Relationship between variants of the leptin gene and obesity and metabolic biomarkers in Brazilian individuals

Abstract

Objective:The relationship between variants of the leptin gene (LEP) and obesity and metabolic biomarkers was investigated in Brazilian individuals. Subjects and methods: One-hundred-ten obese (BMI > 30 kg/m 2 ) and 100 non-obese individuals (145 women and 65 men, aged 49 ± 14 years) were randomly selected. Plasma leptin, glycemia, serum lipid measurements and LEP -2548G>A and 3'HVR polymorphisms were analyzed. Results: The LEP -2548GG genotype was associated with a 2.2% and 2.0% increase in BMI (p = 0.009) and plasma leptin (p = 0.031), respectively. 3'HVR I/II (classes I/I+I/II) genotypes contributed with 1.8% of BMI values (p = 0.046). LEP I/G combined genotypes (I/IGG, I/IGA and I/IIGG) were associated with obesity, and increased BMI, waist circumference, leptin and triglycerides (p < 0.05). These relationships were found in women (p < 0.05) but not in men. LEP I/G combined genotypes were not associated with hypertension, hyperglycemia, dyslipidemia and coronary artery disease. Conclusions: LEP I/G combined genotypes are associated with obesity-related metabolic biomarkers and phenotype in a gender-dependent manner. Arq Bras Endocrinol Metab. 2010;54(3):282-8 Keywords Leptin; gene polymorphism; obesity; metabolic biomarkers; plasma leptin rEsUMO Objetivo: A relação entre as variantes do gene da leptina (LEP) e obesidade e biomarcadores metabólicos foi investigada em indivíduos brasileiros. Sujeitos e métodos: Cento e dez indiví-duos obesos (IMC > 30 kg/m 2 ) e 100 não obesos (145 mulheres e 65 homens, idade 49 ± 14 anos) foram selecionados aleatoriamente. Leptina plasmática, glicemia, lípides séricos e polimorfismos LEP -2548G>A e 3'HVR foram analisados. Resultados: O genótipo -2548GG foi associado com aumento de 2,2% e 2,0% no IMC (p = 0,009) e leptina plasmática (p = 0,031), respectivamente, enquanto os genótipos 3´HVR I/II (classes I/I+I/II) contribuíram com 1,8% dos valores de IMC (p = 0,046). Os genótipos combinados LEP I/G (I/IGG, I/IGA e I/IIGG) foram associados com obesidade e IMC aumentado, circunferência abdominal, leptina e triglicérides aumentados (p < 0,05). Essas relações foram encontradas em mulheres (p < 0,05), mas não em homens. Os genótipos LEP I/G combinados não foram associados com hipertensão, hiperglicemia, dislipidemia e doença arterial coronariana. Conclusões: Genótipos combinados LEP I/G são associados com biomarcadores metabólicos e fenótipo de obesidade de forma gênero-dependente. Arq Bras Endocrinol Metab. 2010;54(3):282-8 Descritores Leptina; polimorfismo genético; obesidade; biomarcadores metabólicos; leptina plasmática

Relationship Between Leptin G2548A and Leptin Receptor Q223R Gene Polymorphisms and Obesity and Metabolic Syndrome Risk in Tunisian Volunteers

“…The allele frequency of the G2548A polymorphism observed in our study is in accordance with that of other studies (Le Stunff et al, 2000;Mammès et al, 2000;Walley et al, 2006;Hinuy et al, 2008Hinuy et al, , 2010Huuskonen et al, 2010) except for one population from Taiwan, where the G allele frequency was lower than the A allele (Wang et al, 2006).…”

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

“…The detailed characteristics of these studies are shown in table 1. In 9 articles published between 2006 and 2012, 1,372 obese subjects and 1,616 controls were involved from a wide range of regions including Europe [19,21,22,27], South America [18,23,25] and North Africa [24,26]. Of the selected studies, 6 related to a Caucasian population and 3 to a South American population (mixed race).…”

“…There were 2 studies in which the genotypes in the control group were not in HWE [26,27]. Two studies were performed by the same investigator [23,25], and it is not clear whether different individuals were genotyped or whether some individuals were counted twice (the author rejected our inquiry e-mail). Both studies were included in the final analysis, and the influence of a possible partial overlap on the overall OR was assessed by subgroup analysis after excluding the older one [23].…”

“…While most current published studies have failed to identify a significant association in various populations [18,19,20,21,22,23,24], 3 studies found that the current variant was significantly associated with the risk of obesity (defined as BMI ≥30) in subjects of mixed race (South America) [25] and Caucasians (Turkish and Tunisian) [26,27]. Additionally, while most pieces of evidence have indicated that the frequency of the GG genotype or G allele is higher in the obesity or overweight group compared to that of the control in various populations [16,25,28], Nieters et al [29] found a sharply contrasting outcome, i.e. that the homozygosity for the A allele is significantly associated with an increased risk of obesity.…”

Relationship of short tandem repeats flanking leptin-melanocortin pathway genes with anthropometric profile and leptinemia in Brazilian individuals

“…Obese (n = 100) and non-obese (110) Information on age, hypertension, hyperglycemia, coronary artery disease (CAD) investigated by coronary angiography, smoking and sedentary lifestyle were recorded, and data were described elsewhere (19). Measurements of BMI, waist circumference (WC), waist-to-hip ratio (WHR) were taken.…”