1.
Effect of soybean protein on blood pressure in postmenopausal women: a meta-analysis of randomized controlled trials.
Kou, T, Wang, Q, Cai, J, Song, J, Du, B, Zhao, K, Ma, Y, Geng, B, Zhang, Y, Han, X, et al
Food & function. 2017;(8):2663-2671
Abstract
The effect of soybean protein on blood pressure (BP) in postmenopausal women is controversial, so we aimed to conduct a systematic review and a meta-analysis of published randomized controlled trials (RCTs) to investigate whether supplementation with soy protein improves their blood pressure. PubMed and Embase were searched up to February 2016. Weighted mean differences were calculated for net changes in BP by using fixed-effect or random-effect models. Subgroup and meta-regression analyses were performed to clarify heterogeneity among the trials. A total of twelve trials (1551 postmenopausal women participants) were included in the present meta-analysis. The overall pooled estimates of the effect of soy protein indicated a significant effect on systolic blood pressure (SBP) (mean difference: -3.03 mmHg; 95% CI: -5.03, -1.02; P = 0.003) and diastolic blood pressure (DBP) (mean difference: -0.71 mmHg; 95% CI: -1.26, -0.16; P = 0.012). Subgroup analyses further demonstrated that soy protein intake ≥25 g d-1 significantly reduced BP, and the mean difference in SBP and DBP was -4.62 mmHg (95% CI: -8.42, -0.81; P = 0.04) and -1.63 mmHg (95% CI: -2.85, -0.41; P = 0.009), respectively. Soy isoflavone intake ≥100 mg d-1 had a better reduction effect both in SBP (-5.47 mmHg; 95% CI: -8.42, -2.51; P = 0.00) and DBP (-2.03 mmHg; 95% CI: -3.35, -0.72; P = 0.002). However, soy protein intake <25 g d-1 or soy isoflavone intake <100 mg d-1 had no such effects (P > 0.05). This meta-analysis suggests that ingestion of ≥25 g soy protein per day has BP-lowering effects, and the improvements in BP may be due to the isoflavones component of soy protein. More high-quality RCTs need to be carried out to confirm the present findings.
2.
A comprehensive evaluation of interaction between genetic variants and use of menopausal hormone therapy on mammographic density.
Rudolph, A, Fasching, PA, Behrens, S, Eilber, U, Bolla, MK, Wang, Q, Thompson, D, Czene, K, Brand, JS, Li, J, et al
Breast cancer research : BCR. 2015;(1):110
Abstract
INTRODUCTION Mammographic density is an established breast cancer risk factor with a strong genetic component and can be increased in women using menopausal hormone therapy (MHT). Here, we aimed to identify genetic variants that may modify the association between MHT use and mammographic density. METHODS The study comprised 6,298 postmenopausal women from the Mayo Mammography Health Study and nine studies included in the Breast Cancer Association Consortium. We selected for evaluation 1327 single nucleotide polymorphisms (SNPs) showing the lowest P-values for interaction (P int) in a meta-analysis of genome-wide gene-environment interaction studies with MHT use on risk of breast cancer, 2541 SNPs in candidate genes (AKR1C4, CYP1A1-CYP1A2, CYP1B1, ESR2, PPARG, PRL, SULT1A1-SULT1A2 and TNF) and ten SNPs (AREG-rs10034692, PRDM6-rs186749, ESR1-rs12665607, ZNF365-rs10995190, 8p11.23-rs7816345, LSP1-rs3817198, IGF1-rs703556, 12q24-rs1265507, TMEM184B-rs7289126, and SGSM3-rs17001868) associated with mammographic density in genome-wide studies. We used multiple linear regression models adjusted for potential confounders to evaluate interactions between SNPs and current use of MHT on mammographic density. RESULTS No significant interactions were identified after adjustment for multiple testing. The strongest SNP-MHT interaction (unadjusted P int <0.0004) was observed with rs9358531 6.5kb 5' of PRL. Furthermore, three SNPs in PLCG2 that had previously been shown to modify the association of MHT use with breast cancer risk were found to modify also the association of MHT use with mammographic density (unadjusted P int <0.002), but solely among cases (unadjusted P int SNP×MHT×case-status <0.02). CONCLUSIONS The study identified potential interactions on mammographic density between current use of MHT and SNPs near PRL and in PLCG2, which require confirmation. Given the moderate size of the interactions observed, larger studies are needed to identify genetic modifiers of the association of MHT use with mammographic density.
3.
Effects of exercise dose on endogenous estrogens in postmenopausal women: a randomized trial.
Friedenreich, CM, Neilson, HK, Wang, Q, Stanczyk, FZ, Yasui, Y, Duha, A, MacLaughlin, S, Kallal, C, Forbes, CC, Courneya, KS
Endocrine-related cancer. 2015;(5):863-76
Abstract
Exercise dose comparison trials with biomarker outcomes can identify the amount of exercise required to reduce breast cancer risk and also strengthen the causal inference between physical activity and breast cancer. The Breast Cancer and Exercise Trial in Alberta (BETA) tested whether or not greater changes in estradiol (E2), estrone, and sex hormone-binding globulin (SHBG) concentrations can be achieved in postmenopausal women randomized to 12 months of HIGH (300 min/week) vs MODERATE (150 min/week) volumes of aerobic exercise. BETA included 400 inactive postmenopausal women aged 50-74 years with BMI of 22-40 kg/m(2). Blood was drawn at baseline and 6 and 12 months. Adiposity, physical fitness, diet, and total physical activity were assessed at baseline and 12 months. Intention-to-treat analyses were performed using linear mixed models. At full prescription, women exercised more in the HIGH vs MODERATE group (median min/week (quartiles 1,3): 253 (157 289) vs 137 (111 150); P<0.0001). Twelve-month changes in estrogens and SHBG were <10% on average for both groups. No group differences were found for E2, estrone, SHBG or free E2 changes (treatment effect ratios (95% CI) from linear mixed models: 1.00 (0.96-1.06), 1.02 (0.98-1.05), 0.99 (0.96-1.02), 1.01 (0.95, 1.06), respectively, representing the HIGHMODERATE ratio of geometric mean biomarker levels over 12 months; n=382). In per-protocol analyses, borderline significantly greater decreases in total and free E2 occurred in the HIGH group. Overall, no dose effect was observed for women randomized to 300 vs 150 min/week of moderate to vigorous intensity exercise who actually performed a median of 253 vs 137 min/week. For total and free E2, the lack of differential effect may be due to modest adherence in the higher dose group.