K121Q PC‐1 Gene Polymorphism Is Not Associated with Insulin Resistance in a Spanish Population

Objective : To investigate the effect of the K121Q plasma cell membrane glycoprotein (PC‐1) polymorphism on the components of the insulin resistance syndrome in a population‐based nationwide multicenter study in Spain. Research Methods and Procedures : The subjects of the study were 293 nonrelated adults (44.7% men and 55.3% women) ages 35 to 64 years randomly chosen from a nationwide population‐based survey on obesity and related conditions, including insulin resistance and cardiovascular risk factors. Obesity‐related anthropometric measurements included blood pressure, oral glucose tolerance test, lipid profile (total cholesterol, high‐density lipoprotein‐ and low‐density lipoprotein‐cholesterol, and triglycerides), plasma leptin, insulin levels by radioimmunoassay, and insulin resistance (homeostasis model assessment). K121Q PC‐1 genotypes were determined by restriction fragment‐length polymorphism‐polymerase chain reaction. Results : Overall Q allele frequency was 0.14, with no differences between obese and nonobese individuals (0.15 vs. 0.13). After adjustment for sex, age, BMI, and degree of glucose tolerance, the Q allele was associated with high plasma leptin and triglyceride levels, but not with insulin resistance. Discussion : The results showed that the K121Q PC‐1 polymorphism in the Spanish population has no significant impact on insulin sensitivity.