Obesity, Type II diabetes and the β2 adrenoceptor gene Gln27Glu polymorphism in the Tongan population

Abstract

As there is a high prevalence of obesity in Tonga, we aimed to determine the distribution of the beta2 adrenoceptor gene Gln(27)Glu polymorphism and to assess its relevance to obesity and to Type II diabetes, known to be prevalent in that population. A random sample of 1022 individuals from Tonga were genotyped for the Gln(27)Glu polymorphism in the beta 2 adrenoceptor gene. To assess the prevalence of obesity we measured body-mass index (BMI), fat-free mass, percentage fat and waist-to-hip ratio (WHR). To assess glucose metabolism we measured HbA(1c), fasting blood glucose, fasting serum insulin, and 1- and 2-h glucose; we also measured serum lipid and creatinine levels. We found that 84% of the Tongan men and 93% of the women were overweight or obese (BMI > or = 25 kg/m(2)) and 15.1% had Type II diabetes. Genotype frequencies among the 1022 Tongans were: Gln/Gln 90.3% and Gln/Glu 9.6%; we found one Glu/Glu homozygote. The mean BMI (+/-S.D.) for men was not significantly different for those who were homozygous (30.2+/-5.4 kg/m(2)) or heterozygous (30.1+/-5.5 kg/m(2)) for the Gln allele; this was also true for women (33.7+/-6.2 kg/m(2) for homozygous and 34.0+/-5.6 kg/m(2) for heterozygous). The Glu allele was not associated with other measures of obesity or abnormal glucose metabolism in this generally overweight population. There is a unique frequency of the Gln/Glu beta 2 adrenoceptor polymorphism among Tongans. We found no association of the polymorphism with obesity measures or Type II diabetes-related variables in the Tongan population among whom we documented a high prevalence of obesity and Type II diabetes and a low frequency of the Glu allele.

Association of Codon 16 and Codon 27 β2‐Adrenergic Receptor Gene Polymorphisms with Obesity: A Meta‐analysis

“…• whites (all Europeans (6,8,9,10,12,14,16,18,(19)(20)(21)(22)(23)(24)(25) and the Anglo-Celtic Australian whites (7)). • Asians, Pacific Islanders, and American Indians (Japanese (4,5,11,26,27), Taiwanese Chinese (28), Koreans (29), Tongans (30), and Aymara American Indians (31)). • Americans (mixed races (13,32,33) from United States and Canada).…”

A functional SNP upstream of the beta-2 adrenergic receptor gene (ADRB2) is associated with obesity in Oceanic populations

“…10, 11 A meta-analysis for Arg16Gly and Gln27Glu showed that the 27Glu allele was a significant risk factor for obesity in Asians, Pacific Islanders, and Native Americans. 12 However, in the original study of the Tongan population (ie, Pacific Islanders) referred by the meta-analysis, 27Glu tended to be associated with obesity, but the association was not statistically significant, 13 implying questionable association in Oceanic populations. It is also the fact that few Oceanic populations have been investigated.…”

Using rapid assessment and response to operationalise physical activity strategic health communication campaigns in Tonga

“…Eight predominant themes classified under two key categories 28 of 'barrier' or 'benefit' to netball physical activity behavioural change were identified from the SSIs and FGDs. Themes emerging from the synthesis of stakeholder qualitative data were: (1) cultural issues; (2) gender discrimination; (3) socioeconomic factors; (4) domestic violence; (5) infrastructure issues; (6) training and/or capacity building issues; (7) human resource limitations; and (8) multisectoralism. Additional themes emerging from the barrier analysis of beneficiary groups included a lack of knowledge about the international seven-aside rules and more personalised accounts of jealousy, domestic violence perpetrated by partners and participant and partner substance use.…”

“…5 Tonga is among the top five countries in the world in terms of obesity, 6 with 84% of Tongan men and 93% of Tongan women classified as overweight or obese. 7 Trends in relation to youth are also alarming, with a study of [11][12][13][14][15][16] year olds finding that 36% of boys and 54% of girls were overweight or obese when examined against international standards. 8 As a result of these lifestyle factors, the incidence of associated chronic diseases, such as diabetes and hypertension, is increasing.…”