Cai-Xia Zhang

Effect of long-term intervention of soy isoflavones on bone mineral density in women: a meta-analysis of randomized controlled trials.

INTRODUCTION A number of RCTs have examined the role of soy isoflavones on bone mineral density (BMD) and yielded inconsistent results. This meta-analyses aims to assess the overall effect of soy isoflavones on BMD. METHODS We searched for all articles published in English from January 1990 to March, 2008. We included RCTs of soy isoflavone supplementation in women of at least one year duration. The main outcomes were BMD changes from baseline at the lumbar spine, total hip and femoral neck. RESULTS We identified 10 eligible RCTs containing 896 women. A mean dose of 87 mg soy isoflavones for at least one year did not significantly affect BMD changes. The mean (95%CI) differences in BMD changes (in mg/cm(2)/year) were 4.1 (-1.6, 9.8) (0.4%) at the lumbar spine, -1.5 (-7.2, 4.3) (-0.3%) at the femoral neck under random-effects model, and 2.5 (-0.5, 5.4) (0.2%) at the total hip by fix-effects model, respectively. Similar results were obtained in subgroup analyses by isoflavone sources (soy protein vs. isoflavone extract), ethnic differences (Asian vs. Western). Larger dose (>or=80 mg/d), but not lower dose (<80 mg/d), of isoflavone intervention tended to have a weak beneficial effect on spine BMD (p=0.08 vs. p=0.94). CONCLUSIONS Soy isoflavone supplementation is unlikely to have significant favorable on BMD at the lumbar spine and hip in women.

Association of estrogen receptor α gene polymorphisms with bone mineral density in Chinese women: a meta-analysis

Introduction and hypothesisA large number studies have examined the association between estrogen receptor alpha (ESR-α) gene polymorphisms and bone mineral density (BMD) in the Chinese population. We conducted a meta-analysis to assess their pooled effects.MethodsWe searched for all published articles indexed in MEDLINE, the Chinese Biomedical Database, and the Chinese Journal Full-text Database from January 1994 to April 2006. Any cross-sectional study that tested the association between ESR-α PvuII or XbaI genotypes and BMD at the femoral neck or spine in Chinese women was included in the review. Data were extracted independently by two reviewers using a standardized data extraction form. Sixteen eligible studies involving 4,297 Chinese women were identified.ResultsThe overall frequencies of X and P alleles were 28% and 40%, respectively. The PvuII polymorphism was statistically significantly associated with BMD at the femoral neck (P = 0.038 for PP = Pp = pp) but not at the lumbar spine in all women. The BMD difference for the contrasts of PP versus Pp/pp genotypes was −0.0105 (95%CI, −0.0202 ∼ −0.0008) g/cm2 (P = 0.036). The XbaI polymorphism was not associated with BMD at the femoral neck or lumbar spine.ConclusionThe PvuII polymorphism had a very weak association with femoral neck BMD whereas XbaI polymorphism was unlikely to be a predictor of femoral neck or spine BMD in Chinese women.

Choline and betaine intake is inversely associated with breast cancer risk: A two‐stage case‐control study in China

Few epidemiological studies have evaluated the association of choline and betaine intake with breast cancer risk and the results remain inconsistent. This study aimed to assess the relationship between dietary intake of choline and betaine and the risk of breast cancer among Chinese women. A two‐stage case‐control study was conducted, with 807 cases and 807 age‐ (5‐year interval) and residence (rural/urban)‐matched controls. A validated food frequency questionnaire was used to assess dietary intake by face‐to‐face interview. An unconditional logistic regression model was used to calculate multivariate‐adjusted odds ratios (OR) and 95% confidence intervals (CI). A significant inverse association was found between dietary choline and betaine consumption and breast cancer risk. The adjusted OR for the highest quartile of intake compared with the lowest were 0.40 (95% CI = 0.28–0.57, Ptrend < 0.001) for total choline intake, 0.58 (95% CI = 0.42–0.80, Ptrend < 0.001) for betaine intake and 0.38 (0.27–0.53, Ptrend < 0.001) for choline plus betaine intake, respectively. Intakes of individual choline compouds, choline from glycerophosphocholine, phosphocholine, phosphatidylcholine, sphingomyelin and free choline were also negatively associated with breast cancer risk. The inverse association between choline intake and breast cancer risk was primarily confined to participants with low folate level (<242 g/day), with an OR (95% CI) of 0.46 (0.23–0.91) comparing the fourth quartile with the first quartile of choline intake (Ptrend = 0.005). The present study suggests that consumption of choline and betaine is inversely associated with the risk of breast cancer. The association of choline intake with breast cancer risk is probably modified by folate intake.

Effect of dietary fiber intake on breast cancer risk according to estrogen and progesterone receptor status

Background/Objectives:There is few data on the association between dietary fiber intake and estrogen receptor (ER)/progesterone receptor (PR)-defined breast cancer risk. The present study aimed to investigate the associations between total dietary fiber and dietary fiber fractions intake and breast cancer risk by ER and PR status in a hospital-based case–control study among Chinese women.Subjects/Methods:Four hundred and thirty-eight cases with primary breast cancer were consecutively recruited from June 2007 to August 2008 and frequency matched to 438 controls by age (5-year interval) and residence (rural/urban). A validated food frequency questionnaire was used to assess the dietary intake through a face-to-face interview. Unconditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence interval (CI) after adjusting for various potential confounders.Results:A statistically significant inverse association was found between total dietary fiber and fiber fractions intake and breast cancer risk. The adjusted ORs (95% CIs) for the highest versus the lowest quartile of intake were 0.31 (0.20–0.47) for total dietary fiber, 0.73 (0.48–1.11) for soy fiber, 0.48 (0.22–0.97) for vegetable fiber and 0.54 (0.31–0.92) for fruit fiber. No association was observed for cereal fiber intake and risk. An inverse association between dietary fiber intake and breast cancer risk was observed in ER+, ER−, PR+, ER+PR+ and ER−PR+ tumors.Conclusions:Our results suggest that consumption of total dietary fiber and fiber from vegetable and fruit was inversely associated with breast cancer risk. These inverse associations were more prominent in some subtypes of ER and PR breast cancers.

Moderating effects of coping styles on anxiety and depressive symptoms caused by psychological stress in Chinese patients with Type 2 diabetes

Aims  This study aimed to assess possible interactive effects of coping styles and psychological stress on depression and anxiety symptoms in Chinese patients with Type 2 diabetes.

A higher Dietary Inflammatory Index score is associated with a higher risk of breast cancer among Chinese women: a case–control study

Previous studies have investigated the association between dietary inflammatory potential and the development of cancer. For breast cancer the results have been equivocal. The present study aimed to investigate whether higher Dietary Inflammatory IndexTM (DII) scores were associated with increased risk of breast cancer among Chinese women. A total of 867 cases and 824 controls were recruited into the present case-control study from September 2011 to February 2016. DII scores were computed based on baseline dietary intake assessed by a validated 81-item FFQ. The OR and 95 % CI were assessed by multivariable logistic regression after adjusting for various potential confounders. DII scores in this study ranged from -5·87 (most anti-inflammatory score) to +5·71 (most proinflammatory score). A higher DII score was associated with a higher breast cancer risk (adjusted ORquartile 4 v. 1 2·28; 95 % CI 1·71, 3·03; adjusted ORcontinuous 1·40; 95 %CI 1·25, 1·39). In stratified analyses, positive associations also were observed except for underweight women or women with either oestrogen receptor+ or progesterone receptor+ status (but not both). Results from this study indicated that higher DII scores, corresponding to more proinflammatory diets, were positively associated with breast cancer risk among Chinese women.

Specific serum carotenoids are inversely associated with breast cancer risk among Chinese women: a case-control study.

Previous epidemiological studies have revealed the anti-cancer effect of dietary circulating carotenoids. However, the protective role of specific individual circulating carotenoids has not been elucidated. The purpose of this study was to examine whether serum carotenoids, including α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin, could lower the risk for breast cancer among Chinese women. A total of 521 women with breast cancer and age-matched controls (5-year interval) were selected from three teaching hospitals in Guangzhou, China. Concentrations of α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin were measured using HPLC. Unconditional logistic regression models were used to calculate OR and 95% CI using quartiles defined in the control subjects. Significant inverse associations were observed between serum α-carotene, β-carotene, lycopene, lutein/zeaxanthin and the risk for breast cancer. The multivariate OR for the highest quartile of serum concentration compared with the lowest quartile were 0·44 (95% CI 0·30, 0·65) for α-carotene, 0·27 (95% CI 0·18, 0·40) for β-carotene, 0·41 (95% CI 0·28, 0·61) for lycopene and 0·26 (95% CI 0·17, 0·38) for lutein/zeaxanthin. However, no significant association was found between serum β-cryptoxanthin and the risk for breast cancer. Stratified analysis by menopausal status and oestrogen receptor (ER)/progesterone receptor (PR) showed that serum α-carotene, β-carotene, lycopene and lutein/zeaxanthin were inversely associated with breast cancer risk among premenopausal women and among all subtypes of ER or PR status. The results suggest a protective role of α-carotene, β-carotene, lycopene and lutein/zeaxanthin, but not β-cryptoxanthin, in breast cancer risk.

Folate intake and breast cancer prognosis: a meta-analysis of prospective observational studies.

Some studies have investigated the association between folate intake and breast cancer prognosis, but the results have been far from conclusive. Thus, a meta-analysis was carried out to explore this association. We performed a comprehensive search of the PubMed, Web of Knowledge, and Cochrane databases from inception to May 2013. The summary hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a random effects model. Prespecified stratified analyses, sensitivity analyses, and dose–response analysis were also carried out. Five studies, with a total of 7299 participants, were included in the meta-analysis. The pooled HR (95% CI) of the five studies on the association of dietary folate intake (highest vs. lowest) with all-cause mortality was 0.74 (0.60–0.92). Stratified analyses suggested that the inverse association of dietary folate and all-cause mortality was more easily detected in studies that focused on prediagnosis diets, included more patients (>1000), had longer follow-up periods (>7 years), used structured interviews, or had more categories of folate intake (>3). However, none of these differences was statistically significant. No significant association was found between total (dietary and supplementary) folate intake and all-cause mortality, or dietary folate intake and breast cancer-specific mortality, with pooled HRs (95% CI) of 0.93 (0.75–1.15) and 0.79 (0.61–1.01), respectively. Sensitivity analyses confirmed the robustness of the findings by excluding studies that poorly represented the cohort. Our findings suggest a significant inverse association between dietary folate intake and all-cause mortality, but not between total folate intake and all-cause mortality.

Joint effects of folate intake and one-carbon-metabolizing genetic polymorphisms on breast cancer risk: a case-control study in China.

This study aimed to examine the joint effects of folate intake, polymorphisms of 5,10- methylenetetrahydrofolate reductase (MTHFR), methionine synthesis reductase (MTRR) and methionine synthase (MTR) genes and breast cancer risk. A case-control study of 570 consecutively recruited breast cancer cases and 576 controls was conducted in Guangzhou, China. Multifactor dimensionality reduction and logistic regression approach were used to evaluate gene-gene interaction. The covariates were chosen based on comparison of baseline characteristics of cases and controls. Folate intake was found to be inversely associated with breast cancer risk. The MTRRrs162036 GG genotype was associated with a decreased risk of breast cancer [adjusted odds ratio (OR) 0.41, 95% confidence interval (CI) 0.20–0.85]. Compared with the wild-type group (MTRRrs162036 AA with MTRrs1805087 AA) MTRRrs162036 AA with MTRrs1805087 GA + GG was associated with a decreased risk (OR 0.70, 95% CI 0.48–1.03). With the combined MTHFRrs1801131 TT and MTHFRrs1801133 GG genotypes as a reference, MTHFRrs1801131 TT with MTHFRrs1801133 GA + AA was associated with a decreased risk (OR 0.78, 95% CI 0.57 – 1.08) and MTHFRrs1801131 GT + GG with MTHFRrs1801133 GA + AA was associated with an increased risk (OR 1.35, 95% CI 0.88–2.05). The joint impact of MTRRrs162036 and MTRrs1805087, MTHFRrs1801131 and MTHFRrs1801133, folate and MTHFRrs1801133 may contribute to breast cancer risk.

Passive Smoking and Breast Cancer Risk among Non-Smoking Women: A Case- Control Study in China

Background The role of passive smoking on breast cancer risk was unclear. This study aimed to evaluate the association between passive smoking and breast cancer risk among Chinese women. Methods/Principal Findings A hospital-based case-control study, including 877 breast cancer cases and 890 controls, frequency-matched by age and residence, was conducted. A structured questionnaire was used to collect information on passive smoking history through face-to-face interview by trained interviewers. Unconditional logistic regression models were used to estimate the association between passive smoking and breast cancer risk. A positive association between any passive smoking exposure and breast cancer risk was observed. Compared with women who were never exposed to passive smoking, women who were ever exposed had a higher breast cancer risk, with the adjusted odds ratio (OR) and 95% confidence interval (CI) of 1.35 (1.11-1.65). Similar result was found on home passive smoking exposure and breast cancer risk, but not on workplace passive smoking exposure. Women who were ever exposed to tobacco smoke at home had a higher risk of breast cancer compared with never exposed women, with the adjusted OR (95% CI) of 1.30 (1.05-1.61). Home passive smoking exposure showed significant dose-response relationships with breast cancer risk in smoker-years, cigarettes/day and total pack-years (P trend=0.003, 0.006 and 0.009, respectively). An increased total smoker-years of any passive exposure significantly elevated the risk of breast cancer (P trend<0.001). Positive associations and dose-response relationships were found among postmenopausal women and all subtypes of estrogen receptor (ER) and progesterone receptor (PR) status of breast cancer. Conclusions Passive smoking was associated with an increased risk of breast cancer among non-smoking Chinese women. A stronger positive association with breast cancer risk was seen mainly among postmenopausal women.