Application of machine learning algorithms to predict osteoporosis in postmenopausal women with type 2 diabetes mellitus

PURPOSE

The screening and diagnosis of osteoporosis in patients with type 2 diabetes mellitus (T2DM) based on bone mineral density remains challenging because of the limited availability and accessibility of dual-energy X-ray absorptiometry. We aimed to develop and validate models to predict the risk of osteoporosis in postmenopausal women with T2DM based on machine learning (ML) algorithms.

METHODS

This retrospective study included 303 postmenopausal women with T2DM. To develop prediction models for osteoporosis, we applied nine ML algorithms combined with demographic, clinical, and laboratory data. The least absolute shrinkage and selection operator were used to perform feature selection. We used the bootstrap resampling technique for model training and validation. To test the performance of the models, we calculated indices including the area under the receiver operating characteristic curve (AUROC), accuracy, sensitivity, specificity, positive predictive value, negative predictive value, F1 score, calibration curve, and decision curve analysis. Furthermore, we conducted fivefold cross-validation for parameter optimization and model validation. Feature importance was assessed using the SHapley additive explanation (SHAP).

RESULTS

We identified 10 independent predictors as the most valuable features. An AUROC of 0.616-1.000 was observed for nine ML algorithms. The extreme gradient boosting (XGBoost) model exhibited the best performance, outperforming conventional risk assessment tools and registering 0.993 in the training set, 0.798 in the validation set, and 0.786 in the test set for fivefold cross-validation. Using SHAP, we found that the explanatory variables contributed to the model and their relationship with osteoporosis occurrence. Furthermore, we developed a user-friendly tool for calculating the risk of osteoporosis.

CONCLUSIONS

With the integration of demographic and clinical risk factors, ML algorithms can accurately predict osteoporosis. The XGBoost model showed ideal performance. With the incorporation of these models in the clinic, patients may benefit from early osteoporosis diagnosis and treatment.

Identifying underlying patterns in Alzheimer's disease trajectory: a deep learning approach and Mendelian randomization analysis

Background

Alzheimer's disease (AD) is a heterogeneously progressive neurodegeneration disorder with varied rates of deterioration, either between subjects or within different stages of a certain subject. Estimating the course of AD at early stages has treatment implications. We aimed to analyze disease progression to identify distinct patterns in AD trajectory.

Methods

We proposed a deep learning model to identify underlying patterns in the trajectory from cognitively normal (CN) to a state of mild cognitive impairment (MCI) to AD dementia, by jointly predicting time-to-conversion and clustering out distinct subgroups characterized by comprehensive features as well as varied progression rates. We designed and validated our model on the ADNI dataset (1370 participants). Prediction of time-to-conversion in AD trajectory was used to validate the expression of the identified patterns. Causality between patterns and time-to-conversion was further inferred using Mendelian randomization (MR) analysis. External validation was performed on the AIBL dataset (233 participants).

Findings

The proposed model clustered out patterns characterized by significantly different biomarkers and varied progression rates. The discovered patterns also showed a strong prediction ability, as indicated by hazard ratio (CN→MCI, HR = 3.51, p < 0.001; MCI→AD, HR = 8.11, p < 0.001), C-Index (CN→MCI, 0.618; MCI→AD, 0.718), and AUC (CN→MCI, 3 years 0.802, 5 years 0.876; MCI→AD, 3 years 0.914, 5 years 0.957). In the external validation cohort, our model demonstrated competitive performance on conversion time prediction (CN→MCI, C-Index = 0.693; MCI→AD, C-Index = 0.752). Moreover, suggestive associations between CN→MCI/MCI→AD patterns with four/three SNPs were mediated and MR analysis indicated a causal link between MCI→AD patterns and time-to-conversion in the first three years.

Interpretation

Our proposed model identifies biologically and clinically meaningful patterns from real-world data and provides promising performance on time-to-conversion prediction in AD trajectory, which could promote the understanding of disease progression, facilitate clinical trial design, and provide potential for decision-making.

Funding

The National Key Research and Development Program of China, the Key R&D Program of Zhejiang, and the National Nature Science Foundation of China.

Rates of intravenous thrombolysis and endovascular therapy for acute ischaemic stroke in China between 2019 and 2020

BACKGROUND

In recent years, a series of initiatives have been launched to promote intravenous thrombolysis (IVT) and endovascular therapy (EVT) for acute ischaemic stroke (AIS) in China. We aimed to update the rates of IVT and EVT in China between 2019 and 2020 and to evaluate the current IVT and EVT according to hospital grades.

METHODS

Cross-sectional data on patients receiving IVT/EVT were derived from the Bigdata Observatory platform for Stroke of China (BOSC). The monthly number of discharged patients with a principal diagnosis of AIS was derived from the first pages of medical records of each hospital. The rates and information of IVT and EVT were analysed according to hospital grades.

FINDINGS

During this period, 938 tertiary hospitals and 786 secondary hospitals from 31 provinces continuously reported data to the BOSC. The overall IVT rate for AIS was 5·64%, and the EVT rate was 1·45%. The IVT rate in secondary hospitals was higher than that in tertiary hospitals (6·39% vs. 5·39%, P < 0·001), whereas the EVT rate in secondary hospitals was much lower than that in tertiary hospitals (0·29% vs. 1·84%, P < 0·001). Significant differences in demographic and clinical characteristics of patients receiving IVT/EVT were also shown between tertiary and secondary hospitals.

INTERPRETATION

The rates of IVT and EVT for AIS have greatly increased in China, but there is still a large gap compared with developed countries. Hospital inhomogeneity in IVT and EVT suggests the importance of developing a region-specific network for stroke treatment.

FUNDING

None.

[Clinical characteristics, surgical treatment and prognosis of rolandic and perirolandic drug-resistant epilepsies]

Objective: To explore the clinical characteristics, treatment strategies and prognosis of rolandic and perirolandic drug-resistant epilepsies (DREs). Methods: The clinical data of 53 patients diagnosed with rolandic or perirolandic DRE who were admitted to Epilepsy Center, Sanbo Brain Hospital of Capital Medical University from January 2008 to January 2019 were retrospectively analyzed. The patients were divided into resective therapy group and non-resective therapy group [bipolar electrocoagulation on cortex, stereotactic electroencephalography (SEEG)-guided radiofrequency thermocoagulation, and vagus nerve stimulation]. The outcomes of epilepsy and post-surgical limb function were compared and analyzed. Results: A total of 53 patients were included, aged from 3 to 45 years old [(19±11) years], with 33 males and 20 females. Thirty patients received resective therapy and 23 patients received non-resective therapy. The curative effect of the resective therapy group was significantly better than that of the non-resective therapy group. The rate of Engel Ⅰ in resective therapy group was higher than that of non-resective group [83.3% (25/30) vs 39.1% (9/23), P=0.011). Compared with the non-resective group, the incidence of muscle strength decline in the resective group was higher both at 1 week [73.3% (22/30) vs 21.7% (5/23), P=0.006] and 3 months [30% (9/30) vs 0, P=0.016] after surgery. Conclusions: During the diagnosis and treatment, the multimodal method is conducive to the qualitative and localized diagnosis of the rolandic or perirolandic epilepsy, while SEEG has important value in the diagnosis, functional localization and treatment of the disease. Resective therapy is still the most effective method to terminate epilepsy, but it has a higher risk of post-surgical dysfunction.

Soil microbial community succession and interactions during combined plant/white-rot fungus remediation of polycyclic aromatic hydrocarbons

Despite combined plant/white-rot fungus remediation being effective for remediating polycyclic aromatic hydrocarbon (PAH)-contaminated soil, the complex organismal interactions and their effects on soil PAH degradation remain unclear. Here, we used quantitative PCR, analysis of soil enzyme activities, and sequencing of representative genes to characterize the ecological dynamics of natural attenuation, mycoremediation (MR, using Crucibulum laeve), phytoremediation (PR, using Salix viminalis), and plant-microbial remediation (PMR, using both species) for PAHs in soil for 60 days. On day 60, PMR achieved the highest removal efficiency of all three representative PAHs (65.5%, 47.5%, and 62.4% for phenanthrene, pyrene, and benzo(a)pyrene, respectively) when compared with the other treatments. MR significantly increased the relative abundance of Rhizobium and Bacillus but antagonized the other putative indigenous PAH-degrading bacteria, which were enriched by PR. PR significantly reduced soil nutrients, such as NO₃^- and NH₄⁺, and available potassium (AK), thereby changing the microbial community composition as reflected by redundancy analysis, significantly reducing the soil bacterial biomass relative to that in other treatments. These disadvantages hampered phenanthrene and pyrene removal. MR provided additional nutrients, which counteracted the nutrient consumption associated with PR, thereby maintaining the microbial community diversity and bacterial biomass of PMR at a level achieved in the NA treatment. Combination remediation therefore overcame the disadvantages of using PR alone. These results indicated that inoculation with the combination of S. viminalis and C. laeve synergistically stimulated the growth of indigenous PAH-degrading microorganisms and maintained bacterial biomass, thus accelerating the dissipation of soil PAHs.

Enhancing Salix viminalis L.-mediated phytoremediation of polycyclic aromatic hydrocarbon-contaminated soil by inoculation with Crucibulum laeve (white-rot fungus)

Although plant-white-rot fungi (WRF) remediation is considered efficient in improving polycyclic aromatic hydrocarbon (PAH)-contaminated soil, the prospects for using it remain poorly known. Therefore, we evaluated whether the WRF Crucibulum laeve could improve the phytoremediation of PAH-contaminated soil by Salix viminalis L. A 60-day pot experiment was conducted to investigate the effects of C. laeve inoculation (using two inoculation treatments and a non-inoculated control) on the phytoremediation potential, growth, and antioxidant metabolism of S. viminalis cultivated in PAH-contaminated soil. The S. viminalis-C. laeve association synergistically caused the highest PAH removal rate. Under the S. viminalis-C. laeve treatment, 80% of the biological concentration and translocation factors for all tissues of S. viminalis were > 1, whereas only 20% of these factors were > 1 when S. viminalis was used alone. C. laeve inoculation remarkably enhanced phytoremediation by promoting S. viminalis-based phytoextraction of PAHs from soils. Furthermore, although C. laeve inoculation altered the antioxidant metabolism of S. viminalis by inducing oxidative stress, thereby inhibiting plant growth, the plant's hardiness enabled it to survive and grow normally for 60 days after treatment. Therefore, phytoremediation using S. viminalis inoculated with C. laeve can be considered a feasible approach for the phytoremediation of PAH-contaminated soil.

Lacune and Large Perivascular Space: Two Kinds of Cavities Are of Different Risk Factors and Stroke Risk

BACKGROUND AND PURPOSE

To compare the risk factors and risk of stroke between lacune and large perivascular spaces (PVSs) in a community-based sample.

METHODS

Large PVSs were assessed using 3.0T MRI in a population-based cohort consisting of 1,204 participants. The relationship between cardiovascular risk factors, neuroimaging changes, and incidental stroke risk and the presence of lacune or large PVSs was assessed with univariate and multivariable ordinal logistic regression analysis.

RESULTS

Of the 1,204 study participants (55.7 ± 9.3 years, 37.0% men), a total of 347 large PVSs were detected in 235 (19.5%) subjects, while a total of 219 lacunes were detected in 183 subjects (15.2%). The presence of lacunes was found to be significantly associated with age, male gender, hypertension, and diabetes, whereas only age (p < 0.01) and ApoEε4 carrier status (p < 0.01) were related to the presence of large PVSs. Those who had lacunes detected on MRI at baseline had a significant increased risk of stroke (hazard ratio [HR] 4.68; 95% confidence interval [CI], 1.15-19.07) during the 3-year follow-up independent of age, gender, and other vascular risk factors. However, there was no significant relationship between the presence of large PVSs and incident stroke (HR 3.84; 95% CI, 0.82-18.04).

CONCLUSIONS

The lack of association between large PVSs and cardiovascular risk factors or risk of stroke indicated a nonvascular pathogenic mechanism underlying large PVSs, suggesting the importance of distinguishing large PVSs from lacunes in clinical practice.

Carotid artery stiffness in rural adult Chinese: a cross-sectional analysis of the community-based China stroke cohort study

OBJECTIVES

To derive normative carotid artery stiffness data in rural adult Chinese population-based study of ultrasound measurements of carotid elasticity by using quality arterial stiffness (QAS), and to assess the changes of relevant parameters in Chinese adults 40 years of age and older.

DESIGN

A China stroke cohort study (total number: 1586) in the northern countryside were carried out between June 2013 and April 2016, designed to investigate the risk factors of cardiovascular and age-related diseases.

SETTING

The present study was a cross-sectional analysis of an ongoing community-based Shunyi cohort study in China.

PARTICIPANTS

A total of 583 participants (227 men and 356 women; aged 40-80 years) with ultrasound carotid QAS examination were retrieved from the study to analyse.

PRIMARY AND SECONDARY OUTCOME MEASURES

Arterial stiffness parameters included diastolic diameter (Dd), pulse wave velocity (PWV), stiffness indices α and β were calculated by QAS. Other clinical indicators included physical measurements, medical histories and blood biochemical test.

RESULTS

In the entire study sample, mean Dd was 7.93±0.88 mm, mean PWV was 9.4±2.4 m/s, mean α was 7.65±5.13 and mean β was 15.53±10.29. PWV was significant higher in participants with hypertension (9.9 m/s vs 9.2 m/s in those without, p=0.002), and with diabetes (10.3 m/s vs 9.2 m/s in those without, p=0.003). PWV were significantly higher in participants with HbA1c at 5.8%-6.4% versus <5.8%, but no difference was found between subjects with glycohaemoglobin (HbA1c) at 5.8%-6.4% versus >6.4% (p=0.005, p=0.955, respectively). Age increase by every 10 years was associated with Dd increased by 0.27 mm, PWV increased by 1.2 m/s, α increased by 1.34 and β increased by 2.71. Systolic blood pressure (SBP) increase by every 10 mm Hg was associated with Dd increased by 0.15 mm, PWV increased by 0.35 m/s, α increased by 0.13 and β increased by 0.15.

CONCLUSION

Among the participants older than 40 years, stiffness of the carotid artery had differences between hypertension and non-hypertension adults, as well as between diabetes and non-diabetes adults. Stiffness of the carotid artery also have differences between adults with HbA1c at 5.8%-6.4% versus <5.8%. Stiffness of the carotid artery increases with increasing age and increasing SBP at a range from 40 and up.

Heterologous Expression of SvMBD5 from Salix viminalis L. Promotes Flowering in Arabidopsis thaliana L

Methyl-CpG-binding domain (MBD) proteins have diverse molecular and biological functions in plants. Most studies of MBD proteins in plants have focused on the model plant Arabidopsis thaliana L. Here we cloned SvMBD5 from the willow Salix viminalis L. by reverse transcription-polymerase chain reaction (RT-PCR) and analyzed the structure of SvMBD5 and its evolutionary relationships with proteins in other species. The coding sequence of SvMBD5 is 645 bp long, encoding a 214 amino acid protein with a methyl-CpG-binding domain. SvMBD5 belongs to the same subfamily as AtMBD5 and AtMBD6 from Arabidopsis. Subcellular localization analysis showed that SvMBD5 is only expressed in the nucleus. We transformed Arabidopsis plants with a 35S::SvMBD5 expression construct to examine SvMBD5 function. The Arabidopsis SvMBD5-expressing line flowered earlier than the wild type. In the transgenic plants, the expression of FLOWERING LOCUS T and CONSTANS significantly increased, while the expression of FLOWERING LOCUS C greatly decreased. In addition, heterologously expressing SvMBD5 in Arabidopsis significantly inhibited the establishment and maintenance of methylation of CHROMOMETHYLASE 3 and METHYLTRANSFERASE 1, as well as their expression, and significantly increased the expression of the demethylation-related genes REPRESSOR OF SILENCING1 and DEMETER-LIKE PROTEIN3. Our findings suggest that SvMBD5 participates in the flowering process by regulating the methylation levels of flowering genes, laying the foundation for further studying the role of SvMBD5 in regulating DNA demethylation.

Utility of arterial spin labelling MRI for discriminating atypical high-grade glioma from primary central nervous system lymphoma

AIM

To evaluate the ability of arterial spin labelling (ASL) magnetic resonance imaging (MRI) in differentiating primary central nervous system lymphoma (PCNSL) from atypical high-grade glioma (HGG), as well as exploring the underlying pathological mechanisms.

METHODS AND MATERIALS

Twenty-three patients with PCNSL and 17 patients with atypical HGG who underwent ASL-MRI were identified retrospectively. Absolute cerebral blood flow (aCBF) and normalised cerebral blood flow (nCBF) values were obtained, and were compared between PCNSL and atypical HGG using the Mann-Whitney U-test. The performance in discriminating between PCNSL and atypical HGG was evaluated using receiver-operating characteristics analysis and area-under-the-curve (AUC) values for aCBF and nCBF. The correlation between microvessel density (MVD) and aCBF was determined by Spearman's correlation analysis.

RESULTS

Atypical HGG demonstrated significantly higher aCBF, nCBF, and MVD values than PCNSL (p<0.05). The diagnostic accuracy of discriminating PCNSL from atypical HGG showed AUC=0.877 (95% confidence interval [CI] 0.735-0.959) for aCBF, and AUC=0.836 (95% confidence interval [CI] 0.685-0.934) for nCBF. There was a moderate positive correlation between aCBF values of region of interest (ROI >30 mm²) in the enhanced area and MVD values (rho=0.579, p=0.0001), and a strong positive correlation between aCBF values MVD based on "point-to-point biopsy" (rho=0.83, p=0.0029). Interobserver agreements for aCBF and nCBF were excellent (ICC >0.75).

CONCLUSIONS

ASL perfusion MRI is a useful imaging technique for the discrimination between atypical HGG and PCNSL, which may be determined by the difference of MVD between them.

[Neuropathologic findings in intractable epilepsy: a clinicopathologic analysis of 822 cases]

Objective: To investigate the clinicopathologic characteristics of intractable epilepsy. Methods: Based on the classification criteria proposed by the International League Against Epilepsy (ILAE), a retrospective analysis of the pathological characteristics was done in 822 patients who underwent epilepsy surgery in Sanbo Brain Hospital, Capital Medical University, from June 2008 to December 2012. Results: The mean age of epilepsy onset was 9.9 years, mean duration of epilepsy was 11.9 years. Complex partial seizures were the main presenting features. Histopathological study showed 33 cases (4.01%) with mild forms of cortical malformations, 690 cases (83.94%) with focal cortical dysplasia (FCD) and 99 cases with others (including 39 pure hippocampal sclerosis, 20 cystosclerosis, 19 Sturge-Weber syndrome, 8 tuberous sclerosis complex, 6 without significant pathological changes, 5 gyral malformations and 2 hamartoma). Among the 690 FCD cases, 106 were FCD typeⅠ, 91 were FCD typeⅡ and 493 were FCDⅢ(Ⅲa: 160, Ⅲb: 106, Ⅲc: 26 and Ⅲd: 201). Conclusions: FCDⅢd is the most common histopathological subtype causing intractable epilepsy, mainly due to focal hypoxia/ischemia in the perinatal period, which results in scarring of local brain tissue; this is followed by other isolated forms of FCD (FCDⅠand FCDⅡ), and then FCD Ⅲa and FCD Ⅲb. The reason to distinguish isolated forms of FCD (types Ⅰ and Ⅱ) from FCD Ⅲ and to subclassify FCD Ⅲ is to allow better definition of cortical dyslamination. Therefore, the pathogenic factors of intractable epilepsy can be grouped in greater details, and facilitate the diagnosis and potential curative treatment of intractable epilepsy.

Amyotrophic Lateral Sclerosis and Myasthenia Gravis Overlap Syndrome: A Review of Two Cases and the Associated Literature

Objective

To describe the characteristics of patients with amyotrophic lateral sclerosis (ALS) and myasthenia gravis (MG) overlap syndrome and explore the relationship between the two diseases.

Methods

We conducted a search of medical records at Peking Union Medical University Hospital from 1983 to 2015 for coexistence of ALS and MG and searched the PubMed database for all literature describing ALS and MG overlap syndrome published through December 2016. We analyzed the clinical and neurophysiological characteristics of patients by groups according to strict diagnostic criteria.

Results

We presented 2 patients in our database with combined ALS and MG, and together with 25 cases reported in the literature, the patients were divided into 4 groups: 12 patients with MG followed by ALS, 8 patients with ALS followed by MG, 5 ALS patients with false-positive anti-acetylcholine receptor, and the other 2 ALS patients with only myasthenia symptoms. Most patients had limb onset ALS, and myasthenia symptoms mainly affected ocular and bulbar muscles. Clinical and neurophysiological characteristics were summarized.

Conclusion

These findings support the conclusion that immunological mechanisms and alterations in the neuromuscular junction are related to ALS pathogenesis.

Male and Female Subpopulations of Salix viminalis Present High Genetic Diversity and High Long-Term Migration Rates between Them

Dioecy distributed in 157 flowering plant families and 959 flowering plant genera. Morphological and physiological differences between male and female plants have been studied extensively, but studies of sex-specific genetic diversity are relatively scarce in dioecious plants. In this study, 20 SSR loci were employed to examine the genetic variance of male subpopulations and female subpopulations in Salix viminalis. The results showed that all of the markers were polymorphic (Na = 14.15, He = 0.7566) and workable to reveal the genetic diversity of S. viminalis. No statistically significant difference was detected between male and female subpopulations, but the average genetic diversity of male subpopulations (Na = 7.12, He = 0.7071) and female subpopulations (Na = 7.31, He = 0.7226) were high. Under unfavorable environments (West Liao basin), the genetic diversity between male and female subpopulations was still not significantly different, but the genetic diversity of sexual subpopulations were lower. The differentiation of the ten subpopulations in S. viminalis was moderate (FST = 0.0858), which was conformed by AMOVA that most of genetic variance (94%) existed within subpopulations. Pairwise FST indicated no differentiation between sexual subpopulations, which was accompanied by high long-term migrate between them (M = 0.73~1.26). However, little recent migration was found between sexual subpopulations. Therefore, artificial crossing or/and transplantation by cutting propagation should be carried out so as to increase the migration during the process of ex situ conservation.

Fatty and lean red meat consumption in China: differential association with Chinese abdominal obesity

AIM

We examined the longitudinal association between red meat (RM) consumption and the risk of abdominal obesity in Chinese adults.

METHODS AND RESULTS

Our data are from 16,822 adults aged 18-75 in the China Health and Nutrition Survey from 1993 to 2011. We assessed RM intake with three 24-h dietary recalls. We defined abdominal obesity as a waist circumference (WC) ≥85 centimeters (cm) for men and ≥80 cm for women. Multilevel mixed-effect regression models showed that men experienced WC increases of 0.74 cm (95% confidence interval [CI]: 0.39-1.09) from a higher total intake of fresh RM and 0.59 cm (95% CI: 0.24-0. 95) from a higher intake of fatty fresh RM but 0.14 cm (95% CI: -0.39 to 0.66) from a higher intake of lean fresh RM in the top quartile versus non-consumers when adjusted for potential confounders. In contrast, after additional adjustment for baseline WC, the odds ratios of abdominal obesity in men were attenuated for total fresh RM (1.25 [95% CI: 1.06-1.47]) and fatty fresh RM (1.22 [95% CI: 1.03-1.44]) but were still not affected by lean fresh RM (0.95 [95% CI: 0.75-1.22]). Women also showed a positive association of fatty fresh RM intake with abdominal obesity.

CONCLUSION

Greater intake of fatty fresh RM was significantly associated with higher WC (men only) and abdominal obesity risk in Chinese adults. The gender-specific differential association of fatty versus lean fresh RM warrants further study.

Nutrition of elderly people in China

Cross-sectional data from the 1991 (n = 1657) and 1993 (n = 1773) China Health and Nutrition Surveys were used to describe patterns in the diets, activity levels and body mass index (BMI) of elderly Chinese (aged 60 or older). In 1991 and 1993, the prevalence of low BMI (BMI < 18.5 or BMI < 22.0) exceeded 15%, while the prevalence of high BMI (BMI > 25.0 or BMI > 27.0) ranged between 4% and 24%. The BMI was consistently, positively and significantly associated with urban residence. Urban residence and income were consistently and positively associated with energy from fat and protein intakes, and decreasing physical activity levels. The results suggest that under- and overnutrition coexist among Chinese elders and are differentially distributed across income and urban/rural strata.

Programme and policy options for preventing obesity in China

By 2002, China's prevalence of overweight and obesity among adults was 18.9 and 2.9%, respectively. The replacement of traditional Chinese diet with 'Western diet', major declines in all phases of activity and increased sedentary activity are cited as the main reasons explaining the rapid increase in overweight and obesity, which bring major economic and health costs. The Nutrition Improvement Work Management Approach was released in 2010. Overweight and obesity prevention-related policies were added to national planning for disease prevention and control. The Guidelines for Prevention and Control of Overweight and Obesity of Chinese Adults and the School-age Children and Teenagers Overweight and Obesity Prevention and Control Guidelines in China were promulgated in 2003 and 2007, respectively. Few education programmes have been implemented. Selected academic intervention research projects dominate with a focus on reducing child obesity and promoting healthier diets; increasing physical activity and reducing sedentary time; and facilitating changes in family, school, social and cultural environments. Intervention samples are small and have not addressed the increasing rates of obesity throughout the entire population. Government provision of effective policy measures, multisectoral cooperation and increasing corporate social responsibility are keys to curbing the trend towards overweight and obesity in China.

Valley-dependent Brewster angles and Goos-Hänchen effect in strained graphene

We demonstrate theoretically how local strains in graphene can be tailored to generate a valley-polarized current. By suitable engineering of local strain profiles, we find that electrons in opposite valleys (K or K') show different Brewster-like angles and Goos-Hänchen shifts, exhibiting a close analogy with light propagating behavior. In a strain-induced waveguide, electrons in K and K' valleys have different group velocities, which can be used to construct a valley filter in graphene without the need for any external fields.

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.

Closing the energy gap to prevent weight gain in China

To estimate the energy gap (i.e. degree of positive energy balance) that is causing weight gain in the population of China in order to provide a quantitative goal for how much behaviour change is required to prevent excess weight gain in the population. This is based on data collected in the China Health and Nutrition Survey. 2288 adults (20-45 years) who took part in both the 1989 and 2000 surveys were selected.

RESULTS

from 1989 to 2000, the average weight of this population increased from 55.4 kg to 59.1 kg. The medium increasing rate was 0.33 kg year(-1). During this time, the prevalence of overweight in the population increased dramatically from 9.0% to 23.2%. By assuming that each kilogram of body weight gained represents 7700 kcal, the estimated medium energy accumulation in the sample was 7.0 kcal day(-1) and the 90th percentile was 22.5 kcal d(-1). Further, assuming that the energy derived from mixed composition diets is stored with an average efficiency of 50%, the estimated energy gap for the population was 45 kcal day(-1). This is the degree of positive energy balance that is causing weight gain in 90% of the population. The estimate suggests that the behaviour change needed to close the energy gap is small and achievable without dramatically altering current lifestyle in China. For example, reducing energy intake by just 2-3% less each day or walking an extra 10-15 minutes each day could offset weight gain in roughly 90% of the population in China. By providing an estimate of the energy gap it can be predicted that weight gain in most of the population of China could be prevented with small lifestyle changes. It is critical that these lifestyle changes be implemented in order to prevent acceleration of the obesity epidemic in China.

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.

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.

Longitudinal relationships between occupational and domestic physical activity patterns and body weight in China

OBJECTIVES

To examine the longitudinal relationship between occupational and domestic sources of physical activity and body weight in a sample of Chinese adults.

METHODS

Population-based longitudinal observational study of Chinese adults (4697 women and 4708 men) aged 18-55 from the 1991, 1993, 1997, and 2000 waves of the China Health and Nutrition Survey. Measured height and weight and detailed self-reported energy expenditure from multiple occupational and domestic sources were assessed over a 9-year period. Longitudinal relationships were modeled using linear random effects models.

RESULTS

Increased occupational physical activity resulted in overall lower body weight for both men and women (beta-coefficients (95% confidence interval (CI)) for high levels: -0.46 (-0.76, -0.15) for men, -0.36 (-0.62, -0.10) for women, and increased domestic physical activity resulted in overall lower body weight in men (beta-coefficient (95% CI): -0.40 (-0.62, -0.18)).

CONCLUSIONS

Physical activity that occurs in the occupational and domestic sectors is often overlooked; yet our research suggests they have important effects on body weight in Chinese adults. As China continues to urbanize, energy expenditure from these sources is decreasing, and our results point out the need to explore these types of physical activity more broadly across the world as potential sources of weight gain.

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.

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.

Trends in the distribution of body mass index among Chinese adults, aged 20-45 years (1989-2000)

OBJECTIVE

To describe body mass index (BMI, in kg/m(2)) distribution patterns and trends among Chinese adults, aged 20-45 years (1989-2000).

DESIGN

A descriptive, population-based study of BMI change.

SETTING

Chinese provinces (eight in 1989 and 1997; nine in 2000), representative of the household-based surveys (the China Health and Nutrition Survey, 1989-2000) using multistage, random cluster sampling, supplemented with annual household consumption survey data of the State Statistical Bureau (SSB).

SUBJECTS

A total of 4527, 4507 and 4046 adults, aged 20-45 years, in 1989, 1997 and 2000, respectively.

MEASUREMENTS

BMI (underweight: BMI<18.5 kg/m(2) and overweight: BMI>/=25 kg/m(2)). Percentile curves for BMI in 1989 and 2000 were constructed by gender and age using the LMS (lambda, mu, sigma) method.

RESULTS

Compared with 1989, the 2000 BMI distribution curves flattened at higher levels of BMI (men and women). There was a 13.7% increase in the proportion of men and a 7.9% increase of women who were overweight or obese with a resulting greater change in the annualized prevalence rate for men. This increase in the prevalence of overweight and obesity was far greater than the decrease (2.1% for men; 2.2% for women) in that of underweight. Age-gender-specific percentile curves showed BMI increases mainly among women, aged 35-45 years, and among men at all age groups.

CONCLUSIONS

Chinese BMI dynamics show much greater rates of change among men, aged 20-45 years, than among women, with the increase among women concentrated between ages 35 and 45 years. These changes portend large shifts in other diet-related non-communicable diseases in China over the following decades. Controlling the increasing trends of BMI, especially in men, is an important public health problem facing China.

Trends in eating behaviours among Chinese children (1991 -1997)

This study examined the trends in snacking behaviours and eating food-prepared-outside-the-home (FPOH) by Chinese children and adolescents using data from the China Health and Nutrition Survey. The sample consisted of 3223 subjects aged 6-18 in 1991 and 2836 in 1997. Three days of 24hr recall dietary data and per capita income (deflated to 1989) was used. The percentage of Chinese children having snacking behaviours was significantly differentiated according to the income level while percentage of eating FPOH increased in middle and high income groups. Snacking contributed about 8% of the energy intake (EI) for snackers, compared with over 15% from FPOH for those who ate FPOH. Fruit was a major component of snacking: snacks based on fruit intake almost doubled over the study period as did snacks based on soft drink consumption. Animal source food consumption was a key component of FPOH and its intake also increased.

Intrahousehold food distribution: a case study of eight provinces in China

A longitudinal survey of health and nutrition in China was undertaken in eight provinces (Liaoning, Jiangsu, Shandong, Henan, Hubei, Hunan, Guangxi, Guizhou). Data were collected in 1989, 1991, 1993 and 1997. The 1991 and 1993 data were used to investigate factors affecting intrahousehold food distribution. The discrepancy score and the ratio of food share to energy share were used to describe food distribution within households. Findings indicated that, in most cases, males had a higher proportion of nutrient intake than females, particularly in the young adult group where men presented with a higher discrepancy score than women for energy and all nutrients observed. The food and nutrient distribution tends to be more favourable to the middle-aged group, although the youngest group, while accepting relatively smaller amounts of cereals, ate much bigger amounts of meat, dairy products and fruits. Household members with higher incomes are more favoured in terms of food consumption and nutrient intake. Household leaders accepted a higher share of energy and nutrients in comparison with other members of the household across all age and sex groups. Administrators and people working in service or trade industries in rural areas are favoured in terms of food distribution relative to farmers and manual workers. Well-educated people accepted a better food allocation than others and those in employment received more nutrients than the unemployed. The 'contribution rule' (individuals who make a greater contribution to the family receive a larger share of the family's food) is discussed and deemed to be applicable in explaining the discrepancy in food distribution and nutrient intake among household members.

[Distributions of body mass index of Chinese adults]

Based on the Third China National Nutrition Survey conducted in 1992, the distribution of body mass index (BMI) in 44,485 adults aged 20-60 y was analyzed, and the cutoff points of BMI for overweight and obesity were also explored. The results showed that the BMI of Chinese adults was in logarithmic normal distribution. The average BMI of this population was 22.1 +/- 3.1. The 50th, 85th and 95th percentiles of BMI were 21.6, 24.9 and 27.4 kg/m2 respectively. The 85th percentile of BMI was much closer to the BMI cutoff points for overweight recommended by WHO, but the 95th percentile was much lower than WHO's cutoff points for obesity. The distribution of BMI based on age, gender and urban/rural areas was different and with statistical significance. It is considered that age and gender should be taken into account while setting up BMI cutoff points for the overweight and obesity of a population, as well as considering the relationships among BMI and morbidity and mortality, body fat composition, and some blood biochemical indexes.

[Complementary feeding practice in Chinese rural children]

The information of complementary foods consumed by 14649 children aged from 4 to 24 months in poor rural areas was analyzed. On average, it was at 6 months old for children to start complementary feeding. Approximately one third of children started complementary feeding at 4-6 months old and 16.4% children were fed cereal foods before 4 months old. Only 50% of children aged 12 months and above consumed vegetables/fruits daily and 38% of them consumed animal foods. However, 15.8% children never ate animal foods, and 20% children were fed formula milk daily after weaning time. The impact of family dietary pattern on children's diet increased along with the growth of children. It is obvious that the irrational food pattern would undermine growth of children and such diet behavior would eventually result in malnutrition. Poor complementary feeding practice in some selected rural areas in China played a negative role on children's growth. Hence, nutrition education to the mothers and caretaker should be emphasized so that to improve their awareness of the importance of good nutrition practice and guide them to feed weaning children reasonably.

[Transition of dietary pattern in China]

The implications of dietary transition in China during the past 50 years were investigated. Data were collected from the representative national surveys, China Health and Nutrition Survey (1989-1997), China National Nutrition Survey (1982 and 1992), the Annual Household Consumption Surveys of the State Statistic Bureau and the Annual Death Report of China. In the early part of the major economic transformation, cereal intake increased before 1985 and decreased thereafter. There was also a long-term reduction of vegetable consumption, which has stabilized now. Intakes of animal foods increased slowly before 1979 and more quickly after the economic reforms occurred. The total energy intake has reduced, as energy expenditure has, large changes in the composition of energy have occurred. The proportion of energy from fat increased quickly and reached 27.3% in average and 32.8% in urban residents in 1997. More than one third of all Chinese adults and 58.4% of adults in urban areas consuming over 30% of their energy from fat. These changes resulted in rapid increases the prevalence of overweight and obesity and dietary-related chronic non-communicable diseases in urban residents. The traditional Chinese diet is shifting towards a diet with high fat, high energy density and low dietary fiber. The Chinese diets have entered into a new stage of transition.

[A survey on the effects of "Dietary Guideline" nutrition education project]

A survey on the nutrition knowledge, attitude and behavior of 5145 persons from five cities of four provinces, Shandong, Guangdong, Sichuan and Heilongjiang, before and after the nutritional education project on "Dietary Guideline" has been effectively conducted. An obviously good effect has been achieved among the residents, middle and primary school students and elderly people. Before the nutritional educational project has been carried out, the people who understanding the "Dietary Guideline" was only 12.0%, 29.2% and 15.2% of residents, the elderly and students respectively. But after education, the rates raised to 93.4%, 99.0% and 91.9% respectively. Nearly 90% of residents and the elderly got to know the "Dietary Guideline" through the materials distributed from the project. The nutrition knowledge score was improved greatly after the project was conducted. The attitude towards learning nutrition knowledge was good. At the same time, some dietary behavior and the life style of people had been modified. These results indicated that nutrition education is very important on improving people's nutrition knowledge level, changing people's unhealthy living attitudes and dietary habits.

[Radiotherapy for 308 patients with non-small cell lung cancer (NSCLC)]

BACKGROUND

To analyze the survival results retrospectively of the patients with NSCLC treated by radiotherapy alone and the clinical factors affecting the survival results.

METHODS

Three hundred and eight patients with NSCLC from January, 1985 to December, 1991 were included in this study (stage I, 11 cases; stage II, 68 cases; stage IIIA, 155 cases; stage IIIB, 74 cases). All patients were confirmed by pathology and cytology. They were treated by 10 MV-X ray or cobalt-60, conventionally fractionated, with weekly dose 7-11.5 Gy. In 47 patients of them treatment planning system was used at the beginning or in the middle of radiotherapy as to have the primary lesion and mediastinum in the full course of radiotherapy. In the rest of patients whose mediastinal dose was 40Gy by anterior and posterior fields, irradiation dose to the spinal cord was avoided and irradiation dose to the primary lesion got to the definitive treatment. The survival rate was analyzed by Kaplan-Meier and tested by Log-rank.

RESULTS

The median survival was 10 months. The 1-, 3- and 5-year survival rates were 43%, 15% and 9% respectively. The earlier the clinical stage, the better the prognosis (P=0.0001). The survival rate of the patients with complete remission at the end of radiotherapy was better than that of the patients with residual tumor (P=0.0001). The survival of the patients with weekly dose larger than 10 Gy was better ( P=0.0461). There was no relationship among the survival rate and the total dose and mediastinal dose.

CONCLUSIONS

The results show the survival rate of patient with NSCLC treated by radiotherapy alone was related to clinical stage, instant response and weekly dose, but not to the total dose and the mediastinal dose.

Current methods for estimating dietary iron bioavailability do not work in China

Three current equations for estimating iron bioavailability were evaluated, and adjustments were proposed that would allow us to most effectively study iron bioavailability in China. Dietary intake data were obtained from 24-h dietary recalls taken over three consecutive days as part of the third Chinese National Nutrition Survey. Hemoglobin status was measured for 42,606 Chinese adults aged 18-60 y. The mean iron intake was 24.4 mg per capita per day, which was 177% of the Chinese RDA (209% of U.S. RDA). About 18% of the sample was classified as being anemic, indicating a large iron deficiency anemia and iron bioavailability problem in China. A number of methods proposed by World Health Organization and U.S. scholars were examined for adjusting iron bioavailability. Even the methods that consider several iron enhancers and inhibitors did not work adequately for the Chinese diet. The statistical assessment of the fit between iron bioavailability and hemoglobin status provided direction for adjusting the best of these predictive equations. We propose a new predictive approach for iron bioavailability which is more predictive of Chinese iron status. Consideration of additional dietary elements such as rice and bean consumption patterns are important. Our findings provide insight into additional factors which may influence iron bioavailability as well as possible improved methods for estimating the combined effect of multiple dietary factors on iron bioavailability, particularly in a vegetarian diet.

[Dietary intake of some micronutrients in different provinces of China]

Based on the data collected in 1992 China National Nutrition Survey, which covered 100,201 persons of all ages in 29 provinces, the dietary intakes of some micronutrients were calculated. The intake of calcium, retinal equivalent and riboflavin were the most insufficient nutrients; zinc, selenium and thiamin were close to (80%-90%) of Chinese RDAs. The intakes of niacin, ascorbic acid and vitamin E were sufficient. The regions in the northeast, northwestern and the southeastern inland were more at risk of nutrition deficiency. Dietary intervention or food fortification with some micronutrients could be used for improving the situation.

Sex difference in measures of body fatness and the possible difference in the effect of dietary fat on body fatness in men and women

OBJECTIVES

To examine the sex difference in anthropometric measures of body fatness and to explore the possibility that diet may have differential effects on body fatness in men and women.

DESIGN

Prospective study design.

SETTING

The first and second China Health and Nutrition Survey conducted in 1989 and 1991, respectively.

SUBJECTS

1449 men and 1683 women age 20-35 y at the baseline (1989) survey.

METHODS

Anthropometric measures of body fatness in men and women were compared. Statistical methods were used to explore the potential difference in the effect of dietary fat on body fatness in men and women.

RESULTS

Measures of body fatness, especially peripheral fatness, differed markedly between men and women in this study sample. Statistical analysis suggested that the effect of dietary fat on body fatness may be different in men compared to women.

CONCLUSIONS

Sexual dimorphism in body fatness has important implications for both clinical and epidemiologic research of obesity. The possibility that diet may have differential effect on body fatness in men and women needs to be investigated.

[Effect of nutrition on the health improvement of preschool children in rural areas]

"Surveillance and Improvement of Children's Nutrition" is the largest project in connection with the nutrition of preschool children in China up to now. It focused on nutrition improvement of preschool children in rural areas. The results of the baseline survey and the project final evaluation surveys showed that the nutritional status of children was improved from 1990 to 1995. The prevalence of moderate and severe stunting and underweight at the national level decreased by 23.1% and 28.6% respectively. Anemia decreased by 48%. It was identified that the benefits of nutrition improvement were associated with nutrition education and other integrated nutrition interventions, e.g., improvement the dietary habit of the target children.

Food price policy can favorably alter macronutrient intake in China

The rapid change in diets, physical activity and body composition in low income countries has led to the coexistence of large pockets of undernutrition and overnutrition. Public health strategies for addressing this situation may be necessary, and price policy options are examined for China. Longitudinal dietary data collected in China in 1989-1993 on a sample of 5625 adults aged 20-45 y were examined. Three-day averages of food group consumption and nutrient intake were used in longitudinal statistical models to examine separately the effects of food prices on the decision to consume each food group and then the amount consumed. The effects of changes in six food prices on the consumption of each of six food groups, not just the food group whose price had changed, and on three macronutrients were estimated. The effects show large and significant price effects. If the joint effects of the nutrition transition are to be considered, then there are clear tradeoffs among which foods to tax and which to subsidize. Most important is the effect of prices in reducing fat intake of the rich but not adversely affecting protein intake for the poor. Increases in the prices of pork, eggs and edible oils are predicted to lower fat intake. Only increases in pork prices led to reduced protein intakes. This raises questions about earlier policy changes being implemented in China and provides insight into an important and controversial area for public health policy.

[Impact of maternal occupation on the dietary and nutritional status of preschool children. A case study in 8 provinces of China]

This analysis is based on the data from China Health and Nutrition Survey (undertaken in 8 provinces of China from 1989 to 1998) in collaboration with the University of North Carolina at Chapel Hill. Totally, 1461 and 1087 mother-child pairs under age 6 were selected to investigate the impact of maternal occupation on the dietary and nutritional status of children in 1991 and 1993. The results show that the nutrients intake and nutritional status of children whose mothers worked in administrative, scientific, technological and other professional units were better than any other groups. The status of children whose mothers were workers, waiters etc. in factories or service sectors was better than that of children whose mothers were farmers or self-employed laborers. The children of non-working mothers were better nourished than the children whose mothers were farmers, or self-employed laborers, but were more undernourished than the children whose mothers worked in administrative, scientific, technological and other professional units. The associations among maternal occupation, income and education level of mothers were significant. Mothers working in administrative, scientific, technological units etc. had higher yearly income and education level than other groups. But the income and education level of farmers and self-employed laborers were the lowest. The time allocation of mothers was also studied and the results suggested that maternal occupation affected the time spent for child care and food preparing.

[Studies on the factors affecting the individual's animal protein intake by a multi-level model]

In this article, the influence of factors related to different levels (seg, provincial, county and household) on the proportion of protein intake from animal food was evaluated by using multi-level modeling. It was found that after being adjusted by individual factors, the factors related to the household, such as household income, dietary habit and knowledge of nutrition were the most important factors affecting the individual's showed animal protein intake. In addition, the results showed that the difference of animal protein intake in various places depended not only on the increase of household income, but also dietary behavior and agriculture crops in different areas. Comparison of different models indicates that in analyzing the data from large-scale health survey with hierchical structure, multi-level modeling is strongly recommended.

The nutritional status and dietary pattern of Chinese adolescents, 1991 and 1993

OBJECTIVE

To increase understanding about current dietary patterns and short-term relationships between economic change and adolescent nutrition in a lower-income country, using the 1991 and 1993 China Health and Nutrition Survey data.

DESIGN

Cross-sectional study.

SETTING

Eight provinces in China that vary substantially in geography, economic development, public resources, and health indicators.

SUBJECTS

2236 and 2018 adolescents aged 10-18 years who completed three 24-hour recalls in the 1991 and 1993 survey, respectively.

RESULTS

Chinese adolescents experienced an improvement of diet and nutritional status. The prevalence of stunting declined from 23% in 1991 to 19% in 1993. Under-nutrition was a problem of concern although the prevalence (12-13%) was relatively low. Overweight was emerging as a problem associated with young, high-income and urban adolescents, but the prevalence (4%) was quite low compared with developed countries. Chinese adolescents' energy and protein intakes were adequate compared with the American RDA. About 27% of the participants derived more than 30% of their dietary energy from fat and 16% of them derived over 10% of energy from saturated fat by 1993.

CONCLUSION

Chinese adolescents have experienced an improvement in diet and nutritional status, but undernutrition is still an important nutrition problem, especially among young and poor groups. More attention should focus on the increase of dietary fat intake and obesity.

[The impact of maternal education on the dietary and nutritional status of preschool children--a case study in 8 provinces of China]

This analysis is based on the data from China Health and Nutrition Survey in collaboration with University of North Carolina at Chapel Hill undertaken in 8 provinces of China from 1993 to 1996. Totally, 1098 mother-child pairs under age 6 were investigated. Descriptive analysis and stratified analysis are applied to investigate the impact of maternal education on the dietary and nutritional status of children. Both the crude analysis and after controlling for confounding variables, maternal education in the population remains statistically relevant to children's dietary and nutritional status. The proportion of low body weight and stunting children is the highest in the group with maternal education level being below preliminary school, the lowest in the group with education level being above high middle school. Moreover, in these three groups, the higher the level of maternal education, the greater the percentage of nutrients intake of China RDA, especially those from animal food. These results fully illustrate the importance of maternal education for the prevention of malnutrition in children.

[Impact of maternal income on the nutrients intake of preschool children--a case study in 8 provinces of China]

The data of this study are based on the project "China Health and Nutrition Survey" carried out in 8 provinces of China from 1989 to 1998 in collaboration with the University of North Carolina at Chapel Hill, USA. Totally, 1180 and 916 mother-child pairs aged 2-6 were investigated in 1991 and 1993 respectively. Descriptive and stratified analysis is applied to investigate the impact of maternal income on the nutrients intake of children. It is found that the nutrients intake of children in higher maternal income group is greater than that in lower maternal income group. After adjusting for family income, the results show that the more contribution of the mother's income to the family, the more nutrients intake of their children, especially in lower income families. It is illustrated that the income of mother may be more important for children's dietary status than that of other members of the family.

[Effect of cyclin D1 protein expression on the prognosis of esophageal squamous-cell carcinoma treated with preoperative radiotherapy]

OBJECTIVE

To study the effect of cyclin D1 protein expression on the prognosis of esophageal carcinoma treated with preoperative radiotherapy.

METHODS

From Nov. 1979 to Dec. 1996, 164 patients were treated with preoperative radiation followed by radical esophagectomy in our hospital. All cases were confirmed by pathology as squamous-cell carcinoma. Two vertical radiation fields were used to deliver a total tumor dose of 30-40 Gy, with 15-20 fractions in 3-4 weeks. Immunohistochemical staining of cyclin D1 was performed using a streptavidin-biotin staining technique.

RESULTS

Cyclin D1 protein expression was positive in 62.5%(65/104) and 60.8%(93/153) for pre- and post-radiation tumor specimens, respectively. The expression level did not change following radiation. Post-radiation cyclin D1 expression influenced the survival (P = 0.055), and the survival rate differed significantly between patients who expressed cyclin D1 and those who did not (P = 0.02).

CONCLUSION

Cyclin D1 expression is of prognostic value for esophageal carcinoma. It may provide a reference criterion for the clinical staging of esophageal cancer.