Association of Leptin Gene -2548 G/A Polymorphism with Obesity: A Meta-Analysis

Abstract

Background: A common single-nucleotide polymorphism identified in the 5′-untranslated region of the leptin gene (LEP -2548 G/A polymorphism) may be associated with obesity, but the existing research findings are inconsistent, so we conducted this meta-analysis. Methods: Medline, Embase and ISI Web of Science databases were searched to identify relevant studies. Meta-analysis of the total and subgroup populations was conducted using allelic, additive, dominant and recessive models, and odds ratios and their 95% confidence intervals were calculated in a fixed-effect model if no heterogeneity (evaluated as I² statistic) existed. Otherwise, a random-effects model was adopted. Subgroup analysis was performed by ethnicity. Meta-regression and the HETRED analysis were used to explore the potential sources of between-study heterogeneity. Egger's test and influence analysis were conducted to evaluate the publication bias and study power, respectively. Results: The final selection enrolled 9 studies, including 2,988 subjects (1,372 obese subjects and 1,616 controls). No significant association was identified between the LEP -2548 G/A polymorphism and obesity for all genetic models in the overall population and Caucasians. We found a significant association with allelic, additive and dominant models for subjects of mixed race from South America. Notwithstanding, this significance should be treated cautiously for it is based on a rather small sample (788 involved subjects). Conclusions: In total, the combined analysis of data from current and published studies suggested that the LEP -2548 G/A polymorphism does not contribute to the development of obesity, despite the fact that a significant association exists in a small subgroup from South America. Further studies are needed to elucidate the relationship.

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“…Leptin is a small pleiotropic hormone composed of 167 amino acids playing a key role in energy balance, food intake, lipid utilization, immune and reproductive function (Friedman, ). Leptin was identified as the product of the obese ( ob ) gene in the mouse (Zhang et al., ); therefore, several studies focused on its crucial role for the regulation of body weight and appetite in humans and other mammals (Klok, Jakobsdottir, & Drent, ). It is well known that leptin acts on the hypothalamus, in particular on two populations of arcuate nucleus neurons in mammals (Pinto et al., ).…”

Prevalence of mutations in LEP, LEPR, and MC4R genes in individuals with severe obesity

“…Studies regarding the role of this polymorphism in obesity remains controversial; however, since its effect could be specific to an ethnicity (Zhang et al, 2014;Fujiwara et al, 2015), we evaluated this polymorphism for possible associations with obesity in Italian individuals.…”

Study of Ghrelinand LeptinHormones Changes in Obese Postmenopausal Patients

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