Yu-Tang Gao

Dietary calcium and magnesium intakes and the risk of type 2 diabetes: the Shanghai Women's Health Study

BACKGROUNDnDiet plays a key role in the development of type 2 diabetes (T2D), but little is known about the contributions of specific nutrients in populations in which dietary patterns differ from Western populations.nnnOBJECTIVEnWe examined associations between calcium and magnesium intakes and the risk of T2D in a Chinese population.nnnDESIGNnWe used data from a population-based, prospective study of 64,191 women who were free of T2D or other chronic diseases at study recruitment and were living in urban Shanghai, China. Dietary intake, physical activity, and anthropometric measurements were assessed through in-person interviews. A Cox regression model was used to evaluate the association of the exposures under study with the risk of T2D.nnnRESULTSnAn inverse association between calcium and magnesium intakes and T2D risk was observed. The relative risks for the lowest to the highest quintiles of calcium intake were 1.00, 0.82, 0.73, 0.67, and 0.74 (P for trend < 0.001), and for magnesium they were 1.00, 0.84, 0.84, 0.79, and 0.86 (P for trend < 0.001). Milk intake was also inversely associated with the risk of T2D.nnnCONCLUSIONnOur data suggest that calcium and magnesium intakes may protect against the development of T2D in this population.

Prospective Study of Urinary Prostaglandin E2 Metabolite and Colorectal Cancer Risk

PURPOSEnOverexpression of cyclooxygenase-2 (COX-2) has been shown to play a major role in colorectal cancer pathogenesis. However, no human study has directly investigated whether biomarkers of COX-2 overexpression may predict colorectal cancer risk. We evaluated the association of urinary prostaglandin E2 metabolite (PGE-M) levels and colorectal cancer risk.nnnMETHODSnA nested case-control study was conducted within the Shanghai Womens Health Study, in which 74,942 Chinese women ages 40 to 70 years were recruited from 1997 to 2000. Urinary PGE-M in 150 cohort members who developed colorectal cancer during the follow-up were compared with 150 matched controls.nnnRESULTSnThe baseline level of urinary PGE-M was more than 50% higher in cases than in controls. The relative risks (RRs) of developing colorectal cancer were elevated from 1.0 to 2.5 (95% CI, 1.1 to 5.8), 4.5 (95% CI, 1.9 to 10.9), and 5.6 (95% CI, 2.4 to 13.5) with increasing quartiles of urinary PGE-M levels (P for trend < .001). The positive association was observed for both colon cancer (RR = 4.9; 95% CI, 1.7 to 14.7 for the highest v lowest quartile; P for trend = .009) and rectal cancer (RR = 7.2; 95% CI, 1.7 to 30.7; P for trend = .048), and for colorectal cancer cases diagnosed in the first 30 months (RR = 7.6; 95% CI, 1.8 to 32.0; P for trend = .035) and subsequent months (RR = 4.4, 95% CI, 1.5 to 13.3; P for trend = .012) of follow-up.nnnCONCLUSIONnGiven its strong association with colorectal cancer risk, urinary PGE-M may be a promising biomarker for risk assessment of this common malignancy.

Cruciferous vegetable consumption is associated with a reduced risk of total and cardiovascular disease mortality

BACKGROUNDnAsian populations habitually consume a large amount of cruciferous vegetables and other plant-based foods. Few epidemiologic investigations have evaluated the potential health effects of these foods in Asian populations.nnnOBJECTIVEnWe aimed to examine the associations of cruciferous vegetables, noncruciferous vegetables, total vegetables, and total fruit intake with risk of all-cause and cause-specific mortality.nnnDESIGNnThe analysis included 134,796 Chinese adults who participated in 2 population-based, prospective cohort studies: the Shanghai Womens Health Study and the Shanghai Mens Health Study. Dietary intakes were assessed at baseline through in-person interviews by using validated food-frequency questionnaires. Deaths were ascertained by biennial home visits and linkage with vital statistics registries.nnnRESULTSnWe identified 3442 deaths among women during a mean follow-up of 10.2 y and 1951 deaths among men during a mean follow-up of 4.6 y. Overall, fruit and vegetable intake was inversely associated with risk of total mortality in both women and men, and a dose-response pattern was particularly evident for cruciferous vegetable intake. The pooled multivariate hazard ratios (95% CIs) for total mortality across increasing quintiles of intake were 1 (reference), 0.91 (0.84, 0.98), 0.88 (0.77, 1.00), 0.85 (0.76, 0.96), and 0.78 (0.71, 0.85) for cruciferous vegetables (P < 0.0001 for trend) and 0.88 (0.79, 0.97), 0.88 (0.79, 0.98), 0.76 (0.62, 0.92), and 0.84 (0.69, 1.00) for total vegetables (P = 0.03 for trend). The inverse associations were primarily related to cardiovascular disease mortality but not to cancer mortality.nnnCONCLUSIONnOur findings support recommendations to increase consumption of vegetables, particularly cruciferous vegetables, and fruit to promote cardiovascular health and overall longevity.

Soyfood intake and breast cancer survival: a followup of the Shanghai Breast Cancer Study.

Soy and its constituents have been shown in many in vivo and in vitro studies and in some epidemiological studies to have anti-cancer effects. Some soy constituents, however, also stimulate cell proliferation, which has raised concerns in promoting soy intake among breast cancer survivors. To investigate whether soy intake may be associated with breast cancer survival, we evaluated data from a cohort of 1459 breast cancer patients who participated in the Shanghai Breast Cancer Study between 1996 and 1998. Usual soy food intake was assessed using a validated food frequency questionnaire at baseline. The median follow-up time for this cohort of women was 5.2u2009years. We found that soy intake prior to cancer diagnosis was unrelated to disease-free breast cancer survival (adjusted hazard ratio [HR]=0.99, 95% confidence interval [CI], 0.73–1.33 for the highest tertile compared to the lowest tertile). The association between soy protein intake and breast cancer survival did not differ according to ER/PR status, tumor stage, age at diagnosis, body mass index (BMI), waist to hip ratio (WHR), or menopausal status. Additionally, the soy-survival association did not appear to vary according to XbaI or PvuII polymorphisms in ER-alpha, or C(14206)T, G(25652)A, or A(50766)G polymorphisms in ER-beta. These data suggest that soyfoods do not have an adverse effect on breast cancer survival.

Fish, shellfish, and long-chain n−3 fatty acid consumption and risk of incident type 2 diabetes in middle-aged Chinese men and women

BACKGROUNDnLong-chain polyunsaturated n-3 (omega-3) fatty acids, found mainly in fish, have been postulated to reduce type 2 diabetes (T2D) risk. However, the role of long-chain n-3 fatty acids and fish intake in the development of T2D remains unresolved.nnnOBJECTIVEnWe examined associations between fish, shellfish, and long-chain n-3 fatty acids and the risk of T2D in a middle-aged Chinese population.nnnDESIGNnThis was a prospective population-based cohort study in 51,963 men and 64,193 women free of T2D, cardiovascular disease, and cancer at baseline with valid dietary information. Dietary intake, physical activity, and anthropometric measurements were collected. A Cox regression model was used to evaluate the association of fish, shellfish, and long-chain n-3 fatty acid (in g/d) with risk of T2D.nnnRESULTSnFish, shellfish, and long-chain n-3 fatty acid intakes were inversely associated with T2D in women. The relative risks [RRs (95% CI)] for quintiles of fish intake were 1.00, 0.96 (0.86, 1.06), 0.84 (0.75, 0.94), 0.80 (0.71, 0.90), and 0.89 (0.78, 1.01) (P for trend = 0.003) and for shellfish were 1.00, 0.91 (0.82, 1.01), 0.79 (0.71, 0.89), 0.80 (0.71, 0.91), and 0.86 (0.76, 0.99) (P for trend = 0.006). In men, only the association between shellfish intake and T2D was significant. The RRs (95% CI) for quintiles of fish intake were 1.00, 0.92 (0.75, 1.13), 0.80 (0.65, 1.00), 0.89 (0.72, 1.11), and 0.94 (0.74, 1.17) (P for trend = 0.50) and for shellfish intake were 1.00, 0.93 (0.76, 1.12), 0.70 (0.56, 086), 0.66 (0.53, 0.82), and 0.82 (0.65, 1.02) (P for trend = 0.003).nnnCONCLUSIONSnAn inverse association between fish and shellfish intake and T2D in women was found. No evidence of a detrimental effect of fish intake in this population was observed.

Dietary patterns are associated with lower incidence of type 2 diabetes in middle-aged women: the Shanghai Women’s Health Study

BACKGROUNDnData linking risk of type 2 diabetes (T2D) and dietary patterns in Chinese populations are scarce.nnnMETHODSnA population-based prospective study of 64,191 middle-aged women in urban Shanghai, China, who were free of T2D and other chronic diseases at study recruitment, was conducted. Dietary intake, physical activity and anthropometric measurements were assessed through in-person interviews. Dietary patterns were assessed by using K-means cluster analysis. Cox regression model was used to evaluate the association of dietary patterns with the risk of T2D.nnnRESULTSnWe identified three dietary clusters in this population. Cluster 1 (56.3%; N = 36,159) had the highest intake of staples, cluster 2 (40.4%: N = 25,948) had the highest intake of dairy milk, and cluster 3 (2.9%; N = 1843) had the highest energy intake. Participants in cluster 2 had lower prevalence of obesity, central obesity and hypertension at baseline. Using cluster 1 as the reference, participants in cluster 2 had a lower incidence of T2D after 6.9 years of follow-up [relative risk (RR) 0.78; 95% confidence interval (CI) 0.71-0.86]. The RR for the incidence of T2D for cluster 3 compared with cluster 1 was 1.05 (95% CI 0.81-1.35). The association was not modified by age category, body mass index category, waist-to-hip ratio category or exercise participation.nnnCONCLUSIONSnWe identified and characterized dietary patterns in middle-aged Chinese women by using cluster analysis. We identified a dietary pattern low in staple foods and high in dairy milk, which was associated with lower risk of T2D. Study of dietary patterns will help elucidate links between diet and disease, and contribute to the development of healthy eating guidelines for health promotion.

Adherence to dietary guidelines and mortality: a report from prospective cohort studies of 134,000 Chinese adults in urban Shanghai

BACKGROUNDnA higher adherence to dietary recommendations, such as the Dietary Approaches to Stop Hypertension (DASH) and the Alternative Healthy Eating Index (AHEI), has been associated with lower morbidity and mortality from chronic diseases in Western populations. However, the health benefits of following the Dietary Guidelines for Chinese remain unknown.nnnOBJECTIVEnWe examined adherence to the Chinese Food Pagoda (CHFP) in association with total and cause-specific mortality and compared associations with those of the DASH and AHEI.nnnDESIGNnParticipants included 61,239 men and 73,216 women (aged 40-74 y) from 2 population-based prospective studies in Shanghai, China. Habitual dietary intakes were assessed at baseline in-person interviews by using validated food-frequency questionnaires. Deaths and underlying causes were identified through the Shanghai Vital Statistics Registry and follow-up home visits.nnnRESULTSnWe documented 2954 deaths in men and 4348 deaths in women during mean follow-ups of 6.5 and 12.0 y, respectively. A higher CHFP score was associated with lower total mortality with multivariable-adjusted HRs of 0.67 (95% CI: 0.60, 0.75) in men and 0.87 (95% CI: 0.80, 0.95) in women when extreme quartiles were compared (both P-trend < 0.005). Decreased risks associated with a higher CHFP score were observed for cardiovascular disease, cancer, and diabetes mortality, particularly in men. A significantly lower total mortality was shown for adherence to specific recommendations on vegetables, fruit, legumes, fish, and eggs but not grains, dairy, meat, fat, and salt. A higher DASH score and AHEI also predicted lower mortality from all causes, cardiovascular disease, and diabetes but not cancer.nnnCONCLUSIONSnA greater compliance with Chinese or US dietary guidelines is associated with lower total mortality in Chinese adults. Favorable associations are more evident in men than women and more consistent for cardiometabolic mortality than cancer mortality.

Resting heart rate and risk of type 2 diabetes in women

BACKGROUNDnResting heart rate has been shown to predict risk of cardiovascular disease; its association with diabetes remains unclear, particularly in non-Western populations.nnnMETHODSnWe evaluated the association between resting heart rate and risk of type 2 diabetes in the Shanghai Womens Health Study, a population-based prospective cohort study. The analysis included 47 571 Chinese women with no prior history of diabetes, cancer, cardiovascular disease or thyroid dysfunction at the time when resting heart rate was measured. Incident diabetes was ascertained through biennial in-person interviews.nnnRESULTSnDuring a mean follow-up of 4.9 years, 849 women developed type 2 diabetes. For heart rate categories of < or =68, 69-72, 73-76, 77-80 and >80 beats/min, the incidence rates of diabetes per 1000 person-years were 2.91, 3.31, 3.71, 4.16 and 5.34, respectively. The multivariable-adjusted hazard ratios (HRs) [95% confidence intervals (CIs)] for diabetes across increasing heart rate categories were 1, 1.21 (0.99-1.47), 1.30 (1.05-1.62), 1.37 (1.12-1.69) and 1.60 (1.28-2.00), respectively. Further analyses of the joint effects of heart rate with body mass index (BMI), waist-hip ratio (WHR) and blood pressure (BP) showed increased risk of diabetes with increasing heart rate in all categories of BMI, WHR or BP. The combinations of the highest heart rate category with highest BMI, WHR or BP category were associated with the highest HRs, ranging from 4.81 to 6.34.nnnCONCLUSIONSnA high resting heart rate is independently associated with an increased risk of type 2 diabetes in women. The combinations of high heart rate with high BMI, WHR or BP level are associated with a substantially increased risk.

Urinary isoflavonoids and risk of coronary heart disease

BACKGROUNDnWhether soy food consumption may protect against coronary heart disease (CHD) remains controversial. No previous study has used biomarkers of soy intake in assessing the relationship between soy consumption and CHD. Biomarkers that reflect both intake and metabolism may be more informative than self-reports of dietary intake.nnnMETHODSnWe examined associations of urinary isoflavonoids, a biomarker of soy or soy isoflavone intake, with risk of CHD in a case-control study nested within two prospective cohort studies of Chinese adults in Shanghai. Cases were defined as subjects with no history of CHD at baseline who developed incident CHD during follow-up. Control subjects were randomly selected from those who remained free of CHD and matched to cases by sex, age, date and time of sample collection and antibiotic use. Baseline urinary isoflavonoids (daidzein, genistein, glycitein, equol, O-desmethylangolensin, dihydrodaidzein and dihydrogenistein) were compared between cases (n = 377) and control subjects (n = 753). Conditional logistic regression was used to evaluate the associations.nnnRESULTSnTotal urinary isoflavonoids were not associated with CHD in either women or men. However, urinary equol excretion showed a significant inverse association with CHD in women. The adjusted odds ratios (95% confidence intervals) for CHD across increasing quartiles of equol levels in women were 1 (reference), 0.61 (0.32, 1.15), 0.51 (0.26, 0.98) and 0.46 (0.24, 0.89) (P = 0.02 for trend).nnnCONCLUSIONSnOur study suggests for the first time that equol, a bioactive metabolite of soy isoflavone daidzein, may be inversely associated with risk of CHD in women.

Soy Food Intake and Risk of Lung Cancer: Evidence From the Shanghai Women's Health Study and a Meta-Analysis

The authors prospectively evaluated the association of soy food intake with lung cancer risk, overall and by tumor aggressiveness, and performed a meta-analysis of published data. Included in the analysis were 71,550 women recruited into the Shanghai Womens Health Study (Shanghai, China) in 1997-2000. Usual soy food intake was assessed at baseline and reassessed during follow-up through in-person interviews. During a mean follow-up period of 9.1 years, 370 incident lung cancer cases were identified; 340 patients were lifetime never smokers. After adjustment for potential confounders, soy food intake was inversely associated with subsequent risk of lung cancer (P(trend) = 0.004); the hazard ratio for the highest quintile of intake compared with the lowest was 0.63 (95% confidence interval: 0.44, 0.90). This inverse association appeared predominately among women with later age at menopause (P(interaction) = 0.01) and for aggressive lung cancer as defined by length of survival (<12 months vs. ≥12 months; P(heterogeneity) = 0.057). Meta-analysis of 7 studies conducted among nonsmokers found a summary relative risk of 0.59 (95% confidence interval: 0.49, 0.71) for the highest categories of soy or isoflavone intake versus the lowest. This study suggests that soy food consumption may reduce lung cancer risk in nonsmoking women, particularly for aggressive tumors, and its effect may be modified by endogenous estrogens.