGNKQ is an effective tool to assess the nutrition knowledge level of Japanese adults.

Dietary inflammatory index and risk of upper aerodigestive tract cancer in Japanese adults

Background

The inflammatory potential of diet that has been shown to be associated with cancer risk. We examined the association between dietary inflammatory potential as measured by the dietary inflammatory index (DII^®) and risk of upper aerodigestive tract cancers in a Japanese case-control study.

Results

A positive association was observed between increasing DII scores and overall upper aerodigestive tract cancers, and across anatomic subsites. For upper aerodigestive tract cancers, the OR_Q4vsQ1 = 1.73 (95% CI: 1.37–2.20); head and neck cancer, the OR_Q4vsQ1 was 1.92 (95% CI: 1.42–2.59); and for esophageal cancer, the OR_Q4vsQ1 was1.71 (95% CI: 1.54–1.90). Risks for hypopharyngeal and nasopharyngeal cancers were greatly elevated: (OR_Q4vsQ1 = 4.05 (95% CI: 1.24–13.25) for hypopharyngeal cancer and OR_Q4vsQ1 = 4.99 (95% CI: 1.14–21.79) for nasopharyngeal cancer.

Conclusion

A more pro-inflammatory diet was associated with an elevated risk of upper aerodigestive tract cancers after accounting for important confounders. All anatomic subsites, except larynx, showed the consistently elevated risk with increasing DII score. Those subsites with known etiological associations with persistent infection showed the largest elevation in risk. These results warrant further evaluation in future studies.

Materials and Methods

This is a case-control study of 1,028 cases and 3,081 age- and sex-matched non-cancer controls recruited at Aichi Cancer Center. DII scores were computed based on estimates of macro- and micro-nutrients from a self-administered food frequency questionnaire. Scores were further categorized into quartiles (based on the distribution in controls). Conditional logistic regression models were fit to estimate odds ratio (OR) and 95% confidence intervals (CIs) adjusted for smoking, ethanol consumption, alcohol flushing, number of teeth, and occupation group.

High Tomato and Tomato Product Consumption is Protective Against the Decline in Handgrip Strength Among Japanese Adults: The Oroshisho Study

Background

There is scarce epidemiological evidence regarding the relationships of the consumption of different types of vegetables or fruits with change in skeletal muscle strength. We prospectively examined the relationships among Japanese adults, using handgrip strength to assess skeletal muscle strength.

Methods

A 3-year study was carried out with 259 Japanese adults who were 22–68 years of age. The frequency of consumption of different types of vegetables or fruits were obtained using a validated self-administered dietary history questionnaire. Handgrip strength was measured with a handheld digital Smedley dynamometer.

Results

After adjustment for confounding factors, the mean change in handgrip strength in participants stratified according to the level of tomato and tomato product consumption at baseline were −3.2 (95% confidence interval [CI], −4.0 to −2.3) for <1 time/week, −2.7 (95% CI, −3.6 to −1.8) for 1 time/week, −1.6 (95% CI, −2.5 to −0.8) for 2–3 times/week, and −1.7 (95% CI, −2.8 to −0.7) for ≥4 times/week, (P for trend = 0.022). However, the significant relationships of consumption of other types of vegetables and different types of fruits with change in handgrip strength were not observed.

Conclusion

Higher consumption of tomato and tomato product at baseline was significantly associated with reduced decline in handgrip strength among Japanese adults over a 3-year follow-up period. This study suggests that consumption of tomato and tomato product could be protective against the decline in skeletal muscle strength associated with aging.

Monetary value of self-reported diets and associations with sociodemographic characteristics and dietary intake among Japanese adults: analysis of nationally representative surveys

OBJECTIVE

To examine the relationships of monetary value of diets with sociodemographic and lifestyle characteristics and dietary intake among Japanese adults.

DESIGN

Cross-sectional study based on two nationally representative surveys: the Comprehensive Survey of Living Conditions and the National Health and Nutrition Survey, 2013. Dietary intake was assessed by a 1 d semi-weighed household dietary record with information on individual proportion of intakes. Diet cost was estimated by linking dietary data with retail food prices. A wide variety of sociodemographic and lifestyle variables were obtained from the two surveys.

SETTING

A random sample of nationally representative households in Japan.

SUBJECTS

Japanese adults aged 20 years or older (n 4658).

RESULTS

Lower energy-adjusted diet cost (Japanese yen/4184 kJ) was significantly associated with being younger, having a lower education, less equivalent monthly household expenditure, large household size, less physical activity and living in rented houses. Lower diet cost was associated with a lower intake of pulses, vegetables, fruits, fish, meat and dairy products, and a higher intake of grain, eggs, and fats and oils. At the nutrient level, lower diet cost was associated with a lower intake of protein, alcohol, dietary fibre, cholesterol and all vitamins and minerals examined, and a higher intake of carbohydrate. Diet cost was inversely associated with dietary energy density.

CONCLUSION

These data suggest that certain low socio-economic subgroups in Japan consume diets of lower monetary value, resulting in a lower quality of food and nutrient intake pattern except for lower sodium, cholesterol and alcohol consumption.

Relationship between thigh intermuscular adipose tissue accumulation and number of metabolic syndrome risk factors in middle-aged and older Japanese adults

BACKGROUND

To evaluate the association between thigh intermuscular adipose tissue accumulation and number of metabolic syndrome risk factors in middle-aged and older Japanese adults.

METHODS

Thigh muscle cross-sectional area, subcutaneous adipose tissue, thigh intermuscular adipose tissue, abdominal subcutaneous adipose tissue, and visceral adipose tissue were measured in 166 middle-aged and older (mean age, 69years) Japanese adults using magnetic resonance imaging. Daily physical activity was calculated using pedometers, and energy intake per day was evaluated using 3-day dietary records. Multiple linear regression analysis was used to assess the association between intermuscular adipose tissue and the number of metabolic syndrome risk factors.

RESULTS

Multiple regression analysis indicated that intermuscular adipose tissue was significantly associated with the number of metabolic syndrome risk factors, after adjusting for age, sex, body mass index, daily physical activity, energy intake, thigh muscle cross-sectional area, and visceral adipose tissue (p<0.05).

CONCLUSIONS

Thigh intermuscular adipose tissue accumulation was significantly associated with the number of metabolic syndrome risk factors in middle-aged and older Japanese adults, independent of age, sex, body mass index, daily physical activity, energy intake, thigh muscle cross-sectional area, and visceral adipose tissue.