Cumulative consumption of tea is associated with lower risk of liver cancer: Updated results from the Shanghai Women's Health Study.

Prospective epidemiological studies have provided limited evidence for an association between tea consumption and liver cancer risk. Based on a population-based prospective cohort study in middle-aged Chinese women, we investigated the association between tea consumption and the risk of primary liver cancer. Detailed information on tea drinking habits and other potential confounders was obtained at the baseline interview. Incident liver cancer cases were identified through record linkage with the population-based cancer registry and verified through home visits and review of medical charts by medical experts. Multiple aspects of tea drinking habits including starting age, duration, intensity and cumulative consumption of any type of tea and green tea were considered. Multivariable-adjusted hazard ratios (aHRs) and their 95% confidence intervals (CIs) were derived from the Cox regression models. After a median follow-up time of 18.12 (interquartile range = 1.59) years, 253 incident liver cancer cases were identified from 71 841 cohort members. Compared with never tea drinkers, the risk of liver cancer for participants who have consumed over 30 kg of dried tea leaves cumulatively was 0.56 (95% CI: 0.32-0.97). For those who drank green tea only, the aHR was 0.54 (95% CI: 0.30-0.98). This updated study suggested an inverse association between cumulative consumption of tea, especially green tea and the risk of primary liver cancer.

Cross-sectional relationships between general and central adiposity and plasma amino acids in Chinese adults.

Adiposity is an important determinant of blood metabolites, but little is known about the variations of blood amino acids according to general and central adiposity status among Chinese population. This study included 187 females and 322 males who were cancer-free subjects randomly selected from two cohorts in Shanghai, China. Participants' plasma concentrations of amino acids were measured by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Linear regression models were used to examine the cross-sectional correlations between general and central adiposity and amino acid levels. A total of 35 amino acids in plasma were measured in this study. In females, alanine, aspartic acid and pyroglutamic acid were positively correlated with general adiposity. In males, glutamic acid, aspartic acid, valine and pyroglutamic acid showed positive correlations, and glutamine, serine and glycine showed negative correlations with both general and central adiposity; phenylalanine, isoleucine and leucine were positively correlated and N-phenylacetylglutamine was negatively correlated with general adiposity; asparagine was negatively correlated with central adiposity. In summary, general adiposity and central adiposity were correlated with the concentrations of specific plasma amino acids among cancer-free female and male adults in China. Adiposity-metabolite characteristics and relationships should be considered when studying blood biomarkers for adiposity-related health outcomes.

Dietary fat intake and liver cancer incidence: A population-based cohort study in Chinese men.

To date, limited studies have focused on the association between dietary fat and liver cancer risk, especially in China. Our study aims to evaluate the association between dietary fat intake and liver cancer incidence risk in men. Dietary fat intake was obtained through a validated food frequency questionnaire in a Chinese prospective cohort. The Cox regression model was utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). After exclusion, 59 998 recruitments were finally analyzed with a total follow-up time of 714 339 person-years, 431 incident liver cancer cases were newly identified among them. The adjusted HRs (95% CIs) for the highest vs lowest quartile of total fat, saturated fat, monounsaturated fat (MUFA), and polyunsaturated fat (PUFA) were 1.33 (1.01-1.75), 1.50 (1.13-1.97), 1.26 (0.96-1.65), and 1.41 (1.07-1.86), and the corresponding P-trend values were .008, .005, .034, and .005, respectively. In the secondary analysis among participants tested for hepatitis B virus, we found that higher intakes of saturated fat and PUFA were also associated with increased liver cancer risks. Besides, high risks of per standard deviation alterations of the total fat, saturated fat and MUFA were detected in liver cancer, and these results were similar to those concluded from the full-cohort analysis. In conclusion, dietary intakes of total fat, saturated fat, PUFA, and probably MUFA might increase liver cancer risks. Our study provides suggestive advice to public administration on dietary suggestions, and related measures taken from managing dietary fat intake might reduce liver cancer incidence.

Personal Characteristics Effects on Validation of Self-reported Type 2 Diabetes From a Cross-sectional Survey Among Chinese Adults.

BACKGROUND: The objective was to evaluate the effects of personal characteristics on the validation of self-reported type 2 diabetes among Chinese adults in urban Shanghai. METHODS: During 2015 through 2016, 4,322 participants were recruited in this validation study. We considered the criteria of diabetes verification to use the laboratory assays of fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), or self-reported use of diabetic medication. RESULTS: When taking diabetic medication or FPG ≥7.0 mmol/L was as identified diabetes, the measurements of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Kappa value of self-reported diabetes were 72.0%, 99.2%, 95.1%, 93.9%, and 0.78, respectively. If an additional HbA1c test was used for 708 subjects (aged <65 years), slightly lower values of sensitivity, NPV, and Kappa were observed. More potential diabetes cases were found compared to only using FPG. Subjects who were female, older, or had a family history of diabetes had sensitivity over 75% and excellent Kappa over 0.8, while the sensitivity and Kappa of opposite groups had poorer values. Specificity, PPV, and NPV were similar among groups with different demographic or disease characteristics. The prevalence of type 2 diabetes was 19.3% in the study (14.1% diagnosed diabetes, 5.2% undiagnosed diabetes). About 26.2% of subjects were pre-diabetic. Additional HbA1c test indicated an increased prevalence of undiagnosed diabetes and pre-diabetes. CONCLUSIONS: Findings support self-reported diabetes is sufficiently valid to be used in large-scale, population-based epidemiologic studies. Participants with different characteristics may have different indicators in terms of validation, such as age, gender, and family history of diabetes in first-degree relatives.

Dietary glycemic index, glycemic load, and cause-specific mortality: two population-based prospective cohort studies.

BACKGROUND: Epidemiological studies on the relationship between dietary glycemic index (GI), glycemic load (GL) and all-cause and cause-specific mortality yielded conflict results. We aimed to assess these associations in Chinese. METHODS: We conducted this study based on two prospective cohort studies in Shanghai. Dietary information was collected using validated cohort-specific food frequency questionnaires. We used Cox regression model to estimate the hazard ratios (HR) for mortality associated with GI and GL. RESULTS: After median follow-up periods of 12.8 years for 59,770 men and 18.2 years for 74,735 women, 8,711 deaths in men and 10,501 deaths in women were documented. After we controlled the potential confounders, dietary GI, GL, and carbohydrate intake were associated with a higher risk of cardiovascular disease (CVD) mortality (P values for trend = 0.025, 0.001, and 0.001). Dietary GI was associated with lower risk of total and cause-specific mortality in men in the second quartile (Q) (all-cause mortality: HR Q2 vs. Q1 = 0.89, 95%CI: 0.84, 0.95). Dietary GL was associated with lower risk of cancer mortality but higher risk of CVD mortality in men. In women, dietary GI was associated with mortality due to all-cause (HRMax Q4 vs. Q1 = 1.10, 95%CI: 1.04, 1.06), cancer (HRMax Q4 vs. Q1 = 1.12, 95%CI: 1.02, 1.23), and CVD (HRMax Q4 vs. Q1 = 1.10, 95%CI: 1.00, 1.22). CONCLUSIONS: The present study indicates that diet with higher GI and GL was associated with an increased risk of CVD mortality in Chinese adults. The association may vary for men and women, which need further investigating in other Asian populations.

Dose-response relationship between fat distribution and liver cancer incidence: A prospective cohort study in Chinese men.

BACKGROUND: Based on a prospective cohort study in middle-aged Chinese men, the current study characterized the dose-response relationships between fat distribution measurements and the incidence of primary liver cancer. METHODS: Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated by Cox regression models for the association between waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), a body shape index (ABSI), and body roundness index (BRI) with liver cancer incidence. Dose-response curves were characterized using a restricted cubic spline function. RESULTS: After a mean follow-up time of 11.9 (SD = 2.4) years, 440 liver cancer cases were identified from 60,625 participants. WC, WHtR, ABSI, and BRI were found to be associated with an increased risk of liver cancer at a given level of body mass index (BMI), with multivariable-adjusted HRs of 1.19 (95% CI: 1.01-1.41), 1.26 (95% CI: 1.02-1.50), 1.12 (95% CI: 1.05-1.23) and 1.28 (95% CI: 1.08-1.53) for per SD increment, respectively. Dose-response curves suggested that the risk increased rapidly above the median levels of WC, WHtR, and BRI. For ABSI, the risk decreased from the minimum level to about the 35th percentile and increased slowly thereafter. CONCLUSIONS: The current study suggested an association between abdominal obesity in middle age and increased risk of primary liver cancer at a given level of BMI. WHtR and BRI were better predictors of liver cancer risk compared with WC and ABSI.

Visible-light-promoted 3,5-dimethoxyphenyl glycoside activation and glycosylation.

A new glycosylation method promoted by visible light with 3,5-dimethoxyphenyl glycoside as the donor was developed. This protocol delivers both O-glycosides and N-glycosides in moderate to excellent yields using a wide range of O-nucleophiles and nucleobases as the glycosyl acceptors.

Gender differences of relationship between serum lipid indices and type 2 diabetes mellitus: a cross-sectional survey in Chinese elderly adults.

BACKGROUND: To investigate the gender differences of the relationships between clinical serum lipid indices and type 2 diabetes mellitus (T2DM) in Chinese elderly adults. METHODS: Between 2014 and 2016, participants selected from three communities in an urban district of Shanghai were measured for serum lipid indices of low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), total cholesterol (TC), and triglyceride (TG). Age and multivariate adjusted logistic regression models were utilized to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of serum lipid indices on T2DM prevalence. RESULTS: In total, 4,023 male and 3,862 female participants were included in this study, with the T2DM prevalence proportions of 13.03% and 11.73%, respectively. In association analysis, the serum levels of LDL-c, HDL-c, TC were significant between non-T2DM individuals and T2DM patients in men, but the HDL-c and TG in women. LDL-c/HDL-c, TG/HDL-c, and TC/HDL-c ratios were associated with the T2DM prevalence only in women. In the multivariate analysis, a higher serum LDL-c level was positively associated with a reduced risk of T2DM prevalence in men with OR (95% CI) of 0.57 (0.39-0.85) (P=0.006). Higher ratios of LDL-c/HDL-c, TG/HDL-c, and TC/HDL-c were all more likely associated with the decreased risks of T2DM prevalence with the ORs ranging from 0.45 to 0.62 in men (all P<0.05), but not in women. CONCLUSIONS: High LDL-c concentration was significantly associated with a lower T2DM prevalence in men. A gender difference of the associations between the lipid ratios and T2DM prevalence was observed for LDL-c/HDL-c and TC/HDL-c ratios, which might be validated in female T2DM prevalence in the future.

VEGFR-2 inhibitors and the therapeutic applications thereof: a patent review (2012-2016).

INTRODUCTION: Angiogenesis is an important component of certain normal physiological processes, but aberrant angiogenesis contributes to some pathological disorders and in particular to tumor growth. Activation of vascular endothelial growth factor receptor-2 (VEGFR-2) by vascular endothelial growth factor (VEGF) is a critical step in the signal transduction pathway that initiates tumor angiogenesis. Inhibition of angiogenesis via blocking VEGF/VEGFR-2 signaling pathway has emerged as a potential approach to anticancer therapy. Indeed, this approach has recently been clinically validated with the approvals of VEGFR-2 inhibitors. Areas covered: This review accounts for small-molecule inhibitors and antibodies of VEGFR-2 reported in the patent literature covering between January 2012 and June 2016, and their potential use as therapeutics for cancers, angiogenesis-related disorders and inflammatory diseases. Expert opinion: Despite the attractiveness of anti-angiogenic therapy by VEGF inhibition alone, several issues may limit this approach. VEGF expression levels can be elevated by numerous diverse stimuli such as the activation of other RTK signaling transduction pathway. Therefore, the development of multi-targeted tyrosine kinase inhibitors and the strategy of using these agents in conjunction with other anti-cancer agents are recent interesting therapeutic approaches that could give promising results.

Design, synthesis and biological evaluation of N-phenylquinazolin-4-amine hybrids as dual inhibitors of VEGFR-2 and HDAC.

A single agent that simultaneously inhibits multiple targets may offer greater therapeutic benefits in cancer than single-acting agents through interference with multiple pathways and potential synergistic action. In this work, a series of hybrids bearing N-phenylquinazolin-4-amine and hydroxamic acid moieties were designed and identified as dual VEGFR-2/HDAC inhibitors. Compound 6fd exhibited the most potent inhibitory activity against HDAC with IC50 of 2.2 nM and strong inhibitory effect against VEGFR-2 with IC50 of 74 nM. It also showed the most potent inhibitory activity against a human breast cancer cell line MCF-7 with IC50 of 0.85 µM. Docking simulation supported the initial pharmacophoric hypothesis and suggested a common mode of interaction at the active binding sites of VEGFR-2 and HDLP ((Histone Deacetylase-Like Protein), which demonstrates that compound 6fd is a potential agent for cancer therapy deserving further researching.

Impact of season of food frequency questionnaire administration on dietary reporting.

PURPOSE: Foods consumed near the time of food frequency questionnaire (FFQ) administration may prime the memory, such that FFQ responses emphasize recently consumed foods. This study investigates the effect of season of FFQ administration, a proxy for the recent diet, on FFQ responses. METHODS: FFQ data from 74,958 Shanghai Women's Health Study (SWHS) subjects were compared with FFQ data from these subjects by season of FFQ administration (i.e., winter, spring, summer, and fall). All analyses were adjusted for age, BMI, and energy intake. Furthermore, quintile categories derived from all study subjects were compared with categories derived from the distribution of subjects recruited in the same season. RESULTS: Compared with the study group as a whole, subjects completing the FFQ in winter reported higher intakes of meat (2.1%), vegetable (3.9%), fish (3.1%), and soy foods (4.1%), but lower fruit (- 3.9%) intake. Subjects completing the FFQ in summer reported lower than average meat (- 2.0%), vegetable (- 3.2%), fish (- 2.3%), and soy food (- 4.6%) intakes, but greater fruit intake (0.9%). Completion of the FFQ in spring and fall usually led to intermediate differences from the group average, although fruit intake was 5.9% higher among subjects completing the FFQ in the fall. Variations across macronutrients and micronutrients by season of FFQ administration were smaller. If seasonal FFQ reporting is ignored, up to 13% of subjects would be classified to a different diet intake exposure category. However, reclassification was always to an adjacent category. CONCLUSIONS: FFQ responses varied with season of FFQ administration, consistent with theory that current diet intake influences reporting of habitual past diet intake. However, season of FFQ administration did not alter dietary exposure category assignments sufficiently to effect interpretation of most epidemiologic studies.

Birthweight, childhood growth and hypertension in adulthood.

BACKGROUND: Low birthweight (BW) and childhood growth have been hypothesized to be associated with an increased risk of hypertension in later life. METHODS: We analysed data among 13,467 women with a recalled BW from the Shanghai Women's Health Study. Cases included those with a self-reported hypertension with ('confirmed cases') or without ('possible cases') antihypertensive medication(s) use. Logistic regression was used to derive adjusted odds ratios (OR) and 95% CI. RESULTS: Birthweight was inversely associated with the odds of early onset (at age 20-40 years) hypertension in a dose response manner (P for trend = 0.01). This association is stronger for 'confirmed' hypertension (only OR for 'confirmed' hypertension are referred to subsequently). Being heavier or taller than average at 15 years of age were both related to elevated odds of early onset hypertension. Women who had a low BW but were heavier than average at age 15 were more than four times (OR = 4.63, 95% CI: 2.40-8.94) more likely to have an early onset hypertension, and those who had a low BW and became taller at 15 years of age had an OR of 1.87 (95% CI: 1.05-3.31). A significant interaction between BW and weight at age 15 was observed (P = 0.04). CONCLUSION: Our study suggests that low BW, particularly if accompanied by accelerated childhood growth, may increase the risk of early onset hypertension in adulthood.

Human metabolic correlates of body mass index.

BACKGROUND: A high body mass index (BMI) is a major risk factor for several chronic diseases, but the biology underlying these associations is not well-understood. Dyslipidemia, inflammation, and elevated levels of growth factors and sex steroid hormones explain some of the increased disease risk, but other metabolic factors not yet identified may also play a role. DESIGN: In order to discover novel metabolic biomarkers of BMI, we used non-targeted metabolomics to assay 317 metabolites in blood samples from 947 participants and examined the cross-sectional associations between metabolite levels and BMI. Participants were from three studies in the United States and China. Height, weight, and potential confounders were ascertained by questionnaire (US studies) or direct measurement (Chinese study). Metabolite levels were measured using liquid-phase chromatography and gas chromatography coupled with mass spectrometry. We evaluated study-specific associations using linear regression, adjusted for age, gender, and smoking, and we estimated combined associations using random effects meta-analysis. RESULTS: The meta-analysis revealed 37 metabolites significantly associated with BMI, including 19 lipids, 12 amino acids, and 6 others, at the Bonferroni significance threshold (p<0.00016). Eighteen of these associations had not been previously reported, including histidine, an amino acid neurotransmitter, and butyrylcarnitine, a lipid marker of whole-body fatty acid oxidation. Heterogeneity by study was minimal (all Pheterogeneity >0.05). In total, 110 metabolites were associated with BMI at the p<0.05 level. CONCLUSION: These findings establish a baseline for the BMI metabolome, and suggest new targets for researchers attempting to clarify mechanistic links between high BMIs and disease risk.

Metabolomics in epidemiology: sources of variability in metabolite measurements and implications.

BACKGROUND: Metabolite levels within an individual vary over time. This within-individual variability, coupled with technical variability, reduces the power for epidemiologic studies to detect associations with disease. Here, the authors assess the variability of a large subset of metabolites and evaluate the implications for epidemiologic studies. METHODS: Using liquid chromatography/mass spectrometry (LC/MS) and gas chromatography-mass spectroscopy (GC/MS) platforms, 385 metabolites were measured in 60 women at baseline and year-one of the Shanghai Physical Activity Study, and observed patterns were confirmed in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening study. RESULTS: Although the authors found high technical reliability (median intraclass correlation = 0.8), reliability over time within an individual was low. Taken together, variability in the assay and variability within the individual accounted for the majority of variability for 64% of metabolites. Given this, a metabolite would need, on average, a relative risk of 3 (comparing upper and lower quartiles of "usual" levels) or 2 (comparing quartiles of observed levels) to be detected in 38%, 74%, and 97% of studies including 500, 1,000, and 5,000 individuals. Age, gender, and fasting status factors, which are often of less interest in epidemiologic studies, were associated with 30%, 67%, and 34% of metabolites, respectively, but the associations were weak and explained only a small proportion of the total metabolite variability. CONCLUSION: Metabolomics will require large, but feasible, sample sizes to detect the moderate effect sizes typical for epidemiologic studies. IMPACT: We offer guidelines for determining the sample sizes needed to conduct metabolomic studies in epidemiology.

[Epidemiological prospective studies on physical activities and the risk of colon cancer: a meta-analysis].

OBJECTIVE: To explore the relationship between physical activity (PA) and the risk of colon cancer. METHODS: Cohort studies on physical activity and risk of colon cancer were identified by searching MEDLINE, EMBASE, Chinese Bio-medicine and Chinese Wanfang databases from January 1979 to December 2009. Results from the individual studies were synthetically combined in our study. Inverse variance weighting was used in fixed effects model and the random effects estimate was based on the DerSimonian-Laird method. Variance-weighted least squares method was used for trend test of summarized dose-response data. RESULTS: A total of 28 studies were included in our analysis. An inverse association between physical activities and the risk of colon cancer was observed with the relative risks (RR) as 0.75 [95% confidence interval (CI): 0.66 - 0.86] in males and 0.85 (95%CI: 0.76 - 0.95) in females, respectively. However, the findings from those documents with high quality showed significant and borderline significant associations between PA and colon cancer in both males (RR = 0.74, 95%CI: 0.61 - 0.90) and females (RR = 0.99, 95%CI: 0.95 - 1.02). Meanwhile, the dose-response trend was not observed either in males (P = 0.142) or in females (P = 0.417). For men, the pooled RRs differed by subsites were 0.62 (95%CI: 0.45 - 0.85) and 0.74 (95%CI: 0.56 - 0.99) for highest level PA, compared with lowest level PA in proximal colon and distal colon cancer, respectively. For women, the pooled RRs were 0.84 (95%CI: 0.69 - 1.01) in proximal colon and 0.75 (95%CI: 0.53 - 1.05) in distal colon cancer, respectively. CONCLUSION: These results added to the evidence for the protective effects in colon cancer among men and women.

Validity of a physical activity questionnaire in Shanghai.

PURPOSE: In large epidemiologic studies, physical activity (PA) is often assessed using PA questionnaires (PAQ). Because available PAQ may not capture the full range of PA in which urban Chinese adults engage, a PAQ was developed for this purpose. We examined the validity of this PAQ and the 1-yr stability of PA in 545 urban Shanghai adults. METHODS: The PAQ was interview-administered twice, approximately 1 yr apart, and participants also wore an accelerometer and completed a PA-log for seven consecutive days every 3 months during the same year. The intraclass correlation coefficient (ICC) was used to evaluate the stability of PA across questionnaire administrations, and Spearman correlation coefficients (ρ) and mean differences and 95% limits of agreement were used to examine the validity of the questionnaire compared against accelerometry and the PA-log. RESULTS: When measured by accelerometry, estimates of time spent in moderate-to-vigorous PA were lower and estimates of time spent sedentary were higher than when self-reported on the PAQ (P < 0.001). Total PA (ICC = 0.65) and PA domains (ICC = 0.45-0.85) showed moderate to high stability across PAQ administrations. Total PA (ρ = 0.30), moderate-to-vigorous activity (ρ = 0.17), light activity (ρ = 0.36), and sedentary behavior (ρ = 0.16) assessed by PAQ and by accelerometry were significantly and positively correlated, and correlations of the PAQ with the PA-log (ρ = 0.36-0.85) were stronger than those observed with accelerometry. CONCLUSIONS: The PAQ significantly overestimated time spent in moderate-to-vigorous activity and underestimated time spent in light activity and sedentary behavior compared with accelerometry, but it performed well at ranking participants according to PA level.

Accelerometer-measured physical activity in Chinese adults.

BACKGROUND: Following adoption of a Western lifestyle, China is experiencing a decline in physical activity levels, which is projected to contribute to future increases in the burden of chronic diseases. PURPOSE: This study aims to target public health interventions and identify personal characteristics associated with physical activity and sedentary behavior in urban Chinese adults. METHODS: In a sample of 576 men and women aged 40-74 years from Shanghai, multiple logistic regression was used to examine demographic, anthropometric, and lifestyle factors in relation to levels of physical activity and sedentary behavior assessed by Actigraph accelerometers. RESULTS: Participants spent 317 minutes/day in physical activity and 509 minutes/day sedentary. In multivariate models, people aged > or =60 years were significantly less likely than those aged <50 years to engage in physical activity (OR=0.29, 95% CI=0.17, 0.49) and more likely to spend time sedentary (OR=2.77, 95% CI=1.53, 5.05). Similarly, obese individuals were less likely to be physically active (OR=0.34, 95% CI=0.17, 0.66) and they were suggestively more likely to be sedentary (OR=1.87, 95% CI=0.94, 3.71) than normal-weight individuals. Furthermore, current cigarette smokers were less physically active than those who formerly or never smoked (OR=0.47, 95% CI=0.28, 0.78). CONCLUSIONS: Physical activity promotion programs in urban China should target older people, obese individuals, and cigarette smokers, as these population subgroups exhibited low levels of physical activity.

[Anthropometry and female breast cancer: a prospective cohort study in urban Shanghai].

OBJECTIVE: To investigate the association between anthropometry and risk of breast cancer among pre-and post-menopausal women in urban Shanghai. METHODS: A total of 73 461 female residents aged 40 to 70 years in urban Shanghai were recruited in a prospective cohort study (the Shanghai women's health study) during 1997 through 2000, and were actively followed up biennially. During mean follow-up period of 5.66 years, 432 incident cases of breast cancer were identified in the cohort. Cox regression model was used to estimate the adjusted relative risks (RRs) and 95% confidence intervals (CIs). RESULTS: After adjustment for some potential confounding factors, baseline weight, body mass index(BMI), waist-to-hip ratio(WHR) and weight gain since age 20 were positively associated with the increased risk of breast cancer among postmenopausal women. The positive association between height and breast cancer was found among premenopausal women. Among them, those with height taller than 161 cm at age 20 experienced 1.84 fold increased risk (95% CI: 1.30-2.61) of breast cancer compared to their counterpart with height shorter than 157.1 cm. Women who were either much heavier or lighter than average at age 20 were at reduced risk. Further analyses mutually adjusted for BMI and WHR did not substantially alter the positive association for both BMI and WHR. After further adjustment for BMI, weight gain since age 20 was significantly associated to an increased risk for postmenopausal breast cancer (RR = 1.61, 95% CI: 1.09-2.37). CONCLUSIONS: Weight gain and central obesity seemed to be strong predictors for the risk of breast cancer among postmenopausal women. Controlling weight and decreasing fat around waist were effective means to prevent postmenopausal breast cancer and height might serve as a risk factor for premenopausal breast cancer.

Sources of variation in nutrient intakes among men in Shanghai, China.

BACKGROUND AND OBJECTIVE: Random errors, from any source, will attenuate epidemiological risk estimates. Before we launched the Shanghai Men's Health Study (SMHS), a large population-based cohort study investigating the diet-cancer association among Chinese men, a dietary calibration study was conducted among 96 men aged 40-75 years (mean age 56.5 years), with biweekly 24-hour dietary recalls (24HDRs) implemented over a 1-year period. Data from this study were analysed to evaluate the nature and magnitude of variances for intake of 26 nutrients among SMHS participants, to compare variance ratios of 26 nutrients among Chinese men and women and individuals in other studies, and to estimate the number of 24HDRs required for future dietary calibration studies in similar populations. DESIGN: Ninety-six healthy, free-living men in Shanghai were administered biweekly 24HDR interviews 24 times over a 1-year period. To assess between-individual and within-individual contributions to variance, a mixed effects model was fitted and ratios of within-individual to between-individual (sigma(w)(2)/sigma(b)(2)) dietary intake variances were computed. SETTING: Shanghai, China. RESULTS: In agreement with reports from studies conducted in the USA and many other countries, we found that within-individual variances were usually larger than between-individual variances in dietary intake for all nutrients. The sum of all other variation (e.g. weekday and weekend, seasonal, interviewer) accounted for less than 5% of total variation. Ratios of within- to between-individual variances (for log-transformed data) ranged from 1.25 for carbohydrate intake to near 8 for delta-tocopherol intake. CONCLUSIONS: The results of this study suggest that among middle-aged and elderly Chinese men in Shanghai, within- and between-individual variation account for more than 95% of the total variation for 26 nutrients. Further dietary validation studies in the same population could be adequately carried out with only 12 days of dietary recalls, if 100 participants were enrolled.