A common variant in the MTNR1b gene is associated with increased risk of impaired fasting glucose (IFG) in youth with obesity.
OBJECTIVE
To explore the role of MTNR1B rs10830963 and G6PC2 rs560887 variants in the pathogenesis of impaired fasting glucose (IFG) in obese adolescents.


METHODS
A total of 346 Caucasians, 218 African-Americans, and 217 Hispanics obese children and adolescents underwent an oral glucose tolerance test (OGTT) and 518 underwent the evaluation of insulin secretion by the oral minimal model (OMM). Also, 274 subjects underwent a second OGTT after 3.0 ± 2.1 years.


RESULTS
The MTNR1B rs10830963 variant was associated with higher fasting glucose levels and lower dynamic beta-cell response in Caucasians and Hispanics (P < 0.05) and conferred an increased risk of showing IFG to Caucasians (P = 0.05), African-Americans (P = 0.0066), and Hispanics (P = 0.024). Despite the association between the G6PC2 rs560887 and higher fasting glucose levels (P < 0.05), there was no association between this variant and IFG at baseline or at follow-up (all P > 0.10).


CONCLUSIONS
It has been shown for the first time in obese youth that the MTNR1B variant is associated with an increased risk of IFG.
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Endocrinology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China.
Chao
C
Zheng
Chiara
C
Dalla Man
Claudio
C
Cobelli
Leif
L
Groop
Hongyu
H
Zhao
Allen E
AE
Bale
Melissa
M
Shaw
Elvira
E
Duran
Bridget
B
Pierpont
Sonia
S
Caprio
Nicola
N
Santoro
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000293:Adolescent; D001741:Black or African American / Q000235:genetics; D001786:Blood Glucose / Q000235:genetics*; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics; D005215:Fasting / Q000378:metabolism; D005260:Female; D006630:Hispanic or Latino / Q000235:genetics; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D063766:Pediatric Obesity / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011236:Prediabetic State / Q000235:genetics*; D044123:Receptor, Melatonin, MT2 / Q000235:genetics*; D044465:White People / Q000235:genetics
D048868:Adaptor Proteins, Signal Transducing; D001786:Blood Glucose; D007328:Insulin; C573871:MTNR1B protein, human; D044123:Receptor, Melatonin, MT2