Mutation Analysis of the APC Gene in a Chinese FAP Pedigree with Unusual Phenotype

Background and Aim. Germline mutations of the adenomatous polyposis coli (APC) gene cause familial adenomatous polyposis (FAP), an autosomal dominant inherited disease mainly characterized by colorectal adenomatous polyposis. Genetic studies of FAP have shown that somatic APC mutations are dependent on the position of the germline APC mutation. However, the molecular mechanism underlying these genotype-phenotype associations for APC in Chinese remain largely unknown. Patients and Methods. In this study, we investigated the APC gene mutation in a Chinese FAP family by systematic screening with multiplex ligation-dependent probe amplification (MLPA), denaturing high-performance liquid chromatography (dHPLC), and DNA sequencing. Promoter methylation was detected by methylation-specific PCR. Results. The identical germline mutation c.1999 C>T (Q667X) of APC was identified in 5 affected members, among which 2 members carried somatic mutations of APC, one with promoter hypermethylation and the other with loss of wild-type allele in their adenomas. The somatic mutations were shown connected with the disease severity, demonstrating a unique genotype-phenotype association in this FAP pedigree. Conclusion. The study revealed the existence of novel pathogenic mutations in Chinese patients with FAP. Somatic mutations are of particular interest because of the unusual phenotypic features shown by patients.

Advanced glycation endproducts increase EPC apoptosis and decrease nitric oxide release via MAPK pathways

OBJECTIVE

Previous studies have shown that advanced glycation endproducts (AGE) can induce endothelial progenitor cells (EPC) apoptosis, which contributes to the pathogenesis of diabetes mellitus. Nitric oxide (NO) signaling is closely associated with apoptosis. We therefore investigated the effects of AGE on human EPC apoptosis, NO release and related signal transduction pathways.

METHODS

EPC isolated from healthy human subjects were cultured with various concentrations of AGE (0, 2, 20 and 200mg/L) for 0, 24, 48 and 72 h in the presence or absence of various MAPK (ERK/P38/JNK) inhibitors, respectively. EPC apoptosis (detected by flow cytometric analyses) and NO concentration in culture supernatant were determined. The mRNA levels of eNOS, COX-2, Bcl-2 and Bax were assessed by RT-PCR and the protein expressions of NF-kappaB and Caspase-3 assessed by Western blot.

RESULTS

Increased EPC apoptosis and reduced NO release were induced by 200mg/L AGE, accompanied by a downregulation of eNOS and Bcl-2 expressions as well as an elevation in COX-2, Bax, NF-kappaB and Caspase-3 expressions in a time-dependent manner (all P<0.05). These changes were significantly attenuated by pretreatment with various MAPK (ERK/P38/JNK) inhibitors (P<0.05).

CONCLUSIONS

AGE can promote EPC apoptosis and decrease NO release via MAPK pathways.

Cytotoxicity of adenoviruses expressing the wild-type p53 gene to esophageal carcinoma cells is linked with the CAR expression level and indirectly with the endogenous p53 status

We examined cytotoxic effects of adenoviruses (Ad) expressing the p53 gene (Ad-p53) in nine human esophageal carcinoma cell lines with respect to the Ad receptor expression and the endogenous p53 gene status. Ad-p53-mediated cytotoxicity was related with an expression level of the coxsackievirus adenovirus receptor (CAR) but not with that of CD51, both of which are type 5 Ad receptors. Contrary to earlier studies, we found that the cytotoxicity was greater in tumor cells with the wild-type p53 gene than in those with mutated p53. The cytotoxic activity of Ad defective of E1B55kDa molecules (Ad-delE1B55), however, was not linked with the CAR expression level or the endogenous p53 status. We noticed that the tumor cells with the wild-type p53 gene showed greater CAR expression levels, although transduction with Ad-p53 did not upregulate the CAR expression in the mutated cells. We also examined the Ad-53-mediated cytotoxicity in two kinds of paired fibroblasts, parent and immortalized with loss of the p53 functions, and showed that the CAR expression level was more influential than the endogenous p53 status in the cytotoxicity. These data suggest that CAR expression level is a better predictive marker than endogenous p53 status for Ad-p53-mediated cytotoxicity in esophageal carcinoma.

Relationship between vitamin D status, body composition and physical exercise of adolescent girls in Beijing

Little is known about the prevalence of actual vitamin D deficiency in healthy school-aged adolescents, particularly in China. The aim of this study was to examine the prevalence of hypovitaminosis D and to identify whether there was any association between vitamin D status, body composition and physical exercise in 323 Chinese adolescent girls in Beijing, China (40 degrees N).

INTRODUCTION

It is well recognized that persistent severe vitamin D deficiency is associated with the bone abnormalities of rickets and osteomalacia. However, there is now evidence suggesting that low vitamin D status, not previously considered to be a state of deficiency is associated with secondary hyperparathyroidism, increased bone remodelling and other clinical signs thought only to be found in severe vitamin D deficiency. Hypovitaminosis D in healthy children and adolescents has been reported frequently in many countries, especially in winter.

METHODS

We performed a cross-sectional analysis of 323 Chinese adolescent girls in Beijing in winter. Mean age of the subjects was 15.0 (+/-0.4) years. About 32.8%, 68.4% and 89.2% of the subjects were at risk of vitamin D deficiency when defined as plasma concentrations of 25OHD of 25, 37.5 or 50 nmol/L, respectively.

RESULTS

This cross-sectional analysis of 323 Chinese adolescent girls in Beijing in winter showed that hypovitaminosis D was common in these subjects. In addition, body mass index, milk intake, participation in organized sports and total physical activity were all significant independent determinants of vitamin D status. An inverse association was found between plasma 25OHD and intact-parathyroid hormone (iPTH) concentration. Body mass index (BMI), milk intake, participation in organized sports and total physical activity all emerged as major independent determinants of vitamin D status as assessed by plasma 25OHD concentration. Vitamin D status was positively associated with lean body mass (LBM), but there was no association with the degree of body adiposity. Regardless of the concentration of 25OHD in blood used to define vitamin D deficiency, hypovitaminosis D was common in these subjects.

CONCLUSION

It is recommended that policies be developed to prevent vitamin D deficiency in adolescent girls. Further studies are needed to identify the mechanisms whereby vitamin D status is related to exercise and to body composition during growth.

Association between CpG island methylation of the WWOX gene and its expression in breast cancers

OBJECTIVES

The aim of the present study was to evaluate the expression of the WWOX gene in breast carcinoma and to analyze the relationship between its expression and methylation.

METHODS

Methylation of the WWOX promoter and exon 1 as well as WWOX expression were determined by methylation-specific PCR, reverse transcription PCR and immunohistochemistry in 20 breast cancer tissue samples and corresponding nonneoplastic tissues. The expression of WWOX protein was evaluated by immunohistochemistry in 2 breast cancer cell lines.

RESULTS

WWOX mRNA expression was reduced in breast cancer tissues as compared to adjacent tissues (p < 0.001). WWOX mRNA and protein expression was significantly reduced in breast cancer tissues with methylated WWOX CpG islands when compared to tissues without methylation (p < 0.001 and p = 0.008, respectively). Immunohistochemical analysis also showed that WWOX levels were significantly decreased in tissues with WWOX methylation (p = 0.001). WWOX mRNA and protein expression was greatly reduced in MDA-MB-231 cells, partly due to the methylation of WWOX CpG islands, and recovered after hydralazine treatment.

CONCLUSIONS

Differential regulation of the WWOX gene plays an important role in the carcinogenesis of breast cancer, due partially to methylation of the WWOX DNA CpG islands.

The relationship between admission blood glucose levels and hospital mortality

AIMS/HYPOTHESIS

The purpose of this study was to examine the relationship between blood glucose level (BGL) on admission with mortality rates among patients admitted to hospital through the Emergency Department.

METHODS

In a prospective observational study, BGLs were routinely measured on 6,187 consecutive patients requiring blood testing and admitted through the Emergency Department of a tertiary referral hospital. These measurements were matched against demographic data and hospital mortality rates.

RESULTS

Overall in-hospital mortality was 4.8%. Admission BGL was an independent predictor of mortality (HR 1.04 per 1 mmol/l increase, 95% CI 1.02-1.06, p=0.02). There was a significant interaction between diabetes status and increasing BGL on mortality (p<0.001), with higher BGLs being associated with greater mortality among non-diabetic than among diabetic patients. Among non-diabetic patients, the lowest mortality rate (3.0%) was in people with a BGL of 4.0-5.9 mmol/l. Compared with this group, patients with a BGL of 8.0-9.9 mmol/l had increased mortality rate (7.6%, HR 1.56, 95% CI 1.03-2.35, p=0.04, after adjustment for age and sex). The risk increased further at higher glucose levels. In the cohort with diagnosed diabetes, the increase in mortality rates at higher BGL bands was not significant.

CONCLUSIONS/INTERPRETATION

Among people who do not have diabetes, even modest degrees of hyperglycaemia on hospital admission are associated with increased mortality.

Increased expression of osteopontin in patients with triple-negative breast cancer

BACKGROUND

Patients with triple-negative [oestrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER-2/neu) negative] breast cancer, accounting for about 15% of breast cancer cases, are associated with aggressive histology, poor prognosis and shorter survival. Osteopontin is a chemokine-like phosphorylated glycoprotein that plays important role in cancer progression and is found to be a metastasis-associated protein in breast cancer. The goal of the study was to evaluate osteopontin protein expression levels in triple-negative breast carcinomas to determine if they correlated with clinicopathological parameters, thus providing additional support for osteopontin functioning and better understanding of triple-negative breast cancer.

MATERIALS AND METHODS

A database of 239 patients, in whom all three markers (ER, PR, and HER-2/neu) were available, was reviewed. We performed osteopontin protein expression analyses by means of immunohistochemistry on 117 breast carcinoma tissue samples, and then assessed the mean value of osteopontin expression against triple-negative status and clinicopathological parameters.

RESULTS

Of the 239 patients in the study, 47 were classified as triple negative. Of the 117 osteopontin-test patients in this cohort, mean osteopontin levels were significantly higher in the triple-negative breast cancers than in non-triple-negative subtype (P = 0.035). TNM (tumours, nodes, metastases) stage were significantly associated with osteopontin levels (P = 0.038). Univariate analysis showed tumour cell osteopontin positivity above an optimized cut-point to be significantly associated with decreased disease-free survival, but not overall survival. In the multivariate model, osteopontin was an independent prognostic factor for disease-free survival.

CONCLUSIONS

Patients with osteopontin overexpression develop predominantly triple-negative tumours. Osteopontin overexpression is associated with tumour aggressiveness and poor prognosis.

IL-27-mediated activation of natural killer cells and inflammation produced antitumour effects for human oesophageal carcinoma cells

Interleukin IL-27, composed of p28 and EBV-induced gene 3 subunits, has diverse functions in enhancing cell-mediated immunity and silencing the immunity. We examined whether forced expression of the p28-linked EBI3 gene in human oesophageal carcinoma cells (Eca109) produced antitumour effects in a T cell-defective condition. Tumour growth of Eca109 cells expressing IL-27 (Eca109/IL-27) was retarded in nude mice compared with parental and vector DNA-transduced tumours and survival of the mice inoculated with Eca109/IL-27 cells was prolonged. Expression of the tumour necrosis factor-alpha, IL-1beta and IL-6 genes was up-regulated in Eca109/IL-27 tumour specimens while the tumours remained small in size but the increased transcription was subsequently down-regulated in enlarged tumours. Spleen cells from mice-bearing Eca109/IL-27 tumours produced interferon-gamma and showed YAC-1-targeted cytotoxic activities greater than those of mice inoculated with parental or vector DNA-transducer tumours. Numbers of DX5+CD69+ natural killer cells in spleen of mice-bearing Eca109/IL-27 tumours and those of CD31+ cells within Eca109/IL-27 tumours remained the same as found in mice-bearing parental or vector DNA-transduced tumours. These data collectively suggest that the IL-27-mediated antitumour effects produced in a mature T cell-defective condition were attributable to enhanced interferon-gamma production and natural killer activities.

Physical activity level and its association with metabolic syndrome among an employed population in China

The purpose of the present study was to estimate the association of physical activity level (PAL) with metabolic syndromes among the employed population in China. Using data from the 2002 China National Nutrition and Health Survey, the PAL of 21 834 subjects aged 18-59 years was described, and its relationship with the risk of metabolic syndrome was studied after adjusting for the relative effects of smoking, drinking, diet and socioeconomic status. Information on physical activity was collected by trained investigators using a 1-year physical activity questionnaire. PAL was classified into four categories: sedentary (PAL 1.00-1.39), low active (PAL 1.40-1.59), active (PAL 1.60-1.89) and very active (PAL 1.90-2.50). The definition of metabolic syndrome by the International Diabetes Federation 2005 was applied. The percentage of people being sedentary, low active, active and very active was 12.3%, 13.7%, 20.1% and 53.9% respectively. The crude prevalence of metabolic syndrome in the sedentary, low active, active and very active groups was 9.7%, 6.9%, 5.6% and 4.9% respectively. After adjusting for the effect of other risk factors, the higher the PAL, the lower the relative risk of metabolic syndrome as well as the individual metabolic abnormalities. The risk of overweight/obesity and metabolic syndrome was 50% and 59% less, respectively, in the adults who were very active and whose dietary fat contributed less than 20% to energy intakes when compared with their counterparts who were sedentary and consumed more fat (> or = 30% energy). PAL was an independent risk factor for obesity and multiple metabolic syndrome abnormalities among the employed population in China. The high-risk population were middle-age males living in large cities with high incomes who drink alcohol.

Evaluation of a classroom-based physical activity promoting programme

The purpose of the present study was to evaluate the effect of the Happy 10 programme on the promotion of physical activity, physical growth and development of primary school students, and on obesity control and prevention. Two similar primary schools from one district of Beijing, China were selected, one as an intervention school and the other as a control school. A Happy 10 programme was implemented at least once every school day in the intervention school for two semesters, whereas no intervention was adopted in the control school. The information on energy expenditure and duration of physical activity was collected by a validated 7-day physical activity questionnaire. Height and weight were measured by the trained investigators following standardized procedure. Energy expenditure and intensity of each Happy 10 session were measured by a physical activity monitor. The average energy expenditure and duration of total physical activity per day among students in the intervention school increased significantly from 15.0 to 18.2 kcal kg(-1) and 2.8 to 3.3 h, respectively, whereas the figures significantly decreased in the control school. There was a significant difference in change of weight and body mass index between girls in the intervention and control school (2.4 kg vs. 4.6 kg; 0.47 kg m(-2) vs. 0.66 kg m(-2)). The prevalence of overweight and obesity in the intervention school decreased by 0.4-5.6%, as compared with the increase by 0.6-4.5% in the control school. The average energy expenditure and intensity per 10-min session ranged from 25.0 to 35.1 kcal and from 4.8 to 6.2 kcal kg(-1) h(-1), respectively, in grades 1-5. The Happy 10 programme provides a useful strategy to promote physical activity among school children, and also plays a positive role in building up physical growth and development of girls.

Childhood obesity and its health consequence in China

Analyses of data from the representative 2002 National Nutrition and Health Survey were used to assess the likelihood of metabolic complications of overweight and obesity in Chinese children aged 7-17 years. Chinese criteria for body mass index classification were used for overweight and obesity with the 75th percentile US adolescent values for waist circumferences and all the metabolic criteria for blood pressure, lipids, fasting glucose established for US adolescents. Diabetes in 7-12-year-olds was 0.2% and 0.4% in children aged 12-18 years. Prevalences of dyslipidaemia (61.9%), hypertriglyceridaemia (18.2%) and low high-density lipoprotein cholesterol (56.1%) were high and 16.0% of 15-18 years had hypertension. The overall prevalence of the metabolic syndrome was 3.3% with more than half the children having at least one metabolic abnormality and 19.8% having at least two. All the metabolic parameters were significantly elevated in the overweight and obese children except high-density lipoprotein cholesterol. These data emphasize the marked sensitivity of Chinese children to the metabolic complications of overweight and obesity and amplify the need for early preventive measures.

Effects of surface pressure on the structure of the monolayer formed at the air/water interface by a non-ionic surfactant

The monolayer formed at an air/water interface by the synthetic non-ionic surfactant, 1,2-di-O-octadecyl-rac-glyceryl-3-(omega-methoxydodecakis (ethylene glycol)) (2C18E12) has been characterized using Langmuir trough measurements, Brewster angle microscopy (BAM), and neutron reflectometry. The BAM and reflectometry studies were performed at four different surface pressures (pi) in the range 15-40 mN/m. The BAM studies (which give information on the in-plane organisation of the surfactant layer) demonstrate that the 2C18E12 molecules are arranged on the water surface to form distinct, approximately circular, 5 microm diameter domains. As the surface pressure is increased these domains retain their size and shape but are made progressively more close-packed, such that the monolayer is made more or less complete at pi=40 mN/m. The neutron reflectometry measurements were made to determine the structure of the interfacial surfactant layer at pi=15, 28, 34 and 40 mN/m, providing information on the thickness of the 2C18E12 alkyl chains', head groups' and associated solvent distributions (measured along the surface normal), along with the separations between these distributions, and the effective interfacial area per molecule. Partial structure factor analyses of the reflectivity data show that the effective interfacial area occupied decreases from 217 A2 per 2C18E12 molecule at pi=15 mN/m down to 102 A2 at pi=40 mN/m. There are concomitant increases in the widths of the surfactant's alkyl chains' and head groups' distributions (modelled as Gaussians), with the former rising from 12 A (at pi=15 mN/m) up to 19 A (at pi=40 mN/m) and the latter rising from 13 A (at pi=15 mN/m) up to 24 A (at pi=40 mN/m). The compression of the monolayer is also shown to give rise to an increased surface roughness, some of which is due to the thermal roughness caused by capillary waves, but with a significant contribution also coming from the intrinsic/structural disorder in the monolayer. At all surface pressures studied, the alkyl chains and head groups of the 2C18E12 are found to exhibit a significant overlap, and this increases with increasing pi. Given the various trends noted on how the structure of the 2C18E12 monolayer changes as a function of pi, we extrapolate to consider the structure of the monolayer at pi>40 mN/m (making comparison with its single chain (CnEm) counterparts) and then relate these findings to the observations recorded on the structure and solute entrapment efficiency of 2C18E12 vesicles.

Prevalence of the metabolic syndrome in Chinese adolescents

Since national figures on the occurrence of metabolic syndrome among Chinese adolescents are lacking, this study aims to estimate its prevalence and distribution among Chinese youngsters. The 2002 China National Nutrition and Health Survey is a nationally representative cross-sectional study. Applying the criteria for US adolescents, we estimated the prevalence of metabolic syndrome among 2761 adolescents aged 15 to 19 years. The prevalence of metabolic syndrome among Chinese adolescents overall was 3.7 % (10 % in US adolescents). It was 35.2 %, 23.4 % and 2.3 % among adolescents who were overweight (BMI > or = 95th percentile), at risk of overweight (BMI between 85th and 95th percentile) and normal weight (BMI below the 85th percentile), respectively. Urban boys had the highest rate (5.8 %) compared with girls and rural youngsters. Among adolescents who had a BMI > or = 85th percentile and one or two parent(s) with metabolic syndrome, the prevalence was 46.4 %. A total of 96 % of overweight adolescents had at least one and 74.1 % overweight adolescents had at least two abnormalities of metabolic syndrome. Based on these figures, it is estimated that more than three million Chinese adolescents have metabolic syndrome. Both overweight and metabolic syndrome prevalence among adolescents are still relatively low in China, but the prevalence of metabolic syndrome among Chinese overweight adolescents is similar to those living in the USA.

Prevalence of thyroid disease in an older Australian population

AIM

To determine the prevalence of thyroid disease in an older Australian population in a population-based cross-sectional study.

BACKGROUND

Community-living subjects, aged 49 years or older, in two Blue Mountains postcodes were invited to participate in an eye, nutrition and health study between 1997 and 2000.

METHODS

Three thousand five hundred and nine of the 4489 identified persons participated. Fifty-seven per cent of 3504 who completed questionnaires were women; their mean age was 66.8 years. Thyroid-stimulating hormone (TSH) was measured in 2665 subjects (76% of those completing the questionnaire). The main outcome measures were serum TSH and free thyroxine levels, serum lipids, urate and sugar levels and questionnaire responses.

RESULTS

The prevalence of recognized thyroid disease (either self-reported history of thyroid disease or current thyroxine treatment) was 10% (95% confidence interval (CI) 8.9-11.1%). An additional 3.6% (95%CI 2.9-4.3%) of participants had unrecognized thyroid disease (abnormal TSH). The TSH was abnormal in 7.1% (95%CI 5.8-8.4%) of women and 3.7% (95%CI 2.6-4.8%) of men. Sixty-five per cent of those with an abnormal TSH did not report a history of thyroid disease, whereas 25% of those taking thyroxine replacement therapy had an abnormal TSH level. The prevalence of hypothyroidism increased with increasing age in women. The mean fasting cholesterol was 0.36 mmol/L (95%CI 0.15-0.57) higher in hypothyroid subjects than in euthyroid subjects.

CONCLUSION

Thyroid disease in older Australian women is relatively common and may be undiagnosed. Ongoing monitoring of patients on thyroxine replacement therapy is important, given that 25% of treated patients had an abnormal TSH.

Determinants of childhood overweight and obesity in China

In order to investigate the determinants of childhood overweight and obesity in China, the prevalence of overweight (including obesity) was compared according to different dietary and physical activity patterns and parental body weight status. A total of 6826 children aged 7-17 years from the 2002 China National Nutrition and Health Survey were included in the study. Information for dietary intake was collected using three consecutive 24-h recalls by trained interviewers. The amounts of cooking oil and condiments consumed were weighed. An interview-administered 1-year physical activity questionnaire was used to collect physical activity information. The results showed that the heavier the parental bodyweight, the higher the overweight prevalence in children. The prevalence ratio increased if parent(s) were overweight and/or obese, up to 12.2 if both parents were obese. Overweight children consumed significantly more dietary energy, protein and fat, but less carbohydrate than their normal weight counterparts. On average, overweight children spent 0.5 h less on moderate/vigorous activities and 2.3 h more on low intensity activities per week. The following prevalence ratios were statistically significant: walking to and from school (0.6); moderate/vigorous activities > or =45 min/d (0.8); low intensity physical activities >2 h/d (1.3); the consumption of > or =25 g/d cooking oil (1.4); > or =200 g/d meat and meat products consumption (1.5); > or =100g/d dairy products (1.8). After adjustment for parental body weight status and socioeconomic status, only cooking oil consumption and walking to and from school remained significantly related to child overweight. In conclusion, parental weight status is an import-ant determinant. Fat intake, low intensity activities and active transport to/from school may be suitable entry points for overweight prevention among Chinese school children.

Continued reduction in the incidence of birth trauma and birth asphyxia related to instrumental deliveries after the study period: Was this the Hawthorne effect?

BACKGROUND

The incidence of birth trauma and birth asphyxia related to instrumental deliveries in our obstetric unit was high (2.8%) in 1998-1999. A study was performed in 2000 to identify the risk factors. Unexpectedly, the incidence (0.6%) was reduced significantly during the study period. We attributed this phenomenon to the famous Hawthorne effect (tendency to improve performance because of awareness of being studied).

OBJECTIVES

The objectives were to study whether there is a continued reduction in the incidence of birth trauma and birth asphyxia related to instrumental deliveries in the post-study period (2001-2003) and to investigate the presence of underlying confounding factors apart from the Hawthorne effect.

METHOD

To compare the hospital obstetric statistics among the pre-study period (1998-1999), the study period (2000) and the post-study period (2001-2003), in particular the incidence of birth trauma and birth asphyxia related to instrumental deliveries, the instrumental delivery rate, the overall Caesarean section rate, the Caesarean section rate for no progress of labour, the incidence of failed instrumental delivery, the incidence of attempted instrumental delivery in the operating theatre, and incidence of direct second-stage Caesarean sections.

RESULTS

The incidence of birth trauma and birth asphyxia related to instrumental deliveries (0.6%) during the study period (2000) was significantly lower than that (2.8%) during the pre-study period (1998-1999; RR 0.27, 95% CI 0.11-0.70). This phenomenon continued into the post-study period (2001-2003) when the incidence of 1.0% was similarly lower than that in the pre-study period (RR 0.35, 95% CI 0.20-0.64). The instrumental delivery rate decreased further in the post-study period (13.5%) compared with those in the study (16.6%) and pre-study (19.5%) periods (RR 0.81, 95% CI 0.75-0.89 and RR 0.69, 95% CI 0.65-0.74, respectively). There was a marked increase in the direct second-stage Caesarean section rate in the post-study period (7.1%) compared to those in the study (0.4%) and pre-study (0.7%) periods (RR 15.9, 95% CI 5.05-49.73 and RR 9.77, 95% CI 5.28-18.08, respectively).

CONCLUSION

A change in obstetric practice was identified that may explain the continued reduction in the incidence of birth trauma and birth asphyxia related to instrumental deliveries in the post-study period.

Phytate intake and molar ratios of phytate to zinc, iron and calcium in the diets of people in China

OBJECTIVE

To assess the phytate intake and molar ratios of phytate to calcium, iron and zinc in the diets of people in China.

DESIGN

2002 China Nationwide Nutrition and Health Survey is a cross-sectional nationwide representative survey on nutrition and health. The information on dietary intakes was collected using consecutive 3 days 24 h recall by trained interviewers.

SUBJECTS

The data of 68 962 residents aged 2-101 years old from 132 counties were analyzed.

RESULTS

The median daily dietary intake of phytate, calcium, iron and zinc were 1186, 338.1, 21.2 and 10.6 mg, respectively. Urban residents consumed less phytate (781 vs 1342 mg/day), more calcium (374.5 vs 324.1 mg/day) and comparable amounts of iron (21.1 vs 21.2 mg/day) and zinc (10.6 vs 10.6 mg/day) than their rural counterparts. A wide variation in phytate intake among residents from six areas was found, ranging from 648 to 1433 mg/day. The median molar ratios of phytate to calcium, iron, zinc and phytate x calcium/zinc were 0.22, 4.88, 11.1 and 89.0, respectively, with a large variation between urban and rural areas. The phytate:zinc molar ratios ranged from 6.2 to 14.2, whereas the phytate x calcium/zinc molar ratios were from 63.7 to 107.2. The proportion of subjects with ratios above the critical values of phytate to iron, phytate to calcium, phytate to zinc and phytate x calcium/zinc were 95.4, 43.7, 23.1 and 8.7%, respectively. All the phytate/mineral ratios of rural residents were higher than that of their urban counterparts.

CONCLUSIONS

The dietary phytate intake of people in China was higher than those in Western developed countries and lower than those in developing countries. Phytate may impair the bioavailability of iron, calcium and zinc in the diets of people in China.