Obesity risk associated with the K121Q polymorphism of the glycoprotein PC-1 gene.
BACKGROUND
Obesity is considered to be a multifactorial trait resulting from the combined influence of genetic and environmental determinants. Insulin resistance plays an important role in the development of obesity. Plasma-cell membrane differentiation antigene-1 (PC-1) inhibits insulin receptor signalling when overexpressed and thus causes insulin resistance. PC-1 gene polymorphism might be associated with adipocyte metabolism disturbance and energy imbalance. The purpose of this study was to determine whether K121Q polymorphism in PC-1 gene is involved in obesity susceptibility in Chinese Han population.


METHODS
The genotype of the polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism analysis for 338 unrelated subjects of Beijing, China. Their Body mass index (BMI), plasma glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL), free fatty acid (FFA) and insulin level were measured. Chi-square analyses were applied to test the significance differences in genotypic and allelic frequencies. Association studies were undertaken using the t-test and logistic regression analyses.


RESULTS
The obese had significantly higher frequency of KQ/QQ genotype or Q allele than non-obese in females (26.7% vs. 10.9%, p = 0.014 and 13.3% vs. 5.5%, p = 0.021). Significant elevation of insulin amongst the Q121 carrier women in obesity individuals and higher FFA level of Q121 carrier men in non-obese controls (BMI < or = 23 kg/m2) were observed. Binary logistic regression analysis revealed that PC-1 genotype together with higher glucose, total cholesterol, triglyceride and serum HDL were independently associated with the presence of obesity.


CONCLUSIONS
The observed genotype distributions revealed a significant association of PC-1 K121Q with obesity. PC-1 Q121 carriers are more likely to be insulin-resistant or get fatter in respect to KK subjects and carriers of the Q allele are at higher risk for the development of obesity in female.
Wan
C
C
Center for Human and animal Genetics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
Zhang
T
T
Wang
B
B
Han
Y
Y
Zhang
C
C
Zhang
Y
Y
Gong
H
H
Jin
F
F
Wang
L
L
D000328:Adult; D000368:Aged; D015992:Body Mass Index; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000235:genetics*; D010641:Phenotype; D010727:Phosphoric Diester Hydrolases / Q000235:genetics*; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D011755:Pyrophosphatases / Q000235:genetics*
D008055:Lipids; D010727:Phosphoric Diester Hydrolases; C065962:ectonucleotide pyrophosphatase phosphodiesterase 1; D011755:Pyrophosphatases