Spatial analysis of urine zinc (Zn) concentration for women of reproductive age and school age children in Malawi

Zinc (Zn) is an essential micronutrient, and Zn deficiency remains a major global public health challenge. Recognised biomarkers of population Zn status include blood plasma or serum Zn concentration and proxy data such as dietary Zn intake and prevalence of stunting. Urine Zn concentration is rarely used to assess population Zn status. This study assessed the value of urine Zn concentration as a biomarker of population Zn status using a nationally representative sample of non-pregnant women of reproductive age (WRA) and school-aged children (SAC) in Malawi. Spot (casual) urine samples were collected from 741 WRA and 665 SAC. Urine Zn concentration was measured by inductively coupled plasma mass spectrometry with specific gravity adjustment for hydration status. Data were analysed using a linear mixed model with a spatially correlated random effect for between-cluster variation. The effect of time of sample collection (morning or afternoon), and gender (for SAC), on urine Zn concentration were examined. There was spatial dependence in urine Zn concentration between clusters among SAC but not WRA, which indicates that food system or environmental factors can influence urine Zn concentration. Mapping urine Zn concentration could potentially identify areas where the prevalence of Zn deficiency is greater and thus where further sampling or interventions might be targeted. There was no evidence for differences in urine Zn concentration between gender (P = 0.69) or time of sample collection (P = 0.85) in SAC. Urine Zn concentration was greater in afternoon samples for WRA (P = 0.003). Relationships between urine Zn concentration, serum Zn concentration, dietary Zn intake, and potential food systems covariates warrant further study.

Vitamin Status and Diet in Elderly with Low and High Socioeconomic Status: The Lifelines-MINUTHE Study

Socioeconomic health inequalities are an important global public health problem. However, it is not well known to what extent socioeconomic inequalities culminate in impaired vitamin status and whether this is mediated by diet. We, therefore, aimed to assess vitamin status in a population already at increased risk of micronutrient deficiency, i.e., elderly with high and low socioeconomic status (SES), and to investigate whether potential differences therein were mediated by diet quality. Vitamin status in 1605 individuals (60–75 years) from the Lifelines- Micronutrients and Health inequalities in Elderly (MINUTHE) Study was assessed by measuring folic acid and the vitamins B6, B12, D, A, E, and K. Multinomial logistic and linear regression analyses were applied to test the associations between SES and vitamin status. Mediation analysis was used to explore the interrelationship between SES, diet quality, and vitamin status. Low SES was associated with poorer status of vitamin B6, vitamin B12, and, notably, folic acid. Moreover, multivitamin deficiencies were more prevalent in the low SES group. Diet quality was found to mediate the associations of SES with folic acid (for 39.1%), vitamin B6 (for 37.1%), and vitamin B12 (for 37.2%). We conclude that low SES is a risk factor for a spectrum of vitamin deficiencies. Diet quality can partially explain the socioeconomic differences in vitamin status, suggesting that policymakers can mitigate socioeconomic inequality in nutritional status through improving diet quality.

Food Sources of Dietary Potassium in the Adult Japanese Population: The International Study of Macro-/Micronutrients and Blood Pressure (INTERMAP)

A lower-than-recommended potassium intake is a well-established risk factor for increased blood pressure. Although the Japanese diet is associated with higher sodium intake and lower potassium intake, few studies have examined the source foods quantitatively. Studies on dietary patterns in association with potassium intake will be useful to provide dietary advice to increase potassium intake. Twenty-four-hour (hr) dietary recall data and 24-hr urinary potassium excretion data from Japanese participants (574 men and 571 women) in the International Study of Macro/Micronutrients and Blood Pressure (INTERMAP) were used to calculate food sources of potassium and compare food consumption patterns among quartiles of participants categorized according to 24-hr urinary potassium excretion per unit of body weight (UK/BW). The average potassium intake was 2791 mg/day per participant, and the major sources were vegetables and fruits (1262 mg/day), fish (333 mg/day), coffee and tea (206 mg/day), and milk and dairy products (200 mg/day). Participants in the higher UK/BW quartile consumed significantly more vegetables and fruits, fish, and milk and dairy products, and ate less rice and noodles. Conclusion: Advice to increase the intake of vegetables and fruits, fish, and milk may be useful to increase potassium intake in Japan.

Concentration of Zinc, Copper, Iron, Calcium, and Magnesium in the Serum, Tissues, and Urine of Streptozotocin-Induced Mild Diabetic Rat Model

The present study aimed to investigate, in the streptozotocin-induced mild diabetic rat model, the zinc (Zn), copper (Cu), iron (Fe), calcium (Ca), and magnesium (Mg) concentration in serum, liver, and kidney tissues, and urine samples from adult Wistar rats treated neonatally with streptozotocin (STZ). Diabetes was induced by subcutaneous administration of streptozotocin (100 mg/Kg) in female Wistar rats of 2 days old (STZ, n = 10). Control group (CG, n = 10) received only sodium-citrate buffer. The mineral concentrations were measured by atomic absorption spectrophotometry. The validity and accuracy were checked by conventional methods. STZ neonatal injection successfully leaded to mild diabetes in the adult rats. Serum concentrations of Zn, Cu, Fe, Ca, and Mg showed no changes (p > 0.05) due to diabetes. The Zn, Fe, Ca, and Mg concentrations in liver and kidney tissues were not different (p > 0.05) between STZ and CG. The mean values of Cu were higher (p < 0.05) in liver and kidney samples from STZ as compared to CG. Urine minerals concentrations (Zn, Cu, Fe and Ca) in STZ-rats group were lower (p < 0.05) than CG. However, the content of all evaluated minerals in the excreted urine were higher (p < 0.01) in STZ-rats during a 24 h collection period. Urinary excretion of Zn, Cu, Fe, Ca, and Mg was strongly correlated with urinary volume during the 24 h period (r > 0.7; p < 0.001). Observed changes in mineral metabolism of STZ-induced mild diabetes model could be due to the endocrine imbalance associated with the diabetic condition.

Efficacy of multi-micronutrient fortified biscuits on urinary iodine levels of adolescent girls from Jaipur, India

INTRODUCTION

Iodine deficiency disorders are a public health problem in India. The aim of the study was to examine the effect of multi-micronutrient-fortified biscuits on urinary iodine levels of adolescent girls (n = 51, 10-16 years) studying in a government school in Jaipur city, India.

METHODS

The study was designed as an intervention study. Biscuits fortified with 150 mcg iodine, 30 mg iron, 100 mcg folic acid, 600 mcg vitamin A and 40 mg vitamin C were provided daily to the subjects on all working days over a 4-month period. The iodine status of the adolescent girls was determined through urinary iodine levels.

RESULTS

Supplementation with biscuits resulted in a significant increase in the mean urinary iodine level from 118.2 to 157.2 mcg/l and in the median value from 121 to 149 mcg/l. Prior to the intervention, 21.6% of the subjects had mild iodine deficiency but at the end of the intervention period, all the girls were iodine sufficient. Hence, iodine supplementation using biscuits resulted in improved iodine status of Indian adolescent girls.

CONCLUSION

It is, therefore, recommended that the school system be used for micronutrient supplementation interventions to improve the nutritional status of children and adolescents as there is more regimentation in a school setting for distribution of nutrient fortified food products to students.

Exposure to polycyclic aromatic hydrocarbons, arsenic and environmental tobacco smoke, nutrient intake, and oxidative stress in Japanese preschool children

The association between oxidative stress and exposure to environmental chemicals was assessed in a group of Japanese preschool children. The concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 1-hydroxypyrene (1-OHP), inorganic arsenic (iAs) and monomethylarsonic acid (MMA), and cotinine in spot urine samples, collected from 134 children (3-6 yrs) from a kindergarten in Kanagawa, Japan, were measured as biomarkers of oxidative stress or exposure to environmental chemicals. For 76 subjects of the 134, intakes of anti-oxidant nutrients (vitamins A, C, and E, manganese, copper, zinc and selenium (Se)) were estimated from a food consumption survey carried out 2-4 weeks after urine sampling and by urine analysis (Se). The median (min-max) creatinine-corrected concentrations of urinary biomarkers were 4.45 (1.98-12.3), 0.127 (0.04-2.41), 4.78 (1.18-12.7), and 0.62 (<0.6-19.0) μg/g cre for 8-OHdG, 1-OHP, iAs+MMA, and cotinine, respectively. Multiple regression analysis was carried out using 8-OHdG concentration as a dependent variable and urinary biomarkers of exposure and Se intake, intakes of vitamins and biological attributes of the subjects as independent variables. To explain 8-OHdG concentrations, intake of vitamin A and age were significant variables with negative coefficients, while 1-OHP concentration had a positive coefficient. These results indicated that oxidative stress of children is affected by chemical exposure at environmental levels, by nutrient intake and by physiological factors in a complex manner. On the other hand, unstable statistical results due to sub-grouping of subject, based on the availability of food consumption data, were found: the present results should further be validated by future studies with suitable research design.

Nutritional inadequacies in patients with stable heart failure

Sodium restriction is the primary nutritional strategy in heart failure; however, other diet-related concerns may also occur. We characterized dietary intake among stable patients with heart failure and a non-heart-failure cardiac control group to quantify and determine prevalence of inadequate micronutrient intake. Two 3-day food records were completed by 123 patients with heart failure and 58 controls. A subset of each group provided two 24-hour urine collections. Mean intake of sodium (2,540+/-1,122 vs 2,596+/-1,184 mg/day) and potassium (3,190+/-980 vs 3,114+/-828 mg/day) was similar between the heart failure and control groups. Prevalence of inadequate potassium intake was 94% among patients with heart failure and 91% among controls. More than 50% in each group had inadequate intakes of calcium, magnesium, folate, and vitamins D and E. In stable patients with heart failure, sodium intake was not excessive. However, we demonstrated widespread dietary inadequacies of other vitamins and minerals. These findings highlight the importance of diet beyond that of sodium restriction.

Impact of milk consumption on performance and health of primary school children in rural Vietnam

This is a follow-up study to an investigation on the prevalence of malnutrition and micronutrient deficiencies among Vietnamese primary schoolchildren. A total of 454 children aged 7 to 8 years attending three primary schools in the Northern delta province of Vietnam were either provided with regular milk, milk fortified with vitamins, minerals and inulin or served as a reference control group. Children were monitored for anthropometrics, (micro)-nutritional status, faecal microbiota composition, school performance, and health indices. Both weight-for-age (WAZ) and height-for-age (HAZ) significantly improved during 6 months of milk intervention; and underweight and stunting dropped by 10% in these groups. During intervention the incidence of anemia decreased and serum ferritin levels increased significantly in all groups. Serum zinc levels increased and consequently the incidence of zinc deficiency improved significantly in all three groups. Serum retinol levels and urine iodine levels remained stable upon intervention with fortified milk whereas in the control group the incidence of iodine deficiency increased. Bifidobacteria composed less than 1% of the total faecal bacteria. After three months of milk intervention total bacteria, bifidobacteria and Bacteroides sp. increased significantly in both milk and inulin fortified milk groups. Children in the milk consuming groups had significantly better short-term memory scores. Parent reported that health related quality of life status significantly improved upon milk intervention. In conclusion, (fortified) milk consumption benefited the children in rural Vietnam including lowering the occurrence of underweight and stunting, improving micronutrients status and better learning indicators as well as improving the quality of life.

Impact of the revision of a nutrient database on the validity of a self-administered food frequency questionnaire (FFQ)

BACKGROUND

Revision of the national nutrient database in 2000 had a strong impact on the absolute level of estimated nutrient intake in dietary assessments. However, whether it influenced the ranking of individuals by estimated intake, a more important function in epidemiologic studies, has not been investigated. Here, we investigated the effect of this revision of the nutrient database on the validity of a food frequency questionnaire (FFQ) used to estimate nutrient intake in the Japan Public Health Center-based prospective Study (JPHC Study).

METHODS

Subjects were a subsample of the JPHC Study who volunteered to participate in the validation study of the FFQ. Validity of the FFQ was evaluated by reference to the 28-day weighed dietary records as a gold standard. Nutrient intake according to the FFQ was recalculated using the revised database, and the results were compared to those using the previous database. Spearman’s rank correlation coefficients (CCs) between intakes estimated by the FFQ and dietary records were computed using the revised database, and were compared to CCs computed using the previous database.

RESULTS

For most of the nutrients, mean intake increased or decreased significantly using the revised database. However, no notable change was seen for the CC between estimated intake according to dietary records and FFQ when the revised database was used for calculation. Differences in the point estimates of the CCs ranged from -0.14 to 0.15. Likewise, CCs between biomarkers and estimated intake according to FFQ were similar for the two databases.

CONCLUSION

Despite changes in intake levels for many nutrients, the validity of our FFQ using rank correlation by nutrient intake was not influenced by revision of the nutrient database in Japan.

Association between protein intake and blood pressure: the INTERMAP Study

BACKGROUND

Findings from epidemiological studies suggest an inverse relationship between individuals' protein intake and their blood pressure.

METHODS

Cross-sectional epidemiological study of 4680 persons, aged 40 to 59 years, from 4 countries. Systolic and diastolic blood pressure was measured 8 times at 4 visits. Dietary intake based on 24-hour dietary recalls was recorded 4 times. Information on dietary supplements was noted. Two 24-hour urine samples were obtained per person.

RESULTS

There was a significant inverse relationship between vegetable protein intake and blood pressure. After adjusting for confounders, blood pressure differences associated with higher vegetable protein intake of 2.8% kilocalories were -2.14 mm Hg systolic and -1.35 mm Hg diastolic (P<.001 for both); after further adjustment for height and weight, these differences were -1.11 mm Hg systolic (P<.01) and -0.71 mm Hg diastolic (P<.05). For animal protein intake, significant positive blood pressure differences did not persist after adjusting for height and weight. For total protein intake (which had a significant interaction with sex), there was no significant association with blood pressure in women, nor in men after adjusting for dietary confounders. There were significant differences in the amino acid content of the diets of persons with high vegetable and low animal protein intake vs the diets of persons with low vegetable and high animal protein intake.

CONCLUSIONS

Vegetable protein intake was inversely related to blood pressure. This finding is consistent with recommendations that a diet high in vegetable products be part of healthy lifestyle for prevention of high blood pressure and related diseases.

Effect of the diuretic furosemide on urinary essential nutrient loss and on body stores in growing rats

Studies using a model of non-infectious diarrhea, have shown that increasing fecal mass by using laxatives resulted in greater fecal losses of nutrients and lower intestinal absorption. In the present study we used a diuretic to determine if increasing urine volume could result in greater urinary losses of essential nutrients. This is a relevant question because diuretics are widely and successfully used in the treatment of diseases associated with water retention and hypertension. They are known to increase potassium losses. However, there is less information on the effect of diuretics on the urinary losses of essential nutrients. Accordingly, urinary nitrogen, phosphorous, sodium, potassium, magnesium, zinc and retinol were measured in young rats consuming increasing concentrations of furosemide (0, 0.5, 1.0, 1.5 mg/g diet) in the diet over 15 days. The results showed that dietary furosemide caused a dose-dependent polyuria. In addition it reduced food intake and feed efficiency and leaded to poor growth and greater urinary losses of all the measured nutrients and electrolytes. These losses were proportional to urine volume and represented an important fraction of the rats daily intake. The losses were negatively associated with the body and liver content of the same electrolytes and nutrients. In general, this study showed that the diuretic furosemide caused malnutrition in a short period of time by reducing food intake as well as the capacity of retaining macro and micronutrients including the liposoluble vitamin A in a relatively short period of time. This study, together with our previous studies on diarrhea, indicate that proper nutrient utilization requires both an adequate intestinal and renal function.

Dietary intake in male and female smokers, ex-smokers, and never smokers: the INTERMAP study

This report examines dietary intakes in smokers, ex-smokers, and never smokers in INTERMAP. The 4680 participants aged 40-59 years-from 17 population samples in four countries (China, Japan, UK, USA)-provided four 24-h recalls to assess nutrient intakes and two 24-h urine collections to assess excretion of urea, sodium (Na), potassium (K), etc. Compared to never smokers, current smokers generally consumed more energy from alcohol and saturated fats (SFA), less energy from vegetable protein and carbohydrates, less dietary fibre, vitamin E, beta carotene, vitamin C, thiamine, riboflavin, folate, vitamin B6, calcium, iron, phosphorus, magnesium (Mg), and K per 1000 kcal, excreted less K and urea (marker of dietary protein), had a lower ratio of polyunsaturated fat (PFA) to SFA intake, higher Keys dietary lipid score, and higher dietary and urinary Na/K. There were few differences between smokers and never smokers for total energy intake, energy from total and animal protein, monounsaturated fats, PFA, omega 3 and omega 6 PFA, dietary cholesterol, total vitamin A, retinol, vitamin D, vitamin B12, and urinary and dietary Na. Compared to ex-smokers, smokers generally consumed less energy from vegetable protein, omega 3 PFA, carbohydrates, less dietary fibre, beta carotene, vitamin E, vitamin C, thiamine, riboflavin, folate, vitamin B6, iron, phosphorus, Mg, had lower PFA/SFA, and excreted less urea and K. In conclusion, INTERMAP results are consistent with other reports indicating that smokers have less healthful diets than nonsmokers. Public health interventions in smokers should focus not only on helping them to quit smoking but also on improving their diets to further reduce cancer and cardiovascular disease risks.

Molybdenum supply of very low-birth-weight premature infants during the first months of life

This explorative study was performed to assess basic data on the Mo metabolism of premature infants. Premature (n = 18, gestational age < or = 32 wk, birth weight < or = 1,500 g) and healthy formula-fed term infants (n = 14) were nourished and corrected for gestational age, identically. Plasma was collected at 3, 16, and 52 wk and 72 h balances were performed at 3 wk of age. In the premature infants, these investigations were preceded by two balance studies and an initial plasma collection. Increased Mo intake and low relative urinary excretion resulted in a retention of 4.4 (0.99-7.77) microg Mo/kg initially in premature infants (median, range). Parallel plasma concentrations were 5.5 (2.5-7.3) microg Mo/L, declining to 2.36 (0.73-3.87) microg Mo/L at 4 wk. Term infants rendered 1.49 (0.29-1.7) microg Mo/L (p < 0.05), with no significant differences later. It was concluded that the supplementation of formulas for premature infants with Mo should be recinded until there is evidence for its necessity. Index Entries: Mo; premature infants; trace elements; formula; nutrition.