The association of fruit and vegetable intake with the changes of serum lipid levels in middle-aged and older Chinese population / 中华预防医学杂志

Objective@#To investigate the association of fruit and vegetable intake with long-term changes of serum lipid levels in middle-aged Chinese and older Chinese population.@*Methods@#The study analyzed the data collected in the 2004 and 2007-2008 cohorts of China Multicenter Collaborative Study of Cardiovascular Epidemiology. Finally, 4 495 participants from 10 groups in various regions of China, who both were followed up in the two cohorts, were included for data analysis. They were aged 41-66 years in 2004. Fruit and vegetable consumption were collected with a simple food frequency questionnaire. The percent changes (Δ%) of serum TC, TG, HDL-C and LDL-C between the two surveys were calculated. Multivariate linear regression models were used to estimate the association of fruit and vegetable intake in 2004 with percentage changes of serum lipid levels during the two surveys.@*Results@#The proportions of individuals who consumed fruits <250, 250-499 and ≥500 g/week were 24.0%, 21.8% and 54.2%, respectively. The proportions of individuals who consumed vegetables <500 and ≥500 g/day were 76.7% and 23.3%, respectively. Compared with fruit intake <250 g/week, the regression coefficients (95% CI) of ΔTC% in 250-499 and ≥500 g/week group were -1.54 (-2.71, -0.37) and -1.77 (-2.79, -0.76). And the regression coefficients (95% CI) of ΔLDL-C% were -2.43 (-4.39, -0.48) and -2.89 (-4.59, -1.19). Compared with vegetable intake <500 g/d, the regression coefficients (95%CI) of ΔTC% and ΔLDL-C% in vegetable intake ≥500 g/d group were -1.01 (-1.95, -0.06) and -1.83 (-3.41, -0.24). However, fruit and vegetable intake had no relationship with ΔTG% and ΔHDL-C%.@*Conclusion@#The consumption of fruit and vegetable was inversely related to long-term changes of TC and LDL-C in middle-aged and older population, but no association was found for changes of TG and HDL-C.

Relationship between overnight urinary sodium to potassium ratio and the risk of cardiovascular disease / 中华心血管病杂志

Objective@#To explore the relationship between overnight urinary sodium to potassium ratio and the risk of cardiovascular disease (CVD).@*Methods@#A subsample of 10 percent of the participants (35-59 years old) from the People's Republic of China-United States Collaborative Study of Cardiovascular and Cardiopulmonary Epidemiology (prospective survey) were used. Three consecutive overnight urine samples were collected in the autumn of 1983-1984 and the spring in 1985-1986, respectively. Urinary sodium and potassium were detected and calculated for 8 hours excretion. The occurrences of cardiovascular events were recorded in 2 years interval from 1987-1988 until December 31, 2005. Participants were divided into first ratio group, second ratio group, and third ratio group based on the tertiles of sodium to potassium ratio. Cox proportional hazard regression model was used to determine the relationship between sodium to potassium ratio and risk of CVD. In addition, participants were divided into 2 subgroups by the median of overnight urinary sodium and potassium, and then combined each other for 4 subgroups including low sodium-low potassium group, low sodium-high potassium group, high sodium-low potassium group, and high sodium-high potassium group, to explore the relationship between different sodium-potassium combinations and the risk of CVD.@*Results@#A total of 954 participants were included in the final analysis, of whom 459 (48.1%) were males. There were 318 cases in the first, second and third ratio group, respectively. There were 347 cases in low sodium-low potassium group and high sodium-high potassium group, and 130 cases in low sodium-high potassium group and high sodium-low potassium group. After a median follow-up of 18.6 (18.3, 19.3) years, cardiovascular events occurred in 81 participants, including 64 stroke and 20 coronary heart disease events. Multivariate analysis showed that comparing with the first ratio group, the hazard ratios (HR) in the second and the third ratio groups were 2.04 (95%CI 1.06-3.95, P=0.034) and 2.07 (95%CI 1.07-4.03, P=0.032), respectively. The CVD risk in low sodium-low potassium group was 24% higher than the low sodium-high potassium group (reference), but this result did not reach statistical significant level (P=0.685). The risks in high sodium-high potassium group (HR=3.32, 95%CI 1.26-8.76,P=0.015) and high sodium-low potassium (HR=3.04, 95%CI 1.05-8.83, P=0.041) group were both significantly increased.@*Conclusions@#Overnight urinary sodium to potassium ratio is positively correlated with the risk of cardiovascular events. High urinary sodium plays a more important role for the increased risk of cardiovascular events than low potassium.

A Cross-sectional Study for the Relationship Between Tea Drinking and Blood Lipids in Middle and Aged Population / 中国循环杂志

Methods: A cross-sectional study was conducted based on the data cohort of China multicenter collaborative study of cardiovascular epidemiology in 2007-2008. A total of 7227 participants were enrolled including 3304 male and 3923 female at the mean age of (55.6±7.1) years. Tea drinking information was collected by questionnaire; participants were stratified by gender and grouped by regular tea drinking. Relationship between tea drinking and blood lipids, lipoprotein levels were assessed by covariance analysis. Results: There were 3012/7227 (41.7%) participants (male: 58.9% and female: 27.2%) regularly drunk tea. With adjusted age, urban and rural, education level, cigarette smoking, alcohol drinking, body mass index (BMI), daily red meat intake, physical work intensity, exercise intensity, histories of hypertension, diabetes and hypercholesterolemia, in male gender, compared with non-regular tea drinker, regular tea drinker had decreased blood level of low density lipoprotein cholesterol (LDL-C), the difference was -0.12 mmol/L, P=0.0001 and increased triglyceride (TG), the difference was 0.11 mmol/L, P=0.0001; in female gender, regular tea drinker showed increased high density lipoprotein cholesterol (HDL-C), the difference was 0.06 mmol/L, P<0.0001. Conclusion: In our research, regular tea drinking was negatively related to blood LDL-C level and positively related to TG in male gender, while it was positively related to HDL-C in female gender; the above correlations were independent from possible influencing factors. The impact of long term regular tea drinking on blood lipids and lipoprotein levels should be further prospectively investigated in community based middle and aged population.

Evaluation of Statistical Methods for Articles Published in《Chinese Circulation Journal》 / 中国循环杂志

Objective: To evaluate the applications and problems of statistical methods for articles published in《Chinese Circulation Journal》. Methods: We reviewed the statistical methods for original articles published in《Chinese Circulation Journal》in 2010, 2011 and 2015; general status with problems was analyzed and the situations were compared among different years. Results: A total of 404 articles were enrolled, statistical hypothesis testing was performed in 366 of them, 32 had descriptive statistics only and 6 articles were meta-analysis. The most frequently used statistical methods were student'st-test (57.4%), followed by chi-squared analysis (56.7%), analysis of variance (35.2%) and regression analysis (23.0%). The main statistical problems in Methods included in described method un-matched to really used method and insufifcient or wrong description. The proportion of insufifcient or wrong description in 2010 and 2011 was 36.6% (71/194), while in 2015 was 26.2% (55/210),P=0.02. The major wrong application of statistical approach was ignoring design with improper method and using unsatisifed precondition for speciifc analysis. The proportion of improper statistical method application in 2010 and 2011 was 19.1% (33/173), in 2015 was 19.7% (38/193),P=0.88. Conclusion: The quality of statistics was improved in 2015 than 2010 and 2011 for articles published in《Chinese Circulation Journal》; while there were still problems at certain degree, enhanced statistical review should be conducted in medical journals.

A Cross-sectional Study for the Relationship Between Exercise and Serum Lipid Level in Middle-aged Population / 中国循环杂志

Objective: To investigate the relationship between exercise and serum lipid level in middle-aged population. Methods: Based on “multicenter collaborative study of cardiovascular epidemiology” research, a total of 3482 subjects at the age of (35-59) years from urban and rural areas of Beijing and Guangzhou were enrolled in this study. According to daily energy expenditure of exercise (EEexer), the participants were divided into 3 groups: No exercise group, (daily) EEexer below median group and (daily) EEexer above median group. The type and duration of exercise were collected by the questionnaire, daily EEexer was calculated and the relationship between exercise and serum lipid level was estimated by covariance analysis. Results: There were 47.1% (807/1712) male and 41.1% (727/1770) female participants having exercise. With controlled age, area, education level, smoking, drinking, BMI and energy expenditure of physical activity outside of exercise (EEPA), serum levels of TC, LDL-C, non-HDL-C and TG were decreased in women by elevated EEexer groups accordingly, and among them, there were significant differences in LDL-C and non-HDL-C levels between groups, P<0.05; compared with No exercise group, in female daily EEexer above median group, LDL-C and non-HDL-C levels decreased about 0.14 mmol/L,P=0.0063 and 0.14 mmol/L, P=0.0155 respectively; while in men, TC, LDL-C, non-HDL-C and TG levels showed a decreasing trends by elevated EEexer groups but with no statistical significance. No association was found for HDL-C in men and women. Conclusion: Serum levels of LDL-C and non-HDL-C were lower in female daily EEexer above median group than No excise group, the effects were independent from working and other physical activities.

Relationship between body weight status in early adulthood and body weight change at middle age in adults and type 2 diabetes mellitus / 中华流行病学杂志

Objective To explore the relationship between weight status in early adulthood and body weight change at middle age in adults and type 2 diabetes mellitus (T2DM).Methods The data of 14 population samples from China Multicenter Collaborative Study of Cardiovascular Epidemiology conducted in 1998 were used.Approximately 1 000 men and women in each sample were surveyed for cardiovascular disease risk factors,including body weight at age 25 years.The body mass index (BMI) at the age 25 years was calculated.The association between body weight in early adulthood and body weight change at middle age and T2DM was examined by using logistic regression model.Results The incidence of T2DM in low weight group (BMI＜ 18.5 kg/m2),normal weight group (BMI:18.5-23.9 kg/m2),overweight group (BMI:24.0-27.9 kg/m2) and obese group (BMI:≥28.0 kg/m2) at 25 years old were 2.4％(30/1 263),2.8％(266/9 562),4.0％(70/1 739) and 6.4％ (7/110),respectively (P value for trend＜0.01).The incidence of T2DM for adults with weight change ＜-7.5 kg,-7.5--2.6 kg,-2.5-2.5 kg,2.6-7.5 kg,7.6-12.5 kg and ＞ 12.5 kg at middle age were 2.5％ (18/712),1.3％(21/1 629),2.1％(48/2 330),2.3％(59/2 585),3.7％(94/2 518),and 4.6％(133/ 2 900) respectively.(P value for trend ＜0.01),Multivariate logistic regression analysis showed that overweight and obesity at age 25 years and subsequent weight gain were positively correlated with T2DM after adjusted other risk factors (all P values for trend ＜0.01).Conclusion Overweight and obesity in early adulthood and weight gain at middle age were both independently associated with the increased risk of T2DM in middle-aged men and women.

Relationship Between the Changes of Plasma Levels of Resistin With the Contemporary Body Weight Changes in the Same Population / 中国循环杂志

Objective: To explore the relationship between the changes of plasma levels of resistin with the contemporary body weigh changes in the same population. Methods: The community based epidemiological surveys were carried out in the same population in Shijingshan district of Beijing at the year of 2005 and year of 2010. A total of 943 subjects with the entire information of cardiovascular related risk factors were enrolled including 316 male with the mean age of (58.2 ± 8.5) years and 627 female with the mean age of (59.3 ± 7.5) years. Plasma levels of resistin in both year of 2005 and year of 2010 in all subjects were recorded, and the subjects were divided into 4 groups based on the quartile levels of resistin. Group①, the subjects with plasma level of resistin ≤ (-0.66) mmol/L,n=239, Group②, resistin level (from -0.67 to 0.25) mmol/L,n=233, Group③, resistin level (0.26-1.24) mmol/L, n=235 and Group④, resistin level ≥1.25 mmol/L,n=236. Pearson correlation study with uni- and multi- regression analysis were conducted to investigate the relationship between the changes of plasma levels of resistin with the contemporary body weight changes in the same population.Results: The uni-variate analysis showed that in female subjects, plasma levels of resistin were obviously related to the percentage (%) of body weight changes (correlation coefifcient: 0.1173), body weight index (kg/m2) changes (0.1521), the% of body weight index changes (0.1412), the waist circumference (cm) changes (0.1228) and the % of waist circumference changes (0.1057) respectively, allP0.05. Multi-regression analysis indicated that with adjusted baseline variables, in female subjects, the plasma levels of resistin were obviously related to body weight (kg) changes and the % of body weight changes (regression coefifcient: 0.0261 and 0.2916), body weight index (kg/m2) changes and % of body weight index changes (0.2157 and 0.3072), the waist circumference (cm) changes and the% of waist circumference changes (0.0532 and 0.2738) respectively, allP0.05. Conclusion: The changes of plasma levels of resistin are signiifcantly related to contemporary body weight changes in female subjects, but not in male subjects.

Relationship Between Body Weight Changes From Early Adulthood to Middle Age and the Prevalence of Hypertriglyceridemia by Large-scale Cardiovascular Risk Factor Investigation / 中国循环杂志

Objective: To explore the relationship between body weight changes from early adulthood to middle age and the prevalence of hypertriglyceridemia by large-scale cardiovascular risk factor investigation. Methods: A total of 15 population groups from China multi-center collaborative study of cardiovascular epidemiology in 1998 were enrolled. There were approximately 1000 participants in each group including 50% of each male and female at the age of (35-59) years which was deifned as middle age. The participants were surveyed for cardiovascular risk factors including the body weight and body mass index (BMI) at the age of 25 years which was deifned as early adulthood. The participants were divided into 4 groups based on BMI at early adulthood: Low body weight group, BMI 12.5 kg. The relationship between body weight status at 25 years of age with subsequent changes and the prevalence of hypertriglyceridemia were investigated. Results: A total of 13883 participants finished the investigation.①The prevalence of hypertriglyceridemia by 4 BMI groups were at 22.8%, 26.0%, 27.4% and 30.8% respectively (the trend ofP Conclusion: Overweight and obesity in early adulthood with subsequent weight gain were independently related to the risk of hypertriglyceridemia at the middle age in our survey.

Cut-off values of waist circumference for central obesity in Chinese adults / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the appropriate cut-off values of waist circumference(WC)for central obesity and severe central obesity in Chinese adults.</p><p><b>METHODS</b>A total of 10 265 participants aged 35-69 years from the cross-sectional survey of the PRC-USA Collaborative Study of Cardiovascular and Cardiopulmonary Epidemiology between 1993 and 1994 with integral data were included. Each integer unit in centimeters of WC in a given range was used as the cut-off point to detect clustering of risk factors, which was defined as an individual with 2 or more risk factors including hypertension, diabetes, hypercholesterolemia, hypertriglyceridemia and low levels of high-density lipoprotein cholesterol. Sensitivity, specificity and distance from the receiver operating characteristic (ROC) curves to the upper left corner of the ROC graph were calculated. The WC value corresponding to the point on the ROC curve nearest to the upper left corner was considered as the optimal cut-off value for central obesity and the value corresponding to the point with specificity of 90% or more was considered as the optimal cut-off for severe central obesity.</p><p><b>RESULTS</b>The mean WC was (80.5 ± 9.9) cm in men and (77.8 ± 10.0) cm in women; 18.1% (890/4 921) of men and 14.5% (776/5 344) of women were identified with two or more major risk factors. Based on the ROC curve analysis, the optimal value of WC to detect clustering of risk factors was ≥ 84 cm for men and ≥ 80 cm for women, and the shortest distance to the upper left corner was 0.430 and 0.450, respectively. The cut-off values of WC to detect clustering of risk factors with specificity of 90% or more were ≥ 93 cm and ≥ 91 cm for men and women, respectively.</p><p><b>CONCLUSION</b>The cut-off points of WC for central obesity and severe central obesity in Chinese adults obtained from this study are equal or similar to the WC cut-off values proposed by the Guidelines for Prevention and Control of Overweight and Obesity in Chinese Adults.</p>

Incidence of obesity and its modifiable risk factors in Chinese adults aged 35-74 years: a prospective cohort study / 中华流行病学杂志

<p><b>OBJECTIVE</b>To examine the incidence of obesity and its modifiable risk factors in Chinese adults aged 35-74 years.</p><p><b>METHODS</b>A total of 27 020 participants aged 35 to 74 years from two prospective cohort studies in China were followed up in the years of 2007 and 2008. Obesity and overweight were defined as body mass index ≥ 28.0, and 24.0-27.9 kg/m(2), respectively. Relative risks of obesity for risk factors were computed by using logistic regression.</p><p><b>RESULTS</b>The annual incidence rates of obesity and overweight were 6.97 ‰ and 24.83 ‰ in Chinese adults aged 35-74 years, respectively. Women had a higher incidence of obesity than men (7.74 ‰ vs. 6.10 ‰). Participants in northern China had a higher incidence than those in southern (9.29 ‰ vs. 5.10 ‰) part of the country. Adults in rural had a higher incidence than those in urban (7.28 ‰ vs. 6.52 ‰). After adjusting for the baseline variables, such as gender, age, geographic region, degree of urbanization, the relative risk for obesity was 0.82 (95% CI:0.68-0.99) for participants with ≥ 12 years' education, compared with those <12 years. Participants with middle income, less physical activity at work/housework or being retirees, consuming more red meat and scented tea etc, had higher risk of incidence of obesity. Participants who consumed milk and moderate amount of fruits, would show a lower risk of obesity.</p><p><b>CONCLUSION</b>The incidence of obesity was 6.97 ‰ in Chinese middle and older adults. Our results underscored that the promotion of healthy lifestyle which include issues as increasing physical activity, consuming moderate amount of fruits and milk but less red meat, drinking less scented tea etc, could play key roles in obesity prevention and control among the Chinese adults, especially among people with low education level or with middle income.</p>

Relationship Between the Progression Rate of Corotid Maximal Plaque Area and the Risk of New Ischemic Cardiovascular Disease / 中国循环杂志

Objective: To explore the progression rate of cortid maximal plaque area and the risk of new ischemic cardiovascular disease (ICVD) in a rural cohort in Beijing. Methods: The PRC-USA collaborative study had been regularly conducted in Shijingshan area in Beijing. The carotid ultrasound examination, ICVD risk factor and acute cardiovascular events follow-up were conducted in those participants. A total of 1479 subjects who received at least 2 carotid ultrasound examinations and had no cardiovascular disease before the second ultrasound were studied. They were divided into 5 groups:①Control group, the participants had no plaque detected by 2 ultrasounds; ② New plaque group, new plaque was found at the second ultrasound examination; ③ Plaque regression group; ④ Plaque stabilized group and ⑤ Plaque progression group. The hazard ratio (HR) between the progression rate of corotid maximal plaque area and new ICVD events was estimated by Cox proportional hazard regression analysis . Results: Compared with Control group, the HR for new ICVD events were higher in groups②,③,④and⑤at 3.5, 5.7, 6.2 and 7.3 respectively, all P Conclusion: The progression rate of maximal corot id plaque area rate could predict the risk of new ICVD events in clinical practice.

The effects of lifestyle factors on the incidence of central obesity in Chinese adults aged 35-74 years / 中华预防医学杂志

<p><b>OBJECTIVE</b>To understand the incidence of central obesity and its characteristics, and explore the effects of lifestyle factors on incidence of central obesity in Chinese adults aged 35-74 years.</p><p><b>METHODS</b>A total of 27 020 Chinese adults aged 35 to 74 years were enrolled in a prospective follow-up study (the study cohort was built from 1998 to 2000, respectively) during 2007 and 2008. Central obesity was defined as waist circumference ≥ 90 cm in men, ≥ 85 cm and ≥ 80 cm in women, respectively. Multivariate logistic regression was used to estimate relative risks (RR) of central obesity for lifestyle factors after adjusting factors including genders, age, southern and geographic region, urbanization, lifestyles, and so on.</p><p><b>RESULTS</b>Among Chinese adults aged 35-74 years, the standardized annual incidence of central obesity (waist ≥ 90 cm) was 2.19% for men and this rate decreased gradually with age among people younger than 65 years old. The incidence of central obesity was 2.64% (waist ≥ 85 cm) and 4.06% (waist ≥ 80 cm) for women, respectively, and this rate increased obviously among people aged 55 to 74 years. Participants with ≥ 12 years' education (RR = 0.84, 95%CI:0.74-0.96) had a lower risk of central obesity(waist ≥ 90 cm for men, waist ≥ 85 cm for women). And this risk increased as the monthly household per capita income increased. Compared with the reference group, people involved in housework or retirees (RR = 1.17; 95% CI: 1.01-1.36), drinking alcohol (RR = 1.15, 95% CI: 1.01-1.32) or scented tea (RR = 1.49, 95%CI:1.28-1.72) had a higher risk of developing central obesity, while drinking milk (RR = 0.85, 95% CI: 0.74-0.97) or black tea (RR = 0.74, 95% CI: 0.58-0.95), had a lower risk of developing central obesity.</p><p><b>CONCLUSION</b>A healthy lifestyle plays a key role in the prevention and control of central obesity in Chinese adults, and a healthy way of lifestyle should be promoted in the whole society to decelerate the epidemic of the central obesity.</p>

Alcohol consumption and the incidence of metabolic syndrome in Chinese population / 中华健康管理学杂志

Objective To examine the relationship between alcohol consumption and the incidence of metabolic syndrome (MS) in Chinese adults.Methods A total of 27020 Chinese adults aged 35 to 74years were enrolled in this prospective cohort study.Frequency or type of alcohol consunption was assessed in 1998 and 2000.Follow-up study on MS was conducted during 2007 and 2008.Results Over an average 8years' follow-up,2362 MS patients were identified among 14 572 individuals who did not have MS at baseline.After adjustment for age,location,education level,physical activity,cigarette smoking,body mass index and the number of MS components,compared with non-drinkers,relative risk ( RR ( 95％ confidence interval (CI))) and the Population Attributable Risk Percent (PARP) of MS of male drinkers was 1.24( 1.06 to 1.45 ) and 10.13％,respectively.RR (95 ％ CI) of MS was 1.36 ( 1.02 to 1.82 ),1.34 ( 1.03 to 1.74) and 1.41 (1.13 to 1.77) for male drinkers consuming alcohol 10.1 -20 g/d,20.1 -40 g/d,and ＞40 g/d.RR(95％ CI) of MS was 1.25 ( 1.01 to 1.55) for males drinking 2 -5 times/week and 1.26(1.04 to 1.52) for males drinking ≥6 times/week.RR (95％ CI) of MS was 1.60 ( 1.05 to 2.45),1.30(1.02 to 1.65) and 1.27 (1.06 to 1.52) for beer,liquor and the beer + liquor male consumers.The corresponding RR(95％ CI) was 2.67(1.26 to 5.65) and 3.38 (1.35 to 4.22) for female drinkers consuming alcohol 10.1 -20 g/d and ＞20 g/d.Conclusions Drinking alcohol more than 10 g/d may be associated with an increasing risk of MS,especially for women.Drinking more than twice per week,beer and/or liquor consumption can significantly increase the risk of MS in men.

Reliability of Home Blood Pressure Measurement / 中华高血压杂志

Objective To verify the reliability of home blood pressure measurement in clinic and research works by comparison three methods[home(H),office(O) and ambulatory(A)]of blood pressure(BP) measurements. Methods The"study-effects of salt substitution on blood pressure among the hypertensive patients and their families"was a randomized,double blinded control trial.In this study,BP was measured in 220 hypertensive patients using office,home and ambulatory BP measurements concurrently at the baseline and the end of the intervention. Two hundred seventeen patients had baseline eligible data,while at the end of the intervention,only 189 patients had eligible data.Bland-Altman method and Person's correlation analysis were used to compare the agreement of BP levels by 3 methods,and McNemar chi-square test compared rates of the agreement,assuming the ambulatory as the reference.Results The mean BP levels using office,ambulatory and home BP measurements were 149.5?16.4/87.2?9.5 mm Hg,137.8?17.1/83.2?10.3 mm Hg,and 138.0?14.2/82.4?9.3 mm Hg,respectively. H BP was more strongly related with ambulatory BP(SBP/DBP)(H:r=0.55/0.62 vs O:r= 0.36/0.46).The difference of BP between H and A was smaller[H:A—0.2 mm Hg/—0.7 mm Hg vs O:A(ll.7 mm Hg/4.0 mm Hg)].Intra-individual agreement between H and A SBP was significantly higher than that between O and A(28.3%vs 16.5%for≤|5| mm Hg and 49.7%vs 33.5%for≤|10| mm Hg,all P0.05).Conclusion Home and ambulatory BP was more strongly related and better agreement than office-ambulatory BP measurement.

Radioactivity of phosphorus implanted TiNi alloy / 生物医学工程学杂志

Exposed to neutron flow, the phosphorus implanted TiNi alloy gets radioactive. This radioactive material is used in vascular stent for prevention and cure of restenosis. Phosphorus implantation is carried out in a plasma immerged ion implantation system, and the dose of phosphorus implantation is in the range of 2-10 x 10(17) cm-2. After ion implantation, the alloy is exposed to the slow neutron flow in a nuclear reactor, the dose of the slow neutron is 1.39-5.88 x 10(19) n/cm2. The radioactivity of the TiNi alloy was measured by liquid scintillation spectrometry and radio-chromic-film dosimetry. The result shows that whether the phosphorus is implanted or not, the TiNi alloy comes to be radioactive after exposure to neutron flow. Just after neutron irradiation, the radiation dose of phosphorus implanted TiNi alloy is about one hundred times higher than that of un-phosphorus implanted TiNi alloy. The radiation difference between phosphorus and un-phosphorus implanted alloy decreases as time elapses. Within three months after neutron irradiation, the average half-decay period of phosphorus implanted TiNi alloy is about 62 days. The radiation ray penetration of phosphorus implanted TiNi alloy is deeper than that of pure 32P; this is of benefit to making radiation uniformity between stent struts and reducing radiation grads beyond the edge of stent.

Prevalence of overweight and obesity in Chinese middle-aged populations: Current status and trend of development / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the current status on prevalence of overweight and obesity in Chinese middle-aged population, and to quantify the magnitude of the trends of development in the past two decades.</p><p><b>METHODS</b>Body mass index (BMI) was measured on 15 389 middle-aged men and women from 15 natural populations all over China with different geographical, economical (urban/rural) and occupational status. Overweight was defined as BMI >/= 25 while obesity as BMI >/= 30.</p><p><b>RESULTS</b>1) The rates of prevalence on overweight and obesity varied dramatically between populations. 2) In general, the prevalence rates were higher in the northern areas, in urban areas, and in women. 3) The current problem of obesity was related to 'pre-obese' stage, with less than 10% in most populations. 4) The prevalence of overweight and obesity started to show significantly increase from early 80's to early 90's but more prominant in the late 90's.</p><p><b>CONCLUSION</b>Prevention and intervention of overweight and obesity are in urgent need in the Chinese populations, especially in those economically fast developing areas.</p>

A prospective study on body mass index and mortality / 中华流行病学杂志

<p><b>OBJECTIVE</b>To assess the relationship between body mass index (BMI, weight in kilograms divided by the square of height in meters) and both all-causes mortality and mortality from specific cause.</p><p><b>METHODS</b>Cardiovascular disease (CVD) risk factors were studied in 1982 - 1985 on more than 30 thousands participants aged 35 - 59 from 10 Chinese populations. 30 560 participants (15 723 for men, 148 837 for women) without known myocardial infraction, stroke or cancer was followed from 1999 to 2000. All-causes of death were documented.</p><p><b>RESULTS</b>Three thousand two hundred and twelve death cases occurred during follow-up of average 15.2 years, including 676 CVD (coronary heart disease and stroke) deaths, 1 281 cancer deaths and 1 255 deaths for other reasons. Cox proportional hazards model adjusting age and gender showed that the relative risks of all causes of death in groups of low BMI (BMI < 18.5), normal BMI (BMI from 18.5 to 23.9), overweight (BMI from 24 to 27.9) and obesity (BMI >/= 28) which were defined according to the strata of BMI for Chinese were 1.21 (95% CI: 1.10 - 1.33), 1.00, 0.91 (95% CI: 0.82 - 1.01) and 1.12 (95% CI: 0.93 - 1.37), respectively ("U" shaped relation). The relative risk of low BMI group (RR = 1.01, 95% CI: 0.84 - 1.21) was not significant different and the relative risk of obesity significantly increased (RR = 1.36, 95% CI: 1.04 - 1.80) while the lowest relative risk was in normal BMI group. The relative risks increased for CVD death, but decreased for cancer death with increased levels of BMI and a "U" shaped relationship was found between BMI groups and mortality for other reasons, which remained after excluding the early death and smokers.</p><p><b>CONCLUSION</b>BMI in normal level was not only related to low risk of all causes of death, but also with relative low risk of CVD, cancer and other deaths. Data were important to public health.</p>

Serum TC/HDL-C ratio and the risk of ischemic and hemorrhagic stroke incidence in middle aged Chinese population / 中华神经科杂志

ObjectiveTo explore the predictive effect of serum TC/HDL-C ratio on ischemic and hemorrhagic stroke incidence in middle aged Chinese population.MethodsA prospective study was conducted based on the PRC-USA Collaborative Study on Cardiovascular and Cardiopulmonary Epidemiology. A total of 10 121 individuals (4921 men and 5200 women), aged 35—59 years were selected from 4 cohorts, in Beijing and Guangzhou, urban and rural. The average following up time was 15.9 years. During the follow-up period, 277 ischemic and 125 hemorrhagic stroke cases were diagnosed.ResultsThe age adjusted incidence rate of ischemic stroke was 144.1,169.4,166.7,226.9 and 282.2 in the group of TC/HDL-C ratio