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Objective: To analyze the trends of the age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019. Methods: Data were extracted from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019. A total of 253 037 Han girls aged 9 to 18 years with complete data on menarche were selected in this study. They were asked one-on-one about their menstrual status, age and residence information. The median age of menarche was estimated by probability regression. U tests were used to compare the difference in median age at menarche in different years. Results: The median age at menarche (95%CI) among Chinese Han girls was 12.47 (12.09-12.83) years in 2010, 12.17 (11.95-12.38) years in 2014 and 12.05 (10.82-13.08) years in 2019, respectively. Compared with that in 2010, the median age at menarche in 2019 decreased by 0.42 years (U=-77.27, P<0.001). The annual average changes were -0.076 years from 2010 to 2014 (U=-57.19, P<0.001) and -0.023 years from 2014 to 2019 (U=-21.41, P<0.001), respectively. The average annual changes in urban areas in the periods of 2010 to 2014 and 2014 to 2019 were -0.071 years and 0.006 years, respectively, while those in rural areas were -0.082 years and -0.053 years, respectively. The average annual changes in the regions of north, northeast, east, south central, southwest and northwest were -0.064, -0.099, -0.091, -0.080, -0.096 and -0.041 years in the period of 2010 to 2014 and 0.001, -0.040, -0.002, -0.005, -0.043 and -0.081 years in the period of 2014 to 2019. Conclusion: The age of menarche among Chinese Han girls aged 9 to 18 years shows an advanced trend from 2010 to 2019, and the trends in urban and rural areas and different regions have different characteristics.
Subject(s)
Female , Humans , Child , Adolescent , Menarche , Probability , East Asian PeopleABSTRACT
Objective: To analyze the trends of the age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019. Methods: Data were extracted from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019. A total of 253 037 Han girls aged 9 to 18 years with complete data on menarche were selected in this study. They were asked one-on-one about their menstrual status, age and residence information. The median age of menarche was estimated by probability regression. U tests were used to compare the difference in median age at menarche in different years. Results: The median age at menarche (95%CI) among Chinese Han girls was 12.47 (12.09-12.83) years in 2010, 12.17 (11.95-12.38) years in 2014 and 12.05 (10.82-13.08) years in 2019, respectively. Compared with that in 2010, the median age at menarche in 2019 decreased by 0.42 years (U=-77.27, P<0.001). The annual average changes were-0.076 years from 2010 to 2014 (U=-57.19, P<0.001) and-0.023 years from 2014 to 2019 (U=-21.41, P<0.001), respectively. The average annual changes in urban areas in the periods of 2010 to 2014 and 2014 to 2019 were-0.071 years and 0.006 years, respectively, while those in rural areas were-0.082 years and-0.053 years, respectively. The average annual changes in the regions of north, northeast, east, south central, southwest and northwest were-0.064, -0.099, -0.091, -0.080, -0.096 and-0.041 years in the period of 2010 to 2014 and 0.001, -0.040, -0.002, -0.005, -0.043 and-0.081 years in the period of 2014 to 2019. Conclusion: The age of menarche among Chinese Han girls aged 9 to 18 years shows an advanced trend from 2010 to 2019, and the trends in urban and rural areas and different regions have different characteristics.
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Objective: To analyze the prevalence trend of malnutrition among Chinese Han children and adolescents aged 7-18 years from 2010 to 2019. Methods: Based on the data from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019, about 215 102, 214 268 and 212 713 Han students aged 7-18 years were included in this study. According to the National Screening Standard for Malnutrition of School-age Children and Adolescents, the detection rate of malnutrition among Chinese Han children and adolescents aged 7-18 was calculated, and the prevalence trend of malnutrition from 2010 to 2019 was analyzed. Results: In 2019, the detection rate of malnutrition among Chinese Han students aged 7-18 years was 8.64% (18 381/212 713), of which the rate of growth retardation, moderate-to-severe wasting and mild wasting was 0.50% (1 062/212 713), 3.25% (6 914/212 713) and 4.89% (10 405/212 713), respectively. In 2019, the detection rate of malnutrition in these boys was higher than that of girls (9.97% vs. 7.31%), and the detection rate in rural areas was higher than that in cities (9.30% vs. 7.98%). The detection rates were 9.74% (5 252/53 916), 8.17% (4 408/53 937), 7.29% (3 885/53 310), and 9.38% (4 836/51 550) in 7-9, 10-12, 13-15, and 16-18 years groups, and 8.14% (6 563/80 618), 7.61% (4 237/55 694) and 9.92% (7 581/76 401) in the eastern, central, and western regions. Malnutrition among students in China was mainly caused by mild wasting, and the detection rate of growth retardation accounted for only 5.78% (1 062/18 381). Malnutrition was mostly concentrated in the southwest region, and the rate was relatively low in eastern provinces. In three surveys from 2010 to 2019, the detection rate of malnutrition among Han students aged 7-18 in China decreased gradually, and the differences were statistically significant (P<0.05). Among them, the detection rates in western rural areas decreased significantly, as well as the gap between urban and rural areas. Compared with that in 2014, the detection rate of malnutrition in Shandong, Hunan, Qinghai and Hainan provinces in 2019 decreased significantly (P<0.05). Conclusion: In 2019, the malnutrition of Chinese children and adolescents aged 7-18 years is dominated by wasting malnutrition. The detection rate shows a downward trend from 2010 to 2019, with regional differences.
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Objective To evaluate the performance of contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) LR-5 in the diagnosis of hepatocellular carcinoma (HCC). Methods The clinical research reports with the application of CEUS LI-RADS in the diagnosis of HCC were collected from PubMed,Embase,Cochrane Library,CNKI,and Wanfang Data from inception to November 14,2021.Two researchers respectively screened the literature and extracted relevant information.The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) was used to evaluate the quality of all the included articles.RevMan 5.4,Meta disc 1.4,and Stata 16.0 were employed to analyze the diagnostic performance of LR-5 for HCC in high-risk patients. Results Twenty original studies were included,involving a total of 6131 lesions,of which 5142 were HCC.The results of meta-analysis showed that the LR-5 in CEUS LI-RADS for diagnosing HCC in the high-risk population had the overall sensitivity of 0.72 (95%CI=0.66-0.77),the overall specificity of 0.93 (95%CI=0.87-0.96),the overall positive likelihood ratio of 9.89 (95%CI=5.31-18.41),the overall negative likelihood ratio of 0.30 (95%CI=0.25-0.37),and the area under the summary receiver operating characteristic curve of 0.88 (95%CI=0.85-0.91).There was heterogeneity among the included studies (I2=95.31,P<0.001).The funnel plot indicated the existence of publication bias (P=0.04). Conclusion The CEUS LI-RADS can effectively diagnose HCC in high-risk patients based on the LR-5 criteria.
Subject(s)
Humans , Carcinoma, Hepatocellular/diagnostic imaging , Liver Neoplasms/diagnostic imaging , Diagnostic Imaging , UltrasonographyABSTRACT
The secondary metabolites of plants are important sources of natural drugs. Betula plants have abundant pharmacological value, complex mechanism and wide applications, which are closely related to the triterpenoids of theirs. Triterpenoids in Betula species are mainly divided into dammarane-type, ocotillol-type, oleanane-type, lupane-type and cycloaltunane-type. The extracts of Betula species have varieties of activities such as anti-tumor, anti-inflammatory, anti-oxidant, anti-bacterial, etc. And the biosynthetic pathways of triterpenoids after 2,3-oxidosqualene are split into four branches of dammarenediol-II, lupeol, cycloartenol and amyrin according to the different oxidosqualene cyclases. This review summarizes the chemical constituents, pharmacological activities and biosynthetic pathways of triterpenoids in Betula plants. It provides a reference for the research and development of new drugs and the production of these triterpenoids in microbial cell factories by synthetic biology methods.
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Objective@#To establish an ultra-sensitive, ultra-fast, visible detection method for Vibrio parahaemolyticus (VP) .@*Methods@#We established a new method for detecting the tdh and trh genes of VP using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 12a (CRISPR/Cas12a) combined with recombinase polymerase amplification and visual detection (CRISPR/Cas12a-VD).@*Results@#CRISPR/Cas12a-VD accurately detected target DNA at concentrations as low as 10 -18 M (single molecule detection) within 30 min without cross-reactivity against other bacteria. When detecting pure cultures of VP, the consistency of results reached 100% compared with real-time PCR. The method accurately analysed pure cultures and spiked shrimp samples at concentrations as low as 10 2 CFU/g.@*Conclusion@#The novel CRISPR/Cas12a-VD method for detecting VP performed better than traditional detection methods, such as real-time PCR, and has great potential for preventing the spread of pathogens.
Subject(s)
CRISPR-Cas Systems , Nucleic Acid Amplification Techniques/methods , Recombinases/genetics , Vibrio parahaemolyticus/geneticsABSTRACT
OBJECTIVE@#To examine the association between family socioeconomic status (SES) and body mass index (BMI) z-score of children and adolescents, and the mediating effect of milk intake in this association.@*METHODS@#In the study, 2 496 students and their parents were selected from 16 schools (4 urban middle schools, 4 rural middle schools, 4 urban primary schools, and 4 rural primary schools) using a stratified cluster sampling method. The frequency and amount of weekly milk intake from the 7-day Food Records reported by the students were extracted. The parents' education and household income were the indicators of family SES. The mediating effect of milk intake between family SES and BMI z-score of children and adolescents were tested using the PROCESS add-on SPSS software.@*RESULTS@#Parents' education level and household income were positively correlated with BMI z-score of children and adolescents (P=0.001 and 0.038, respectively). The overall average daily intake of milk was (0.92±0.84) servings, and the frequency was (4.43±2.70) days per week. The students of primary school, in urban areas, with higher parents' education level, with higher household income, and being non-obese were likely to have higher frequency and amount of milk intake. Milk intake was one of the mediating factors in the relationship between family SES and BMI z-score of children and adolescents. Specifically, the mediating effect of the frequency of milk intake accounted for -6.57% and -10.21% of the total effects of the association between the parents' education and the household income with BMI z-score of children and adolescents, respectively. The mediating effect of the daily intake of milk accounted for -3.63% and -5.86% of the total effects of the association between the parents' education and the household income with BMI z-score of children and adolescents, respectively.@*CONCLUSION@#The milk intake of Chinese children and adolescents still needs to be improved. High family SES was found to contribute to high BMI z-score, mediated by the milk intake which was the protective factors of BMI z-score. Further research is needed to study other dietary or physical exercise behaviors that mediate the relationship between family SES and BMI z-score of children and adolescents in order to adopt more targeted interventions.
Subject(s)
Adolescent , Animals , Child , Humans , Body Mass Index , Cross-Sectional Studies , Diet , Milk , Schools , Social ClassABSTRACT
10-Deacetylbaccatin III (10-DAB) C10 acetylation is an indispensable procedure for Taxol semi-synthesis, which often requires harsh conditions. 10-Deacetylbaccatin III-10-
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Taxol is a "blockbuster" antitumor drug produced by species with extremely low amount, while its analogue 7--xylosyl-10-deacetyltaxol is generally much higher in the plants. Both the fungal enzymes LXYL-P1-1 and LXYL-P1-2 can convert 7--xylosyl-10-deacetyltaxol into 10-deacetyltaxol for Taxol semi-synthesis. Of them, LXYL-P1-2 is twice more active than LXYL-P1-1, but there are only 11 significantly different amino acids in terms of the polarity and acidic-basic properties between them. In this study, single and multiple site-directed mutations at the 11 sites from LXYL-P1-1 to LXYL-P1-2 were performed to define the amino acids with upward bias in activities and to acquire variants with improved catalytic properties. Among all the 17 mutants, E12 (A72T/V91S) was the most active and even displayed 2.8- and 3-fold higher than LXYL-P1-2 on -xylosidase and -glucosidase activities. The possible mechanism for such improvement was proposed by homology modeling and molecular docking between E12 and 7--xylosyl-10-deacetyltaxol. The recombinant yeast GS115-P1E12-7 was constructed by introducing variant , the molecular chaperone gene and the bacterial hemoglobin gene . This engineered yeast rendered 4 times higher biomass enzyme activity than GS115-3.5K-P1-2 that had been used for demo-scale fermentation. Thus, GS115-P1E12-7 becomes a promising candidate to replace GS115-3.5K-P1-2 for industrial purpose.
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<p><b>OBJECTIVE</b>To analyze and assess secular change in stature in rural children and adolescents in China from 1985 to 2010.</p><p><b>METHODS</b>Data were obtained from the 6 rounds of the Chinese National Survey on Student's Constitution and Health. The subjects enrolled in the study were children and adolescents aged 7-18 years in rural areas of provincial capitals.</p><p><b>RESULTS</b>An overall positive secular trend in stature occurred in rural areas of provincial capitals in China from 1985 to 2010. The overall average increase rates were 3.1 and 2.4 cm/decade for boys and girls, respectively. The total body height increases for grown up boys and girls were 3.6 and 2.3 cm and the increase rates were 1.4 and 0.9 cm/decade, respectively. There were differences in body height increase among eastern, central and western regions. The average body height of the children or adolescents in eastern region was highest, followed by central region and western region. The overall increase rates in central region were highest among the three regions. The difference between eastern/central region and western region was obvious.</p><p><b>CONCLUSION</b>Positive secular trend in stature of children or adolescents has occurred in rural area of China, and rural boys and girls showed a great potential for continuous growth. More attention should be paid to the differences in children's body height between western region and eastern/central region.</p>
Subject(s)
Adolescent , Child , Female , Humans , Male , Asian People , Body Height , Physiology , Child Development , China , Rural PopulationABSTRACT
<p><b>OBJECTIVE</b>To analyze the change in Body Mass Index (BMI) distribution among Chinese children and adolescents for the development of more effective intervention for childhood obesity.</p><p><b>METHODS</b>Data on the national students' constitution and health survey between 1985 and 2010 was used for this study. Subjects were students aged 7-18 randomly selected from 30 provinces in China. BMI for-age curves were developed by LMS method, and the trend of BMI distribution was determined by comparing the upper BMI percentiles and analyzing the skew shift of distribution between 1985 and 2010.</p><p><b>RESULTS</b>An overall positive swift trend of BMI between 1985 and 2010 was observed among the Chinese school-age children and adolescents. The average median of the BMI increased from 16.8 and 17.0 kg/m2 to 18.2 and 17.9 kg/m2 in 25 years, with increments 0.56 and 0.36 kg/m2 per decade for males and females, respectively. The more obvious increments were found at the high BMI. The total increments of BMI in this period were 4.03 and 2.20 kg/m2 at the 85th, 6.14 and 3.57 kg/m2 at the 95th, and 6.99 and 4.27 kg/m2 at the 97th percentiles, for males and females, respectively.</p><p><b>CONCLUSION</b>Obvious increments were observed at high BMI of the Chinese children and adolescents. More effective interventions should be taken for control and prevention of obesity and its health consequence for these subgroups. It is necessary to establish a risk-complex system consisting of the identification of BMI scope, the screen of the disease risk factors and the assessment of excessive adiposity.</p>
Subject(s)
Adolescent , Child , Female , Humans , Male , Body Mass Index , China , Epidemiology , Obesity , EpidemiologyABSTRACT
<p><b>OBJECTIVE</b>Research evidence shows a secular trend in Chinese physical growth in recent years. The aim of this study was to analyze and assess changes in stature of children and adolescents during the 25 years from 1985-2010, using national data.</p><p><b>METHODS</b>Data came from successive cycles of the Chinese National Survey on Students' Constitution and Health (CNSSCH). Subjects were 7- to 18-year-old children and adolescents.</p><p><b>RESULTS</b>An overall positive secular trend occurred in urban China during 1985-2010. The overall average rates of increment were 2.4 and 1.7 cm/decade for boys and girls, respectively. Total increases in adult stature for boys and girls were 2.6 and 1.7 cm, yielding rates of 1.0 and 0.7 cm/decade, respectively. Cities with different socioeconomic levels had different characteristic trends. Mean stature increases in big cities were larger than those in moderate and small cities, and boys and girls in moderate and small cities showed greater potential for growth in stature.</p><p><b>CONCLUSION</b>An overall positive secular growth trend was associated with socioeconomic progress and differed with area socioeconomic levels. School policies and strategies should be developed based on increased stature, and should continue narrowing the inequity between different socioeconomic populations.</p>
Subject(s)
Adolescent , Adult , Female , Humans , Male , Body Height , Physiology , Socioeconomic Factors , Time Factors , Urban PopulationABSTRACT
<p><b>OBJECTIVE</b>To determine the extent of the obesity epidemic in school-aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventing childhood obesity are suggested.</p><p><b>METHODS</b>We used a dataset provided by the Chinese National Survey on Students' Constitution and Health from 1985-2010. Subjects were 7-18-year-old students randomly selected from urban and rural areas in 30 provinces. Eight subgroups were created according to region and socioeconomic status.</p><p><b>RESULTS</b>Increased rates of the epidemic (overweight and obesity combined) were greatest in large coastal cities-32.6% and 19.1% among males and females, respectively. These rates has neared that of developed countries. Similar increases were found in all other regions, including the once poverty-stricken rural west. The epidemic in most of the rural areas began after 2000, but has spread swiftly over the last decade. In 2010, it was estimated that 9.9% of Chinese school-aged children and adolescents were overweight and that an additional 5.1% were obese, representing an estimated 30.43 million individuals.</p><p><b>CONCLUSION</b>The prognosis for China's childhood-obesity epidemic is dire. To prevent childhood obesity, we suggest several strategies, including reasonable dietary intake, increase physical activity, a change in sedentary lifestyles and corresponding behavioral modifications.</p>
Subject(s)
Adolescent , Child , Female , Humans , Male , Asian People , China , Epidemiology , Demography , Overweight , Epidemiology , Rural Population , Socioeconomic Factors , Time FactorsABSTRACT
Objective To describe the characteristics of sexual debut among college students in China to provide appropriate sex education in that population. Methods An anonymous questionnaire survey was conducted among 33 653 college students selected by multi-stage stratified cluster sampling method in 18 provinces and cities of China. Results The percentage of students who had initiated sexual intercourse before age 14 was 1.9%. Overall, male students (2.8%) were significantly more likely to have initiated sexual intercourse before age 14, than female students (1.1%). The percentage of students who had initiated sexual intercourse from age 15 to 18 was 6.4% in males versus 2.1% in females. while the rates of students who had initiated sexual intercourse after age 19 were 6.9% in males and 2.6% in females. The first sexual intercourse was significantly associated with parental educational attainment, geographic location and family structure. Students whose parents were relatively well educated, living in the western areas of the country China, or with nucleus/extensive families were more likely to have early sex in their puberties. Conclusion Sexual education should be strengthened especially in the western areas, and targeted on the students whose parents with relatively higher educational background or who were from extensive families.
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Objective To study the distribution of waist circumference (WC) in a representative group of Chinese children for establishing the Chinese WC cut-off points. Methods Cross-sectional data obtained from 15 mainland provinces and Hong Kong were collected. There were 178 865 children and adolescents, aged 7-18 years-old in total. All subjects were divided into five regional groups- costal city, non-coastal city, northern rural, southern rural, and Hong Kong, for analyzing the distribution of WC. Results Large variations in WC distribution were found among the five groups for both sexes. The coastal city group had the highest P85 WC values consistently from the early school age to 18-year-old, when comparing with other groups. In contrast, southern rural group had P85 values consistently lagged behind, in both city group and in the north rural group. Hong Kong group had a high P85 WC at early ages, but because of the smaller increments of WC during adolescence, the P85 curve was gradually exceeded by the northern rural groups. Catch-up trend was found in the two rural groups since peak puberty. These disparities were caused not only by factors related to socioeconomic and urban-rural but also to the geographic differences between the noah and the south. Because of the regional variation of WC, a "gradient" prevalence of central obesity was prospected among these groups. Closed associations were found between WC and height, weight and BMI in all age period. Comparison on the WC distributions between people from China, U.S.A or the Netherlands demonstrated the necessity of setting up China's own WC cutoffs.Sex and age-specific percentiles were obtained and smoothed by using the LMS method.Conclusion Data obtained from this study could be used to develop the national WC cutoff points for Chinese children and adolescents.
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<p><b>BACKGROUND</b>Waist circumference (WC), a proxy measure of central body fat, is a better predictor than overall body fat for cardiovascular risk factors in both adults and children. WC cutoffs have been established in many countries, but the national WC reference has not been developed in China.</p><p><b>OBJECTIVE</b>To study the distribution of WC in a representative group of Chinese children for establishing Chinese WC cutoff points.</p><p><b>METHODS</b>Cross-sectional data obtained from 15 mainland provinces and Hong Kong were collected. There were 160,225 children and adolescents aged 7-18 years old in total. The subjects were divided into five regional groups namely costal city, other city, north rural, south rural, and Hong Kong, for analyzing the distribution of WC.</p><p><b>RESULTS</b>A large variation in WC distribution was found among the five groups for both sexes. Coastal city group had the highest P85 WC values consistently from the early school ages to 18-year-old compared with other groups. In contrast, south rural group had P85 values consistently lagged behind not only the city groups but also the north rural group. Hong Kong group had a high P85 WC at early ages, but because of the smaller increments of WC during adolescence, the P85 curve was gradually exceeded by the north rural groups. Catch-up trend was found in the two rural groups since the peak of puberty. These disparities were caused by not only socioeconomic and urban-rural factors but also north-south differences. Because of the regional variation of WC, a "gradient" prevalence of central obesity was prospected among these groups. Comparisons of WC distributions between the Chinese and the U.S.A. or Netherlands demonstrated the necessary of setting up China's own WC cutoffs. Sex and age-specific percentiles were obtained and smoothed by using LMS method.</p><p><b>CONCLUSION</b>The data obtained from this study could be used to develop national WC cutoff points for Chinese children and adolescents.</p>
Subject(s)
Adolescent , Child , Female , Humans , Male , China , Epidemiology , Demography , Overweight , Epidemiology , Waist Circumference , PhysiologyABSTRACT
<p><b>OBJECTIVE</b>To study the effect of beta3 adrenergic receptor (beta3AR) Trp64Arg and peroxisome proliferator activated receptor gamma 2 (PPARgamma2) Prol2Ala polymorphisms on insulin resistance.</p><p><b>METHODS</b>One hundred and eight dizygotic twin pairs were enrolled in this study. Microsatellite polymorphism was used to diagnose zygosity of twins. Insulin sensitivity was estimated with logarithm transformed homeostasis model assessment (HOMA). PCR-RFLP analysis was performed to detect the variants. As a supplement to the sib-pair method, identity by state (IBS) was used to analyze the association of polymorphisms with insulin sensitivity.</p><p><b>RESULTS</b>The genotype frequencies of Trp64Trg, Trp64Arg, and Arg64Arg were 72.3%, 23.8%, and 3.9%, respectively, while the genotype frequencies of Prol2Pro, Prol2Ala, and Alal2Ala were 89.9%, 9.6%, and 0.5%, respectively. For beta3AR Trp64Arg the interclass co-twin correlations of Waist-to-hip ratio (WHR), blood glucose (GLU), and insulin (INS), homeostasis model assessment insulin resistance index (HOMA-IR) of the twin pairs sharing 2 alleles of IBS were greater than those sharing 0-1 allele of IBS, and HOMA-IR had statistic significance. For PPARgamma2 Pro12Ala most traits of twin pairs sharing 2 alleles of IBS had greater correlations and statistic significance in body mass index (BMI), WHR, percent of body fat (PBF) and GLU, but there were low correlations of either insulin or HOMA-IR of twin pairs sharing 1 or 2 alleles of IBS. The combined effects of the two variations showed less squared significant twin-pair differences of INS and HOMA-IR among twins sharing 4 alleles of IBS.</p><p><b>CONCLUSIONS</b>Beta3AR Trp64Arg and PPARgamma2 Pro12Ala polymorphisms might be associated with insulin resistance and obesity, and there might be slight synergistic effects between this two gene loci, and further studies are necessary to confirm this finding.</p>
Subject(s)
Adolescent , Child , Child, Preschool , Humans , Genotype , Insulin Resistance , Genetics , Obesity , Genetics , PPAR gamma , Genetics , Polymorphism, Genetic , Receptors, Adrenergic, beta-3 , Genetics , Twins, Dizygotic , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To identify the current epidemiological situation of injuries among adolescents in China and to provide basis for prevention and control.</p><p><b>METHODS</b>An anonymous questionnaire survey was conducted among 170 602 middle school students in 18 provinces and cities of China.</p><p><b>RESULTS</b>The overall incidence of injuries among middle school students was 43.7% while the incidence of recurrent injuries was 20.9%. The incidence of boys was higher than that of girls mainly because of the difference of the recurrent injuries incidence. The incidence of injuries decreased with age in our investigation, especially the recurrent injuries. The main causes of injuries were fall and collision, and the most frequent results of injuries were cut and bone-joint injuries among boys and girls. Key school, nucleic family and higher education level of mothers were protective factors to injuries.</p><p><b>CONCLUSION</b>Adolescents seemed high-risk population for injuries. Some preventive measures should be carried out to decrease the incidence of injuries especially on recurrent injuries.</p>
Subject(s)
Adolescent , Female , Humans , Male , China , Epidemiology , Incidence , Risk , Students , Wounds and Injuries , EpidemiologyABSTRACT
<p><b>OBJECTIVE</b>To assess the genetic and environmental influences on the somatotype of children and adolescents, and the effects of sex and age.</p><p><b>METHODS</b>The components of somatotype were calculated by using Heather-Cater method in a total of 376 twin pairs of Han nationality, including 245 monozygotic (MZ) and 131 like-sex dizygotic (DZ) twin pairs aged 6 to 18 years. Model-fitting method by Mx package was performed to evaluate the proportion of variance components and to analyze the effects of sex and age on each component of somatotype using the adjusted data for other two somatotype components. The heritability of each component in different development periods divided by growth spurt was also evaluated.</p><p><b>RESULTS</b>The estimated heritabilities of endomorphic, mesomorphic and ectomorphic components were 0.45, 0.80, 0.44 in boys, 0.82, 0.79 and 0.81 in girls respectively after adjusting age. In boys, the heritability of endomorphic component during late puberty was significantly higher than that during pre-puberty (t = 4.99, P < 0.01) and puberty (t = 6.16, P < 0.01), while the heritability of ectomorphic component during late puberty was significantly lower than that during pre-puberty (t = 3.35, P < 0.01) and puberty (t = 4.12, P < 0.01). In girls, the heritability of endomorphic (t = 2.77, P < 0.01) or mesomorphic (t = 2.08, P < 0.05) component during pre-puberty was significantly higher than that in early puberty.</p><p><b>CONCLUSION</b>The genetic influence on somatotype of girls should be much more than that of boys, especially on the endomorphic and ectomorphic components. For boys, the mesomorphic component is mainly determined by genetic factors, but the other components are mainly affected by environmental ones. The effects of the development periods on the heritability of somatotype should be paid much attention to.</p>
Subject(s)
Adolescent , Child , Female , Humans , Male , Asian People , China , Somatotypes , Genetics , Twins , Genetics , Twins, Dizygotic , Genetics , Twins, Monozygotic , GeneticsABSTRACT
<p><b>OBJECTIVES</b>To study the contribution of the genes and environment to variation of serum levels of lipids and lipoprotein.</p><p><b>METHODS</b>One hundred and forty-three healthy monozygotic (MZ) twin pairs and 93 dizygotic (DZ) ones aged 5 to 19 [with a mean of (11.2 +/- 3.4) years]. Microsatellite polymorphism (STR) was used to diagnose zygosity of twins, and intraclass correlation coefficient method and Falconer formula were performed to investigate heritability of serum lipids and lipoproteins unadjusted or adjusted for age and sex. Logarithmic transformation was used for data with skewed distribution. Influence of relevant physical and biochemical indicators on serum lipids and other components was analyzed with partial coefficients of correlation adjusted for age and sex.</p><p><b>RESULTS</b>In the twin samples, difference in serum level of triglycerides (TG) between MZ and DZ was not statistically significant with intraclass variation and intraclass correlation. There was significant difference in serum levels of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and lipoprotein [Lp(a)] between MZ and DZ, with their heritability estimates of 0.56, 0.55, 0.49 and 0.58 unadjusted, respectively, and 0.63, 0.63, 0.55 and 0.64 adjusted for age and sex, respectively. Serum levels of TC, HDL-C, LDL-C and Lp(a) correlated reversely with age. Serum levels of TC, HDL-C and LDL-C in girls were slightly higher than those in boys. Most indicators for serum levels of lipids and lipoprotein, except for serum level of Lp(a) correlated with body mass index (BMI), body fat ratio, Pelidisi index, and other indexes such as blood pressure, blood sugar, serum level of calcium, adjusted for age and sex.</p><p><b>CONCLUSIONS</b>Serum levels of TC, HDL-C and Lp(a) were influenced more greatly by genetic factors, and serum level of TG was mainly influenced by environmental ones. Levels of blood lipids in children were influenced by age and sex, and correlated with indicators that reflect their body fat and nutritional status.</p>