In addition to reproductive factors, intake of fruits and protein, smoking, tea consumption, lifetime patterns of physical activity, and weight gain influenced the onset of menopause and/or reproductive span in Chinese women.

The association of contraceptive methods, including oral contraceptives (OC), intrauterine devices (IUD) and tubal sterilization (TS), with overall and site-specific cancer were prospectively investigated in a cohort of 66,661 Chinese women in Shanghai, 76.7% of whom used contraception. During a median follow-up time of 7.5 years, 2,250 women were diagnosed with cancer. Everuse of any contraceptive method was not associated with overall cancer risk [adjusted hazard ratio (HR adj ) 5 1.02, 95% CI, 0.92-1.12]. Use of any contraceptive method was associated with increased risk of rectal cancer (HR adj 5 1.68, 95% CI, 1.08-2.62) and reduced risk of thyroid cancer (HR adj 5 0.63, 95% CI, 0.38-1.04). Risk of gallbladder cancer increased with ever use of OC (HR adj 5 2.38, 95% CI, 1.26-4.49). IUD use was associated with a possible reduced risk of thyroid cancer (HR adj 5 0.64, 95% CI, 0.38-1.07). Longer duration of IUD use decreased risk for breast, thyroid and lung cancers. Ever having a TS was associated with increased uterine body cancer (HR adj 5 2.50, 95% CI, 1.47-4.25) and decreased risk of stomach cancer (HR adj 5 0.59, 95% CI, 0.39-0.91). We did not find any contraceptive method to be related to the risk of ovarian cancer but the analyses were based on few events. Although chance findings are a likely explanation for some of the associations found in our study, these findings suggest that various contraceptive methods or reproductive patterns may play a role in the etiology of cancer.

The results suggest that the F(2)-IsoP major metabolite 15-F(2t)-IsoP-M may be a more sensitive marker of endogenous oxidative stress status than are F(2)-IsoPs in the assessment of effects of antioxidants on age-related diseases.

Objective-To determine whether various levels of blood pressure (BP), particularly normal and high normal blood pressure or prehypertension predict cardiovascular mortality among urban Chinese women.Methods-We evaluated the impact of all measures of blood pressure on total mortality and stroke and coronary heart disease (CHD)-specific mortality in a population-based cohort study, the Shanghai Women's Health Study. Included in this analysis were 68,438 women aged 40 to 70 years at baseline for whom BP was assessed.Results-During an average of 5 years of follow-up, we identified 1,574 deaths from all causes, 247 from stroke, and 91 from CHD. Hypertension and higher levels of individual BP parameters including systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), and mean arterial pressure (MAP), were positively associated with all-cause, stroke, and CHD mortality (P trend <0.05 for all except for DBP and CHD mortality). Prehypertension (adjusted hazard ratio (HR adj ) =1.65; 95% CI, 0.98 2.78), particularly high normal BP (HR adj =2.34; 95% CI, 1.32-4.12), was associated with an increased risk of mortality from stroke. Hypertension accounted for 9.3% of mortality from all causes, 25.5% of mortality from stroke, and 21.7% mortality from CHD. High normal BP accounted for 10.8% of mortality from stroke. Isolated SBP also predicted stroke and CHD mortality.Conclusion-Hypertension is a significant contributor to mortality, particularly stroke and CHD mortality, among women in Shanghai. High normal BP is associated with high stroke mortality.

Recent evidence suggests that urinary F(2)-isoprostanes (F(2)-IsoPs) are more accurate markers of oxidative stress than other available biomarkers. Most previous studies used unmetabolized F(2)-IsoPs as a biomarker. Few previous studies measured 15-F(2t)-IsoP-M, a metabolite of one of the most common F(2)-IsoPs, 15-F(2t)-IsoP. Unlike 15-F(2t)-IsoP, 15-F(2t)-IsoP-M is not subject to autoxidation and renal production. To our knowledge, no study has compared the associations of age and body mass index (BMI) with F(2)-IsoPs to those with 15-F(2t)-IsoP-M. Urinary levels of F(2)-IsoPs and 15-F(2t)-IsoP-M were measured using gas chromatography-mass spectrometry for 845 healthy women aged 40-70 years. Both F(2)-IsoPs and 15-F(2t)-IsoP-M were elevated among smokers. The level of 15-F(2t)-IsoP-M increased with age, particularly after menopause, and with BMI. In contrast, F(2)-IsoPs decreased with age, regardless of menopausal status, and was not related to BMI. The association of 15-F(2t)-IsoP-M with age or menopausal status did not differ by BMI category, and the association with BMI was also independent of age or menopausal status. 15-F(2t)-IsoP-M appears to be a valuable biomarker of oxidative stress in age- and obesity-related diseases.

Vitamin D deficiency has been consistently associated with obesity. However, it is unclear whether vitamin D deficiency is the cause or consequence of obesity. We investigated this question by evaluating the association between genetic variants in vitamin D metabolism pathway genes and obesity-related traits. Using directly genotyped and imputed data from a genome-wide association (GWA) study of 6,922 women aged 25–70 years, we examined the association of 198 SNPs in vitamin D pathway genes (CYP27A1, CYP27B1, CYP24A1, CYP2R1, GC, and VDR) with body mass index (BMI) and body weight. Per allele beta (β) estimates were calculated for this association using linear regression models, controlling for age, square of age, menopausal status, and sample sets. Overall, only two SNPs (rs2248359 in CYP24A1 and rs10832313 in CYP2R1) had a nominally significant association with BMI and weight (P=0.02 for both) with no variation observed by menopausal status, physical activity, or dietary energy intake. None of the SNPs examined in the VDR gene were associated with BMI or weight. Our findings suggest that common genetic variations in vitamin D pathway genes do not play a major role in obesity among Chinese women.

Little is known about the association of circulating 25-hydroxyvitamin D (25[OH]D) and blood pressure (BP) parameters, and hypertension in non-Western populations that have not yet been exposed to foods fortified with vitamins and seldom use vitamin D supplements. A cross-sectional analysis of plasma 25(OH)D levels in association with BP measures was performed for 1460 participants (405 men and 1055 women, aged 40–75 years) of two large cohort studies in Shanghai. Multivariable linear and logistic regressions were conducted. Overall, the prevalence of vitamin D deficiency was 55.8% using NHANES/USA criteria and 29.9% using WHO criteria. The median plasma 25(OH)D level was 38.0 nmol/L for men and 33.6 nmol/L for women (P<0.01) among subjects who were not on antihypertensive drugs. Among men, BP parameters (systolic BP, diastolic BP, and MAP) were significantly and inversely associated with higher quintiles of 25(OH)D compared with the lowest quintile (Ptrend <0.05 for all). Vitamin D non-deficient status (WHO criteria) was inversely associated with hypertension (ORadj =0.29, 95% CI: 0.10–0.82). An inverse association was also found between hypertension and the highest quintile of 25(OH)D (ORadj =0.16, 95% CI: 0.04–0.65 for ≥50.6 nmol/L; Ptrend =0.02). Among women, no significant associations were found for BP parameters and hypertension. The present study shows that vitamin D deficiency is common among adults in urban China. Circulating 25(OH)D levels were inversely related to levels of individual BP parameters and hypertension among middle-aged and elderly men but not in women. More research is needed to investigate the potential gender differential associations.

Background-Evidence from some previous studies suggests that lipophilic antioxidants, particularly carotenoids, may reduce the risk of breast cancer. We prospectively investigated the associations of plasma levels of tocopherols, retinol, carotenoids with the risk of developing breast cancer among Chinese women.