An INSIG2 polymorphism affects glucose homeostasis in Sardinian obese children and adolescents.
Allelic variants of a single nucleotide polymorphism (SNP), rs7566605, located approximately 10 kb upstream of the INSIG2 gene have been found in association with body weight and with other clinical features related to obesity in some populations but not in others. Our objective was to test the association of this SNP in obese children and adolescents from the genetically isolated population of Sardinia. We tested the association of rs7566605 with body mass index (BMI) and with serum glucose and insulin concentrations and a surrogate measure of insulin resistance (HOMA-IR) in a cohort of 747 Sardinian obese children and adolescents. A case control analysis was performed using 548 ethnically-matched healthy controls. Allelic frequencies of the SNP were similar between patients and controls. Mean glucose and insulin concentration and mean HOMA-IR values were significantly higher in patients carrying the CC genotype than in the CG and GG carriers. In the patients with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT), allele C was significantly more frequent than in controls. Although INSIG2 polymorphisms do not consistently associate with BMI, the observation of an association with glucose concentration would support a role for this gene in the metabolic complications of obesity.
Zavattari
Patrizia
P
Servizio di Endocrinologia Pediatrica, Ospedale Microcitemico, ASL Cagliari, Italy.
Loche
Alberto
A
Civolani
Patrizia
P
Pilia
Sabrina
S
Moi
Loredana
L
Casini
Maria Rosaria
MR
Minerba
Luigi
L
Loche
Sandro
S
D000293:Adolescent; D001786:Blood Glucose; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D007558:Italy / Q000453:epidemiology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009765:Obesity / Q000150:complications / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism*
D001786:Blood Glucose; C467727:INSIG2 protein, human; D007328:Insulin; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins