[Blood cadmium level and the change of cadmium exposure risk in Chinese urban school-age children in 2002 and 2012].

OBJECTIVE: To investigate the blood cadmium concentrations and the related change in Chinese urban children derived from the China Nutrition and Health Survey 2002 and 2012(CNHS 2002 and CNHS 2012). METHODS: The Chinese urban children aged 6-11 years were selected according to gender, age and regional distribution using the multi-stage stratified cluster random sampling method, as well as the corresponding whole blood samples. The blood cadmium concentration was carefully determined by the quadrupole inductively coupled plasma mass spectrometry(ICP-MS) and the percentage of blood cadmium over 2 µg/L was subsequently estimated. In addition, the upper limit values of the 95%CI of the 95th percentiles of available blood cadmium data was assessed as the threshold of cadmium exposure. RESULTS: Totally, 2182 Chinese urban children were included, and of these, 1036 children were from the CNHS 2002 and 1146 children were from the CNHS 2012. From the CNHS 2002 to the CNHS 2012, the median blood cadmium concentration was increased from 0.28 µg/L to 0.95 µg/L, and the percentage of blood cadmium with over 2 µg/L was elevated from 1.45% to 10.47%. In addition, the new estimated threshold of blood cadmium was ascended from 1.24 µg/L up to 2.89 µg/L. CONCLUSION: The risk of cadmium exposure in Chinese urban children aged 6-11 years was increasingly aggravated from the CHNS 2002 to the CNHS 2012.

Re-exploration of dietary iodine intake in Chinese adult males using a modified iodine balance study.

There is still controversy about optimal dietary iodine intake as the Universal Salt Iodization policy enforcement in China. A modified iodine balance study was thus conducted to explore the suitable iodine intake in Chinese adult males using the iodine overflow hypothesis. In this study, thirty-eight apparently healthy males (19·1 (sd 0·6) years) were recruited and provided with designed diets. After the 14-d iodine depletion, daily iodine intake gradually increased in the 30-d iodine supplementation, consisting of six stages and each of 5 d. All foods and excreta (urine, faeces) were collected to examine daily iodine intake, iodine excretion and the changes of iodine increment in relation to those values at stage 1. The dose-response associations of iodine intake increment with excretion increment were fitted by the mixed effects models, as well as with retention increment. Daily iodine intake and excretion were 16·3 and 54·3 µg/d at stage 1, and iodine intake increment increased from 11·2 µg/d at stage 2 to 118·0 µg/d at stage 6, while excretion increment elevated from 21·5 to 95·0 µg/d. A zero iodine balance was dynamically achieved as 48·0 µg/d of iodine intake. The estimated average requirement and recommended nutrient intake were severally 48·0 and 67·2 µg/d, which could be corresponded to a daily iodine intake of 0·74 and 1·04 µg/kg per d. The results of our study indicate that roughly half of current iodine intakes recommendation could be enough in Chinese adult males, which would be beneficial for the revision of dietary reference intakes.

Exploration of the lower threshold of iodine intake in Southern Chinese young adults based on 'overflow theory' in an iodine balance study.

BACKGROUND: Appropriate iodine intake for adults is essential to reduce the prevalence of thyroid diseases, but there is little research data on iodine requirement of Chinese population. This study aimed to explore the iodine requirement of young adults to maintain a healthy status based on 'overflow theory'. METHODS: Iodine-balance experiment has been performed in this project. We conducted an 18-day study consisted of a 6-day acclimation period and 3 consecutive experimental stages in 37 Chinese healthy young adults (23 female and 14 male). Each stage was consumed for 4 days. Strictly-controlled low-iodine intake diets were provided for adults in the first period, an egg or 125mL milk was added in the second and third period, respectively. The dietary samples, 24-h urine specimens and faeces of volunteers were collected daily for assessment of iodine intake and excretion in volunteers. RESULTS: Mean values of iodine intake (22.7±3.6, 35.1±3.7, and 52.2±3.8µg/d), excretion (64.7±13.9, 62.3±12.6, and 94.3±14.5µg/d) and iodine balance (-35.2±19.5, -21.0±19.8, and -33.5±26.9µg/d) were significantly different among three periods for male (P<0.001 for all); mean values of iodine intake (16.6±3.1, 29.7±2.7, and 48.0±2.7µg/d), and excretion (47.0±9.9, 55.5±8.1, and 75.7±12.4µg/d) were significantly different among three periods for female (P < 0.001 for all). No significant difference was observed among the 3 periods for female in the iodine balance (-30.5±9.3, -25.9±7.3, and -27.6±12.1µg/d). The linear regression equation of iodine excretion on iodine intake was Y=0.979X+37.04 (male) and Y=0.895X+31.48 (female). Compared with stage 2, iodine excretion increments in stage 3 had exceeded the iodine intake increment for men. The ratio of increment was 1.675 for male when the average iodine intake was 52.2µg/d in stage 3. When the iodine excretion increment equaled to the iodine intake increment, the daily iodine intake of men was 47.0µg. CONCLUSION: We have evaluated the iodine requirement of young adults in southern China based on overflow theory. Our results indicate the lower limit of iodine requirement for Chinese young men is 47.0µg/d. The trial was registered at www.chictr.org.cn as ChiCTR1800014877.

Basal energy expenditure, resting energy expenditure and one metabolic equivalent (1 MET) values for young Chinese adults with different body weights.

BACKGROUND AND OBJECTIVES: Accurately assessing energy expenditure (EE) of people with different body weight is essential to facilitate weight management. The aim of this study was to measure basal energy expenditure (BEE), resting energy expenditure (REE) and to explore the true 1 MET value for young Chinese adults with different body weight. METHODS AND STUDY DESIGN: A total of 251 young Chinese adults were divided into three groups: the normal weight group, the overweight group and the obese group. Their BEE, REE and 1 MET values were measured by Cortex Metamax 3B (MM3B). Multiple linear regressions and correlation analysis were used to examine factors that influence EE in Chinese population. RESULTS: The mean measured BEE and REE of young Chinese adults with normal weight, overweight and obesity was 1429, 1609, 1778 kcal/day and 1522, 1712, 1885 kcal/day, respectively. The EE per kilogram body weight decreased with the increasing body weight. The mean oxygen consumption in the three group was 3.78, 3.47, 3.21 mL/kg/min respectively. There was no significant difference in BEE and REE after adjustment for fat-free mass (FFM). The significant influencing factors were body mass index (BMI) and sex in BEE, FFM and BMI in REE in Chinese population. CONCLUSIONS: BEE and REE were significantly different for different body weights while these differences disappeared after adjustment for FFM, and people with different body weights may have different 1 MET values. Further studies should be conducted to obtain more accurate daily energy requirement and 1MET value for specific Chinese populations.

Bioavailability and incorporation of nonheme iron from a representative Chinese diet in young urban Chinese women.

BACKGROUND AND OBJECTIVES: This study assessed the bioavailability and biological incorporation of nonheme iron from staple food diets in healthy young urban Chinese women and determined the relevant effects of typical regional patterns of staple foods in South and North China. METHODS AND STUDY DESIGN: Twenty-two young urban Chinese women aged 20-23 years were enrolled and randomly allocated to two groups, with rice (rice group) and steamed buns (steamed buns group) as the staple food, respectively. Each participant received three meals daily containing approximately 3.25 mg of stable 57FeSO4 for 2 consecutive days, along with daily intravenous injection of approximately 2.0 mg of 58FeSO4. Nonheme iron absorption and infused iron incorporation rates were assayed. RESULTS: In all participants, the rice group, and the buns group, nonheme iron intake was 7.2±1.6, 5.9±0.6, and 8.4±1.2 mg, respectively; mean 57FeSO4 absorption rate was 22.2%±9.6%, 22.2%±10.6%, and 22.2%±8.9%, respectively; and the mean infused 58FeSO4 incorporation rate was 91.6%±8.2%, 93%±7.3%, and 90%±9.1%, respectively. No substantial differences existed in the nonheme iron intakes and the 57FeSO4 absorption and 58FeSO4 incorporation rates between the rice and buns groups (all p>0.05). CONCLUSIONS: The bioavailability and incorporation rates of nonheme iron from representative comprehensive Chinese diets in healthy young urban Chinese women were evaluated. Our results can facilitate the establishment of dietary reference intake for iron in Chinese women.

[Assessment of iodine nutritional status for pregnant women using adjusted urine creatinine from spot and 24-hour urine].

OBJECTIVE: To establish a reliable method of iodine nutritional assessment for pregnant women using the adjusted urinary creatinine of spot urine and 24-hour urine samples. METHODS: The spot urine in the morning at 8 00-11:30 and the following 24-hour urine samples of pregnant women were collected in Peking Union Medical College Hospital during March to October in 2016. The urinary iodine and urinary creatinine concentrations were determined. The estimated 24-hour urinary iodine excretion( 24-h UIE) was calculated using the urinary iodine/urinary creatinine( UIC/Cr) ratio of spot urine, and 24-hour urinary creatinine excretion( 24-h UCr E). RESULTS: There was a significant difference in the UIC, UIC/Cr ratio between spot urine and 24-h urine( P <0. 05). The UIC, UIC/Cr ratio of spot urine, and the estimated 24-h UIE all were significantly correlated with the real 24-h UIE( P < 0. 01), especially the estimated 24-h UIE were taking up 70%-80% for the real 24-h UIE in the period of gestation. CONCLUSION: The UIC, UIC/Cr, and the estimated 24-h UIE cannot directly replace the relevant values derived of the 24-hour urine samples. But the estimated 24-h UIE can reflect the iodine nutritional status of pregnant women in recent days, and the method could be a reliable reference for the iodine nutritional assessment of the pregnant women in practice.

[Thyroid function for Chinese pregnant women in 2010-2012].

OBJECTIVE: To evaluate thyroid function and iodine nutritional status for pregnant women from various regions of China by determining plasma levels of thyrotrophin( TSH), free triiodothyronine( FT3), and free thyroxine( FT4). METHODS: Plasma samples were obtained from pregnant women that participated in the 2010-2012 China National Nutrition and Health Survey. Plasma levels of TSH, FT3, and FT4 were determined by using an automated chemiluminescence immunoassay analyzer. Thyroid function was evaluated according to the determined levels. RESULTS: A total of 877 plasma samples collected from pregnant women residing in different regions of China wereanalyzed for levels of TSH, FT3, and FT4. The median TSH levels detected in the first, second, and third trimesters of pregnancy were 1. 56, 1. 84, and 1. 89 m IU/L, respectively. The median FT4 levels were 17. 21, 16. 29 and 16. 35 pmol/L, respectively. The median FT3 levels were 4. 70, 4. 39 and 4. 18 pmol/L, respectively. The rate of normal thyroid function for this cohort was 78. 1%, and for the pregnant women that resided in large cities the rate was 71. 2%. The most common type of abnormal thyroid function that was detected was subclinical hypothyroidism. It had an overall incidence of10. 5%, and those residing in regions of rural poverty had the highest rate( 14. 5%). The normal rate of thyroid function for adult pregnant women at the end of the trimester( 28-40 weeks) during pregnancy was significantly lower than that of the pregnant women in the first and second trimester. CONCLUSION: The rate of normal thyroid function in pregnant women is low( less than 80%). Subclinical hypothyroidism is the main type of thyroid dysfunction during pregnancy. It should be continued to pay attention to the relationship between the high incidence of subclinical hypothyroidism and iodine nutritional status of pregnant women, especially subclinical hypothyroidism caused by insufficient iodine intake.

Vitamin D status among the elderly Chinese population: a cross-sectional analysis of the 2010-2013 China national nutrition and health survey (CNNHS).

BACKGROUND: Vitamin D inadequacy is common among the elderly, especially within the Asian population. The vitamin D status among healthy adults in the elderly Chinese population was evaluated. METHODS: A total of 6014 healthy adults aged 60 years or older (2948 men, 3066 women) participated in this descriptive cross-sectional analysis. Possible predictors of vitamin D inadequacy were evaluated via multiple logistic regression analyses. RESULTS: The median serum 25-hydroxyvitamin D (25(OH)D) levels were 61.0 nmol/l (interquartile range (IQR) 44.3-80.6, range 5.1-154.5) for men and 53.7 nmol/l (IQR 38.8-71.0, range 6.0-190.0) for women, with 34.1% (95% confidence interval (CI) 32.4-35.8) of men and 44.0% (95% CI 42.2-45.8) of women presenting vitamin D inadequacy (25(OH)D <50 nmol/l). According to the multivariate logistic regression analyses, vitamin D inadequacy was positively correlated with female gender (P <0.0001), underweight (P = 0.0259), the spring season (P <0.0001), low ambient UVB levels (P <0.0001) and living in large cities (P = 0.0026). For men, vitamin D inadequacy was positively correlated with the spring season (P = 0.0015), low ambient UVB levels (P <0.0001) and living in large cities (P = 0.0022); for women, vitamin D inadequacy was positively correlated with the spring season (P = 0.0005) and low ambient UVB levels (P <.0001). CONCLUSIONS: Vitamin D inadequacy is prevalent among the elderly population in China. Because residing in regions with low ambient UVB levels increases the risk of vitamin D inadequacy both for men and women, vitamin D supplementation and sensible sun exposure should be encouraged, especially during the cooler seasons. Further studies are required to determine the optimal vitamin D intake and sun exposure levels to maintain sufficient vitamin D levels in the elderly Chinese population.

Vitamin D deficiency prevalence and risk factors among pregnant Chinese women.

OBJECTIVE: To evaluate vitamin D deficiency prevalence and risk factors among pregnant Chinese women. DESIGN: A descriptive cross-sectional analysis. SETTING: China National Nutrition and Health Survey (CNNHS) 2010-2013. SUBJECTS: A total of 1985 healthy pregnant women participated. Possible predictors of vitamin D deficiency were evaluated via multiple logistic regression analyses. RESULTS: The median serum 25-hydroxyvitamin D level was 15·5 (interquartile range 11·9-20·0, range 3·0-51·5) ng/ml, with 74·9 (95 % CI 73·0, 76·7) % of participants being vitamin D deficient (25-hydroxyvitamin D <20 ng/ml). According to the multivariate logistic regression analyses, vitamin D deficiency was positively correlated with Hui ethnicity (P=0·016), lack of vitamin D supplement use (P=0·021) and low ambient UVB level (P<0·001). In the autumn months, vitamin D deficiency was related to Hui ethnicity (P=0·012) and low ambient UVB level (P<0·001). In the winter months, vitamin D deficiency was correlated with younger age (P=0·050), later gestational age (P=0·035), higher pre-pregnancy BMI (P=0·019), low ambient UVB level (P<0·001) and lack of vitamin D supplement use (P=0·007). CONCLUSIONS: Vitamin D deficiency is prevalent among pregnant Chinese women. Residing in areas with low ambient UVB levels increases the risk of vitamin D deficiency, especially for women experiencing advanced stages of gestation, for younger pregnant women and for women of Hui ethnicity; therefore, vitamin D supplementation and sensible sun exposure should be encouraged, especially in the winter months. Further studies must determine optimal vitamin D intake and sun exposure levels for maintaining sufficient vitamin D levels in pregnant Chinese women.

[Relationship of diabetes mellitus in older Han adults in China with leptin receptor gene rs1137100 and rs1137101 polymorphrism].

OBJECTIVE: To explore the relationship of diabetes in older Han adults with leptin receptor gene rs1137100 and rs1137101 single nucleotide polymorphism( SNP). METHODS: A total of 511 older Han adults were selected for this study and divided into diabetes and control groups, with 241 and 270 people in each group. The genotypes of rs1137100 and rs1137101 and the allele frequency were determined by Taqman method. The correlations between genotypes of leptin receptor gene SNPs with diabetes wereanalyzed. Blood concentrations of lipids, fasting serum glucose( FBG), leptin and insulin were also measured. RESULTS: The distribution of GG, GA and AA genotypes in rs1137100 in the diabetes group and the healthy group was 73. 0%, 24. 5%, 2. 5% and 68. 9%, 28. 9%, 2. 2%, respectively. The difference was not significant between the two groups( χ~2= 1. 27, P = 0. 53). There was no significance in the difference of the frequency of "A"allele in rs1137100 in the two groups, with 14. 7% and 16. 7% in each group( χ~2= 0. 72, P = 0. 40). In rs1137101, the distribution of GG, GA and AA genotypes in the diabetes group and the healthy group was 77. 6%, 21. 2%, 1. 2% and 77. 8%, 21. 1%, 1. 1%, respectively. The difference was not significant between the two groups( χ~2= 0. 02, P = 0. 99). There was no significance in the difference of the frequency of"A"allele in rs1137101 in the two groups, with 11. 8% 11. 7% in each group( χ~2=0. 01, P = 0. 94. The Logistic analysis showed that GA and AA genotypes carriers in rs1137100 had similar risk for diabetes when comparing with the GG genotypes( OR =1. 06, 95% CI 0. 34-3. 34, OR = 0. 80, 95% CI 0. 54-1. 19). The GA and AA genotypes carriers in rs1137101 had similar risk for diabetes when comparing with the GG genotypes, and the OR values were 1. 12( 95% CI 0. 22-5. 63) and 1. 01( 95% CI0. 66-1. 54), respectively. CONCLUSION: The rs1137100 and rs1137101 polymorphism are not significantly associated with the prevalence of diabetes in older Han adults.

[Vitamin A nutritional status of Chinese rural children and adolescents in 2010-2012].

OBJECTIVE: To analysis the vitamin A nutritional status of 6-to 17-year-old children and adolescents between 2010-2012 in rural China. METHODS: Based on the China Health and Nutrition Survey 2010-2012 project, the serum vitamin A samples of children and adolescents from survey sites of rural area were selected by random sampling method, and 5888 cases of samples were detected using the high performance liquid chromatography method to evaluate their vitamin A nutritional status. RESULTS: The serum retinol concentration of children and adolescents in rural area was( 1. 44 ± 0. 58) µmol/L, and were( 1. 40 ± 0. 56) µmol/L in general rural areas and( 1. 46 ± 0. 60) µmol/L in poverty rural areas respectively( t = 1. 88, P < 0. 05). The serum retinol concentration of6-to 11-year-old were( 1. 31 ± 0. 53) µmol/L and( 1. 37 ± 0. 60) µmol/L, and serumretinol concentration of 12-to 17-year-old were( 1. 52 ± 0. 57) µmol/L and( 1. 52 ±0. 60) µmol/L( t = 11. 90 and t = 5. 54, P < 0. 05). The prevalence of vitamin A deficiency was 5. 53%, and were 6. 14% in general rural areas and 4. 55% in poverty rural areas, respectively( P > 0. 05). The prevalence of marginal vitamin A deficiency were 18. 75%, and were 19. 17% in general rural areas and 18. 07% in poverty rural areas, respectively( P > 0. 05). CONCLUSION: The situation of vitamin A deficiency in rural China are still widespread, the high prevalence of marginal vitamin A deficiency is more prominent.

[Vitamin A nutritional status of Chinese rural fertile women in 2010-2012].

OBJECTIVE: To evaluate nutritional status of vitamin A( VA) among Chinese rural fertile women in 2010-2012. METHODS: A multi-stage stratified sampling and population proportional stratified random sampling method was used and the participants of rural fertile women who were 18-44 years old and had completed personal information data during the 2010-2012 National Nutrition and Health Survey were included( n = 1279). The level of serum retinol, rate of VA marginal deficiency anddeficiency among the fertile women were analyzed. RESULTS: In 2010-2012, the P50( P25-P75) level of serum retinol was 1. 63( 1. 28-2. 10) µmol/L for Chinese rural fertile women, 1. 60( 1. 25-2. 05) µmol/L for fertile women from ordinary rural area and1. 70( 1. 32-2. 17) µmol/L for fertile women from poverty rural area. The level of serum retinol of fertile women from poverty rural area was statistically higher than that of ordinary rural area( P = 0. 007). The rate of VA marginal deficiency and deficiency among the Chinese rural fertile women was 9. 46% and 3. 05%, respectively. The rate of VA marginal deficiency and deficiency among the fertile women from ordinary rural area and poverty rural area was 9. 82%, 4. 13%, 9. 03% and 1. 74%, respectively. The rate of VA deficiency among the fertile women from ordinary rural was statistically higher than that of poverty rural( P = 0. 013), but no statistically differences in the rate of VA marginal deficiency were found( P > 0. 05). Moreover, the statistically differences of rate of VA marginal deficiency and deficiency were also observed in the different regions and educational level( only VA deficiency). There were no statistically differences of VA marginal deficiency and deficiency were found in the other variables. CONCLUSION: The different extent of VA deficiency still present and more popular for the VA marginal deficiency among Chinese fertile women.

[Serum vitamin D levels of Chinese rural women of childbearing age in 2010-2012].

OBJECTIVE: To obtain the serum 25-hydroxyvitamin D status for women of child-bearing age aged 18-44 years from rural areas in China Health and Nutrition Survey2010-2012( CHNS 2010-2012). METHODS: We randomly selected the 1520 representative women of childbearing age from the 75 monitoring spots derived in the CNHS 2010-2012. The information of study population were collected using questionnaires and the serum 25-hydroxyvitamin D concentration was determinedusing the RIA kits. The vitamin D nutritional status was classified by the standards suggested by the America Endocrine Society. Multiple Logistic regression analysis was explored therelationship between vitamin D status with the potential relevant factors. RESULTS: The median serum 25-hydroxyvitamin D concentration was 22. 7 ng/m L ranged from 8. 2 to42. 0 ng/m L. The prevalence of vitamin D deficiency was 38. 7%, insufficiently 39. 5%and sufficiently 21. 8%. Multiple Logistic regression analysis showed that nationality, geographical regions and income per capita was the significant. CONCLUSION: s The nutritional status of vitamin D in women of child bearing-age is not better in the CNHS2010-2012. We suggest that it should be pay more attention on the women of childbearing age for the minority, north China, family income per year between 10000 and 30000 Yuan.

[Serum retinol concentrations of Chinese rural elderly residents in 2010-2012].

OBJECTIVE: To assess the vitamin A status of Chinese rural elderly population by analyzing the serum retinol levels of Chinese rural elderly residents in 2010-2012. METHODS: Data were from the Chinese National Nutrition and Health Survey in2010-2012. Using the multistage stratified cluster sampling method, serum samples from the elderly residents aged above 60 years old( including), were obtained from 45 general rural and 30 poor rural. The basic situation of the survey object was collected by the questionnaire survey. The concentration of serum retinol was determined by high performance liquid chromatography( HPLC). The vitamin A deficiency( VAD) was judged by the related standard recommended by WHO. A total of 2 413 elderly residents were included in the study. The levels of serum retinol and the prevalence of vitamin A deficiency and marginal vitamin A deficiency were also compared. RESULTS: The level of serum retinol for rural elderly residents was 1. 88( 1. 45-2. 45) µmol/L. The serum retinol level of poor rural resident was( 1. 92( 1. 46-2. 48) µmol/L), which was significant for the ordinary rural residents( 1. 86( 1. 44-2. 41) µmol/L)( χ~2= 5. 1428, P = 0. 0233). The serum retinol of male elderly( 1. 97( 1. 48-2. 54)) was statistically higher than female( 1. 82( 1. 42-2. 33))( χ~2= 22. 3383, P < 0. 0001). The prevalence of VAD among Chinese rural elderly residents was 2. 28%, 2. 79% for ordinary rural residents and 1. 53% for poor rural residents. The marginal VAD rate of Chinese rural elderly residents was 6. 30%, 6. 84% for ordinary rural residents and 5. 51% for poor rural residents. The prevalence of VAD and marginal VAD for male was 2. 18% and5. 57%, respectively. The prevalence of VAD and marginal VAD for female was 2. 38%and 7. 21%, respectively. No statistically difference was observed between different genders. The prevalence of VAD was 1. 93%, 3. 17% and 1. 47% for different age groups( 60 ~ 69, 70 ~ 79 and above 80 years old), and no statistically difference was observed between different age groups. The prevalence of marginal VAD was 5. 87%, 6. 20% and 11. 74% for different age groups, and statistically difference was observed between different age groups( χ~2= 7. 3858, P = 0. 039). CONCLUSION: Chinese rural elderly population has a certain degree of vitamin A deficiency and marginal deficiency, the marginal deficiency of the elderly over 80 years old is more common.

Prevalence and influence factors of vitamin A deficiency of Chinese pregnant women.

BACKGROUND: Vitamin A plays an important role in the periods of rapid cellular growth and differentiation, especially during pregnancy, which is supplied by the mother to the fetus. The aim of this study is to assess the prevalence and potential influence factors of prenatal VAD of Chinese pregnant women. METHODS: China National Nutrition and Health Survey 2010-2013(CHNNS2010-2013) is a nationally representative cross-sectional study. It involved the random selection of 150 districts (urban) or counties (rural). Each site randomly selected 30 pregnant women. Because volume of blood and incomplete data was taken into consideration,the final sample was formed by 1209 participants. Serum retinol concentrations were measured by high performance liquid chromatography. Characteristics of the pregnant women were collected by a questionnaire. Comparing retinol level across categories of independent variables was tested by the Mann-Whitney U test. Logistic and linear regression analyses were used to identify influence factors of Chinese pregnant women. RESULTS: The mean serum retinol level of the pregnant women was 1.63 µmol/L (95 % CI 1.60-1.67) and 64[5.3 % (95 % CI 4.03-6.56)] had VAD. The odds of VAD were significantly higher among the pregnant women in the poor rural areas and without college or university education and low- income. Pregnant women in the second and third trimester had 2.40 (95 % CI 1.05-5.46) and 2.82 (95 % CI 1.34-5.93) times increased odds of VAD compared with those in the first trimester respectively. Pregnant women of drinker had 3.10(1.65-5.81) times increased odds of VAD compared with those no drinker. Pregnant smokers had 5.68 (95 % CI 2.23-14.49) times higher odds of VAD compared with pregnant with non-smoker without passive smoking. CONCLUSIONS: VAD is of mild public-health issue in Chinese pregnant women. Such as : in the poor rural areas and without received college or university education and low- income and advanced gestational age and unhealthy lifestyles of pregnant women such as smoking and drinking. These were pertinent influence factors of VAD.

Comparison on the status of vitamin A in 6- to 13- year-old children between 2002 and 2012 in China.

BACKGROUND: Vitamin A deficiency is recognized as a major public-health nutrition issue in the developing countries. Limited hospital sources and sample sizes are available in most of the existing studies associated with healthy school-age children. The aim of this study was to compare vitamin A status of 6- to 13-year-old healthy children in China between 2002 and 2012. METHODS: According to China National Nutrition and Health Survey 2002 (CHNNS2002) and CHNNS2010-2013, we choose 6- to 13-year-old children as the research object. We measure the serum retinol concentrations of the children using high performance liquid chromatography (HPLC). The children were divided into two groups: 6- to 9-year-old and 10- to 13-year-old. The areas were divided into urban and rural area. RESULTS: Total number of the children (6- to 13-year old) was 8170 in 2002 survey, and it was 6016 in 2012 survey. In 2012, the vitamin A level of the children was higher than that in 2002 (t = 39.26, p = 0.000). The level of vitamin A in 10- to 13-year-old group was higher than that in 6- to 9-year-old group across areas and genders between 2002 and 2012. There was no difference on the incidence of vitamin A deficiency in all the children between 2002 and 2012, but in 2012 the incidence of vitamin A deficiency in the urban children was higher than that in 2002 (x (2) = 45.456,p = 0.000). The incidence of vitamin A deficiency in 10- to 13-year-old group was lower than that in 10- to 13-year-old group across areas and genders between 2002 and 2012. In 2012, the incidence of marginal vitamin A deficiency in the children was lower than that in 2002 (x (2) = 861.604, p = 0.000). Similar phenomena were also found in across area groups. The incidence of marginal vitamin A deficiency in 10- to 13-year-old group was lower than that in 6- to 9-year-old group across areas and genders between 2002 and 2012. There was no difference in vitamin A status of the children across the area, gender and age groups between 2002 and 2012. CONCLUSION: Vitamin A nutritional status of the children in 2012 has been significantly improved compared with that in 2002. However, vitamin A deficiency was still a moderate public health problem in Chinese children, especially in younger school-age children. Consequently, controlling the incidence of vitamin a deficiency is imperative for promoting Chinese children's health.

[Study on the anemia status of Chinese urban residents in 2010-2012].

OBJECTIVE: The level of blood hemoglobin and the anemia status of Chinese urban residents in 2010-2012 was analyzed. METHODS: All the data in this study came from the China Nutrition and Health Survey in 2010-2012. By using multi-stage stratified sampling and population proportional stratified random sampling method, 74 276 residents aged above 6 from 34 metropolis and 41 middle-sized and small cities were included in this study. The concentration of blood hemoglobin was determined by cyanmethemoglobin method. Anemia was judged by the anemia standard recommended by WHO, combined with elevation correction standard. The level of blood hemoglobin, the prevalence of anemia and the 95%CI value were analyzed by using the complex sampling weighted processing, combined with the population figures released by the National Bureau of Statistics in 2009. RESULTS: In 2010-2012, the level of blood hemoglobin of Chinese city population was(144.16 ± 0.78)g/L, (152.88 ± 0.94)g/L for male and(135.01 ± 0.71)g/L for female, while (145.65 ± 1.22)g/L for metropolis and (143.90 ± 0.89)g/L for small and medium-sized. The anemia prevalence of Chinese city population (pregnant women were not included) was 9.7%(95%CI: 9.4%-10.1%), 6.8%(95%CI: 6.4%-7.3%) for male and 12.8%(95%CI: 12.2%-13.4%) for female, while 8.5%(95% CI: 8.0%-9.0%) for metropolis and 10.0%(95%CI: 9.5%-10.4%) for small and medium-sized. The anemia prevalence of 18-44 women (15.4%, 95%CI: 14.3%-16.6%) was the highest among all the age-groups, and the average anemia prevalence of people more than 60 years-old (including) (12.5%, 95%CI: 11.8%-13.2%) was higher than the other age-groups. CONCLUSION: The anemia prevalence of Chinese city population in 2010-2012 was obviously decreased in comparison of 10 years ago, while, more attention and improvement measures should be take upon women at reproductive age and the elder people.

[Systemic evaluation of zinc nutritional status for children aged 2-5 years from rural areas of China in 2002].

OBJECTIVE: To perform zinc nutritional assessment of children aged 2- 5years in rural areas of China according to the joint recommendation by the WHO /UNICEF / IAEA / IZi NCG. METHODS: Based on the project of China Nutrition and Health Survey 2002( CNHS 2002), a stratified sampling combined with the probability proportional to population size sampling method was employed. The concentration of plasma zinc was determined by high resolution inductively coupled plasm mass spectrometry, and the data of dietary zinc intake and the physical examination was collected. The assessment of zinc nutrition was obtained by 3 aspects of indicators involving plasma zinc, dietary zinc intake and the development of growth. RESULTS: Plasma zinc concentration was 714. 9 µg / L, and 45. 5% of children with zinc deficiency. Dietary zinc intake was 5. 9 mg / d, and the prevalence of inadequate dietary zinc intake was 18. 1%. The height for age Z score was- 0. 8, with 18. 2% of children who were stunted. CONCLUSION: Zinc nutritional status of children aged 2- 5 years in rural areas is poor in the CNHS 2002. The status of plasma zinc is utmost serious in comparison withother indicators. The status of zinc nutrition in children aged 2- 5 years from the 4th rural areas is required to be continuous attention. Zinc nutrional assessment provides an extremely useful information and technical reference for early childhood.

[Application of three different methods for estimating of the plasma volume in children].

OBJECTIVE: To investigate the difference between three methods for estimating the plasma volume in children. METHODS: The blood volume of 57 children from 10 to 12 years old were estimated by weight, formula proposed by Woodhead, and by bioelectrical impedance analysis( BIA), the effect and consistency of three methods were also compared. RESULTS: There was no difference between three methods in blood volume estimating( P > 0. 05). According to the results of Passing & Bablok regression regression analysis, the residual standard deviation( RSD) was 85. 88, 122. 83 and 111. 24. The regression equation were: y_(Woodhead)= 577. 356224 + 0. 800525x_(BW); y_(BIA)=1091. 590338 + 0. 653032x( BW); y( BIA)= 560. 545257 + 0. 843899x_(Woodhead), and there was no obvious departure from the linear correlation( P > 0. 05). After regrouping by the percent body fat, there were differences between three methods in weight in overweight and obese children group( P < 0. 05), the blood volume estimated by weight was thehighest, and by the BIA was the lowest. While in normal group there was no difference between three groups(P<0. 05). CONCLUSION: Three methods in blood volume estimating has a good consistency, estimating by body weight and formula have the virtue of convenience. Method of BIA is extremely fit for application in children with higher body fat.

[Association of leptin receptor gene polymorphrism with metabolic syndrome in older Han adults from major cities in China].

OBJECTIVE: To investigate the relationship of leptin receptor gene rs1137100 and rs1137101 single nucleotide polymorphrism (SNP) with metabolic syndrome (MS) in older Han adults from major cities in China. METHODS: A total of 2082 older Han adults were selected from 18 major cities including 15 provinces/municipalities of China National Nutrition and Health Survey in 2002. According to the MS definition proposed by Joint Interim Statement (JIS), the subjects were divided into MS and control groups. Plasma leptin and insulin levels were measured. The genotypes of rs1137100 and rs1137101 were detected by Taqman method. Association of genotypes of leptin receptor gene SNPs with MS was investigated. RESULTS: The MS group showed higher body mass index (BMI), waist circumference, fasting serum glucose, systolic blood pressure (SBP) and diastolic blood pressure (DBP), triglycerides (TG), serum total cholesterol (TC), insulin, homeostasis model of assessment for insulin resistence index (HOMA-IR) and leptin levels than those of control individuals, while the high density lipoprotein cholesterol (HDL-c) was significantly lower than the control group. The, GG, AA, GA genotypes distribution and the A allele frequency of rs1137100 and rs1137101 were similar between the two groups. The DBP and SBP level were obviously higher in AA genotype. The HDL-c concentration Was significantly lower in AA and GA + AA genotype. The AA and GA genotypes carriers in rs1137100 had similar risk for MS when comparing with the GG genotypes, and the OR values were 1.23 (95% CI 0.90-1.67) and 2.23 (95% CI 0.83-6.44), respectively. The AA and GA genotypes carriers in rs1137101 had similar risk for MS when comparing with the GG genotypes, and the OR values were 1.23 (95% CI 0.90-1.67) and 2.23 (95% CI 0.83-6.44), respectively. CONCLUSION: Leptin receptor genes rs1137100 and rs1137101 are not associated with pathogenesis of MS in older Han adults, but it may relate with hypertension or lipid abnormality.