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


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National University of Athens, Athens, Greece.
Theodoros N
TN
Sergentanis
Second Department of Neurology, "Attikon" University Hospital, Medical School, National University of Athens, Athens, Greece.
Georgios
G
Tsivgoulis
Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National University of Athens, Athens, Greece.
Christina
C
Perlepe
Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National University of Athens, Athens, Greece.
Ioannis
I
Ntanasis-Stathopoulos
Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National University of Athens, Athens, Greece.
Ioannis-Georgios
IG
Tzanninis
Hôpital de Psychiatrie, Hôpitaux Universitaires de Genève, Geneva, Switzerland.
Ioannis N
IN
Sergentanis
Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National University of Athens, Athens, Greece.
Theodora
T
Psaltopoulou
D015992:Body Mass Index; D001932:Brain Neoplasms / Q000209:etiology; D016543:Central Nervous System Neoplasms / Q000209:etiology*; D005260:Female; D005910:Glioma / Q000209:etiology*; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000209:etiology*; D008579:Meningioma / Q000209:etiology*; D009765:Obesity / Q000150:complications*; D050177:Overweight / Q000150:complications; D012307:Risk Factors; D012737:Sex Factors