Estimated 24-hour urinary sodium excretion and sodium-to-potassium ratio among Japanese elementary school teachers and school lunch cooks.

Background:Dietary salt intake is largely responsible for increase in blood pressure that is commonly seen with aging. In our previous study carried out in 2015, we calculated the 24-hour urinary sodium excretion and sodium-to-potassium (Na/K) ratio among elementary school children. In the present study, we aimed to examine the same items among the school children's teachers and lunch cooks.Methods:Of 153 recruited participants, urine samples were collected from 129 subjects (84.3%), and 124 subjects (81.0%; 37 male teachers, 65 female teachers, and 22 female cooks) whose dietary habits were confirmed were included in the final study analysis.Results: The median estimated 24-hour urinary salt excretion (g/day) was 8.2 in male teachers, 7.4 in female teachers, and 8.9 in cooks. The median urinary Na/K ratio (mEq/mEq) was 4.1 in male teachers, 3.6 in female teachers, and 4.0 in cooks. In both male and female teachers and cooks, no association was found between urinary salt excretion or urinary Na/K ratio and an awareness of the need to restrict salt intake. The proportion of subjects with both a urinary salt excretion and Na/K ratio above the median was high in male teachers and cooks, whereas the proportion of subjects who scored below the median in both tests was high in female teachers.Conclusion:It should be considered that elementary school teachers and cooks who have been provided with the results of their own salt excretion could realize the importance of reducing salt consumption from early childhood and the continuous salt intake reduction education for children.

Characteristic dietary habits associated with high values of estimated 24-hours urinary sodium excretion and sodium-to-potassium ratio assessed by age group among the residents of a rural town in Japan.

Excess salt intake causes hypertension and cardiovascular disease (CVD). We examined estimated 24-h urinary sodium (Na) excretion and sodium-to-potassium (Na/K) ratio and analyzed the association between estimated 24-h urinary salt excretion (urinary salt excretion) and dietary habits by age group to develop effective public health programs to promote salt reduction. A total of 4,051 subjects aged 30-74 years old received information during periodic health checkups. In the analysis, 1,202 subjects without hypertension whose urine samples and dietary habits were confirmed (29.7%; 483 men and 719 women) were included. The median urinary salt excretion was 9.1 g/day in men and 8.6 g/day in women. Daily intake of soups in men aged <50 years old and daily intake of beans, soups, or pickles in women aged ≥70 years old were associated with high values of urinary salt excretion (p = .03, p < .01, p = .01, and p = .02, respectively). The median urinary Na/K ratio (mEq/mEq) was 4.4 in both men and women. Daily intake of vegetables in men aged <50 years old and more than 3 days/week intake of fruit in women aged 50-59 and 60-69 years old were associated with lower values of urinary Na/K ratio (p = .03, p < .01, and p < .01, respectively). These findings revealed that dietary salt reduction should be promoted according to age group with regard to differences in dietary habits associated with high values of estimated 24-h urinary Na excretion and urinary Na/K ratio.

Male Infants Born to Older Pregnant Women Are Affected by Maternal Physique at the Beginning of the Pregnancy through Birth until 18 Months of Age.

We have previously reported a positive correlation between the body mass index (BMI) of mothers and the Kaup index of infants at birth and that this correlation may have a stronger influence on the male infants, born to older mothers. Therefore, in this study, we aimed to clarify the correlation between maternal age and gender of the infants as maternal BMI and the Kaup index of infants from birth till 18 mo of age. This study was conducted from April 2010 to September 2011 in Japan. Public health nurses and registered dietitians interviewed the mothers individually under anonymous conditions, and they transferred the required information from the maternity passbook at the 18-mo health checkup. In male infants, significant positive correlations were demonstrated between maternal BMI at the beginning of pregnancy and the Kaup index of infants in mothers older than 35 y when the infants were at birth, at 4 mo and at 18 mo old. In female infants, there was no correlation between maternal BMI and the Kaup index of infants at birth. However, significant positive correlations were demonstrated between maternal BMI and the Kaup index of infants in mothers in their 20s and older than 35 y old when the infants were 4 and 18 mo old. Women who plan on pregnancy and medical professionals need to know that the maternal physique at the beginning of pregnancy affects the physique of the infants at birth and at 4 mo and 18 mo old by gender of the infants.

Estimation of salt intake and sodium-to-potassium ratios assessed by urinary excretion among Japanese elementary school children.

Dietary salt intake is largely responsible for the increase in blood pressure with age. It is important to start effective prevention approaches during childhood. In this study, we estimated salt intake and sodium-to-potassium (Na/K) ratios assessed by urinary excretion among elementary school children in Kyoto, Japan. A total of 331 subjects aged 9-11 years participated in school checkups in April 2015. Urinary concentrations of sodium, potassium, and creatinine were measured in first morning urine samples. The subjects' dietary habits were confirmed by questionnaires completed by their parents. The median estimated urinary sodium excretion was 129.0 mmol/day (5.7g/day of salt). In 30.2% of the subjects, their estimated salt intake exceeded their age-specific dietary goal for salt intake recommended by the Dietary Reference Intakes for Japanese 2015. Multivariate linear regression model analysis after adjustment for age revealed a significant positive correlation between seaweeds or fish paste products consumption and the estimated salt intake (p = 0.02 and 0.02, respectively). The median urinary Na/K ratio (mEq/mEq) was 4.5. Multivariate linear regression model analysis revealed a significant negative correlation between fruit consumption and urinary Na/K ratio (p = 0.04). These results suggest that the high sodium intake and the high Na/K ratios occur among Japanese elementary school children, and that the urinary Na/K ratio in children may be reduced by the daily consumption of fruit.

High Maternal Age and Low Pre-Pregnancy Body Mass Index Correlate with Lower Birth Weight of Male Infants.

In Japan, the percentage of leanness has been increasing in young women, and the percentage of low birth weight infants (< 2,500 g) has increased. Moreover, the average age of primiparas rose 3.5 years during the last 30 years. The purpose of this study was to clarify the relationship between maternal age and the influence of maternal pre-pregnancy physique on the neonatal physique of infants. Questionnaires were issued to the participants and collected when they submitted their gestational notifications at their local ward office in Kyoto Prefecture. After delivery, we obtained information on the course of the pregnancy and the neonatal physique of the infants from the participant's maternal passbooks. A total of 454 mothers (age 20 ≥) were analyzed: 161 young mothers (aged 20 to 29 years), 185 mothers (aged 30 to 34 years), and 108 older mothers (age ≥ 35). Overall, the mean rate of leanness (pre-pregnancy BMI < 18.5) was 23.8%. We found that birth weight was significantly lower in female infants, born to lean young mothers, compared to non-lean young mothers, whereas no significant difference was detected in other mothers (age ≥ 30), irrespective of pre-pregnancy BMI. By contrast, male infants, born to older lean mothers (age ≥ 35), showed significantly lower birth weight. Thus, maternal pre-pregnancy BMI exerts differential effects on the fetal growth (neonatal physique), depending on the maternal age and the sex of infants. We need to improve BMI in pre-pregnancy women, especially those in the twenties and 35 years old or over.

Maternal Body Mass Index Correlates with the Neonatal Physique of Male Infants.

Recently, in Japan, the percentage of leanness has risen in young women, and the average birth weight has decreased. An increase in the risk of low birth weight has been reported in lean expectant mothers. In this study, we aimed to clarify the relationship between mother's physique at the beginning of pregnancy and the infant's physique, by focusing on sex differences. The participants were 3,722 mothers who attended health checkups for 18-month-old infants in an urban Japanese city. The participants were limited to those with full-term births, thereby excluding the influence of gestational length. A total of 1,287 mothers, with 621 boys and 666 girls, were analyzed. Public health professionals interviewed the mothers, and transferred the required information from their maternity passbooks. We examined the physical characteristics of the mothers and their infants. Partial correlation analysis, adjusted by gestational length and the mother's age at delivery, was applied to study the association between the mother's BMI and the infant's physique at birth. In the primipara group, only the boys showed significant positive correlation between the mother's BMI and the birth weight (P = 0.025) and the Kaup index (P = 0.035). In the pluripara group, only the boys showed significant positive correlation between the mother's BMI and the head circumference (P = 0.035). Thus, mother's physique may have a stronger influence on the physique of male infants, compared to female infants. The growth-promoting effect of the mother's physique is more apparent in the infants born to the pluripara.

Relationship between physique and food avoidance in infants: a study conducted in a community setting in Japan.

The relationship between food avoidance during infancy and the growth of Japanese infants in a community health setting has not been well evaluated. In order to assess the growth of infants who avoided either of the three major allergen foods in Japan, eggs, milk or wheat, we employed the results of 4 physical checkups recorded in maternity passbooks and administrated a questionnaire on allergic diseases, height and weight at birth to the guardians of 1,132 infants at the age of 3.5 years. Data was obtained from 890 subjects (78.6%) and 662 subjects (58.5%) who met the inclusion criteria were analyzed. The height, weight and body mass index percentile scores of each subject were calculated. Subjects who avoided either of the three foods at 3.5 years had lower weight percentile scores at 1.5 years, lower height and weight percentile scores at 3.5 years, and lower weight growth rates, compared with the subjects who did not avoid any of the three foods at 3.5 years (P=0.02, 0.03, 0.03, 0.01). The results suggested that there was a negative relationship between physique and food avoidance in infants, and that physical and nutritional assessments are important for food avoiders.