Are higher protein intake and distribution of protein intake related to higher appendicular muscle mass among an older Japanese population?: A cross-sectional analysis of the National Health and Nutrition Survey 2017

AIM

Protein intake is an important component in retaining muscle mass, especially among older people. This study examined the relationship between total protein intake and/or the distribution of protein intake in each meal and appendicular muscle mass, using data from the National Health and Nutrition Survey (NHNS) in Japan.

METHODS

Data from the NHNS were re-analyzed in this study. We used data from a one-day dietary record, physical examination, and lifestyle questionnaire completed by 1766 participants aged over 60 years. Appendicular muscle mass was assessed by multiple-frequency bioimpedance measurement. Leucine intake was calculated by the weighted average amino acid content from all 98 food subcategories used in the NHNS, based on amino acid composition data in the 2020 Standard Tables of Food Composition.

RESULTS

Participants with higher protein intake showed significantly higher appendicular muscle mass. This relationship was independent of physical activity, including steps taken per day, exercise habit, and physical labor. Frequent intake of ≥0.4 g protein/kg/meal was not related to appendicular muscle mass. The combination of higher total protein intake and higher physical activity seemed to have the largest association with appendicular muscle mass.

CONCLUSIONS

Higher protein intake may be related to higher appendicular muscle mass, independent of higher physical activity, among older Japanese people. Geriatr Gerontol Int 2024; ••: ••-••.

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.

A scoping review of dietary assessment questionnaires potentially suitable for assessing habitual dietary intake in the National Health and Nutrition Survey, Japan

This scoping review aimed to identify questionnaire-based dietary assessment methods for use in the National Health and Nutrition Survey (NHNS) in Japan. The search was conducted in three databases (PubMed, Web of Science, and Ichushi) to identify questionnaire such as food frequency questionnaire and dietary history questionnaire validated against dietary recalls or food records for the intakes of both food groups and nutrients among Japanese adults. Study quality was assessed based on previously developed criteria. We extracted the questionnaire characteristics and the design and results of the validation studies. We identified 11 questionnaires, with the number of food items ranging from 40 to 196, from 32 articles of good quality. In the validation studies, participants were aged 30-76 years and 90% of the articles used ≥3 d dietary records as reference. The number of nutrients and food groups with a group-level intake difference within 20% against the reference method ranged from 1 to 30 and 1 to 11, respectively. The range of mean correlation coefficients between questionnaire and reference methods were 0.35-0.57 for nutrients and 0.28-0.52 for food groups. When selecting a survey instrument in the NHNS from the 11 existing questionnaires identified in this study, it is important to select one with high group-level comparison and correlation coefficient values on the intended assessment items after scrutinizing the design and results of the validation study. This review may serve as a reference for future studies that explore dietary assessment tools used for assessing dietary intake in specific representative populations.

Time Trends in Income-related Differences in Food Group Intakes: The National Health and Nutrition Survey, Japan in 2010, 2014, and 2018

BACKGROUND

We aimed to clarify whether differences in food group intake according to household income have changed over the last decade in Japanese people aged 20 years or older.

METHODS

This cross-sectional study was based on the 2010, 2014, and 2018 National Health and Nutrition Surveys in Japan. Food intake was assessed using a 1-day semi-weighed household dietary record. The participants were categorized into three groups based on their income. The mean of each food intake according to the income group was estimated by adjusting for age, occupation, and number of participants from the same household. The significance of the interaction terms between income and survey year was evaluated to assess the change in income-related differences in food intake over time.

RESULTS

Cereal intake was lower in the middle- and the highest-income groups than in the lowest-income group, regardless of sex, and the interaction between income and year was nonsignificant for cereal intake. In the former two surveys, vegetable intake was higher among the highest-income women, while in the 2018 survey, the vegetable intake decreased in the women in the middle- and the highest-income groups. The interaction between income and year was significant for vegetable intake among the women. For other foods, the differences in intake among the income groups did not significantly change over time.

CONCLUSION

The tendency for lower cereal intake in the higher-income groups was consistent over time in both the sexes, and the tendency for higher vegetable intake in the highest income women disappeared over time.

Factors associated with physical growth status among children aged 12-59 months in the Japanese National Growth Survey on Preschool Children: A retrospective analysis

This study aimed to examine the factors associated with physical growth status among children aged 12-59 months in Japan. Data from the 2010 National Growth Survey on Preschool Children, a nationwide cross-sectional survey, were used for this analysis (n = 4196). After adjustment for confounding factors, multiple logistic regression analyses showed that boys who were born small-for-gestational-age were more likely to be underweight (adjusted odds ratio [aOR]: 12.55, 95% confidence interval [CI]: [6.76-23.3], p < 0.001), stunted (aOR: 5.78, 95% CI: [3.48-9.60], p < 0.001) and wasted (aOR: 7.02, 95% CI: [3.30-15.0], p < 0.001), while boys who were large-for-gestational-age were less likely to be stunted (aOR: 0.26, 95% CI: [0.11-0.60], p < 0.01). Girls who were born small-for-gestational-age were more likely to be underweight (aOR: 5.42, 95% CI: [2.73-10.7], p < 0.001), stunted (aOR: 4.04, 95% CI: [2.43-6.73], p < 0.001) and wasted (aOR: 6.27, 95% CI: [2.55-15.4], p < 0.001), while girls who were large-for-gestational age were more likely to be overweight (aOR: 5.90, 95% CI: [1.64-21.3], p < 0.001). Moreover, the following factors were associated with the physical growth status in children: maternal prepregnancy body mass index, complications during pregnancy, continuous breastfeeding, initiation age of complementary feeding, smoking status of the father or those living with the mother during pregnancy and birth order. Further research is needed to expand support for high-risk families and to verify their effectiveness.

[Corrigendum: How accurate are self-reported anthropometrics among the Japanese? A scoping review]

　Nihon Koshu Eisei Zasshi(JAPANESE JOURNAL OF PUBLIC HEALTH), Vol. 70 (2023) No. 12 pp.817-827.

[How accurate are self-reported anthropometrics among the Japanese? A scoping review]

Objectives　Monitoring of obesity and underweight prevalence in general populations is crucial for the implementation of effective public health measures. Self-reported height and weight values are often used to assess the body mass index (BMI) in such epidemiological surveillance. However, it is known that using self-reported height and weight may underestimate the prevalence of obesity (BMI≥25 kg/m2), while its accuracy for underweight (BMI<18.5 kg/m2) prevalence is not well-understood. The aim of this study was to conduct a scoping review on the accuracy of self-reported anthropometrics in the Japanese population, where both obesity and underweight are prevalent.Methods　Using PubMed and CiNii Research, a literature search was conducted for studies published in English or Japanese by 2022 that were conducted in Japan and compared self-reported and measured height, weight, or/and BMI. The study design and mean reported errors (mean of reported values－mean of measured values) were extracted and tabulated, and differences by BMI categories were also considered.Results　A total of 17 studies, with 11 being published in English, were included in this review. These studies were conducted in nationwide cohort studies (n=4), local populations (n=4), workplaces (n=3), and educational institutions (n=6), with diverse age ranges (10-91 years) and sample sizes (<100 to >30,000). Although the degree of mean reporting error varied between studies, most of the studies reported that height was overreported, weight was underreported, and BMI was underestimated. In the three studies that reported mean reporting errors by BMI category, the direction of reporting error for height remained consistent across all body size categories, while weight and BMI were overreported and overestimated only among the underweight. Four studies in adults showed that 14.2-37.6% of actually obese individuals and 11.1-32.3% of underweight individuals were misclassified as 'normal range' (18.5≤BMI<25 kg/m2) based on self-reporting, while 0.8-5.4% and 1.2-4.1% of individuals actually within the normal range were misclassified as 'underweight' and 'obese' based on self-report, respectively.Conclusion　This study suggests that using BMI based on self-reported height and weight can underestimate the prevalence of both obesity and underweight in the Japanese population. These biases should be taken into consideration when using self-reported anthropometrics in epidemiological studies.

National Nutrition Surveys Applying Dietary Records or 24-h Dietary Recalls with Questionnaires: A Scoping Review

Development of an accurate and efficient dietary method is required for national nutrition surveys. Some countries conduct dietary surveys and combine 24-h dietary records or 24-h dietary recalls with dietary questionnaires. This scoping review aimed to summarize studies that used results from national surveys that combined detailed dietary surveys (dietary records or 24-h dietary recall) and dietary questionnaires and identify the purpose of combining the two methods. The PubMed database and manual searches were used for the literature review. We extracted 58 articles from 16 national nutrition surveys from 14 countries. Most studies used 24-h dietary recall for detailed dietary surveys and the food frequency questionnaire (FFQ) or food propensity questionnaire (FPQ) for questionnaire surveys. Among 37 studies from eight countries, the purpose of combining the two dietary survey methods was to estimate energy and nutrient intakes from detailed dietary surveys and habitual food intake from questionnaires. These findings are useful as a reference when introducing new dietary survey methods in future national nutrition surveys.

Trends in Mean Energy and Nutrient Intakes in Japanese Children and Adolescents: The National Health and Nutrition Survey, 1995-2019

This study aimed to describe the national trends in mean energy and nutrient intakes in Japanese children and adolescents from 1995 to 2019. We used data obtained from the National Health and Nutrition Survey and included 54,871 participants aged 1-19 years. The dietary intake was estimated using a 1-day, semi-weighed, household-based, dietary record. The trends of mean energy and nutrient intakes were analyzed using the Joinpoint Regression Program. A declining trend in the mean energy intake was observed in toddlers aged 1-6 years, school girls aged 7-14 years, and adolescent girls aged 15-19 years, while the mean energy intake from protein, fat, and carbohydrates changed little over time. The mean salt equivalent showed a decreasing trend in all age groups, although the 2019 mean values were above the tentative dietary goal for preventing lifestyle-related diseases, especially in adolescent boys. Declining trends in mean vitamin (vitamin A, vitamin B12, folate, vitamin D, and vitamin K) and mineral (calcium, iron, and copper) intakes were observed, while trends in the mean vitamin B6 and zinc intakes were unchanged since 2001. Continuous monitoring of dietary intake and further research are required to raise awareness of unhealthy diet habits and to improve the food environment for the healthy growth and development of children and adolescents.

Current Findings from the Japan National Health and Nutrition Survey

In this Special Issue, six articles using the Japan National Health and Nutrition Survey (NHNS) were published [...].

Diet Quality and Its Relationship with Weight Characteristics in Pregnant Japanese Women: A Single-Center Birth Cohort Study

Maternal underweight and inadequate gestational weight gain (GWG) are problems in Japan. However, increases in food intake aimed at weight gain alone are not sufficient for mother-child health. This study assessed diet quality based on the 3-day dietary records of pregnant women in an urban area of Japan in order to show the importance of evaluating diet quality, using the Nutrient-Rich Food Index 9.3 (NRF9.3), which is one metric based on nutrition profiling, and the Japanese Food Guide Spinning Top (JFGST). After excluding misreporters of energy intake, we stratified women (n = 91) by pre-pregnancy body mass index (BMI) and determined energy intake, diet quality status, and their relationship with GWG. Intakes of carbohydrate-containing staple foods, vegetable dishes, and fruit were insufficient regardless of BMI. Most of the underweight women with inadequate GWG had insufficient energy intake but high diet quality, as assessed by NRF9.3. In contrast, most women who consumed energy within the recommended range had low diet quality and gained weight at inappropriate levels. These results highlight the importance for pregnant Japanese women to maintain diet quality through a nutrient-dense diet, while simultaneously increasing energy intake after evaluation of their individual diet quality.

Validation of Dietary Intake Estimated by Web-Based Dietary Assessment Methods and Usability Using Dietary Records or 24-h Dietary Recalls: A Scoping Review

The goal was to summarize studies comparing the accuracy of web-based dietary assessments with those of conventional face-to-face or paper-based assessments using 24-h dietary recall or dietary record methods in the general population. Using two databases, mean differences and correlation coefficients (CCs) for intakes of energy, macronutrients, sodium, vegetables, and fruits were extracted from each study independently by the authors. We also collected information regarding usability from articles reporting this. From 17 articles included in this review, the mean dietary intake differences in the web-based dietary assessment compared to conventional methods, were -11.5-16.1% for energy, -12.1-14.9% for protein, -16.7-17.6% for fat, -10.8-8.0% for carbohydrates, -11.2-9.6% for sodium, -27.4-3.9% for vegetables, and -5.1-47.6% for fruits. The CC was 0.17-0.88 for energy, protein, fat, carbohydrates, and sodium, and 0.23-0.85 for vegetables and fruits. In three out of four studies reporting usability, more than half of the participants preferred the web-based dietary assessment. In conclusion, % difference and CC of dietary intake were acceptable in both web-based dietary records and 24-h dietary recalls. The findings from this review highlight the possibility of wide-spread application of the web-based dietary assessment in the future.

Global Comparison of Nutrient Reference Values, Current Intakes, and Intake Assessment Methods for Sodium among the Adult Population

Excess sodium intake is a risk factor for non-communicable diseases (NCDs), such as cardiovascular diseases and hypertension. Therefore, many countries have set nutrient reference values for sodium, specifically for the prevention of NCDs, and intake is routinely monitored by nutrition surveys. In this review, we aimed to compare the global nutrient reference values and national intakes of sodium, along with the methods of intake assessment used. Data were obtained for Australia, Canada, Ireland, Japan, the UK, the US, and the European Food Safety Authority (EFSA), where information was accessible online in English or Japanese. We collected the following information regarding sodium intake: the term used for reference values to prevent NCDs; year when reference values were established or revised; reference values to prevent NCDs; target NCDs; designation of nutrition survey; method for estimating intake; and average intake. The reference values ranged from 2,000 mg (Australia and EFSA) to 2,953 mg (Japan). Sodium intake ranged from 2,431 mg (Australia) to 3,958 mg (Japan). Out of seven countries/institutions, five used dietary assessment, and two used sodium urinary excretion for estimating dietary sodium intake. Among the dietary assessment methods, the 24-h dietary recall was most frequently used. National sodium intake exceeded the reference values in all countries, and reduction of sodium intake remains a global challenge.

Nutritional Adequacy Assessment of the Japanese Diet Using the Number of Dishes Compared to Existing Dietary Diversity Indices: A Cross-Sectional Analysis from the 2012 National Health and Nutrition Survey, Japan

The Japanese diet has attracted attention as a factor contributing to the Japanese population's longevity. A typical Japanese meal, traditionally called "ichiju-sansai," is composed of various dishes. This study assessed the nutritional adequacy of the Japanese diet using the number of dishes in all meals (NDAM) compared to existing dietary diversity indices (DDIs). This cross-sectional study used data from the 2012 National Health and Nutrition Survey. A total of 25,976 participants aged ≥20 y were included in this study. NDAM was calculated for whole dishes or single foods (except supplements and beverages) from one-day weighted dietary records. The food variety score (FVS), number of foods, dietary diversity score (DDS), and number of food groups are some of the existing DDIs. NDAM had relatively high positive correlation coefficients with potassium, magnesium, and dietary fiber. The partial correlation coefficients with an indicator of the overall nutrient adequacy of NDAM was 0.42 for men and 0.42 for women. It was almost the same as that of the FVS (men: 0.44, women: 0.42) and DDS (men: 0.44, women: 0.43). On the other hand, NDAM, similar to existing DDIs, was also positively correlated with nutrient restriction in both sexes. These findings indicate that the nutrient adequacy of NDAM is similar to that of the existing DDIs. Because of the higher sodium intake and cholesterol intake in higher NDAM and existing DDIs, the effect of higher NDAM on health outcomes must be investigated in future studies.

Association of daily nutrient intake with breakfast and snack consumption among young Japanese adults aged 20-39 years: data from the 2012 National Health and Nutrition Survey

Eating frequency has been associated with nutrient intake and diet quality. The aim of this study was to examine the association between daily nutrient and food group intake and consumption of breakfast and/or snacks among young Japanese adults, as secondary analysis of the 2012 National Health and Nutrition Survey in Japan involved 1420 men and 1659 women aged 20-39 years. Dietary intake data were collected using a one-day semi-weighed household dietary record. Participants were classified into four groups based their breakfast and snack consumption, defined as the consumption of any food or beverage that contained energy based on participant-defined eating occasions; both breakfast and snack consumption (B+S+), breakfast consumption without snacking (B+S-), breakfast skipping and snack consumption (B-S+) and breakfast skipping without snacking (B-S-). The proportion of breakfast skippers among men and women was 11·8 % and 6·6 %, whereas that of snack consumers among men and women was 55·3 % and 68·2 %, respectively. Energy, Mg potassium (in both sexes), vitamin B2, Ca, (only men) and folate and dietary fibre (only women) intakes were higher among breakfast and snack consumers than in the B+S- group. The nutrient intake level of the B+S- group was similar to that of the B-S+ group, whereas the B-S- group had lower energy (both sexes), Cu, dietary fibre and potassium (only women) intakes than the B+S- group. Snack consumption could supplement nutrients that may not be adequately consumed by three meals among young Japanese adults.

Determination of Optimal Daily Magnesium Intake among Physically Active People: A Scoping Review

Little is known about the optimal daily magnesium (Mg) intake for individuals with high levels of physical activity. The aim of this study was to clarify the optimal dietary Mg intake for people with high levels of physical activity in a scoping review. In this review, we searched MEDLINE and Japan Medical Abstracts Society for studies published up to May 31, 2020. We conducted two searches, one for studies using gold standard measurement methods such as the balance method and factorial calculation (Search 1), and the other for studies using estimation from daily food intake (Search 2). We also performed a meta-analysis of studies that compared the Mg intake among physically active people with the Mg intake among controls. After the primary and secondary screening, 31 studies were included in the final review. All of the included studies examined professional or recreational athletes. We found no studies that examined the optimal intake of Mg using gold standard measurement methods. The Mg intake among physically active individuals was below the recommended dietary allowance in most studies. In five studies that conducted meta-analyses, physically active individuals had significantly higher intakes of Mg than controls, although these levels were still below the recommended dietary allowance. The present review revealed that evidence regarding the optimal daily magnesium intake is currently scarce, and further studies are needed.

A Scoping Review of Epidemiological Studies on Intake of Sugars in Geographically Dispersed Asian Countries: Comparison of Dietary Assessment Methodology

Previous systematic reviews, which focused on sugar intake and its relation with health issues, were mainly conducted in Western countries, not Asian countries characterized by differences in dietary habits and disease prevalence. The scarcity of Asian studies may be attributed to the lack of assessment tools for estimating sugar intake. To provide an overview of the epidemiological studies on sugar intake in Asian countries, with a primary focus on dietary assessment methodology for estimating sugar intake, we conducted a scoping review of the epidemiological studies estimating sugar intake in Asian countries (the United Nations' definition) and Taiwan using PubMed and Web of Science. Study quality was evaluated based on its assessment of sugar intake in the whole diet, dietary assessment methods, and data sources used for estimating sugar content. We identified 143 studies from 136 publications from Eastern (n = 63), Southern (n = 30), South-Eastern (n = 26), and Western (n = 24) Asia. Total sugars were investigated in 95 studies, while 23-30 studies investigated sucrose, fructose, added sugars, and free sugars. The main aim of the selected studies was assessment of diet-disease relations (n = 85) and estimation of dietary intake (n = 40), and 62 studies assessed sugars as the primary exposure/outcome. A total of 120 studies assessed sugar intake in the whole diet, and 62 studies used validated FFQs or multiple-day dietary assessment methods. Only 41 studies used country-specific comprehensive food-composition databases or directly measured sugar content. Only 17 studies reported high-quality data. This review elucidated a sufficient number of epidemiological studies estimating sugar intake across Asian countries; however, most studies reported low-quality data. The results from our review showed that both feasible and validated dietary assessment methods, as well as comprehensive country-specific sugar-composition databases, are essential for producing high-quality studies with accurate sugar intake to examine its association with health outcomes.

[A literature review on the relationship between questionnaires for assessing minor health complaints and health status indices among Japanese people]

Objectives　Minor health complaints related to stress, mental health, sleep, and fatigue are closely associated with each other, and their deterioration may cause lifestyle diseases. The health status of people can be predicted through a questionnaire by exploring the relationship between their state of minor health complaints and objective health status indices. Therefore, we conducted a systematic review of the relationship between a questionnaire on the state of minor health complaints and health status indices among Japanese people who have a high level of stress, which they experience on a daily basis, using epidemiological literature. Additionally, we considered items for the questionnaire which were necessary for an index development.Methods　The PubMed database was searched for papers on "autonomic nervous system," "sleep disorders," "mental health and stress," and "fatigue," using keywords mentioned in previous studies on minor health complaints.　The extracted research papers were screened according to the following inclusion criteria: 1) the participants were healthy Japanese people; 2) descriptions included characteristics of the target population; 3) use of analytic epidemiological study design, intervention studies, and systematic reviews; 4) minor health complaints assessed by a questionnaire; 5) evaluation of the relationship between the questionnaires for minor health complaints and the health index; and 6) written in Japanese or English. Based on this, ten papers were adopted.Results　Of the 10 papers collected, one was a cohort study, three were case-control studies, and six were cross-sectional studies. The participants in five of them were working adults. Reports on three out of six questionnaires on stress, four out of seven on sleep, and all two on comprehensive health status showed significant associations between minor health complaints assessed by the questionnaires and the index for health status. The increase in responses about work-related stress from the questionnaire was associated with an increase in the "risk of developing depression" [odds ratio 2.96 (confidence interval: 1.04-8.42)]. Poor sleep quality was associated with an increase in "changes in autonomic index," "number of comorbidities and the rate of depression," and the "risk of work-related injuries." Moreover, the health score was associated with the "autonomic nervous system index".Conclusion　These results suggest that a questionnaire evaluating minor health complaints should include questions about "stress," "sleep quality," and "comprehensive health status." Since studies that appropriately adopted for risk of bias were limited, it is necessary to further examine these relationships by applying prospective studies such as cohort studies and intervention studies.

Trends in dietary salt sources in Japanese adults: data from the 2007-2019 National Health and Nutrition Survey

Identifying trends in dietary salt sources is essential for effectively reducing salt/Na intake. This study aimed to examine the trends in dietary salt sources among Japanese adults using the 2007-2019 National Health and Nutrition Survey data collected from 95 581 adults aged ≥ 20 years. Dietary intake was estimated using the 1-d household-based dietary record. Foods reported as potential sources of salt intake in Japan and other countries were categorised into twenty-one groups. Salt intake for each food group was adjusted using the density method based on the energy intake. Trends in dietary salt intake based on food sources by sex and age groups (20-39 years, 40-59 years and ≥ 60 years) were analysed using the Joinpoint Regression Program. Salt intake for each age group in both men and women decreased from 2007 (5·3 g/1000 kcal-6·4 g/1000 kcal) to 2019 (4·9 g/1000 kcal-5·6 g/1000 kcal). The major dietary source of salt continued to be seasonings such as soya sauce and soyabean paste (approximately 70 %). Salt intake from seasonings decreased over time in adults aged ≥ 40 years but did not change in those aged 20-39 years. Additionally, a decreasing salt intake from unprocessed fish and shellfish and an increasing salt intake from unprocessed meat were observed across all age categories for both sexes. This study demonstrated that a strategy targeting different age groups may be needed to reduce salt consumption from seasonings among the Japanese population. Further studies on salt content in seasonings and continued monitoring of trends in dietary salt sources are required.

Adult height in relation to the risk of colorectal cancer among the Japanese population: an evaluation based on systematic review and meta-analysis

OBJECTIVE

The association between adult-attained height and risk of colorectal cancer remains elusive among the Japanese population. We performed a systematic review and meta-analysis of epidemiological studies in Japan.

METHODS

We systematically searched the MEDLINE (PubMed) and Ichushi databases and complemented it with manual search to identify eligible studies. We extracted relative risks or odds ratios from the selected studies and conducted meta-analysis to estimate the summary relative risk with 95% confidence interval. We made the final judgment based on a consensus of the research group members considering both epidemiological evidence and biological plausibility.

RESULTS

This systematic review identified four cohort and one case-control studies among the Japanese. The meta-analysis of these five studies showed the summary relative risk of 1.21 (95% confidence interval: 1.07-1.35) of overall colorectal cancer for the highest vs. lowest categories of height. In the analysis by the cancer subsite, the association was significant for colon cancer with a summary relative risk of 1.26 (95% confidence interval: 1.10-1.45) but not for rectal cancer 1.05 (95% confidence interval: 0.71-1.54). In the analysis by sex, tall stature was associated with a significantly increased risk of overall colorectal cancer in both sexes; the summary relative risk was 1.21 (95% confidence interval: 1.04-1.41) in men and 1.20 (95% confidence interval: 1.00-1.44) in women, respectively.

CONCLUSIONS

The evidence to support that adult-attained height is associated with increased risk of colorectal cancer (colon cancer) among the Japanese population is 'probable'.

Trimester-specific associations between extracellular vesicle microRNAs and fetal growth

OBJECTIVE

Placenta-derived extracellular vesicles and their cargoes, especially microRNAs (EV-miRNAs), may contribute to fetal and placental development. During pregnancy, the levels of several maternal blood EV-miRNAs, including miRNAs of placental origin, vary among individuals and change throughout gestation. However, the effects of these miRNAs on fetal growth and trimester-specificity have not been fully elucidated. The purpose of this study is to test the hypothesis that the serum levels of two extracellular vesicles (EV)-miRNAs (miR-127-3p and miR-26b-5p), which may be involved in fetoplacental regulation, would be significantly associated with fetal growth in a trimester-specific manner.

MATERIALS AND METHODS

This is a single-center birth cohort of maternal serum samples obtained at both the second and third trimesters. To minimize the influence of confounding factors, the analysis was limited to singleton vaginal deliveries, resulting in 27 participants being included in this study. EV RNAs were isolated using a membrane affinity method, and the relative expression levels of miR-127-3p and miR-26b-5p were measured using the RT-qPCR method with miR-484 as control. The associations between the two EV-miRNAs and fetal and placental growth were evaluated using a linear regression model and compared between the two trimesters.

RESULTS

EV-miR-127-3p levels tended to correlate inversely with the z-scores of birth weight for gestational age (BWGA) and placental weight for gestational age (PWGA) in the second trimester, but not in the third trimester. EV-miR-26b-5p levels were positively associated with birth weight in the second trimester, but this association was weakened in the third trimester.

CONCLUSION

Our results suggest a trimester-specific association of circulating miRNA levels with fetal and placental growth. The precise roles of EV-miR-127-3p and EV-miR-26b-5p in fetal and placental development warrant further investigation.

Placenta mediates the effect of maternal hypertension polygenic score on offspring birth weight: a study of birth cohort with fetal growth velocity data

BACKGROUND

Low birth weight (LBW) and fetal growth restriction are associated with the development of cardio-metabolic diseases later in life. A recent Mendelian randomization study concluded that the susceptibility of LBW infants to develop hypertension during adulthood is due to the inheritance of hypertension genes from the mother and not to an unfavorable intrauterine environment. Therein, a negative linear association has been assumed between genetically estimated maternal blood pressure (BP) and birth weight, while the observed relationship between maternal BP and birth weight is substantially different from that assumption. As many hypertension genes are likely involved in vasculature development and function, we hypothesized that BP-increasing genetic variants could affect birth weight by reducing the growth of the placenta, a highly vascular organ, without overtly elevating the maternal BP.

METHODS

Using a birth cohort in the Japanese population possessing time-series fetal growth velocity data as a target and a GWAS summary statistics of BioBank Japan as a base data, we performed polygenic score (PGS) analyses for systolic BP (SBP), diastolic BP, mean arterial pressure, and pulse pressure. A causal mediation analysis was performed to assess the meditation effect of placental weight on birth weight reduced by maternal BP-increasing PGS. Maternal genetic risk score constituted of only "vasculature-related" BP single nucleotide polymorphisms (SNPs) was constructed to examine the involvement of vascular genes in the mediation effect of placental weight. We identified gestational week in which maternal SBP-increasing PGS significantly decreased fetal growth velocity.

RESULTS

We observed that maternal SBP-increasing PGS was negatively associated with offspring birth weight. A causal mediation analysis revealed that a large proportion of the total maternal PGS effect on birth weight was mediated by placental weight. The placental mediation effect was remarkable when genetic risk score was constituted of "vasculature-related" BP SNPs. The inverse association between maternal SBP PGS and fetal growth velocity only became apparent in late gestation.

CONCLUSIONS

Our study suggests that maternal hypertension genes are strongly associated with placental growth and that fetal growth inhibition is induced through the intrauterine environment established by the placenta.

Associations of Emotional Behavior with Nutritional Status and Lifestyle Habits among Schoolchildren Aged 5-10 Years in Sri Lanka

We aimed to examine the relationships of lifestyle habits and nutritional status with emotional behavior among schoolchildren in Sri Lanka. Five hundred and eight schoolchildren (195 boys and 313 girls) aged 5–10 years were included. Emotional and behavioral problems were assessed using the Strengths and Difficulties Questionnaire. Nutritional status was used for body mass index-for-age z-score. Breakfast consumption, daily moderate- to vigorous-intensity physical activity (MVPA), wake-up time, and bedtime were considered lifestyle habits. The mean total difficulties score ± standard deviation was 12.0 ± 5.3, and the mean prosocial behavior score was 7.4 ± 1.9. In total, 89.2% children ate breakfast, and 41.3% engaged in at least 60 min of MVPA per day. After adjustment for confounding factors, multiple logistic regression analyses showed that breakfast skipping was associated with high scores on conduct problems (adjusted odds ratio (aOR) = 2.95, 95% confidence interval (CI): 1.50 to 5.77, p < 0.01) and that late bedtime was related to low prosocial behavior scores (aOR = 2.43, 95% CI: 1.17 to 5.03, p < 0.05). Our findings suggest that promoting regular lifestyle habits helps reduce psychological difficulties in schoolchildren. However, further research, including longitudinal studies, are required to identify the mechanism underlying this relationship.

874Impact of overweight on diabetes prevalence: 20-year trends in National Health and Nutrition Survey, Japan

Background

Increasing trend of diabetes is significant public health threats. This is a consecutive cross-sectional study aimed to estimate the attribution of overweight for diabetes prevalence in Japan.

Methods

We used individual data aged 20 years and older of National Health and Nutrition Survey in 1997 (2349 men and 3588 women), 2002 (2075 and 3087), 2007 (1614 and 2346), 2012 (5538 and 7981), and 2016 (4327 and 6270). Diabetes was defined as glycated haemoglobin (HbA1c) &gt;6.5% or currently being treated. We estimated multivariable-adjusted odds ratio (OR) and 95% confidence interval (CI) for the association between diabetes and overweight (body mass index &gt;25kg/m2) after adjusting for the number of steps per day, total energy intake (kcal/kg), fat energy ratio (%), smoking and drinking status by logistic regression.

Results

There was significant association between diabetes and overweight in all years: multivariable-adjusted OR (95%CI) were 1.78 (1.32-2.40) in 1997, 1.46 (1.10-1.93) in 2002, 1.77 (1.35-2.32) in 2007, 1.79 (1.55-2.07) in 2012, and 2.15 (1.82-2.54) in 2016 for men and 2.53 (1.92-3.32), 2.53 (1.87-3.42), 2.91 (2.15-3.95), 2.94 (2.51-3.45), and 2.72 (2.27-3.25), for women, respectively. The estimated population attribution on diabetes prevalence due to overweight was 14.8%, 11.9%, 18.1%, 18.0%, and 24.6% for men and 27.0%, 29.4%, 29.9%, 29.5%, and 26.7% for women.

Conclusions

Overweight was a risk factor for diabetes consistently for 20 years. That attribution was increasing among men but decreasing after peaking in 2007 among women.

Key messages

The present study suggested a high burden of diabetes due to overweight in Japan.

Protocol for an interventional study to reduce postpartum weight retention in obese mothers using the internet of things and a mobile application: a randomized controlled trial (SpringMom)

BACKGROUND

Obese pregnant women are known to experience poorer pregnancy outcomes and are at higher risk of postnatal arteriosclerosis. Hence, weight control during and after pregnancy is important for reducing these risks. The objective of our planned randomized controlled trial is to evaluate whether the rate of change in body weight in obese women before pregnancy to 12 months postpartum would be lower with the use of an intervention consisting of Internet of Things (IoT) devices and mobile applications during pregnancy to 1 year postpartum compared to a non-intervention group.

METHODS

Women will be recruited during outpatient maternity checkups at four perinatal care institutions in Japan. We will recruit women at less than 30 weeks of gestation with a pre-pregnancy body mass index ≥ 25 kg/m². The women will be randomly assigned to an intervention or non-intervention group. The intervention will involve using data (weight, body composition, activity, sleep) measured with IoT devices (weight and body composition monitor, activity, and sleep tracker), meal records, and photographs acquired using a mobile application to automatically generate advice, alongside the use of a mobile application to provide articles and videos related to obesity and pregnancy. The primary outcome will be the ratio of change in body weight (%) from pre-pregnancy to 12 months postpartum compared to before pregnancy.

DISCUSSION

This study will examine whether behavioral changes occurring during pregnancy, a period that provides a good opportunity to reexamine one's habits, lead to lifestyle improvements during the busy postpartum period. We aim to determine whether a lifestyle intervention that is initiated during pregnancy can suppress weight gain during pregnancy and encourage weight loss after delivery.

TRIAL REGISTRATION

UMIN: UMIN (University hospital Medical Information Network) 000,041,460. Resisted on 18^th August 2020. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000047278.

Application of the Nutrient-Rich Food Index 9.3 and the Dietary Inflammatory Index for Assessing Maternal Dietary Quality in Japan: A Single-Center Birth Cohort Study

The maternal diet can potentially influence the life-course health of the child. A poor-quality maternal diet creates nutrient deficiencies and affects immune–metabolic regulation during pregnancy. The nutrient-based overall dietary quality can be assessed using the Nutrient-Rich Food Index 9.3 (NRF9.3), which measures adherence to the national reference daily values of nutrient intake. Pro- and anti-inflammatory nutrient intake can be assessed using the energy-adjusted dietary inflammatory index (E-DII), a comprehensive index of diet-derived inflammatory capacity. Using these indices, we assessed the overall dietary quality and inflammatory potential of pregnant women during mid-gestation in an urban area of Japan (n = 108) and found that there was a strong inverse correlation between the NRF9.3 and E-DII scores. Comparison of the scores among the tertiles of NRF9.3 or E-DII indicated that dietary fiber, vitamin C, vitamin A, and magnesium mainly contributed to the variability of both indices. Intake of vegetables and fruits was positively associated with high NRF9.3 scores and negatively associated with high E-DII scores, after adjustment for maternal age, pre-pregnancy body mass index, and educational level. Consistent with the previous studies that used dietary pattern analysis, this study also demonstrated that vegetables and fruits were the food groups chiefly associated with high dietary quality and low inflammatory potential among pregnant Japanese women.

Nutrient Profiles of Dishes Consumed by the Adequate and High-Salt Groups in the 2014-2018 National Health and Nutrition Survey, Japan

Dish-based nutrient profile analyses are essential for setting goals to achieve a balanced diet. In 2014, the Japanese government proposed the “Healthy Meal” criteria, which requires a salt content of 3 g/650 kcal per meal. To examine the current intake status of a nationally representative sample, we conducted a series of secondary analyses of the 2014–2018 National Health and Nutrition Survey data. Participants (aged 18–74 years) were grouped as “high-salt” consumers if their salt intake was 3 g/650 kcal or higher and “adequate” consumers if they consumed less than 3 g/650 kcal. A total of 13,615 participants were identified as “adequate” consumers and 22,300 as “high-salt” consumers. The median salt intake in the “high-salt” group was 11.3 g/day, while that in the “adequate” group was 7.5 g/day. Almost all dishes consumed by the “adequate” group had significantly high energy and fat content but low salt content, compared with those consumed by the “high-salt” group. For example, the median energy, fat, and salt contents in the main dishes consumed by the “adequate” group were 173 kcal, 10.4 g, and 0.9 g/dish, respectively, while those in the main dishes consumed by the “high-salt” group were 159 kcal, 8.9 g, and 1.1 g/dish, respectively. Examples of balanced dishes that are low in both salt and fat content can be proposed to help improve the Japanese consumers’ dietary behavior.

Dietary Intake and Its Patterns Across Summer and Winter Seasons in Hokkaido, Japan

Objectives

The Japanese diet pattern is closely associated with seasonal supply, but there are limited studies on how seasonal changes affect dietary intake in Japan. Hokkaido, located in the northernmost tip of Japan, is a region with abundant dairy and agricultural produce. The diet in Hokkaido may be sensitive to the seasonal supply. This study aimed to assess the effect of seasons on the intake of different nutrients and food groups among the adults of Hokkaido, Japan.

Methods

This study examined the data of adults aged 20–79 years, who participated in the “Sukoyaka-kenko-chosa,” a longitudinal study in Hokkaido, Japan. The participants completed a 1-day dietary food record, and all meals were recorded using a digital camera. Food consumption data were collected from 521 participants in summer and winter in 2019. Intake of various nutrients and food groups were estimated and compared between the two seasons.

Results

The nutrient intake of the participants was found to be lower in carbohydrates but higher in calcium and fat as compared to the National Health and Nutrition Examination Survey results in Japan. On the other hand, seasonal variations were found between summer and winter. The consumption of vegetables and dairy products was lower in winter than in summer, but that of cereals was higher in winter. The intake of vitamin K, folic acid, and potassium was lower and that of carbohydrates was higher in winter than in summer.

Conclusions

Seasonal changes of dietary intake were observed in Hokkaido, Japan. Our results suggest that the estimation method of the average dietary intake across the whole year by conducting dietary survey in one season only is insufficient and warrants further study.

Funding Sources

This work was supported by Cabinet Office, Government of Japan, Cross-ministerial Strategic Innovation promotion Program (SIP), “Technologies for Smart Bo-industry and Agriculture” (funding agency: Bio-oriented Technology Research Advancement institution, NARO).

Nutrient Profiles of Dishes Eaten by High Salt Consumers and Adequate Salt Consumers in the 2013–2018 National Health and Nutrition Survey, Japan

Objectives

Dish based nutrient profile analyses are essential in setting goals to achieve a balanced diet. The Japanese enjoy longevity, but their current diet is still high in salt, which was 10.1g/day among adults in the 2019 National Health and Nutrition Survey. In 2013, the Japanese government's “Health Meal” proposed the salt content of 3g/650 kcal per meal. However, studies are scarce regarding the nutrient profiles of the dishes eaten by the general population, especially who exceed the current standard. In order to examine the current achievement status and related nutritional problems among a nationally representative sample, we conducted the secondary analyses of the 2013–2018 National Health and Nutrition Survey data.

Methods

Dietary data from 35,915 participants in the 2013–2018 National Health and Nutrition Survey aged 18–74 years who ate three meals on the survey day, were applied for analyses. We extracted 554,257 dishes from each meal, and categorized them according to the definition of “staple dish” (grain dish), “main dish”(meat, fish, eggs, or beans), and “side dish”(vegetables, seaweeds, potatoes, or mushrooms) shown in the 2005 “Japanese Food Guide Spinning Top”. Participants were grouped as “high salt” consumers if their intake were 3g/650kcal or higher, and “adequate” consumers if they consumed less. The nutrient profile of each dish category was compared between the two groups by using the Wilcoxon's signed rank test.

Results

22 300 participants were identified as “high salt” and 13 615 as “adequate”. The mean age of the “high salt” group (53.2 years) was higher than the “adequate” group (50.5 years), but their mean energy intake was similar (1901 and 2081 kcal/day, respectively). The mean salt intake in the “high salt” group was 11.8 g/day and the “adequate” group was 7.7 g/day. Among the dishes, 59 936 were categorized as “staple dish”, 47 081 as “main dish”, 45 828 as “side dish”, 30 151 as “combined dish”, and 371 261 as “miscellaneous”. Except for “staple dish”, dishes consumed by the “high salt” group were significantly low in energy and fat but high in salt, compared to the “adequate”.

Conclusions

Older participants were more likely to consume dishes high in salt, but low in fat. Examples of balanced dishes low in both salt and fat could be proposed for further diet modification.

Funding Sources

Ministry of Health, Labour and Welfare research grant.

[Prevalence of frailty and its related factors in community-dwelling middle-aged and elderly adults in Settsu and Hannan cities in Osaka prefecture]

Objectives　The purpose of this study was to examine the prevalence of frailty and its associated factors in community-dwelling middle-aged and elderly adults in Settsu and Hannan cities, which are located in the north and south of Osaka prefecture, respectively.Methods　We conducted a mailed, self-administered, questionnaire survey of individuals aged 40 years and older in Settsu city in 2019 and Hannan city in 2020. There are 10 primary school districts in Settsu city and 8 districts in Hannan city, from each of which 1,000 people were selected according to the age and sex structures of the districts. We included 5,134 individuals from Settsu city and 3,939 individuals from Hannan city. We defined frailty using self-reported questionnaires, the Kihon Checklist (KCL), and Simple Frailty Index (SFI). Multivariate logistic regression analysis was performed for each city to examine the association of frailty with age, sex, body mass index (BMI), family structure, subjective health, economic status, subjective physical fitness, sleeping status, smoking history, alcohol use, meal frequency and awareness of the word "frailty."Results　The average age (standard deviation) of participants was 62.7 (12.5) years in Settsu city and 63.4 (12.2) years in Hannan city. The prevalence of frailty by KCL was 18.7% and 17.9% for participants in their 40s, 18.2% and 14.6% for those in their 50s, 17.0% and 15.7% for those in their 60s, 25.4% and 20.8% for those in their 70s, 39.7% and 36.1% for those 80 years and older from Settsu and Hannan cities, respectively. Using SFI, the prevalence of frailty was 16.2% and 13.5% for participants in their 40s, 15.0% and 11.9% for those in their 50s, 12.5% and 10.0% for those in their 60s, 14.6% and 12.3% for those in their 70s, and 24.7% and 22.3% for those aged 80 years and older in Settsu and Hannan cities, respectively. Significant common independent variables associated with frailty as defined using the KCL and SFI in Settsu and Hannan cities were age, subjective health, economic status, subjective physical fitness, sleeping status, and awareness of the word "frailty."Conclusion　This study found some participants to be frail as early as their 40s or 50s. Thus, efforts must be made to prevent frailty in working-age populations, including those aged 40 years and older. Six factors were associated with frailty. Longitudinal or interventional studies are required to examine their causal relationships and public health significance.

Factors associated with sarcopenia screened by finger-circle test among middle-aged and older adults: a population-based multisite cross-sectional survey in Japan

BACKGROUND

Previous epidemiological studies have demonstrated the prevalence and relationship of various factors associated with sarcopenia in older adults; however, few have examined the status of sarcopenia in middle-aged adults. In this study, we aimed to, 1) evaluate the validity of the finger-circle test, which is potentially a useful screening tool for sarcopenia, and 2) determine the prevalence and factors associated with sarcopenia in middle-aged and older adults.

METHODS

We conducted face-to-face surveys of 525 adults, who were aged 40-91 years and resided in Settsu City, Osaka Prefecture, Japan to evaluate the validity of finger-circle test. The finger-circle test evaluated calf circumference by referring to an illustration printed on the survey form. The area under the receiver operating characteristic curves (AUROC) was plotted to evaluate the validity of the finger-circle test for screening sarcopenia and compared to that evaluated by skeletal muscle mass index (SMI) measured using bioimpedance. We also conducted multisite population-based cross-sectional anonymous mail surveys of 9337 adults, who were aged 40-97 years and resided in Settsu and Hannan Cities, Osaka Prefecture, Japan. Participants were selected through stratified random sampling by sex and age in the elementary school zones of their respective cities. We performed multiple logistic regression analysis to explore associations between characteristics and prevalence of sarcopenia.

RESULTS

Sarcopenia, defined by SMI, was moderately predicted by a finger-circle test response showing that the subject's calf was smaller than their finger-circle (AUROC: 0.729, < 65 years; 0.653, ≥65 years); such subjects were considered to have sarcopenia. In mail surveys, prevalence of sarcopenia screened by finger-circle test was higher in older subjects (approximately 16%) than in middle-aged subjects (approximately 8-9%). In a multiple regression model, the factors associated with sarcopenia were age, body mass index, smoking status, self-reported health, and number of meals in all the participants.

CONCLUSIONS

Sarcopenia, screened by the finger-circle test, was present not only among older adults but also among middle-aged adults. These results may provide useful indications for developing public health programs, not only for the prevention, but especially for the management of sarcopenia.

TRIAL REGISTRATION

UMIN000036880, registered prospectively May 29, 2019,  https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000042027.

A large intermediate domain of vertebrate REV3 protein is dispensable for ultraviolet-induced translesion replication

DNA polymerase ζ (pol ζ) is involved in translesion replication (translesion synthesis, TLS) and plays an essential role in embryogenesis. In adults, pol ζ triggers mutation as a result of error-prone TLS and causes carcinogenesis. The catalytic subunit of pol ζ, REV3, is evolutionarily conserved from yeast and plants to higher eukaryotes. However, the structures are notably different: unlike that in yeast REV3, a large intermediate domain is inserted in REV3 of humans and mice. The domain is mostly occupied with noncommittal structures (random coil…etc.); therefore, its role and function are yet to be resolved. Previously, we reported deficient levels of ultraviolet (UV)-induced TLS in fibroblasts derived from the Rev3-knockout mouse embryo (Rev3KO-MEF). Here, we constructed a mouse Rev3-expressing plasmid with a deleted intermediate domain (532-1793 a.a,) and transfected it into Rev3KO-MEF. The isolated stable transformants showed comparable levels of UV-sensitivity and UV-TLS activity to those in wild-type MEF, detected using an alkaline sucrose density gradient sedimentation. These results indicate that the intermediate domain is nonessential for UV-induced translesion replication in cultured mouse cells.

Spontaneous intranasal tumours in rabbits: 7 cases (2007-2019)

OBJECTIVES

Neoplasms that arise in the nasal cavity are reported infrequently in rabbits. This case series aims to review and determine the clinical behaviour of neoplasms in the nasal cavity in rabbits.

MATERIALS AND METHODS

A retrospective study was conducted on seven pet rabbits diagnosed with intranasal tumours to describe the clinical and histopathological findings and prognoses after surgery and/or radiotherapy.

RESULTS

The most common clinical signs were nasal snoring when breathing, nasal discharge, and subsequent dyspnoea and anorexia. Six different histopathological types of tumours were diagnosed: intranasal adenocarcinoma, squamous cell carcinoma, osteosarcoma, carcinoid tumour, osteoma, and lymphoma. Skull radiography only revealed the abnormalities in three of seven cases but on CT, the intranasal masses were more clearly identified in all cases. All cases received tumour resection through rhinostomy and four cases received radiotherapy after surgery. In the six cases with a known outcome, the survival time after surgery was more than 13 months.

CLINICAL SIGNIFICANCE

This case series provides an insight of the behavior of intranasal neoplasms in rabbits. Surgical treatment and radiotherapy could improve their clinical sings.

Development of a screening method for determining sodium intake based on the Dietary Reference Intakes for Japanese, 2020: A cross-sectional analysis of the National Health and Nutrition Survey, Japan

Background

Although assessing nutrient intake through dietary surveys is desirable, it can be effort- and time-intensive. We aimed to develop a brief screening method for determining sodium intake in order to raise public awareness regarding the Dietary Reference Intakes for Japanese (DRI-J) 2020.

Methods

Using data from the 2015 National Health and Nutrition Survey, we compared dietary behaviours obtained from a self-administered questionnaire according to sodium intake, which was assessed from one-day dietary records by a semi-weighed method. Participants were divided into 4 groups based on the reference values of sodium (salt equivalent) shown in the DRI-J. We also randomly divided the participants into development and validation groups, and used logistic regression analysis to identify predictive factors for sex-specific DRI-J (<7.5 g/day in men and <6.5 g/day in women) and above-average intakes (≥10 g/day in men and women).

Results

Among the 6,172 Japanese individuals aged ≥20 years old, participants with lower sodium intake were found to use nutrition labels and had a lower frequency of eating out than those with higher intakes (P for difference < .001). Our final model for predicting sodium intake included adjusted sex, age, dietary behaviours, and consumption of mainly processed foods. In the development group, areas under the receiver operating characteristics curves were 0.747 and 0.741 for adherence to sex-specific DRI-J and above-average intake, respectively. The corresponding values in the validation group were 0.734 and 0.730, respectively.

Conclusions

This method could easily identify sodium intake using dietary behaviours and specific food consumption, and is expected to be widely useful for health and nutrition education in Japan.

Change in Growth and Diet Quality Among Preschool Children in Tokyo, Japan

Dietary intake of adequate quality and quantity in early life is essential for healthy growth and development. This study aimed to examine the association between one-year change in growth and diet quality in preschool children in Adachi City, Tokyo, Japan. A total of 110 participants (49% boys, four to five years old at baseline) were included in this analysis. Body mass index for age z-score (BAZ) and height for age z-score (HAZ) were calculated in accordance with WHO reference. Dietary intakes were assessed using the brief-type self-administered diet history questionnaire for children (BDHQ3y), and daily quality score was calculated based on the Japanese Food Guide Spinning Top (JFGST score). Regression analyses found no significant association between one-year change in growth and diet quality (compared to a low JFGST score, BAZ: β = 0.16, 95% CI: −0.29 to 0.60 for a middle JFGST score, β = −0.14, 95% CI: −0.61 to 0.33 for a high JFGST score, HAZ: β = −0.15, 95% CI: −0.50 to 0.21 for a middle JFGST score, β = −0.06, 95% CI: −0.43 to 0.30 for a high JFGST score). Further studies are needed to develop an appropriate diet quality index for healthy growth in Japanese preschool children.

Dietary patterns among Japanese adults: findings from the National Health and Nutrition Survey, 2012

BACKGROUND AND OBJECTIVES

Recent studies have analyzed dietary patterns to assess overall dietary habits, but there have been no studies of dietary patterns among the contemporary Japanese population nationwide. The objective of this study was to identify dietary patterns based on consumption of food items among Japanese adults, and to examine whether these dietary patterns were associated with nutrient intake, demographic characteristics, and lifestyle factors.

METHODS AND STUDY DESIGN

The study population included 25,754 Japanese adults aged 20 years and older registered in the nationwide National Health and Nutrition Survey database in 2012. Dietary patterns were analyzed by factor analysis of 29 food items from the dietary intake survey and household-based semiweighed dietary records.

RESULTS

Five dietary patterns were identified: high-bread and low-rice, high-meat and low-fish, vegetable, wheat-based food, and noodle and alcohol patterns. The lowest quartile of factor scores for high-meat and low-fish, wheat-based food, and noodle and alcohol patterns had higher nutrient intakes, and the highest quartile of factor scores for the vegetable pattern had a higher nutrient intake overall (all p<0.01). Dietary pattern scores were associated with demographic and lifestyle factors such as sex, age, region, smoking status, and alcohol intake.

CONCLUSIONS

Five major dietary patterns among Japanese adults were identified by factor analysis. Dietary pattern scores were associated with differences in nutrient intakes and demographic and lifestyle factors. These patterns were further used for examining the association between Japanese diets and health outcomes.

Dietary pattern and its association with blood pressure and blood lipid profiles among Japanese adults in the 2012 Japan National Health and Nutrition Survey

BACKGROUND AND OBJECTIVES

Little is known about the association between dietary patterns and cardiovascular disease risk factors among Japanese adults based on nationally representative data. This study aimed to explore the association between dietary patterns and hypertension or blood lipid profiles among Japanese people.

METHODS AND STUDY DESIGN

De-identified Japan National Health and Nutrition Survey (NHNS) 2012 data with a total of 8721 subjects (3524 men and 5197 women) aged 40-74 years were used. Dietary patterns were derived by principal component analysis (PCA). Generalized linear models and multivariate logistic regression analysis were used to assess the relationship between dietary patterns and blood pressure or lipid profiles.

RESULTS

We identified four dietary patterns: (a) traditional Japanese, (b) bread-dairy, (c) meat-fat, and (d) noodle patterns. Among these, the traditional Japanese pattern was significantly related to lower blood pressure, lower low-density lipoprotein (LDL)-cholesterol in men and lower high-density lipoprotein (HDL)-cholesterol in women. Bread-dairy pattern was associated with high total cholesterol in women and higher LDL cholesterol in both men and women. Noodle pattern was associated with higher total cholesterol and HDL-cholesterol in men. No significant association was observed between meat-fat pattern and blood pressure or lipid profiles.

CONCLUSIONS

Our study showed that the traditional Japanese pattern with high intake of miso, soy-sauce, vegetables, beans, potatoes and mushroom conferred benefits on blood pressure. Our findings have indicated clearly that it is possible to provide useful information on healthy dietary pattern for health promotion from the one-day dietary records of the NHNS.

Effect of individualised dietary education at medical check-ups on maternal and fetal outcomes in pregnant Japanese women

BACKGROUND AND OBJECTIVES

An increased prevalence of low maternal weight and insufficient pregnancy weight gain may be responsible for an increase in low birthweight infants in Japan. We aimed to examine the effects of individualised dietary education at medical check-ups on maternal/fetal outcomes in Japanese women.

METHODS AND STUDY DESIGN

Four hundred and six underweight and normal weight singleton pregnant women, who attended check-ups at an obstetric facility until ≥30 weeks gestation and delivered at 36-41 weeks gestation, were selected for analyses. Weight gain was assessed at each check-up based on the official "Dietary Guidelines for Pregnant and Lactating Women". Individual dietary advice was provided by dieticians to those with insufficient or excess weight gain status around 28 weeks gestation. The medical records from uncomplicated singleton deliveries (36-41 weeks gestation) at the same facility from 2008-2010 were used (n=792) to examine the effect of dietary education on maternal/fetal outcomes.

RESULTS

Pre-pregnancy underweight was present in >24% of women in both the intervention and non-intervention groups. Adequate weight gain occurred more frequently in the intervention group (p<0.01). There were no significant differences in mean birthweight or the proportion of low birthweight infants. However, the proportion of extremely small for gestational age infants (birthweight <3rd percentile) was lower in the intervention group (p=0.011). There were no differences in the frequency of caesarean delivery, pregnancy induced hypertension, or infant Apgar scores <7.

CONCLUSIONS

Dietary education during pregnancy check-ups promotes adequate maternal weight gain and helps prevent extreme fetal growth restraint.

Comparison of Nutrient Reference Values for Food Labeling in Japan with CODEX Recommendations, Based on DRIs and Nutrient Intake in Japan

To clarify the degree of consistency between the international recommendations and the national Japanese system, the nutrient reference values (NRVs) adopted by the CODEX were compared with current Japanese NRVs 2015, the dietary reference intakes for Japanese (DRIs-J) 2015, and actual nutrient intake levels by the Japanese population. The Japanese NRV for protein was high relative to CODEX NRV-R (i.e., NRV-Requirement). The Japanese NRVs for folate and calcium were low, and vitamin K was high, relative to each CODEX NRV-R. However, it was similar to the DRI-J values, and current intake levels for the Japanese population. For iron, calculation methods were different between the CODEX and Japan. Japanese iron NRV was calculated based on the RDA without menstruatating women, whereas CODEX NRV-R was calculated based on the INL98 of all adult men and women. Actual intake levels of iron for the Japanese population were similarly low. The Japanese NRV for sodium was high and potassium was low based on DRI-J values, relative to the CODEX NRV-NCD. For nutrients that show large discrepancies between the CODEX and Japanese NRVs, the values should be discussed further.

Assessment of energy expenditure using doubly labeled water, physical activity by accelerometer and reported dietary intake in Japanese men with type 2 diabetes: A preliminary study

The aim of the present study was to determine the total energy expenditure, physical activity and dietary intake of men with type 2 diabetes mellitus and control participants without type 2 diabetes mellitus who were matched for age and body mass index. The participants in the present study were 12 well-controlled type 2 diabetes mellitus patients and 10 controls, aged 40-75 years, with a body mass index <30 kg/m2 . Total energy expenditure under free-living conditions was assessed using the doubly labeled water method, and physical activity was measured using a triaxial accelerometer. Dietary intake was assessed using a self-recorded food intake diary during the measurement period. Participants were instructed to record their dietary intake over 3 days, including 2 weekdays. Total energy expenditure was not significantly different between the groups (P = 0.153), nor were energy (P = 0.969) or macronutrient intakes. In conclusion, when age and body mass index are matched, total energy expenditure and self-reported energy intake are not significantly different between type 2 diabetes mellitus patients and healthy controls.

Association between the Portion Sizes of Traditional Japanese Seasonings-Soy Sauce and Miso-and Blood Pressure: Cross-Sectional Study Using National Health and Nutrition Survey, 2012⁻2016 Data

While previous studies have reported the association between food portion size and health outcomes, the association between food seasonings and blood pressure (BP) has not been clarified. This study aimed to investigate the association between the portion sizes of traditional Japanese seasonings and BP. Data on 25,738 Japanese participants (10,154 men and 15,584 women) aged ≥20 years registered in the 2012–2016 National Health and Nutrition Survey (NHNS) were used for this cross-sectional study. The portion sizes of soy sauce or miso were calculated from the reported weight of soy sauce or miso, and the number of dishes. Regression models were used to estimate BP and prevalence of hypertension, and their 95% confidence intervals according to the portion size of soy sauce or miso. We did not observe an association between the portion sizes of soy sauce or miso and BP. A larger portion size of soy sauce or miso was associated with a higher prevalence of hypertension in the crude model among women, but no significant associations were observed in the multivariate model in both sexes. Our findings suggest that the portion sizes of soy sauce or miso are not associated with BP among Japanese adults.

Effect of diurnal variations in the carbohydrate and fat composition of meals on postprandial glycemic response in healthy adults: a novel insight for the second-meal phenomenon

Background

Meals, particularly carbohydrate intake, determine diurnal blood glucose (BG) excursions. However, the effect of meals with variable carbohydrate content on diurnal BG excursions remains poorly understood, despite routine consumption of meals that vary daily.

Objective

The aim of this study was to verify our hypothesis that glycemic response is elevated when a meal with a higher carbohydrate content follows a meal with a lower carbohydrate content.

Design

This was a secondary analysis of a study whose primary endpoint was energy metabolism (e.g., energy expenditure and substrate oxidation). This crossover study was designed to test BG responses to 3 types of meals with different macronutrient contents [regular meals (R), meals with a high-carbohydrate breakfast (CB), and meals with a high-fat breakfast (FB)] using a continuous glucose monitoring system. The R test included 3 meals/d with the same macronutrient composition; the CB test, a high-carbohydrate meal at breakfast, a high-fat meal at lunch, and a high-carbohydrate meal at dinner; and the FB test, a high-fat meal at breakfast, a high-carbohydrate meal at lunch, and a high-carbohydrate meal at dinner. Each test had similar daily macronutrient compositions, except CB and FB had larger variations in carbohydrate content than R. Fourteen healthy young men were tested in random order and underwent whole-body indirect calorimetry.

Results

Daily peak BG concentrations were higher for the CB (mean ± SD: 143.9 ± 25.3 mg/dL) and FB (140.2 ± 24.8 mg/dL) conditions than for the R condition (127.5 ± 15.7 mg/dL). Postprandial BG peaks after a high-carbohydrate meal were ∼20 mg/dL higher when a previous meal was relatively high-fat than when not high-fat (P < 0.05 for all). A multiple regression analysis indicated that the postprandial glycemic response was negatively associated with the preprandial respiratory quotient.

Conclusions

Our findings indicate that switching from high-fat to high-carbohydrate meals contributes to larger postprandial BG excursions, along with alterations in prioritization of carbohydrate utilization. This study was registered at the UMIN Clinical Trials Registry as UMIN000028895.

Food intake patterns and cardiovascular risk factors in Japanese adults: analyses from the 2012 National Health and nutrition survey, Japan

BACKGROUND

There is an increasing global interest in the role of Japanese diet as a possible explanation for the nation's healthy diet, which contributes to the world's highest life-expectancy enjoyed in Japan. However, nationwide studies on current food intake status among general Japanese population have not been established yet. This study examined the association between food intake patterns and cardiovascular risk factors (CVRF) such as waist circumference (WC), body mass index (BMI), blood pressure (SBP, DBP), HbA1c and blood lipid profiles among general Japanese adults.

METHODS

De-identified data on the Japan National Health and Nutrition Survey (NHNS) 2012 with a total of 11,365 subjects aged 20-84 years were applied. Food intake patterns were derived by principal component analysis (PCA) based on 98 food groups. Generalized linear regression analysis was used to assess the relation between the food intake patterns and CVRF.

RESULTS

We identified three food intake patterns: traditional Japanese, Westernized, and meat and fat patterns. Traditional Japanese pattern was significantly related to high WC and BMI in men, and high DBP in women. Westernized pattern was associated with lower SBP, but high total cholesterol and LDL cholesterol in both men and women. Meat and fat pattern was associated with high WC, high BMI, high blood pressure and blood lipid profiles in both men and women (trend P < 0.001).

CONCLUSION

The significant association between cardiovascular disease risks and three food intake patterns derived from the NHNS, showed a similar tendency to other dietary survey methods.