[Evaluation of iron utilization in children using single stable isotopes tracer]

OBJECTIVE

To evaluate the iron utilization in children using single stable isotopes tracer.

METHODS

57 children aged from 10 to 12 from a primary school of Beijing in 2010 were selected, 30 of them were boys and 27 were girls. All the subjects were given 5 ml artificial enriched ⁵⁷FeSO₄ twice per day within 5 days, and the total amount of ⁵⁷Fe was 30 mg. 5 ml blood were taken at 1 day before and 14 days after test, and all the feces during the test were collected. The samples were detected by AAS and MC-ICP-MS after pre-treatment to determine the content and abundances of iron in samples, then the iron utilization in whole blood were calculated.

RESULTS

The blood volume of male and female subjects 14 days after test were (3.19 ± 0.41) and (3.15 ± 0.29) ml respectively, and there was no significantly difference (t = 1.13, P > 0.05) between them; The amount of ⁵⁷Fe intake by male and female subjects were (27.46 ± 0.25) and (27.29 ± 0.15) mg (t = 1.13, P > 0.05); The amount of ⁵⁷Fe in blood were (5.92 ± 0.71) and (6.30 ± 0.65) mg respectively (t = 2.29, P < 0.05); The iron utilization in whole blood at 14 days of male and female subjects were (20.41 ± 2.03)% and (22.04 ± 0.80)% respectively, male subjects were significantly lower than females (t = 2.51, P < 0.05).

CONCLUSION

Single stable isotopes tracer can be used in iron utilization evaluation in children, and the iron utilization in whole blood of female children is higher than males.

Determination of 16 selected trace elements in children plasma from china economical developed rural areas using high resolution magnetic sector inductively coupled mass spectrometry

A rapid, accurate, and high performance method of high resolution sector field inductively coupled plasma mass spectrometry (HR-ICP-MS) combined with a small-size sample (0.1 mL) preparation was established. The method was validated and applied for the determination of 16 selected plasma trace elements (Fe, Cu, Zn, Rb, B, Al, Se, Sr, V, Cr, Mn, Co, As, Mo, Cd, and Pb). The linear working ranges were over three intervals, 0-1  μ g/L, 0-10  μ g/L and 0-100  μ g/L. Correlation coefficients (R (2)) ranged from 0.9957 to 0.9999 and the limits of quantification (LOQ) ranged from 0.02  μ g/L (Rb) to 1.89  μ g/L (Se). The trueness (or recovery) spanned from 89.82% (Al) to 119.15% (Se) and precision expressed by the relative standard deviation (RSD %) for intra-day ranging from 1.1% (Zn) to 9.0% (Se), while ranged from 3.7% (Fe) to 12.7% (Al) for interday. A total of 440 plasma samples were collected from Chinese National Nutrition and Health Survey Project 2002 (CNNHS 2002), which represented the status of plasma trace elements for the children aged 3-12 years from China economical developed rural areas. The concentrations of 16 trace elements were summarized and compared by age groups and gender, which can be used as one of the basic components for the formulation of the baseline reference values of trace elements for the children in 2002.

Long-term toxicity study on transgenic rice with Cry1Ac and sck genes

In the present work, we evaluated the chronic effects of the transgenic insect-resistant rice carrying Cry1Ac and sck genes on Sprague-Dawley (SD) rats through a 78-week feeding study. Based on the gender and weight, 180 SD rats were randomly and evenly assigned into three groups. GM rice and non-GM rice were separately formulated into diets at high levels. AIN-93 diet was used as a nutritional control. Body weight, food consumption, hematology and serum chemistry were monitored regularly. Rats were sacrificed for organ weight measurement and pathological examination at 52 weeks and 78 weeks. Body weight, food consumption, mortality rates, tumor incidences and pathological findings showed no significant difference among the three groups. Although certain differences in some hematology, serum chemistry parameters and relative organ weights were observed between GM rice group and control groups, they were not considered as treatment-related. Taken together, long-term intake of transgenic rice carrying Cry1Ac and sck genes at a high level exerts no unintended adverse effects on rats.

[Study on no-fusion expression and purification of Glycine max dehydration-responsive element-binding protein (GmDREB1) expressed in E. coli]

OBJECTIVE

To obtain enough GmDREB1 protein comparable with native protein for further safety assessment of the protein.

METHODS

The GmDREB1 gene was cloned into no-fusion expression vector pBV220 and the recombinant vector pBV220-GmDREB1 was obtained. The constructed vector was transformed into expression host E. coli DH5a. The protein expression was optimized by improving the codon, induced expression conditions and selecting the appropriate vector. The protein was obtained by cation exchange chromatography and gel filtration chromatography and identified by N-terminal amino acid sequencing, western blotting and activity determination.

RESULTS

The soluble protein was expressed efficiently in E. coli DH5a containing the optimized target gene by 42 degrees C induction for 3 hours and the purified protein consistent with the native protein was obtained through the chromatography.

CONCLUSION

The results of this study illustrated that the GmDREB1 protein could be acquired through prokaryotic host expression which had comparable N-terminal amino acid sequences, immunogenicity and biological activities with those of native GmDREB1 protein.

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

OBJECTIVE

To investigate the association of adiponectin gene rs2241766 (T45G) and rs15011299 (G276T) single nucleotide polymorphrism (SNP) with metabolic syndrome (MS) in older han adults from major cities in China.

METHODS

A total of 907 older Han adults were selected from 18 major cities of the China National Nutrition and Health Survey in 2002. According to the MS definition proposed by International Diabetes Federation, the subjects were divided into MS and control groups. Plasma adiponectin and Genomic DNA was isolated from blood and insulin concentrations were measured. genotypes of rs2241766 and rs15011299 were identified by Taqman method. Association There was of genotypes of adiponectin gene SNPs with MS was analyzed.

RESULTS

significant difference in the distribution of genotypes of rs15011299 SNP between the MS and control group. The T allele frequency of rs15011299 was significantly increased in MS group. For rs15011299 site, there were significant differences of BMI and adiponectin level among the subjects carried GG, GT or TT genotypes. The GG+GT carriers had lower BMI, waist circumference, insulin level and higher adiponectin level than those of TT carriers. For rs2241766 site, there were significant differences of BMI and diastolic blood pressure (DBP) among the subjects carried TT, TG or GG genotypes. The TT carriers had higher BMI, waist circumference and DBP than those of GG+GT carriers. The TT carriers in rsl5011299 had higher risk for MS than GG carriers (OR for TT v. s. GG=3.19; 95% CI 1.31-7.78). No association was found in rs2241766 with MS.

CONCLUSION

The adiponectin gene rs15011299 polymorphrism may be associated with pathogenesis of MS in older Han adults. G-->T variance may be associated with an increased risk of MS and result in a decreased level of aiponectin and increments of waist circumference and BMI.

[Isolation and purification of recombinant human lactoferrin (rhLF) from transgenic rice and its antibacterial activities]

OBJECTIVE

To study the isolation and purification of recombinant human lactoferrin (rhLF) from transgenic rice, and to check its antibacterial activities.

METHODS

After isolated rhLF from transgenic rice via saturated ammonium sulfate precipitation, then purified it through CM Sepharose FF-exchange chromatography and molecular sieve chromatography Sephadex G25. The inhibition effects under different concentrations of rhLF (0.25, 0.5, 1.0, 2.0, 4.0, and 5.0 mg/ml) against Salmonella typhimurium, Staphyloccocus aureus, Bacillus cereus, Listeria monocytogenes were observed, using broth microdilution method.

RESULTS

The rhLF was obtained at a higher purity (about 90%) through successful isolation and purification. After Coomassie blue staining, Westernblot and mass spectrometer analysis, it was identified as the purpose protein with the molecular weight of approximately 79 kDa. The antibacterial experiments showed that 5 mg/ml and 4 mg/ml rhLF could inhibite Salmonella typhimurium and Staphylococcus aureus persistently, 2 mg/ml and 1 mg/ml rhLF showed a significant inhibitory effects in the later period; while 0.5 mg/ml or lower concentration, showed no inhibitory effects. As to Bacillus cereus, only 5 mg/ml and 4 mg/ml rhLF exhibited certain inhibitory effects within 18 hours. Listeria monocytogenes was inhibited within 18 hours just at 5 mg/ml rhLF.

CONCLUSION

The rhLF could be successfully separated and purified from transgenic rice, and the purified protein still has significant antibacterial activities.

[Large-scale purification and acute toxicity of cowpea trypsin inhibitor]

OBJECTIVE

To provide the acute toxicity data of cowpea trypsin inhibitor (CpTI) using recombinant protein purified from E. coli.

METHODS

Recombinant CpTI protein was expressed and purified from E. coli. Bacterial recombinant plasmid was transformed into E. coli and the transformed cells were induced with IPTG. The expressed CpTI protein was purified by hydrophobic interaction chromatography and anion exchange chromatography. Sixty mice, randomly assigned to 6 groups, were administrated 10.0, 4.64, 2.15 and 1.00 g/kg BW of CpTI or 5.00 g/kg BW of BSA control protein or sterile water respectively by oral gavage.

RESULTS

All animals survived with no significant change in body weight and food consumption throughout the study. Macroscopic necropsy examination on day 15 revealed no gross pathological lesions in any of the animals. The maximum tolerated dose (MTD) of CpTI was more than 10.0 g/kg body weight in mice.

CONCLUSION

No toxicity of CpTI protein was found in ICR mice model.

Mixture of ferric sodium ethylenediaminetetraacetate (NaFeEDTA) and ferrous sulfate: an effective iron fortificant for complementary foods for young Chinese children

BACKGROUND

Ferric sodium ethylenediaminetetraacetate (NaFeEDTA) enhances iron absorption in the presence of phytate. However, the amount of NaFeEDTA that would have to be added to a complementary food to provide the necessary intake of iron for an infant or young child if NaFeEDTA were the sole iron fortificant exceeds the Acceptable Daily Intake (ADI) of EDTA for this age group. EDTA increases iron absorption at a molar ratio EDTA:iron of less than 1:1.

OBJECTIVE

To determine whether iron absorption is enhanced with a mixture offerrous sulfate (FeSO₄) and NaFeEDTA.

METHODS

Two studies with a crossover design were conducted in separate groups of 14 and 15 children aged 24 to 31 months. A complementary food consisting of millet porridge with cabbage, tofu, and pork-filled wheat flour dumplings was fortified with 2 mg iron as either FeSO₄ or NaFeEDTA (study 1) or 4 mg iron as FeSO₄ or a mixture of 2 mg each of FeSO₄ and NaFeEDTA (study 2). Iron absorption was determined based on erythrocyte incorporation of stable iron isotopes.

RESULTS

In study 1, the geometric mean (± SD) iron absorption was 8.0% (3.1, 20.8) and 9.2% (3.1, 27.0) from food fortified with FeSO₄ and NaFeEDTA, respectively. In study 2, iron absorption was significantly higher from food fortified with 4 mg iron as 1:1 mixture of FeSO₄/NaFeEDTA than from food fortified with FeSO₄; the geometric mean iron absorption was 6.4% (3.0, 13.5) and 4.1% (1.9, 8.9), respectively.

CONCLUSIONS

The enhancing effect of EDTA on iron absorption is less strong in composite meals containing enhancers; nevertheless, the equal mixture of FeSO₄ and NaFeEDTA significantly enhanced iron absorption and can be a strategy to ensure adequate iron absorption from phytate-containing complementary foods.

[Non-fusion expression and purification of cowpea typsine inhibitor]

OBJECTIVE

To establish a practicable method to express and purify Cowpea Typsine Inhibitor (CpTI), which is comparable with native CpTI, for providing important materials to access the safety of genetically modified rice with CpTI.

METHODS

The non-fusion expression vector PET41EK-CpTI was constructed by cloning the CpTI gene into expression vector PET41EK. And the expression vector was then transformed into E. coli BL21 (DE3) and E. coli Rosetta ( DE3). Purified expression product was obtained through optimizing the induction temperature, induction time and IPTG concentration and then it was identified by western blotting, activity determination and N-terminal amino acid sequencing.

RESULTS

The purified protein was obtained under the condition of E. coli Rosetta (DE3), 20 - 25 degrees C, 130 rpm, and 0.5 mmol/L IPTG, overnight expression, 30kDa ultra-filtration and anion exchange purification. After identification, the CpTI protein with significant immunogenicity and CpTI activity was successfully obtained and its purity is up to 95%.

CONCLUSION

The CpTI protein obtained by the non-fusion method established in this study is comparable with the native CpTI protein in terms of activity, immunogenicity, molecular weight and amino acids sequence. Moreover, the method is easy to operate and satisfied with the requirements of large-scale expression.

[Prevalence of metabolic syndrome among 7-17 year-old overweight and obese children and adolescents]

OBJECTIVE

o describe the prevalence of metabolic syndrome (MS) in 7-17 year-old children and adolescents.

METHODS

A stratified multistage cluster random sampling method was adopted, and 2752 children and adolescents were analyzed. MS was diagnosed according to the definition of Cook.

RESULTS

The prevalence of MS among normal weight, overweight, and obese groups was 0.7%, 8.0% and 23.9% respectively. Excluding other influencing factors, the prevalence of MS among the overweight and obese groups was multiplied when compared to the normal weight group. In overweight and obese groups, the present of abdominal obesity (41.6% and 77.9%), hyperglyceridemia (36.4% and 50.7%), and hypertension (19.6% and 39.0%) were more common. The individuals suffered from at least one metabolic abnormality were 40.3%, 65.6% and 90.6% in these three groups. About 62.9% of obese individuals suffered from at least two metabolic abnormalities and 23.9% suffered from at least three metabolic abnormalities. The individuals suffered from at least four metabolic abnormalities were all overweight or obesity.

CONCLUSION

There are obvious metabolic disorders in overweight and obese children and adolescents.

[Energy expenditure on different physical activities of rural adults in North China]

To test the energy metabolism of healthy adults in rural north China and to obtain the data of energy expenditure on different physical activities, in order to provide the basis for the Dietary Reference Intakes for Chinese people and the prevention and treatment of diseases related to energy and nutrition imbalance.

METHOD

The energy expenditures on different physical activities of 30 healthy adult men and women were investigated under strictly controlled experimental conditions by using portable cardiopulmonary function determinator k4b2 to examine the oxygen consumption (VO2) and carbon dioxide production (VCO2) during basal metabolic conditions and seven kinds of physical activities (walking, brisk walking, jogging, cycling, stair climbing, and watching TV). The content of 24-hour urine nitrogen was measured by micro Kjeldahl method. Combining with the change of body weight, the energy expenditures on different physical activities of normal adult men and women in north China were obtained.

RESULTS

The average energy expenditure on physical activities (kJ x h(-1) x kg(-1)) were: walking 12.60 +/- 5.54 (11.46 +/- 2.19 for male and 15.47 +/- 6.97 for female), brisk walking 20.79 +/- 10.46 (15.95 +/- 3.59 for male and 25.33 +/- 12.70 for female), jogging 34.78 +/- 16.00 (30.45 +/- 5.07 for male and 38.84 +/- 21.58 for female) cycling 16.47 +/- 3.95 (14.77 +/- 2.57 for male and 18.74 +/- 4.85 for female), going up stairs 23.55 +/- 5.05 (23.61 +/- 3.43 for male and 23.49 +/- 6.41 for female) going down stairs 12.46 +/- 6.30 (10.43 +/- 1.27 for male and 14.49 +/- 8.48 for female) and watching TV 3.85 +/- 1.97 (3.56 +/- 0.86 for male and 4.16 +/- 2.79 for female).

CONCLUSION

The average energy expenditure on physical activities of males was lower than that of females (P < 0.05), except of going up stairs, which was roughly equal in males and females. The average energy expenditure on various physical activities was different. Walking, watching TV and going downstairs are low-intensity physical activities; brisk walking, cycling and climbing upstairs are medium-intensity physical activities; and jogging is a high-intensity physical activity.

[Effect of iron supplementation on iron deficiency anemia of childbearing age women in Shanghai]

OBJECTIVE

To investigate the effect of iron supplementation on iron deficiency anemia of childbearing age women, and to find out the optimal amount of iron intake for maintaining their health.

METHODS

74 childbearing age women aged 21 to 45 years with anemia were randomly assigned to intervention or control group by hemoglobin content, and a iron nutrition packet (mainly composed of ferric pyrophosphate and ferrous fumarate, containing iron 8 mg) or a placebo packet was given daily for six months, respectively. Hemoglobin, serum ferritin, food frequency and 24h dietary recall survey were performed before intervention and three and six months after intervention.

RESULTS

Hemoglobin and serum ferritin of the intervention group were significantly higher (P < 0.01) than that in control group after six months. The number of women with hemoglobin > or = 120 g/L in intervention and control group was 15 (44.1%) and 5 (14.3%), respectively (P < 0.01). The number of women with serum ferritin > or = 15 micro g/L in intervention and control group was 11 (34.4%) and 4 (12.5%), respectively (P < 0.05). The average dietary iron intake was 14.0 mg/d, mainly from plant foods. There was a positive correlation of total iron intake (dietary iron plus iron supplements) with hemoglobin (r = 0.57, P < 0.01). More menstrual blood and dietary fiber were the risk factors for iron deficiency anemia (P < 0.05).

CONCLUSION

The anemic status in childbearing age women could be improved by providing iron 8 mg daily for six months consecutively. Daily dietary intake of iron 23.2 mg can meet the requirement of maintaining normal iron storage for childbearing age women.

[Nutritional components and sub-chronic toxicity of genetically modified rice expressing human lactoferrin]

OBJECTIVE

To compare the nutritional components of genetically modified rice expressing human lactoferrin (hLf) with its parental rice, and to observe the sub-chronic toxicity of hLf rice.

METHODS

The nutritional components of hLf rice and its parental rice were determined by the National Standard Methods. Eighty weanling Wistar rats were randomly divided into 4 groups based on their gender and body weight: group A (hLf rice high-dose group with 71.45% rice), group B (hLf rice medium-dose group with 35. 725% rice), group C (parental rice group with 71.01% rice) and group D (AIN-93G diet group), and the latter two groups were used as the control. Body weight, dietary intake, blood routine test, blood biochemical examination, organ coefficient, bone density and the pathology of organs were investigated at the end of a 90-day feeding experiment.

RESULTS

Except for human lactoferrin and Fe, there was no difference of main nutritional components, minerals and vitamins between groups. The differences of some indicators of blood routine (WBC, HGB, RBC and MCH), blood biochemistry (AST and GLU), organ coefficient and bone density between group A and B (hLf rice) with group C (parental rice) or group D (AIN-93G) were significant, while no difference of other indicators.

CONCLUSION

Although some differences were observed, all indicators were still in the normal reference range. Therefore, there was no sign of toxic and adverse effects for hLf rice on rats.

[Energy expenditure of healthy adults engaged in light activities in Southern China measured by energy balance method]

OBJECTIVE

To measure the energy expenditure of healthy adults engaged in light activities in southern China, and to provide reference database for revising Chinese RNI.

METHODS

Thirty four healthy adults eligible for the energy metabolic experiment were selected. A 3-day recycled dietary prescription was designed. The food intake of all foods per person per meal were weighed and recorded, and the energy intake from diets was determined by chemical analysis. The energy expenditure was calculated by combining the change of body weight and dietary consumption.

RESULTS

The average energy intake was (8424 +/- 1616) kJ/d [(2013 +/- 386) kcal/d], which was (9990 +/- 798) kJ/d [(2388 +/- 191) kcal/d] for men and (7032 +/- 384)kJ/d [(1681 +/- 92) kcal/d] for women. The average change of body weight of all subjects in 16 days was reduced 0.02 kg, the men increased 0.15 kg, and the women decreased 0.17 kg. According to the energy balance principle, the ultimate energy expenditure of healthy adults in southern China was (8468 +/- 1762) kJ/d [(2024 +/- 421) kcal/d], the men was (9680 +/- 1759) kJ/d [(2314 +/- 420) kcal/d], and the women was (7391 +/- 827) kJ/d [(1767 +/- 198) kcal/d].

CONCLUSIONS

The energy expenditure of healthy adult male engaged in light activities in southern China was 9680 +/- 1759 kJ/d [(2314 +/- 420 kcal/d)], and that of female was 7391 +/- 827 kJ/d [(1767 +/- 198 kcal/d)]. The energy expenditure of men and women measured in this study were 86kcal and 333kcal lower than the Chinese energy RNI (2400kcal and 2100 kcal) established in 2000.

[Energy zero balance study on the energy intake of healthy adults engaged in light physical activities in southern China]

OBJECTIVE

Using an energy zero balance method to investigate and analyze the level of dietary energy intake of healthy adults in southern China, in order to provide basic data for revising Chinese energy DRIs.

METHODS

A total of 32 healthy adults engaged in light physical activities were recruited randomly. The food intake of each subject including meals and snacks was weighed and made records at same days intervals in a period of 2 month (covering Monday to Sunday of a week). The energy intake was calculated and adjusted with the change of body weight according to the energy balance principle.

RESULTS

The average total energy intake of subjects in energy zero balance was (8.895 +/- 1.535) MJ/d, (10.070 +/- 1.150) MJ/d for male and (7.719 +/- 0.765) MJ/d for female.

CONCLUSION

The energy intake of healthy adults at zero balance could be measured at same days intervals within a 2 month period. The method was convenient, economical, available and practicable.

[Nutrition survey on the collective in Shenzhen public institution]

OBJECTIVE

Nutrition survey on the collective who performs light physical activity.

METHODS

Based on weighing records and two-months energy intake, combined with the Chinese Dietary Guidelines and Chinese Dietary Recommended Nutrient Intake (RNI), 45 healthy volunteers were chosen to evaluate their current nutrient status.

RESULTS

The dietary structure of the collective was simple and unreasonable. Some nutrients, such as dietary fiber, vitamin A, vitamin B1, vitamin B2, calcium, magnesium, iron, zinc, copper, selenium were lower than RNI/AI, while some others (niacin, vitamin C, vitamin E, manganese, phosphorus, etc.) were higher than the standards. The proportion of three nutritious elements in diet was not appropriate. Protein and fat intakes were less than the references obviously, while carbohydrates significantly higher than the reference.

CONCLUSION

The nutrition and health status of the volunteers was not so optimistic with the lack and excess coexist for nutrients and energy.

[Nutrition and health status of pregnant women in 8 provinces in China]

OBJECTIVE

To investigate nutrition and health status of pregnant women in China.

METHODS

16 counties cities in 8 Provinces in China were selected to investigate nutrition and health information for pregnant women.

RESULTS

The averaged age of pregnant women was 27.1 years old, and 6.3 percent of pregnant women are over 35 years old. The proportion rates of pregnant women who consumed supplements before or during pregnance accounted for 81.8% in city and 57.8% in rural (P < 0.01). Anaemia prevalence was 14% with significant difference between urban and rural, P < 0.01. The rate of sural spasm during pregnancy was 39.3%. Low daily intakes of protein, retinol equivalence, calcium, iron were the major nutritional problem. Calcium deficiency was the leading problem. Pregnant women got health improvement kowlege mainly from relatives, friends, hospitals or medical centers, books and televisions, furthermore, internet was a main media for city women.

CONCLUSION

Low daily intakes of protein and micronutrients were major problems for pregnant women.

[Prevalence of anemia and feeding behavior among 2-5 year-old children in poor areas of China]

OBJECTIVE

To understand the prevalence of anemia and its related risk factors among 2-5 year-old children in Chinese poor areas.

METHODS

5927 children aged 2-5 years old in poor areas of 30 counties in 13 provinces (autonomous regions or municipalities) were randomly selected by multi-stage cluster random sampling. Designed questionnaires were used to collect personal information and feeding behavior; and hemoglobin levels were tested.

RESULTS

The prevalence of anemia in children aged 2-5 years in poor areas was 22.4%. The prevalence peak of anemia was in 5-5.9 age group and the distribution of anemia among different areas was significantly different. The result of non-conditional Logistic regression analysis showed that anemia was related to some factors, including weaning time, having breakfast or not, number of people dining at home, education level of mother, the frequency of children having meals at home and family annual per capita income.

CONCLUSION

The prevalence of anemia of 2-5 years old children in poor areas of China is quite serious and more consideration should be given. Anemia is closely related to feeding conditions and feeding behavior. Taking specific measures to develop anemia prevention and intervention programs are necessary.

Examination of Chinese habitual dietary protein requirements of Chinese young female adults by indicator amino acid method

OBJECTIVE

To determine protein requirement of Chinese young female adults on habitual Chinese diet through indicator amino acid oxidation (IAAO) technique.

DESIGN

Twenty women with a mean (SD) age of 21.6 (0.9) years were healthy based on questionnaire, physical examinations and screening tests. There were three consecutive periods of 7 days each with six different intakes of protein (0.70, 0.78, 0.86, 0.94, 1.02 and 1.10 g/kg·d) within Chinese habitual diets (proportions of good-quality protein were 40 to 45%). Subjects were randomly allocated equally into two groups (1.10, 0.86, 0.78 g/kg·d for group 1 and 1.02, 0.94, 0.70 g/kg·d for group 2 from period 1 to period 3 in turn). Adaptation days were from day 1 to day 6 and the isotope study day was day 7 in each period. Amino acid kinetics was measured in non-menstrual periods, based on the IAAO technique. Two indicators (rate of release of 13CO2 and rate of leucine oxidation) were used to estimate protein requirement by breakpoint analysis with a two-phase linear regression crossover model.

RESULTS

Mean and population safe protein requirements of Chinese habitual diets in non-menstrual periods from the rate of release of 13CO2 were 0.91 and 1.09 g/kg·d, respectively. And from the rate of leucine oxidation were 0.92 and 1.10 g/kg·d, respectively.

CONCLUSIONS

The protein requirement of young women on Chinese habitual diets in non-menstrual period was lower than the current protein reference intake for Chinese females. Further studies are necessary to explore female protein requirements during the whole menstrual cycle.

Prevalence of diabetes and impaired fasting glucose in Chinese adults, China National Nutrition and Health Survey, 2002

INTRODUCTION

As a result of rapid economic development in China, the lifestyles and dietary habits of its people have been changing, and the rates of obesity, diabetes, and other chronic conditions have increased substantially. We report the prevalence of type 2 diabetes and impaired fasting glucose (IFG) and the association between diabetes and overweight and obesity in Chinese adults. We also compare the results with those from the US National Health and Nutrition Examination Survey, 1999-2002.

METHODS

Data were from adults aged 20 years or older who participated in the China National Nutrition and Health Survey, 2002 (n = 47,729). Diabetes and IFG were defined by the American Diabetes Association 2009 criteria. We assessed the prevalence of diabetes, IFG, and overweight and obesity by sex, age, region of residence, and ethnicity.

RESULTS

The prevalence of diabetes and IFG in Chinese adults was 2.7% and 4.9%, respectively. The prevalence of diabetes increased with age and body mass index. Men and women had a similar prevalence of diabetes, but men had a significantly higher prevalence of IFG. The prevalence of diabetes among Chinese who lived in urban areas was 2 to 3 times higher than the prevalence among those who lived in rural areas (3.9% for urban areas and 6.1% for large cities vs 1.9% for rural areas), and the prevalence of IFG was 1.5 to 2 times higher (6.1% and 8.1% vs 4.2%, respectively). The prevalence of diabetes among Chinese women and young (20-39 y) and middle-aged (40-59 y) adults who lived in large cities was similar to the prevalence of diabetes in the US population.

CONCLUSION

The prevalence of diabetes and IFG was much higher in urban than rural areas, particularly in the large cities of China. Prevention must be emphasized among adults to reduce the future social and economic burden of diabetes in China.

[Energy expenditure at physical activities of young and middle-aged adults in southern China]

OBJECTIVE

To investigate the energy expenditure at physical activities of young and middle-aged adults in southern China.

METHODS

64 healthy young and middle-aged adults living on light physical activity intensity were recruited by questionnaire and physical examination. A Cosmed k4b2 portable metabolic unit was used to measure the oxygen consumption (Vo2) and carbon dioxide production (Vco2) at a status of basic metabolism and during seven physical activities, including slow walking, brisk walking, walking upstairs, walking downstairs, watching TV, jogging and bicycling. The urinary nitrogen excreted in 24 hours was detected by a standard Kjeldahl method. Energy expenditure at physical activities was calculated by Weir equation.

RESULTS

The energy expenditure (kJ x h(-1) x kg(-1)) at physical activities were 14.77 +/- 2.47 for slow walking, 22.18 +/- 3.68 for brisk walking, 41.34 +/- 7.32 for jogging, 18.41 +/- 3.89 for bicycling, 26.11 +/- 4.18 for walking upstairs, 13.68 +/- 2.89 for walking downstairs and 5.06 +/- 1.09 for watching TV. The energy expenditure of males at physical activities was higher than those of females (P < 0.05).

CONCLUSION

There is a significant difference among energy expenditures at different physical activities; watching TV is a physical activity in light intensity; slow walking, brisk walking, walking upstairs, walking downstairs and bicycling are physical activities in moderate intensity, and jogging is a vigorous physical activity.

[Energy requirements of children and adolescents]

Energy cost of growth is one of the most important components of Energy Requirements (ER) for children and adolescents. According to the latest research: ER was calculated as adding another 8.6 kJ (2 kcal) for each gram of weight gain during growth. In the 2004 FAO/WHO/UNU report on human energy requirements, which used the data from doubly labeled water (DLW) and heart rate monitoring (HRM) method, proposed the latest daily energy requirements for children and adolescents (1-18 years of age). This article introduces the advances in recent years on the energy requirements of children and adolescents.

[Basic metabolic rate of young adults in Shenzhen]

OBJECTIVE

To measure the basic metabolic rate (BMR) of young adults with normal BMI in Shenzhen.

METHODS

25 men and 25 women in hospital were selected according to questionnaire, medical examination, blood test, liver function, nephron function, thyroid gland level, and TSH. Their BMR and resting metabolic rate (RMR) were measured by using the K4b2 in normal circumstances. The BMR values were compared with the calculated results from the Schofield equation (adjusted). The body composition was measured by bioelectrical impedance analysis.

RESULTS

The BMR values measured by the K4b2 were 278.54 +/- 45.56 kJ/h (male) and 224.08 +/- 38.24 kJ/h (female).

CONCLUSION

The BMR value of Shenzhen young adults measured by K4b2 is a little higher than that of youth in north China.

[Subchronic toxicity test of genetically modified rice with double antisense starch-branching enzyme gene]

OBJECTIVE

To observe the sub-chronic toxic effects of the genetically modified rice with double antisense SBE gene.

METHODS

Based on gender and weight, weanling Wistar rats were randomly sorted into five groups: non-genetically modified rice group (group A), genetically modified rice group (group B), half genetically modified rice group (group C), quarter genetically modified rice group (group D) and AIN-93G normal diet group (group E). Indicators were the followings: body weight, food consumption, blood routine, blood biochemical test, organ weight, bone density and pathological examination of organs.

RESULTS

At the middle of the experiment, the percentage of monocyte of female group B was less than that of group E (P < 0.05). AST activity of female group B was higher than that of group E (P < 0.05). ALT activity of female group C was higher than that of groups A and E (P < 0.05). At the end of the experiment, AST and ALT activities of female group B were higher than those of group E (P < 0.05). Hematocrit (HCT) and blood urea nitrogen (BUN) level of male group B were less than those of group A (P < 0.05), and monocyte was higher than that of group E (P < 0.05). The brain index of female group B was higher than group A (P < 0.05) and the kidney index of group E were higher than those of groups B, C and D (P < 0.05). There were no significant difference of blood lipids, calcium and bone mineral density among all groups (P > 0.05), and no notable abnormity in the pathological examination of main organs (P > 0.05).

CONCLUSION

There were no enough evidence to confirm the sub-chronic toxicity of genetically modified rice on rats.