1.
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.
2.
MiRNAs as biomarkers of myocardial infarction: a meta-analysis.
Cheng, C, Wang, Q, You, W, Chen, M, Xia, J
PloS one. 2014;(2):e88566
Abstract
BACKGROUND Recent studies have demonstrated that acute myocardial infarction induces a distinctive miRNA signature, suggesting that miRNAs may serve as diagnostic markers. Although many studies have investigated the use of miRNAs in the detection of cardiac injury, some had small sample sizes (<100 patients) or reported different results for the same miRNA. Here, the role of circulating miRNAs for use as biomarkers of myocardial infarction is summarized and analyzed. METHODS AND RESULTS Medline, SCI, Embase, and Cochrane databases were searched up to January 2013 for studies that evaluated associations between miRNAs and myocardial infarction. Relevant publications were identified by searching for combinations of "myocardial infarction," "miRNAs," and their synonyms. Methodological quality was scored using a standardized list of criteria, and diagnostic performance was assessed using estimates of test sensitivity and specificity. These values were summarized using summary receiver-operating characteristic curves. Nineteen studies met the inclusion criteria: 15 studies reported sensitivity, specificity, and AUC, but 4 studies did not. Total miRNAs: sensitivity: 0.78 (95%CI: 0.77-0.80; P = 0.0000); specificity: 0.82 (95%CI: 0.80-0.83; P = 0.0000). miR-499: sensitivity: 0.88 (95%CI:0.86-0.90; P = 0.0000); specificity: 0.87 (95%CI:0.84-0.90; P = 0.0000). miR-1: sensitivity: 0.63 (95%CI:0.59-0.66; P = 0.0000); specificity: 0.76 (95%CI:0.71-0.80; P = 0.0000). miR-133a: sensitivity: 0.89 (95%CI:0.83-0.94; P = 0.0047); specificity: 0.87 (95%CI:0.79-0.92; P = 0.0262). miR-208b: sensitivity: 0.78 (95%CI:0.76-0.81; P = 0.0581); specificity: 0.88 (95%CI:0.84-0.91; P = 0.0000). The correlation between miRNAs and other diagnostic biomarkers of myocardial infarction was obvious. CONCLUSION MiRNAs, especially miR-499 and miR-133a, may be suitable for use as diagnostic biomarkers of myocardial infarction.