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Background: Although statins deteriorate glucose metabolism, their glucose-lowering effects have emerged in some situations. Here, we assessed whether these effects are a consequence of statin's interaction with paraoxonase (PON)1 enzyme polymorphism. Methods: Adult Japanese type 2 diabetes patients (n = 3798) were enrolled in a cross-sectional study. We used Q192R polymorphism of the PON1 gene as a representative single-nucleotide polymorphism and focused on the effects of the wild-type Q allele, in an additive manner. For patients with and without statin therapy, the associations of this allele with fasting plasma glucose (FPG), HbA1c, C-peptide, HOMA2-%β, and HOMA2-IR were investigated separately using a linear regression model, and were compared between groups by testing interactions. Sensitivity analyses were performed using propensity score to further control the imbalance of characteristics between groups. Results: Among patients with statin therapy, there were linear associations of the number of Q alleles with decreased FPG and HbA1c and with increased serum C peptide and HOMA2-%β (all P < 0.01 for trends), while such associations were not observed among those without statin therapy. These differences were statistically significant only for serum C peptide and HOMA2-%β (P < 0.01 for interactions). These associations remained significant after multiple explanatory variable adjustment. Sensitivity analyses using propensity score showed broad consistency of these associations. Conclusions: Patients with the Q allele of the PON1 Q192R polymorphism who were treated with statins exhibited improvement in glucose metabolism, especially in insulin secretion, suggesting the importance of genotyping PON1 Q192R to identify those who could benefit from statin therapy. [ABSTRACT FROM AUTHOR]

Background: It is not clear which glucose measure is more useful in the assessment of atherosclerosis. We investigated the associations of hemoglobin A1c (HbA1c), glycated albumin (GA), 1,5-anhydroglucitol (1,5-AG), fasting plasma glucose (FPG), and 2-hour postload glucose (PG) with carotid intima-media thickness (IMT) in community-dwelling Japanese subjects. Methods: A total of 2702 subjects aged 40-79 years underwent a 75-g oral glucose tolerance test and measurements of HbA1c, GA, 1,5-AG, and carotid IMT by ultrasonography in 2007-2008. Carotid wall thickening was defined as a maximum IMT of >1.0 mm. The crude and multivariable-adjusted linear and logistic regression models were used to analyze cross-sectional associations between levels of glycemic measures and carotid IMT. Results: The crude average of the maximum IMT increased significantly with rising quartiles of HbA1c, GA, FPG, and 2-hour PG levels in subjects with and without glucose intolerance (GI), while no clear association was observed for 1,5-AG. After adjustment for other confounding factors, positive trends for HbA1c, GA, and FPG (all p for trend < 0.05), but not 2-hour PG (p = 0.07) remained robust in subjects with GI, but no such associations were found in those without GI. When estimating multivariable-adjusted β values for the associations of 1 SD change in glycemic measures with the maximum IMT in subjects with GI, the magnitude of the influence of HbA1c (β = 0.021), GA (β = 0.024), and FPG (β = 0.024) was larger than that of 2-hour PG (β = 0.014) and 1,5-AG (β = 0.003). The multivariable-adjusted odds ratios for the presence of carotid wall thickening increased significantly with elevating HbA1c, GA, and FPG levels only in subjects with GI (all p for trend < 0.001). Among subjects with GI, the area under the receiver operating characteristic curve significantly increased by adding HbA1c (p = 0.04) or GA (p = 0.04), but not 1,5-AG, FPG, or 2-hour PG, to the model including other cardiovascular risk factors. Conclusions: In community-dwelling Japanese subjects with GI, elevated HbA1c, GA, and FPG levels were significantly associated with increased carotid IMT, and HbA1c and GA provided superior discrimination for carotid wall thickening compared to 1,5-AG, FPG, and 2-hour PG, suggesting that HbA1c and GA are useful for assessing carotid atherosclerosis. [ABSTRACT FROM AUTHOR]