Obesity and Risk for Brain/CNS Tumors, Gliomas and Meningiomas: A Meta-Analysis

<div><p>Objective</p><p>This meta-analysis aims to examine the association between being overweight/obese and risk of meningiomas and gliomas as well as overall brain/central nervous system (CNS) tumors.</p><p>Study Design</p><p>Potentially eligible publications were sought in PubMed up to June 30, 2014. Random-effects meta-analysis and dose-response meta-regression analysis was conducted. Cochran Q statistic, I-squared and tau-squared were used for the assessment of between-study heterogeneity. The analysis was performed using Stata/SE version 13 statistical software.</p><p>Results</p><p>A total of 22 studies were eligible, namely 14 cohort studies (10,219 incident brain/CNS tumor cases, 1,319 meningioma and 2,418 glioma cases in a total cohort size of 10,143,803 subjects) and eight case-control studies (1,009 brain/CNS cases, 1,977 meningioma cases, 1,265 glioma cases and 8,316 controls). In females, overweight status/obesity was associated with increased risk for overall brain/CNS tumors (pooled RR = 1.12, 95%CI: 1.03–1.21, 10 study arms), meningiomas (pooled RR = 1.27, 95%CI: 1.13–1.43, 16 study arms) and gliomas (pooled RR = 1.17, 95%CI: 1.03–1.32, six arms). Obese (BMI>30 kg/m²) females seemed particularly aggravated in terms of brain/CNS tumor (pooled RR = 1.19, 95%CI: 1.05–1.36, six study arms) and meningioma risk (pooled RR = 1.48, 95%CI: 1.28–1.71, seven arms). In males, overweight/obesity status correlated with increased meningioma risk (pooled RR = 1.58, 95%CI: 1.22–2.04, nine study arms), whereas the respective association with overall brain/CNS tumor or glioma risk was not statistically significant. Dose-response meta-regression analysis further validated the findings.</p><p>Conclusion</p><p>Our findings highlight obesity as a risk factor for overall brain/CNS tumors, meningiomas and gliomas among females, as well as for meningiomas among males.</p></div

Forest plot describing the association between overweight status /obesity and meningioma risk among females,.

<p>Apart from the overall analysis, the subanalyses on cohort (upper panels) and case-control (lower panels) studies are presented.</p

Flow chart describing the successive steps during the selection of eligible studies.

<p>Flow chart describing the successive steps during the selection of eligible studies.</p

Forest plot describing the association between overweight status/obesity and glioma risk among females.

<p>Apart from the overall analysis, the subanalyses on cohort (upper panels) and case-control (lower panels) studies are presented.</p

Characteristics of the included cohort studies.

<p>NR: not reported, NA: Not Applicable</p><p>Characteristics of the included cohort studies.</p

In Vitro Maturation in Women with vs. without Polycystic Ovarian Syndrome: A Systematic Review and Meta-Analysis

<div><p>Objective</p><p>To evaluate in vitro maturation (IVM) in sub-fertile women with polycystic ovarian syndrome (PCOS) undergoing in vitro fertilisation (IVF), by comparing outcomes with a control group of non-PCOS.</p><p>Study design</p><p>A search strategy was developed for PubMed and studies reporting rates of the following outcomes (live birth; clinical pregnancy; implantation; cycle cancellation; oocyte maturation; oocyte fertilization; miscarriage) between patients with PCOS, PCO and controls undergoing IVM were deemed eligible. The review was conducted in accordance to the PRISMA guidelines and included studies quality was assessed through the Newcastle-Ottawa Quality scale. ORs with their corresponding 95% CIs were calculated for the main analysis and subgroup analyses were performed for PCOS cases vs. controls and PCOS vs. PCO cases. Alternative analyses were performed for live birth and clinical pregnancy, based on cycles and on women. Subgroup analyses for FSH stimulation, hCG priming and type of procedure (IVF/ICSI) were undertaken for all meta-analyses encompassing at least four study arms. Random effects models were used to calculate pooled effect estimates.</p><p>Results</p><p>Eleven studies were identified. A total of 268 PCOS patients (328 cycles), 100 PCO patients (110 cycles) and 440 controls (480 cycles) were included in the meta-analysis. A borderline trend towards higher birth rates among PCOS patients emerged (pooled OR = 1.74, 95%CI: 0.99–3.04) mainly reflected at the subgroup analysis vs. controls. Clinical pregnancy (pooled OR = 2.37, 95%CI: 1.53–3.68) and implantation rates (pooled OR = 1.73, 95%CI: 1.06–2.81) were higher, while cancellation rates lower (pooled OR = 0.18, 95%CI: 0.06-0.47) among PCOS vs. non-PCOS subjects; maturation and miscarriage rates did not differ between groups, while a borderline trend towards lower fertilization rates among PCOS patients was observed.</p><p>Conclusion</p><p>The present meta-analysis provides preliminary evidence on the effectiveness of IVM as a treatment option when offered in sub-fertile PCOS women, as the latter present at least as high outcome rates as those in non-PCOS.</p></div

Results of the meta-analyses addressing the three comparisons (PCOS vs. controls; PCO vs. controls; PCOS vs. PCO) in the examined outcomes (Bold cells denote statistically significant associations).

<p>^§number of study arms</p><p>Results of the meta-analyses addressing the three comparisons (PCOS vs. controls; PCO vs. controls; PCOS vs. PCO) in the examined outcomes (Bold cells denote statistically significant associations).</p

PRISMA Flow Diagram of the studies.

<p>PRISMA Flow Diagram of the studies.</p

Description of cycle and outcome parameters.

<p>Footnotes:</p><p>N/A: Not Applicable; NR: Not Reported</p><p>IVF: In Vitro Fertilisation; ICSI: Intracytoplasmic sperm injection; PGD: Pre-implantation genetic diagnosis; ART: Assisted reproductive technology; ESHRE/ASRM: European Society of Human Reproduction and Embryology (ESHRE) and the American Society for Reproductive Medicine (ASRM); HEPES buffer: N-(2-hydroxyethyl) piperazine-N'-2-ethanesulfonic acid; TCM 199: tissue culture medium 199; EMEM: Eagle's minimal essential medium; LH: Luteinizing hormone; FSH: Follicle stimulating hormone; HCG: Human chorionic gonadotropin; ET: Embryo transfer.</p><p>Description of cycle and outcome parameters.</p

Characteristics of included studies.

<p>N/A: Not Applicable; NR: Not Reported</p><p>Characteristics of included studies.</p