[Study on association between gestational diabetes mellitus and sulfonylurea receptor-1 gene polymorphism].
OBJECTIVE
To investigate allelic frequency of sulfonylurea receptor-1 (SUR1) in gestational diabetes mellitus (GDM) women of Han nationality in north China in order to find out susceptible gene associated with GDM, and to assess the association between SUR1 allele and body mass index (BMI) and secretion of insulin.


METHODS
Seventy cases of pregnant women were selected. It included 35 cases of pregnant women with GDM (GDM group), 35 cases of normal pregnant women (normal control group). Another 35 women patients with type 2 diabetes in the same period as T2DM group. By using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), we detected the distribution of SUR1 alleles frequency in all individuals of three groups. We also examined BMI, fasting insulin (INS(0)) and 2 h insulin levels (INS(120)).


RESULTS
There was significantly increased c alleles frequency of SUR1 in GDM and T2DM women compared with normal pregnancy (70.0%, 71.4% and 52.9%, P < 0.05). Also significantly increased A alleles frequency of SUR1 in GDM and T2DM women was found compared with normal pregnancy (41.4%, 44.3% and 24.3%, P < 0.05). In GDM group, women carrying cc genotype had a higher BMI [(29.2 +/- 5.6) kg/m(2)], INS(0) [(14.9 +/- 8.7) mU/L] and INS(120) [(40.2 +/- 12.1) mU/L] as compared with those in carriers of other genotypes (ct and tt) (all P < 0.05). Also they had a lower insulin sensitivity (HOMA-IR) (3.9 +/- 2.5) as compared with carriers of ct genotype. Women carrying AA genotype had a higher INS(0) as compared with carriers of other genotypes (AG and GG) [(15.4 +/- 3.2), (12.1 +/- 4.5) and (11.5 +/- 4.8) mU/L, both P < 0.05]. Logistic regression analysis showed there was relationship between SUR1 cc genotype and severity of GDM (P = 0.005, RR = 25.128).


CONCLUSIONS
There are -3t-->c and A/G polymorphism of SUR1 gene in the Han nationality. Alleles c of SUR1 are significantly implicated in the susceptibility to GDM. It suggests that the defect in SUR1 gene (cc and AA) may contribute to insulin hypersecretion, which might be the cause of increased body weight and decreased insulin sensitivity and genotype cc of SUR1 is connected with severe type of GDM. It might be the predictable index of GDM conversion to type 2 diabetes.
Niu
Xiu-min
XM
Department of Obstetrics and Gynecology, General Hospital of Tianjin Medical University, China.
Yang
Hua
H
Zhang
Hui-ying
HY
Li
Nai-jun
NJ
Qi
Xiao-mei
XM
Chang
Ying
Y
Chang
Zheng
Z
Zhang
Ying
Y
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000328:Adult; D044466:Asian People / Q000208:ethnology / Q000235:genetics; D016022:Case-Control Studies; D016640:Diabetes, Gestational / Q000208:ethnology / Q000235:genetics* / Q000378:metabolism; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007328:Insulin / Q000378:metabolism; D011110:Polymorphism, Genetic; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics*; D011247:Pregnancy; D011955:Receptors, Drug / Q000235:genetics*; D064233:Sulfonylurea Receptors; D055815:Young Adult
C577507:ABCC8 protein, human; D018528:ATP-Binding Cassette Transporters; D007328:Insulin; D024661:Potassium Channels, Inwardly Rectifying; D011955:Receptors, Drug; D064233:Sulfonylurea Receptors