Meta-Analysis of the INSIG2 Association with Obesity Including 74,345 Individuals: Does Heterogeneity of Estimates Relate to Study Design?
نویسندگان
چکیده
The INSIG2 rs7566605 polymorphism was identified for obesity (BMI> or =30 kg/m(2)) in one of the first genome-wide association studies, but replications were inconsistent. We collected statistics from 34 studies (n = 74,345), including general population (GP) studies, population-based studies with subjects selected for conditions related to a better health status ('healthy population', HP), and obesity studies (OB). We tested five hypotheses to explore potential sources of heterogeneity. The meta-analysis of 27 studies on Caucasian adults (n = 66,213) combining the different study designs did not support overall association of the CC-genotype with obesity, yielding an odds ratio (OR) of 1.05 (p-value = 0.27). The I(2) measure of 41% (p-value = 0.015) indicated between-study heterogeneity. Restricting to GP studies resulted in a declined I(2) measure of 11% (p-value = 0.33) and an OR of 1.10 (p-value = 0.015). Regarding the five hypotheses, our data showed (a) some difference between GP and HP studies (p-value = 0.012) and (b) an association in extreme comparisons (BMI> or =32.5, 35.0, 37.5, 40.0 kg/m(2) versus BMI<25 kg/m(2)) yielding ORs of 1.16, 1.18, 1.22, or 1.27 (p-values 0.001 to 0.003), which was also underscored by significantly increased CC-genotype frequencies across BMI categories (10.4% to 12.5%, p-value for trend = 0.0002). We did not find evidence for differential ORs (c) among studies with higher than average obesity prevalence compared to lower, (d) among studies with BMI assessment after the year 2000 compared to those before, or (e) among studies from older populations compared to younger. Analysis of non-Caucasian adults (n = 4889) or children (n = 3243) yielded ORs of 1.01 (p-value = 0.94) or 1.15 (p-value = 0.22), respectively. There was no evidence for overall association of the rs7566605 polymorphism with obesity. Our data suggested an association with extreme degrees of obesity, and consequently heterogeneous effects from different study designs may mask an underlying association when unaccounted for. The importance of study design might be under-recognized in gene discovery and association replication so far.
منابع مشابه
Common Genetic Variant of insig2 Gene rs7566605 Polymorphism Is Associated with Severe Obesity in North India
Background: Obesity is a very common disorder resulting from an imbalance between food intake and energy expenditure, and it has a substantial impact on the development of chronic diseases. The aim of this study was to examine the association of INSIG2 (rs7566605) gene polymorphism with obesity and obesity associated phenotypes in North Indian subjects. Methods: The variants were investig...
متن کاملMeta-analysis of Incidence of Brain Cancer Among Aircrew
Introduction: Previous studies on Brain and other Nervous System Cancers (BNSC) and aircrew have shown inconsistent results, possibly due to their relatively small sample sizes; therefore, the current study aimed to increase the precision of risk estimates.Methods: Systematic searches of PubMed and Embase for pertinent studies up to August 2016 were perfo...
متن کاملAssociation between Food Insecurity and Weight Disorders of Children and Adolescents in Iranian Population: A Systematic Review and Meta-Analysis
Background: The link between food insecurity and weight disorders of children or adolescents remains controversial. Therefore, this systematic review and meta-analysis aimed to clarify the association between food insecurity and weight disorders of children and adolescents in Iran. Methods: PubMed, ISI Web of Science, Scopus, Google Scholar, Magiran, and SID databases were searched up to August...
متن کاملPrevalence of obesity among Iranian female university students (2001-2017): A systematic review and meta-analysis
Abstract Introdution: The prevalence of obesity in the world has been rising and it has involved developing and developed countries. The study aimed to investigate the prevalence of obesity among Iranian female university students and the importance of preventing this problem through a systematic review and meta-analysis. Methods: The study was performed via meta-analysis method, and some rel...
متن کاملThe Association between GNB3 Gene Polymorphism and Obesity: A Systematic Review and Meta-Analysis
The association between Guanine Nucleotide Binding protein β protein polypeptide 3(GNB3) C825T polymorphism and obesity has recently been reported. However, the findings remain inconclusive. The aim of this systematic review and meta-analysis was to detect the relationship between GNB3 C825T polymorphism and obesity. Materials and Methods: Six electronic databases including Embase, Medlin...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 5 شماره
صفحات -
تاریخ انتشار 2009