Evidence of an influence of a polymorphism near the INSIG2 on weight loss during a lifestyle intervention in obese children and adolescents.
OBJECTIVE
Homozygotes for the C-allele of the single nucleotide polymorphism (SNP) rs7566605, located approximately 10 kb upstream of insulin-induced gene 2 (INSIG2), showed a slightly increased risk of becoming obese. The aim of this study was to analyze whether children homozygous for the C-allele lose less weight in an intervention than children with the GG- or GC-genotype.


METHODS
We genotyped rs7566605 in 293 obese children (mean age 10.8 years, 45% male, mean BMI 28.1 kg/m(2)) who presented for a 1-year intervention. The reduction of SD score (SDS) BMI was compared based on an intention-to-treat analysis between the children with different genotypes. Blood pressure, triglycerides, insulin and glucose concentrations, and total, HDL, and LDL cholesterol were measured before and after intervention.


RESULTS
After 1 year, obese children with the CC-genotype had reduced their SDS BMI to a lower extent than obese children with GC- or GG-genotypes (recessive model P = 0.007). There was no evidence for an association of rs7566605 with the cardiovascular risk factor profile (nominal P > 0.1).


CONCLUSIONS
CC-homozygotes at SNP rs7566605 in the vicinity of INSIG2 lost less weight in this lifestyle intervention. This finding further implicates this polymorphism in weight regulation.
Reinehr
Thomas
T
Vestische Hospital for Children and Adolescents, University of Witten/Herdecke, Dr. F. Steiner Str. 5, 45711 Datteln, Germany. t.reinehr@kinderklinik-datteln.de
Hinney
Anke
A
Nguyen
Thuy Trang
TT
Hebebrand
Johannes
J
D000293:Adolescent; D001521:Behavior Therapy; D002648:Child; D002664:Child Nutritional Physiological Phenomena; D005260:Female; D015438:Health Behavior; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008019:Life Style; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009765:Obesity / Q000235:genetics*; D011110:Polymorphism, Genetic; D012307:Risk Factors; D015431:Weight Loss / Q000235:genetics*
C467727:INSIG2 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins