The frequency of Trp64Arg polymorphism of the β3-adrenergic receptor gene in healthy and obese Hungarian children and its association with cardiovascular risk factors

Abstract

Objective: To estimate the frequency of Arg64 allele of the b 3 -adrenergic receptor (3-BAR) gene in healthy (H) and obese (O) Hungarian children, and to look for possible associations between this polymorphism and some clinical and metabolic characteristics of obese children. Patients/methods: In all, 147 healthy (male: 68) and 295 obese (male: 168) children were examined. The average age of the children in the two groups was 12.471.7 vs 12.673.2, respectively. Exon 1 of 3-BAR was amplified by polymerase chain reaction and the fragments were digested with BstN1. In obese children, oral glucose tolerance test was carried out and blood pressure (BP) was checked. Results: The frequency of Trp64Arg polymorphism in normal and obese Hungarian children was similar (H vs O: n ¼ 14/9.5% vs n ¼ 35/11.8%). Obese children carrying the Arg64 allele (n ¼ 35, male: 23) were compared to randomly chosen, obese children without the Arg64 allele (n ¼ 35, male: 20). A significant difference was found between the body weight (81.2723.2 vs 75.6717.7 kg; mean7s.d.; Po0.01), body fat (38.873.9 vs 36.572.3%; mean7s.d.; Po0.05), mean fasting insulin levels (31.4716.7 vs 16.977.6 mIU/ml; Po0.001) and mean systolic BP values (125.2710.1 vs 114.578.3 mmHg; Po0.001) of the two obese groups. Conclusions: The frequency of Trp64Arg polymorphism was similar in Hungary as compared to other European countries. Although the prevalence of this polymorphism was similar in H and O children, the presence of Arg64 allele seems to be associated with increased adiposity, elevated systolic BP and higher fasting insulin levels.European Journal of Clinical Nutrition (2005) 59, 955-959.

Visceral fat accumulation and metabolic syndrome in children: the impact of Trp64Arg polymorphism of the beta3‐adrenergic receptor gene

“…Moreover, in postmenopausal Polish women, the frequency of MS was reported to be higher (22%) in women with the Trp64Arg polymorphism than without (14%) . In children, only a few previous studies have reported significant associations between Trp64Arg polymorphism and high blood pressure, high insulin and HOMA‐IR or low HDL‐C . No previous studies have assessed the relationship between Trp64Arg polymorphism and all of the MS components.…”

“…Because ADRB3 is mainly expressed in fat cells of VF tissue , dysfunction in this receptor may result in a predisposition to impaired lipolysis, resulting in VF obesity . Trp64Arg polymorphism in the ADRB3 gene has been reported to be significantly associated with whole body obesity, VF accumulation and other MS components or their cluster, both in adults and in children of various ethnic groups. In particular, Japanese people have higher frequencies of Trp64Arg polymorphism and VF accumulation, but less gynoid fat, than other ethnic populations.…”

Obesity and eating behaviour in children and adolescents: Contribution of common gene polymorphisms

“…In humans, the beta-3 adrenergic receptor is predominantly expressed in visceral adipose tissue (Krief et al, 1993). Notably, the Arg allele of this SNP has been linked with increased BMI, adiposity and obesity in children (Arashiro et al, 2003;Endo et al, 2000;Erhardt et al, 2005;Ochoa et al, 2004;Park et al, 2005) supporting the evidence in adults Pierola et al, 2007), and the increased risk for obesity at this ADRB3 loci may be driven partly by an interaction effect of the PPARG SNP Pro12Ala Hsueh et al, 2001;Ochoa et al, 2004). Other studies in young children between the ages 4-10 years and in adolescents report no signifi cant effects of Trp64Arg variants on BMI, weight or height when this variant is examined in isolation (Cecil et al, 2007;Haworth et al, 2008a;Hinney et al, 1997;Kurokawa et al, 2003).…”

Pathophysiology of hypertension in obese children: a systematic review

“…The β 3 ‐adrenergic receptor is mainly present in visceral fat and is responsible for thermogenesis in brown adipose tissue. Obese children had significantly higher blood pressure and levels of insulin if they carried the Arg64 polymorphism when compared to obese children without the Arg64 polymorphism . Although another study did not find a significant difference between carriers of variations in the β 3 ‐adrenergic receptor gene, systolic and diastolic blood pressure were highest in Trp64Arg homozygote children .…”