Xh. Yuan et al., BETA(3)-ADRENERGIC RECEPTOR GENE POLYMORPHISM IS NOT A MAJOR GENETIC DETERMINANT OF OBESITY AND DIABETES IN JAPANESE GENERAL-POPULATION, Diabetes research and clinical practice, 37(1), 1997, pp. 1-7
To assess the contribution of a replacement of Trp at codon 64 of beta
(3)-adrenergic receptor by Arg to fat distribution and metabolic distu
rbances in Japanese general population, we examined the missense mutat
ion in 1122 persons consisting of 817 men aged 50.0 +/- 8.9 years and
305 women aged 50.8 +/- 8.5 years in Kyushu, Japan. The incidence of A
rg64 allele was 0.21; no age-dependent decrease of the allele frequenc
y was observed, suggesting that the mutation was not associated with e
arly mortality. The genotype was not significantly correlated with bod
y mass index or the thickness of visceral fat estimated by ultrasonogr
aphy. Glucose tolerance and glucose-induced insulin secretion were not
significantly different among subjects with Trp/Trp, Trp/Arg and Arg/
Arg at codon 64. Although in obese persons the ratio of heterozygotes
for the mutation tended to be higher in subjects with impaired glucose
tolerance than in subjects with normal glucose tolerance, the tendenc
y was not observed in non-obese persons. Furthermore none of 39 non-ob
ese individuals homozygous for the mutation was diabetic, whereas two
out of six obese homozygous persons were diabetic. These observations
suggest that the missense mutation may not be a main determinant of ob
esity in populations taking low fat/low energy Japanese-style diet and
it may not be deleterious at least in non-obese individuals. (C) 1997
Elsevier Science Ireland Ltd.