Adiponectin, as an important adipocytokine, plays a pivotal role in the regulation of insulin sensitivity and metabolism. It has been reported that circulating adiponectin levels were decreased in women with polycystic ovary syndrome (PCOS). However, the results remained inconsistent. In order to derive a more precise estimation of this relationship, a large meta-analysis was performed in this study. A comprehensive systematic electronic search was conducted in electronic databases PubMed, EMBASE, and Web of Science up to November 30, 2013. Pooled weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated to estimate the strength of the association. A meta-analysis technique was used to study 38 trials involving 1,944 PCOS women and 1,654 healthy controls. Overall pooled adiponectin levels in women with PCOS were significantly reduced compared with healthy controls (WMD -2.67, 95% CI -3.22 to -2.13; P = 0.000), yet with significant heterogeneity across studies (I(2) = 95.9%, P = 0.000). In subgroup analysis by HOMA-IR ratio and total testosterone ratio, inconsistent results were presented. No single study was found to affect the overall results by sensitivity testing. Meta-regression suggested that BMI might contribute little to the heterogeneity between including studies. Cumulative meta-analysis demonstrated the reliability and stability of the meta-analysis results. No evidence of publication bias was observed. Our meta-analysis suggested that circulating adiponectin levels in women with PCOS were significantly lower than those in healthy controls, which indicated that circulating adiponectin might play a role in the development of PCOS.
BackgroundCatechol-O-methyltransferase (COMT) is one of the most important enzymes involved in estrogen metabolism and its functional genetic polymorphisms may be associated with breast cancer (BC) risk. Many epidemiological studies have been conducted to explore the association between the COMT Val158Met polymorphism and breast cancer risk. However, the results remain inconclusive. In order to derive a more precise estimation of this relationship, a large meta-analysis was performed in this study.MethodsSystematic searches of the PubMed, Embase and Cochrane Library were performed. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of the association.ResultsA total of 56 studies including 34,358 breast cancer cases and 45,429 controls were included. Overall, no significant associations between the COMT Val158Met polymorphism and breast cancer risk were found for LL versus HH, HL versus HH, LL versus HL, recessive model LL versus HL+HH, and dominant model LL+HL versus HH. In subgroup analysis by ethnicity, source of controls, and menopausal status, there was still no significant association detected in any of the genetic models.ConclusionOur meta-analysis results suggest that the COMT Val158Met polymorphism may not contribute to breast cancer susceptibility.Virtual slidesThe virtual slides(s) for this article can be found here:
http://www.diagnosticpathology.diagnomx.eu/vs4806123577708417
Pregnancy rates decreased with the number of transplant failures. The intrauterine administration of hCG before FET significantly improved the pregnancy rates, especially after one and three or more implantation failures.
ObjectiveThe SNP309 polymorphism (T-G) in the promoter of MDM2 gene has been reported to be associated with enhanced MDM2 expression and tumor development. Studies investigating the association between MDM2 SNP309 polymorphism and endometrial cancer risk reported conflicting results. We performed a meta-analysis of all available studies to explore this association.MethodsAll studies published up to August 2013 on the association between MDM2 SNP309 polymorphism and endometrial cancer risk were identified by searching electronic databases PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature database (CBM). The association between the MDM2 SNP309 polymorphism and endometrial cancer risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).ResultsEight case–control studies with 2069 endometrial cancer cases and 4546 controls were identified. Overall, significant increase of endometrial cancer risk was found when all studies were pooled in the meta-analysis (GG vs. TT: OR = 1.464, 95% CI 1.246–1.721, P < 0.001; GG vs. TG + TT: OR = 1.726, 95% CI 1.251–2.380, P = 0.001; GG + TG vs. TT: OR = 1.169, 95% CI 1.048–1.304, P = 0.005). In subgroup analysis by ethnicity and HWE in controls, significant increase of endometrial cancer risks were observed in Caucasians and studies consistent with HWE. In subgroup analysis according to study quality, significant associations were observed in both high quality studies and low quality studies.ConclusionsThis meta-analysis suggests that MDM2 SNP309 polymorphism contributes to endometrial cancer susceptibility, especially in Caucasian populations. Further large and well-designed studies are needed to confirm this association.
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