Study of the Trp(64)Arg Polymorphism of the beta(3)-adrenergic receptor inGreek women with gestational diabetes

OBJECTIVE - This study assessed whether the Trp(64)Arg polymorphism of the beta(3)-adrenergic receptor (beta(3)-AR), which has been associated with ob esity, insulin resistance, weight gain, and earlier onset of type 2 diabete s, is more frequent in women who develop gestational diabetes mellitus (GDM ) or whether it is associated with weight gain during pregnancy. RESEARCH DESIGN AND METHODS - A total of 311 Greek pregnant women (180 with GDM and 131 without GDM [control]) who underwent a 100-g oral glucose tole rance test (OGTT) in the third trimester of pregnancy were genotyped for th e beta(3)-AR Arg(64) polymorphism. Insulin levels were also determined duri ng the OGTT. RESULTS - The frequency of Trp(64)Arg heterozygotes in this population was similar to 7% and was similar in the GDM and control groups (6.7 vs. 6.9%) as well as in the obese (BMI greater than or equal to 27 kg/m(2)) and the n onobese (6.3 vs. 6.8%) subgroups. In the GDM group, BMI, fasting insulin re sistance index, and diastolic blood pressure were significantly higher in T rp(64)Arg carriers; these differences were no longer observed when obesity was considered. In the 4 subgroups (control Trp(64)Trp and Trp(64)Arg and G DM Trp(64)Trp and Trp(64)Arg), a highly significant trend was evident of an increase in the percentage of subjects with shorter height. CONCLUSIONS - The frequency of the Arg(64) allele in Greek pregnant women i s relatively rare compared with other ethnic groups and is probably not rel ated to the development of GDM or obesity. The observed tendency for shorte r body height in Arg(64) carriers merits further evaluation in larger popul ation samples.