Different pattern of association of paraoxonase Gln192->Arg polymorphism with sporadic late-onset Alzheimer’s disease and coronary artery disease.

The paraoxonase (PON1) Gln192 --> Arg polymorphism was examined in a group of sporadic late-onset Alzheimer's disease (AD) patients, in a group of coronary artery disease (CAD) patients, and in normal subjects. The AD sample showed a PON1 *R allele frequency significantly lower than the control group (0.225 vs. 0.281, P = 0.049). In the CAD patients the *R allele was more frequent than in the controls (0.230 vs. 0.213), though not significantly (P = 0.28). The odds ratios (OR) adjusted for age, gender, and APOE polymorphism by logistic regression analysis highlighted that in AD the PON1 RR genotype was significantly protective (OR = 0.41, 95% CI = 0.19-0.90; P = 0.025), whereas in CAD it appeared to be a significant risk factor (OR = 5.11, 95% CI = 1.09-23.9; P = 0.038) limited to younger patients.