[Suggestions on prevention throughout whole life cycle to curb the rapidly increasing prevalence of noncommunicable diseases in the population].

Chronic non-communicable diseases (NCDs) have become diseases that seriously threaten the health and quality of life of the Chinese population, and also become a major public health problem affecting the national economic and social development. With the intensification of China's population aging, the economic burden caused by NCDs will further increase. More and more evidence has shown that NCDs could be prevented, and the prevention and control of NCDs have been considered as a core task of building a healthy China. Therefore, precise personalized nutrition and the prevention of NCDs from the age of zero, which is called the "Double Zero Strategy", would provide a well-consolidated basis for body tissue structure, and prevention of NCDs should also begin at age zero, and then extend to the first 1 000 days of life. The "Double Zero Strategy" preventive intervention can improve the nutritional status, balance diet and nutrition, and increase physical activity among children, adolescents, adults, and the elderly, all of which can reduce the risk of chronic disease, disability, and death. Therefore, launching the "Double Zero Strategy" for full life cycle prevention will help to achieve China's health goals in the new era, and provide more comprehensive measures and plans for implementing the goal of a healthy China.

[The ten-year retrospect of nutrition and health status of pregnant women in China].

Improvement of the nutrition and health status of pregnant women should be one of the top priority strategies of improving the physical fitness of next generation and reserve of talented person for national sustainable development. This paper reviews the nutrition and health status of pregnant women in China over the recent ten years and discusses the underlying factors and changing trends. The most popular nutrition-related problem is dietary imbalance, and many micronutrient intakes are lower than the recommended dietary intakes or adequate intakes, and some of nutrient intakes are still at a very low level for a long time such as vitamin D and calcium. The nutrition-related health problems are mainly anemia, vitamin D and vitamin A deficiencies; iodine intake is not in optimal state with a large proportion of inadequate and individual cases facing excessive intake risk. Overweight and obesity, pregnancy complications such as gastrocnemius muscle spasms, pregnancy hypertensive disorders and gestational diabetes were prevalent among pregnant women. We should address both malnutrition and nutrition imbalance in the same time in order to improve the nutrition and health status of pregnant women, by developing and implementing relevant laws and regulations, giving higher attention to pregnant women with advanced age, which in turns prevent a variety of micronutrient deficiencies, reduce adverse pregnant outcomes, and improve nutrition and health status of maternal and child.

[Prevalence of calf muscle cramps and influencing factors for pregnant women in China during 2010-2012].

Objective: To investigate the prevalence of calf muscle cramps and possible influencing factors for pregnant women in China. Methods: Using a multi-stage stratified probability proportional to size cluster randomization sampling method during 2010-2012. A total of 3 582 pregnant women were investigated at 150 counties from 31 provinces in China mainland. Information on calf muscle cramps, demographic socio-economic status, pregnancy information, and the physical activities was collected through questionnaires. The semi-quantitative food frequency questionnaire (FFQ) was used to collect food intake of pregnant women. Dynamic cluster analysis was used to assess dietary pattern. Multiple logistic regression was used to investigate the possible influencing factors for calf muscle cramps. Results: The prevalence of calf muscle cramps was 32.9% (1 180/3 582) in Chinese pregnant women, which was 11.6% (87/748), 28.2% (420/1 492), and 50.2% (673/1 342), respectively, during the first, second and third trimester. There were significant differences between them (χ(2)=349.16, P<0.001). Dietary patterns of the pregnant women were classified into three groups, which called relatively balanced pattern, high vegetables and fruits pattern, and high dairy pattern. Among the three groups, the prevalence of calf muscle cramps was 32.0% (952/2 971), 37.2% (186/500), and 37.8% (42/111), with significant differences (χ(2)=6.39, P=0.041). The OR (95%CI) values of calf muscle cramps in the second and third trimester was 2.96 (2.28-3.83), and 8.02 (6.16-10.44), respectively, comparing with the first trimester. The OR (95%CI) values of calf muscle cramps in the women taking calcium before pregnant was 1.45 (1.19-1.76), comparing with the one who was not taken. The OR (95%CI) values of calf muscle cramps in the women who had been diagnosed by pregnancy-induced hypertension was 5.76 (2.06-16.12), comparing with the one who had not been diagnosed. The OR (95%CI) values of calf muscle cramps in the high vegetables and fruits pattern and high dairy pattern was 1.13 (0.91-1.41), and 1.18 (0.76-1.81), respectively, comparing with the relatively balanced pattern. Conclusion: The prevalence of calf muscle cramps was relatively high in Chinese pregnant women, which was significantly different among three trimesters. The residential areas, occupation, and pregnancy-induced hypertension might be related to the prevalence of calf muscle cramps. However, there was no significant difference among different dietary patterns.

[Gestational weight gain and optimal ranges in Chinese mothers giving singleton and full-term births in 2013].

Objective: To analyze the status of gestational weight gain (GWG) among Chinese mothers who gave singleton and full-term births, and to look at optimal GWG ranges. Methods: In 2013, using the multi-stage stratified and population proportional cluster sampling method, we investigated 8 323 mother-child pairs at their 0-24 months postpartum from 55 counties (cities/districts) of 30 provinces (except Tibet) in mainland China. Questionnaire was used to collect data on body weight before pregnancy and delivery, diseases during gestation, hemorrhage or not at postpartum, child birth weight and length, and other information about pregnant outcomes. We measured mother's body weight and height, and child's body weight and length. Based on 'Chinese Adult Body Weight Standard', we divided mothers into four groups according to their body weight before pregnancy: low weight (BMI<18.5 kg/m(2)), normal weight (BMI 18.5-23.9 kg/m(2)), overweight (BMI 24.0-27.9 kg/m(2)) and obesity (BMI≥28.0 kg/m(2)). The status of GWG was assessed by IOM optimal GWG guidelines. Chinese optimal GWG ranges were calculated according to the association of GWG with pregnant outcomes and anthropometry of mothers and children, and according to P25-P75 of GWG among mothers who had good pregnant outcomes and good anthropometry, and whose children had good anthropometry. The status of GWG was assessed by the new optimal ranges. Results: P50 (P25-P75) of GWG among the 8 323 mothers was 15.0 (10.0-19.0) kg. According to the proposed optimal GWG ranges of IOM, the proportions of inadequate, optimal and excessive GWG accounted for 27.2% (2 263 mothers), 36.2% (3 016 mothers) and 36.6% (3 044 mothers). The optimal GWG ranges for low weight, normal weight, overweight and obesity were 11.5-18.0, 10.0-15.0, 8.0-14.0 and 5.0-11.5 kg. Based on these optimal GWG ranges established in this study, the rates of inadequate, optimal and excessive GWG were 15.7% (1 303 mothers), 45.0% (3 744 mothers) and 39.3% (3 276 mothers), and these rates were significantly different from that defined by the IOM standards (χ2=345.36, P<0.001). Conclusion: The median of GWG among Chinese mothers is 15.0 kg, which is at a relatively higher level. This study suggests the optimal GWG ranges for Chinese women who give singleton and full-term babies, which appears lower than IOM's.

[Analysis on maternal anemia rate and related factors in Taicang of Jiangsu Province in 2014-2016].

Objective: To investigate anemia rate and to analyze related factors in maternal women in Taicang of Jiangsu province. Methods: There were 13 278 pregnant women who had prenatal care and gave birth in 25 hospitals during 2014-2016 in Taicang of Jiangsu Province. We excluded 1 179 women who registered after 12 weeks of gestation, 144 women who did not test hemoglobin during gestation, and 25 women whose gestational weeks were incorrect. Finally, data from 11 930 pregnant women were analyzed. From the electronical medical record system of maternal and child health care, we obtained basic information of these pregnant women, their hemoglobin levels and related data during gestation and postpartum. Anemia rate was descripted, and factors associated with anemia were identified using multiple unconditional logistic regression. Results: Age of the 11 930 pregnant women was (27.0±4.5) years old, and the P(50) (P(25)-P(75)) of BMI at the first trimester was 21.4 (19.6-23.7) kg/m(2). The anemia rate during gestation was 37.2% (4 434/11 930). The anemia rate was 5.5% (276/5 035), 24.4% (1 802/7 377), and 47.8% (3 328/6 966) at the first, second and third trimesters, respectively. Anemia rate at 42 days postpartum was 19.9% (680/3 418). Multiple unconditional logistic regression indicated that anemia during gestation was related with maternal age <21 years old at prenatal registration (OR (95%CI): 1.28 (1.07-1.53)), body mass index(BMI) <18.5 kg/m(2) at the first trimester (OR (95%CI): 1.14 (1.00-1.29)), non-local residence (OR (95%CI): 1.35 (1.20-1.52)), education of middle school and lower (OR (95%CI): middle school: 1.24 (1.05-1.47), primary school: 1.36 (1.01-1.82)), occupation of housewife or farmer (OR (95%CI): housewife: 1.21 (1.06-1.38), farmer: 1.21 (1.03-1.44)). Anemia at 42 days postpartum was associated with multipara (OR(95%CI): 1.59 (1.12-2.27)), anemia at the first trimester (OR(95%CI): 3.26 (1.92-5.55)), no folic acid supplementation at the first trimester (OR(95%CI): 1.34 (1.00-1.80)), and hemorrhage≥500 ml during 24 h postpartum (OR(95%CI): 2.26 (1.02-4.97)). Conclusion: Anemia rate was low for maternal women in Taicang of Jiangsu Province. The factors associated with gestational anemia included pregnant women's age, BMI, local or non-local residence, occupation, and education. The factors associated with postpartum anemia included multipara, anemia at the first trimester, no folic acid supplementation at the first trimester, and hemorrhage 24 h postpartum.

[The influencing factors of anemia for pregnant women between 2010-2012 in China].

Objective: To investigate the prevalence of anemia and related risk factors for pregnant women in China. Method: Based on Chinese National Nutrition and Health Surveillance 2010-2012, a total of 3 501 pregnant women were investigated from 150 counties of 31 provinces, municipalities and autonomous regions in China, using a multi-stage stratified cluster randomization sampling method. General information of pregnant women, health status, and food intake during the gestation, was collected through a questionnaire investigation. 6 ml fasting venous blood was collected for the determination of hemoglobin concentration. Data were analyzed using multiple logistic regression to investigate the prevalence of anemia and the related influencing factors. Results: The 605 of 3 501 pregnant women had anemia. The prevalence of anemia was 17.2%; and mild anemia accounted for about 61.0% (369/605). Compared with the pregnant women living in the large cities, the OR (95%CI) of those living in the poor rural areas was 1.46 (1.08-1.98). Compared with the pregnant women living in the south area of China, the OR (95%CI) of those living in the north area of China was 1.39 (1.15-1.68); Compared with the pregnant women in the first trimester, the OR (95%CI) of those in the second trimester and the third trimester were 1.79 (1.33-2.43) and 2.11 (1.56-2.85), respectively. The OR (95%CI) of pregnant women who had used folic acid supplementation within the 6 months prior to gestation was 0.76 (0.63-0.93) compared with those who had not used. Conclusion: From 2010 to 2012, the epidemic characteristics of anemia was mild for the pregnant women in China, and pregnant women residential areas, periods of pregnancy and whether to take folic acid were related to anemia.

[Status and related factors for gestational weight gain of Chinese pregnant women during 2010-2012].

Objective: To examine the status and related factors for gestational weight gain of Chinese pregnant women at different trimesters in 2010-2012. Methods: Participants were from Chinese National Nutrition and Health Surveillance in 2010-2012. Using a multi-stage stratified cluster random sampling method, we recruited 2 805 singleton pregnant women with gestational age 13 weeks or more from 31 provinces of China. A standard questionnaire was used to collect general information and pre-pregnancy weight; body weight and height of pregnant women were measured using a unified weighing scale and stadiometer, dietary intake during the previous year was collected using a food frequency questionnaire. A multiple logistic regression was used to analyze potential factors associated with appropriate gestational weight gain. Results: Among 2 805 pregnant women, 1 441 were in the second (13-27 weeks) and 1 364 in the third trimesters (≥28 weeks) . In the 2(nd) trimester, 229 cases (15.9%), 440 cases (30.5%) and 772 cases (53.6%) were insufficient gestational weight gain, appropriate gestational weight gain and excessive gestational weight gain respectively. So were 256 cases (18.8%), 474 cases (34.8%), 634 cases (46.5%) in the 3(rd) trimester respectively. In the multivariate unconditional logistic model, less fruit intake was associated with insufficient weight gain for women in the 2(nd) trimester (OR (95%CI): 1.58 (1.06-2.34)). Pregnant women with Han ethnicity who live in the small/medium city had lower risk of insufficient weight gain in the 3(rd) trimester (OR (95%CI): 0.58 (0.34-0.98)). Those pregnant women with physical activity <1 hour/day had a higher risk of excessive weight gain (OR (95%CI): 1.33 (1.02-1.73)). Conclusion: The prevalence of appropriate gestational weight gain was low in China. Our study suggests that pregnant weight gain is associated with fruit intake, types of residential area and physical activity.

[Focus on nutrition of lactating women and promoting maternal and child health].

Breastfeeding has been existing from the beginning of human beings. The focus has usually been on breast milk and breastfed infants. However, there have been a few studies on nutrition and health status of lactating women worldwide. Many of these studies suggested that the nutrition and health status of the women not only can affect milk volume and nutrient contents, but also may have short- and long-lasting effects on their health status. Therefore, more research should focus on breastfeeding and the improvement of nutrition and the health status of lactating women.

[The nutrition status of lactating women in China].

Nutritional status of lactating women is considered to be a quantitative indicator reflecting the status of reproductive health. To improve nutrition status of lactating women and promote breastfeeding through targeted intervention measures, their dietary and nutritional situations, and related problems, should be fully understood. Generally, energy and macronutrient intake of lactating women can reach or exceed recommended levels, especially during the first month postpartum. However, the intake of some micronutrients is difficult to meet the requirement. These include vitamin D and vitamin B12, iron and zinc, and calcium, if milk and dairy product consumption is very low, suggesting that extra supplementation should be considered. The percentage of obesity or postpartum weight retention showed an increasing trend in urban and rural areas and was related to decreased or delayed breastfeeding or early weaning. Common micronutrient deficiencies included in vitamin D, vitamin B12, iron and zinc. In this paper, we reviewed various characteristics of the lactating women, including nutritional status, postpartum weight retention and micronutrient deficiencies. We suggest that improved suggestions be developed for China, based on data from National Nutrition Survey, Chinese National Nutrition and Health Surveillance and related studies conducted over the past 10 years.

[Dietary intake status of Chinese lactating women during the first month postpartum in 2013].

Objective: To assess the dietary intake status of Chinese lactating women during the first month postpartum. Methods: Data were extracted from Chinese National Nutrition and Health Surveillance, children aged 0-5 years and lactating women (2013). A total of 55 counties from 30 provinces in China (excluding the Tibet Autonomous Region) were selected using a multi-stage stratified cluster randomization sampling method. A group of 3 623 lactating women, at 1-6 months after delivery, were investigated in the study. The semi-quantitative food frequency questionnaire (FFQ) was used to collect information on frequencies and amounts of food consumed. Differences in food consumption rates and dietary intake in lactating women having different characteristics were analyzed and compared. Results: To eliminate abnormal values, 3 300 lactating women were included in the study. During the first month postpartum, food types with higher consumption rates were animal products (98.2%, 3 239) and vegetables (90.7%, 2 987), in addition to cereals (100%) and liquids (100%). The consumption rate of fruits was 67.4% (2 222) and the lowest consumption rate was for dairy products (38.3%, 1 262). The median intake of cereals, vegetables, fruits and animal products were 247.8, 150.0, 40.0 and 178.6 g/d, respectively. The daily median intake of dairy products and soybean/nut products was 0.0 g/d. Overall, the lactating women consumed 895.7 ml/d liquids. About 49.3% (1 627) of the subjects consumed less than the recommended intake for animal products in Chinese Dietary Guideline (2016). More than 50% of the lactating women consumed less than the recommended intakes for the other types of food, especially dairy, soybean/nut and liquids. The consumption rates for dairy products were 26.9%, 29.4%, 31.8% and 33.8% and those for soybean/nut products were 33.9% , 35.8% , 37.5% and 41.7% for the lactating women living in rural areas, with educations at junior high school level and below, with average family incomes under 15 000 yuan per capita in 2012 and who work as household mothers, respectively. These consumption rates for dairy and soybean/nuts were significantly lower than those in women living in cities (48.4%, 55.0%), with an education level of senior high school or above (48.8%, 55.7%), with average family income over 15 000 yuan per capita in 2012 (45.5%, 52.8%) and who work outside the home (43.7%, 49.4%). P values were <0.05 for all comparisons. Conclusion: The daily intake of all foods by lactating women during the first month postpartum was lower than the levels recommended in Chinese Dietary Guideline (2016). The consumption rate of dairy and soybean/nut products during this time period was low, especially for those living in rural areas, with education levels of junior high school and below, with average family incomes less than 15 000 yuan per capita in 2012 and who are housemothers.

[Risk factors for prevalence of folic acid deficiency in Chinese lactating women in 2013].

Objective: The study aimed to assess the folic acid status of lactating women in China and to analyze factors related to folic acid deficiency in these subjects. Methods: The data on lactating women were extracted from the Chinese National Nutrition and Health Surveillance in 2013. By a multi-stage stratified cluster random sampling method, 10 331 lactating women were selected for the study. The lactating women, 0-24 months postpartum, were from 55 sites in 30 provinces of China, excluding the Tibet Autonomous Region. A standard questionnaire was used to obtain general information and dietary intake during the previous one month period was collected using a food frequency questionnaire. A total of 20% of the total number of lactating women were randomly selected to analyze serum folic acid. Finally, 1 894 lactating women, with questionnaire results and serum folic acid data, were included in the study. Serum folic acid concentrations were analyzed using an electro-chemiluminescence immunoassay method. Folic acid deficiency was defined as a serum folic acid level <2 ng/ml. A multiple logistic regression analysis was used to analyze the factors associated with folic acid deficiency in these women. Results: After excluding abnormal values, 1 894 lactating women were included in the study. Based on our findings, the prevalence of folate deficiency was 3.0% (56/1 894) in lactating women in China. The prevalence of folic acid deficiency was 0.3% (1/388), 1.3% (7/550), 6.0% (38/639) and 3.2% (10/317) in larger, medium or small cities, general rural counties and poor rural counties, respectively. The prevalence of folic acid deficiency was 6.3% (17/269) and 2.4% (39/1 623) for minority and Han ethnic groups, respectively, and was 6.3% (52/823) and 0.4% (4/1 071) for subjects in northern and southern areas of China, respectively. Binary unconditionally logistic regression was used to analyze the factors associated with folic acid deficiency in the lactating women. The results showed that, compared with those living in the south and those in the Han ethnic group, those living in the north and belonging to the minority ethnic group had a greater risk of folic acid deficiency, with (OR=3.63, 95% CI: 1.64-8.05) and (OR=5.42, 95% CI: 1.75-16.74), respectively. With each month of age during childhood, the prevalence of folic acid deficiency decreased by 10% (OR=0.90, 95%CI: 0.85-0.96). Compared with low income subjects, those with middle incomes had OR (95%CI) of 0.25 (0.10-0.60) for folic acid deficiency. A lesser intake of cereal was associated with a greater risk of folic acid deficiency in lactating women (OR=3.04, 95%CI: 1.18-7.79). A lesser intake of tubers was a protective factor for folic acid deficiency in lactating women (OR=0.29, 95% CI:0.12-0.70). Conclusion: The folic acid status of Chinese lactating women has, in general, recently improved. However, living in northern areas, during early lactating periods, belonging to an ethnic minority, living in rural areas, having a low income, lower intake of cereal and excessive intake of tubers were risk factors for folic acid deficiency in lactating women. In these women, folic acid intervention should be considered a priority.

[Nutritional status and influence of vitamin D among Chinese lactating women in 2013].

Objective: To analyze serum vitamin D levels in Chinese lactating women, in 2013, and to evaluate their vitamin D nutritional status and influencing factors. Methods: Data were from the Chinese National Nutrition and Health Surveillance in 2013. Using the multistage stratified cluster sampling method, serum samples from lactating women, at 0-24 months postpartum, were obtained from 55 sites in 30 provinces of China, excluding the Tibet Autonomous Region. The concentration of serum vitamin D was determined by mass spectroscopy. A standard questionnaire was used to obtain basic information and the season of blood collection. Dietary information for one recent month was collected using a food frequency questionnaire. A total of 1 981 lactating women were included in the study. A multiple logistic regression model was used to analyze the factors related to vitamin D levels among lactating women. Results: The mean vitamin D level was (16.6±6.5) ng/ml, the prevalence of vitamin D deficiency (VDD) (vitamin D<12 ng/ml) was 25.2% (499 cases) and the prevalence of vitamin D inadequacy (12 ng/ml≤vitamin D<20 ng/ml) was 45.4% (900 cases). Compared with in the Han ethnic group, the OR value of VDD was 13.37 for Muslim ethnic women. Compared with women having a junior high school education or below, the OR value of VDD was 1.40 for those women with an educational level of senior high, middle school or above. Compared with housewives or nonworking women, the OR value of VDD was 1.62 for professional women. Compared with women living in general rural settings, the OR values of VDD for women living in large cities, medium and small cities or poor rural settings were 1.99, 1.46 and 2.66 respectively. Compared with the women surveyed in the fall, the OR value of VDD was 2.19 for the women surveyed in winter or spring. The VDD prevalence increased with higher latitude (OR=1.12) and decreased with increased meat consumption per day (OR= 0.73). (P<0.05 for all comparisons). Conclusion: Vitamin D deficiency and vitamin D inadequacy were common in lactating women in China. Those with increased risk of VDD included lactating women who were ethnic Muslims, with higher education levels, engaged in a professional occupation, living in higher latitude region and were surveyed in winter and spring.

[Prevalence of and risk factors for delayed onset of lactation in Chinese lactating women in 2013].

Objective: To study the prevalence of delayed onset of lactation (later than 3 days) in lactating women in China and to analyze its influencing factors. Methods: Data were extracted from Chinese National Nutrition and Health Surveillance-Mothers, from mothers with children under 2 years of age (in 2013). A total of 11 178 women who were lactating or had lactated were selected from 55 counties of 30 provinces (excluding the Tibet Autonomous Region) in China, using the multi-stage stratified cluster randomization sampling method. Basic information, including onset of lactation, initiation of breastfeeding, breastfeeding difficulties and breastfeeding knowledge were collected using a questionnaire investigation. The prevalence of delayed onset of lactation were analyzed by the weighted processing of complex sampling from the 6th national population census data. A multiple logistic regression was used to analyze the factors associated with delaged onset of lactation. Results: Among 11 178 lactating women, 3 388 had an onset of lactation later than 3 d. The prevalence of delayed onset of lactation was 30.3%. After complex weighting, the prevalence of delayed onset of lactation was 31.2% (95% CI: 25.7%-36.8%) for lactating women in China. Delivery by Caesarean section (OR=1.28, 95%CI: 1.06-1.53) and initiating breastfeeding ≥4 h (OR= 2.34, 95%CI: 1.76-3.11) were the negative factors for delayed onset of lactation. Compared with those living in large cities, lactating women living in medium or small cities (OR=1.39, 95%CI: 1.05-1.84) had a higher risk of delayed onset of lactation. Compared with the lactating women doing housework, the risk of delayed onset of lactation was lower (P<0.05) among those whose occupations were as leaders of Enterprises/Institutions (OR=0.68, 95%CI: 0.47-0.99), in catering and service trades (OR=0.61, 95%CI: 0.43-0.86), in agriculture/forestry/fishery/herdsmen fields (OR=0.65, 95%CI: 0.44-0.96) and who were unemployed (OR= 0.64, 95%CI: 0.46-0.90). Breastfeeding education during pregnancy might lower the risk of delayed onset of lactation (OR=0.78, 95% CI: 0.62-0.98). Conclusion: The prevalence of delayed onset of lactation was relatively high for Chinese lactating mothers. Caesarean section and late initiation of breastfeeding were the primary risk factors. Lactating mothers living in medium or small cities and those doing housework appear to be high-priority groups for intervention. Based on our findings, breastfeeding education during pregnancy is recommended to lower the risk of delayed onset of lactation.

[The status of postpartum weight retention and its associated factors among Chinese lactating women in 2013].

Objective: To analyze the status of postpartum weight retention and its associated factors among Chinese lactating women in 2013. Methods: This study was based on the databank of Chinese National Nutrition and Health Surveillance in 2013. Using the multi-stage stratified cluster sampling method, we enrolled 12 514 women, at 0-24 months postpartum, from 55 sites in 30 provinces of China (excluding the Tibet Autonomous Region). Questionnaires were used to collect data on basic characteristics, physical activity, lifestyle, food intake, pre-pregnancy weight, weight before delivery, disease history during pregnancy, delivery date, delivery mode, parity and breastfeeding information. Current body weight and height of each subject were measured. Postpartum weight retention in each subject was calculated as the difference between pre-pregnancy and current weights. High postpartum weight retention was defined as ≥5 kg. Survey sample weights were calculated according to the sampling design and number of children under 2 years old from 2010 population census data of China. Associated factors of high postpartum weight retention were identified by multiple logistic regression analysis. Results: A total of 9 972 women were included in this study. P50 (P25-P75) of weight retention for participants was 3.6 (0.2-7.3) kg and high weight retention accounted for 41.5% of the subjects (4 134/9 972). The weighted means (SE) of weight retention was 3.5 (0.1) kg, and it was at 0 to <3, 3 to <6, 6 to <9, 9 to <12, 12 to <18 and 18 to <24 months postpartum were 5.3 (0.2), 4.5 (0.2), 3.8 (0.2), 3.1 (0.2), 2.8 (0.2) and 3.0 (0.2) kg, respectively. The weighted proportion of high postpartum weight retention was 37.4% (95%CI: 36.0%-38.9%). Compared with women aged under 25 years old, the odds ratio of high postpartum weight retention was 1.31 for women over 30 years old. Compared with women at 18 to <24 months postpartum, the odds ratio of high postpartum weight retention was 2.67, 1.61 and 1.31 for women at 0 to <3, 3 to <6 and 6 to <9 months postpartum, respectively. Compared with women having a pre-pregnant BMI from 18.5 to <25.0 kg/m2, the odds ratio of high postpartum weight retention was 1.30 and 0.67 for women having pre-pregnant BMI <18.5 kg/m2 and ≥25.0 kg/m2, respectively. Compared with women having appropriate gestational weight gain, the odds ratio of high postpartum weight retention was 0.47 and 2.24 for women having low and excessive gestational weight gains, respectively. Compared with farmers, the odds ratio of high postpartum weight retention was 1.44 for housewives. (P<0.05 for all comparisons). Conclusion: Postpartum weight retention in Chinese lactating women is at an intermediate level. High postpartum weight retention is primarily associated with age, postpartum period, pre-pregnant BMI, gestational weight gain and career. The key control factor for weight retention is gestational weight gain, and 1 year postpartum is critical period for weight recovery.

Effects of dietary zinc and cadmium on tissue selenium concentration and glutathione peroxidase activity in rats fed DL-selenomethionine or sodium selenite.

The effects of dietary zinc (Zn) and cadmium (Cd) on tissue selenium (Se) concentration and glutathione peroxidase (GSH-Px) activity were studied in weanling male Wistar rats. One group of rats was fed a purified diet based on casein and sucrose, and the other rats used in a 2 x 2 x 2 factorial arrangement of treatment were fed this diet supplemented with 0.1 mg Se/kg, either as DL-selenomethionine or sodium selenite and plus 100 mg Zn/kg as zinc sulfate or 5 mg Cd/kg as cadmium chloride or both for 4 weeks. Se concentrations in plasma, erythrocytes, muscle, heart, and liver were significantly elevated by Zn. Cd significantly decreased Se concentration in muscle. Addition of Zn to the diets markedly increased (p less than 0.001) hepatic GSH-Px activity. However, Cd in the diets produced a significant increase (p less than 0.001) in erythrocyte GSH-Px activity. These results indicate that Zn level of marginal deficiency (8.6 mg/kg diet) can decrease Se availability and a small excess of Zn increases Se availability for hepatic GSH-Px activity.

The necessity of dietary vitamin B6 to selenium biopotency for tissue selenium and glutathione peroxidase in rats.

Necessity of dietary vitamin B6 to the biopotency of selenium (Se) for the levels of Se and glutathione peroxidase (GSH-Px) in tissues was investigated. Male Wistar 12-week-old rats were fed a vitamin B6-Se-deficient basal diet for 3 weeks, and then the rats were divided into 6 groups. One group was fed the basal diet, the others were fed the diet supplemented with 250 micrograms vitamin B6/100 g as pyridoxine.HCl, or 0.25 mg Se/kg as Na2SeO3 (SeL) or DL-selenomethionine (Se-Met), or both (SeL+B6 or Se-Met+B6) for 10 week. The levels of Se and GSH-Px in erythrocytes and muscle were significantly higher in vitamin B6-supplemented groups than in vitamin B6-deficient groups. There was little effect of this vitamin deficiency on Se level in liver of rats fed SeL; however, a higher Se level in liver was observed in vitamin B6-deficient rats fed Se-Met than in the corresponding B6-supplemented rats. A significant decrease of GSH-Px activity in liver was found in vitamin B6-deficient animals fed Se-Met compared with vitamin B6-supplemented animals, whereas no significant decrease was observed in those fed SeL. These results suggest that this vitamin is involved in the transport and deliverance of Se in plasma to the other tissues and the incorporation of Se from Se-Met to GSH-Px in liver.

[The comparison of selenium status between the children suffered from pneumonia and the normal children from kindergarten].

In order to investigate the relationship between selenium (Se) status and pneumonia children, the levels of Se and glutathione peroxidase (GSH-Px) in plasma and white blood cells and Se content in urine were determined in 57 cases with pneumonia and 85 control children under 10 years old. The results showed that the levels of Se and GSH-Px in plasma and white blood cell in the group of pneumonia were significantly lower, but the content of Se in urine was higher. Se content and GSH-Px activity in white blood cells of patients during crisis were significantly lower than those of patients during convalescence.

[Effect of selenium status on the morbidity of interstitial pneumonia in rats infected with mycoplasma].

To investigate the effect of selenium(Se) status on morbidity and process of interstitial pneumonia, we used the Wistar rats as the animal model infected with Mycoplasma Pneumonia (MP). The rats were maintained on the based diets with different doses of Se, infected with MP and exposed to sodium selenite(1.5-2.0 ml/day, containing Se 2 micrograms/ml) or 0.9% NaCl (1.5-2.0 ml/d) by gavage for different time. The experimental rats were divided into five groups, group A, feeding with normal control diet and without infected MP, group B with adequate Se diet and infected MP, group C with Se deficiency diet infected MP and added Se at the same time, group D with Se deficiency diet and added Se after suffered with MP, and group E with Se deficiency diet and infected MP. The results showed that the MP morbidity of the rats fed with high Se diet was significantly lower than that of the rats fed with low Se diet. The pathological change was significant in the low Se group and relatively mild in the high Se group. After infected with MP, the supplementation of sodium selenite to the low Se rats might decrease the MP morbidity and shorten the disease course compared with the group without supplementing Se. The incidence of myocarditis in the infected group with normal Se level diet or in the infected group with Se supplement was lower than that in the group without Se supplementation. The concentrations of Se in plasma and glutathione peroxidase in plasma and white blood cells decreased to a certain level after infection. The present study indicated a positive influence of Se supplement on the morbidity, disease course, and state of interstitial pneumonia in rats.

[Effect of selenium on children suffered from Mycoplasma pneumonia].

In order to evaluate the therapeutic effects of Selenium (Se) on Mycoplasma pneumonia, a clinical study was conducted in hospitalized patients using a double blind controlled method. The patients were randomly divided into two groups, the control patients received the routine treatment, and the supplemented group was given 1 mg sodium selenite one time only in addition to the routine treatment. The present study showed that concomitant of Se and routine treatment was superior to routine treatment alone in terms of improvement of clinical signs, time needed for relieving symptoms and signs (P < 0.05). The levels of Se and glutathione peroxidase in plasma and white blood cell were increased in Se supplemented group (P < 0.05). Higher proportion of patients in the treated group showed normalization of T cell subset parameters as compared with the control group. It can be concluded that supplementation of Se would be conducive to the improvement of the nutritional status and the increase of the ability of resisting-infection.