Effects of a PPARG gene variant on obesity characteristics in Brazil

Abstract

The contribution of genetic factors to the development of obesity has been widely recognized, but the identity of the genes involved has not yet been fully clarified. Variation in genes involved in adipocyte differentiation and energy metabolism is expected to have a role in the etiology of obesity. We assessed the potential association of a polymorphism in one candidate gene, peroxisome proliferator-activated receptor-gamma (PPARGγ), involved in these pathways and obesityrelated phenotypes in 335 Brazilians of European descent. All individuals included in the sample were adults. Pregnant women, as well as those individuals with secondary hyperlipidemia due to renal, liver or thyroid disease, and diabetes, were not invited to participate in the study; all other individuals were included. The gene variant PPARG Pro12Ala was studied by a PCR-based method and the association between this genetic polymorphism and obesity-related phenotypes was evaluated by analysis of covariance. Variant allele frequency was PPARG Ala12 = 0.09 which is in the same range as described for European and European-derived populations. No statistically significant differences were observed for mean total cholesterol, LDL cholesterol, HDL cholesterol, or triglyceride levels among PPARG genotypes in either gender. In the male sample, an association between the PPARG Pro12Ala variant and body mass index was detected, with male carriers of the Ala variant presenting a higher mean body mass index than wild-type homozygotes (28.3 vs 26.2 kg/m 2 , P = 0.037). No effect of this polymorphism was detected in women. This finding suggests that the PPARG gene has a gender-specific effect and contributes to the susceptibility to obesity in this population.

Polymorphisms in LEPR, PPARG and APM1 genes: associations with energy intake and metabolic traits in young children

“…This sample has been originally designed to evaluate the impact of a nutritional intervention in the first year of life on the dietary quality of 3 to 4 years old children (20). Notwithstanding, it seems also to be a good source of information for genetic studies of the general southern Brazilian population, since allele and genotype frequencies observed in the present study were in the same range of those previously reported in European and European-derived populations, including the southern Brazilian population (5,7,10,14,40).…”

“…A previous study in the same population found that the same allele contributing to higher BMI in adult males (10). There is still no consensus in the literature on the association between Pro12Ala genotypes and metabolic profile.…”

“…Previous studies in the same population found an association of some of these SNPs in adults (7,10). Therefore it was our aim to investigate or confirm in children associations that have been proposed in Brazilian adults.…”

“…Several studies have reported an association of the Pro12Ala variant (rs1801282) with obesity, insulin sensitivity and risk of type 2 diabetes, but have yielded conflicting findings (10,11). In children, this SNP was associated with deficiency in energy storage and utilization, leading to reduced growth (12), lower BMI (13), and increased adiposity in girls (14).…”

Study on distribution of Pro12Ala SNP of PPAR gamma 2 gene in randomly sampled diabetic population from Guwahati city

“…Population study in Europe, Africa and some parts of Asia revealed that these SNP's may be responsible for obesity leading to type 2 diabetes. [26][27][28] But all the results were not affirmative. 29 In the previous studies, T2D subjects were found to possess a significantly higher frequency of the Pro12 allele risk than non-diabetic controls, thus providing a supportive role for PPARg2 in the genetic risk for type 2 diabetes in French Caucasians.…”