Short CommunicationQuantitative evaluation of common polymorphism (rs1801282) in the PPARγ2 gene and hypertension susceptibility
Highlights
► The PPARγ2 gene has been implicated in the etiology of hypertension. ► Eight studies (1865 cases and 1416 controls) for rs1801282 variant were identified. ► There was a significant association of PPARγ2 variant with hypertension risk.
Introduction
Hypertension is a serious public health issue worldwide, which affects 18% of Chinese adult population (Wu et al., 2008). Hypertension is a complex disease influenced by genes, environmental factors, and their interactions (Harrison et al., 2008). Twin and family studies have suggested that approximately of 20%–60% of blood pressure variation could be attributed to genetics (Kurtz and Spence, 1993). Up to now, many candidate genes have been reported to be implicated in the regulation of blood pressure and the susceptibility of hypertension. In addition, several genome wide association studies also identified many susceptibility loci which were associated with BP and hypertension (Levy et al., 2009, Newton-Cheh et al., 2009).
Peroxisome proliferator-activated receptor-γ (PPARγ), a member of the nuclear hormone receptor superfamily, is highly expressed in adipocytes and regulates the transcription of many adipocyte-specific genes (Tontonoz et al., 1995). Several polymorphisms in the PPARγ gene have been reported, and rs1801282 (Pro12Ala) is most frequently investigated. This polymorphism was first identified to have a key role in the development of obesity, insulin resistance and type 2 diabetes (Yen et al., 1997). Subsequently, it had been studied as a candidate for susceptibility to hypertension and the results have been conflicting (Dong, 2009, Gao et al., 2010, Gouni-Berthold et al., 2005, Lu et al., 2008, Pan et al., 2007, Rodríguez-Esparragón et al., 2003, Shen and Ha, 2004, Zhang et al., 2005a).
Meta-analysis is a useful method to overcome the disadvantages of individual studies, thereby increasing the statistical power and the precision of effect estimates. In this study, we performed a meta-analysis to assess the association of rs1801282 polymorphism in the PPARγ gene with hypertension susceptibility.
Section snippets
Literature and search strategy
We searched the literature databases including PubMed, Embase, China National Knowledge Infrastructure and Wanfang Data. The search strategy to identify all possible studies involved the use of the following key words: (“Peroxisome proliferator-activated receptor-γ2” or “PPARγ2”) and (“variant” or “polymorphism”) and (“hypertension”). All relevant studies were limited to ones published in English or Chinese language. The reference lists of retrieved articles were hand-searched. If more than one
Characteristics of the studies
The literature search identified a total of 28 potentially relevant papers. Of these, 17 were excluded because of obvious irrelevance by reading the titles and abstracts. In addition, one study (Zhang et al., 2005b) was excluded because it was one duplicated publication; one study was excluded because it defined hypertension as systolic/diastolic blood pressure ≥ 130/85 mm Hg (Kim et al., 2007), and one study (Horiki et al., 2004) was excluded because it did not provide sufficient data for
Discussion
To our knowledge, this is the first meta-analysis which comprehensively assessed the association between rs1801282 polymorphism in the PPARγ2 gene and hypertension risk. In this study, both English and Chinese databases were searched to avoid the language and selection biases. The results indicated that PPARγ2 rs1801282 polymorphism Ala allele was associated with reduced hypertension risk among East Asians. However, no significant association was found among Europeans. It is possible that the
Authors' roles
Chibo Liu designed research/study. Yujun Wang and Chibo Liu performed research/ study, collected data, analyzed data, wrote the paper, reviewed/edited the manuscript.
Conflict of interest
The authors have declared that no conflict of interest exists.
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