Factors associated with all-cause mortality following endovascular abdominal aortic aneurysm repair.

Background: Knowledge of factors that influence all-cause mortality after endovascular abdominal aortic aneurysm repair (EVAR) could improve therapeutic strategies post-EVAR and thus patient prognosis. Our study aimed to evaluate the association between sociodemographic information, comorbidities, laboratory parameters, treatment, selected anatomical and genetic factors and all-cause mortality post-EVAR. Patients and methods: We reviewed all patients who had undergone elective EVAR for non-ruptured abdominal aortic aneurysm (AAA) between January 2010 and December 2019. AAA size (maximum diameter and volume) was measured using CT-angiography. Sac expansion was defined as at least 5 mm increase, sac regression as at least 5 mm decrease in the sac diameter determined at 36±3 months post-EVAR in relation to pre-EVAR AAA diameter. Adjustments were performed for age, hypertension, diabetes mellitus, dyslipidaemia, sex, smoking, number of lumbar arteries, patency of inferior mesenteric artery and number of reinterventions post-EVAR. Results: One hundred and sixty-two patients (150 men, 12 women) with a mean age of 72.6±7.3 years were included in the analysis. Pre-EVAR AAA diameter (HR 1.07; 95% CI 1.03 - 1.12; p=0.001), pre-EVAR AAA volume (HR 1.01; 95% CI 1.002 - 1.011; p=0.008), post-EVAR sac diameter (HR 1.06; 95% CI 1.03 - 1.10; p=0.000), post-EVAR sac volume (HR 1.01; 95% CI 1.002 - 1.011; p=0.006) and anticoagulation therapy (HR 2.46; 95% CI 1.18 - 5.14; p=0.019) were associated with higher mortality in multivariate analysis. Sac regression (HR 0.42; 95% CI 0.22 - 0.82; p=0.011), and treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) (HR 0.71; 95% CI 0.36 - 0.97; p=0.047) were associated with lower mortality. Conclusions: Greater pre- and post-EVAR diameter and volume, failure of sac regression and anticoagulation were associated with higher mortality post-EVAR. Reduced mortality was observed in patients treated with ACE inhibitors or ARBs, and in patients with AAA sac regression.

Higher preprocedural fibrinogen levels are associated with aneurysm sac regression after EVAR.

Background: The aim of our study was to determine the diameter of the aneurysm sac 24 months after endovascular abdominal aortic aneurysm repair (EVAR); to identify factors associated with sac regression, and to determine the impact of sac regression on all-cause mortality during long-term follow-up. Patients and methods: We conducted a retrospective review of prospectively collected data from patients treated with EVAR between January, 2010 and July, 2016. Sac regression was defined as at least 5 mm decrease in aneurysm diameter in relation to the preprocedural diameter seen on computed tomography angiography. Sociodemographic information, comorbidities, treatment, laboratory parameters, selected anatomical and genetic factors were all analysed to determine their impact on sac regression. Results: During the study period, 124 patients with mean age of 71.2 ± 7.2 years met the inclusion criteria. Sac regression was found in 45.2% of patients. Higher preprocedural fibrinogen was found in patients with sac regression in comparison with patients with stable sac or sac expansion (3.84 g/l vs 3.47 g/l; p = 0.028). In multivariate analysis after adjustment for age, hypertension, sex, smoking, dyslipidaemia, volume and percentage of intraluminal thrombus higher fibrinogen was associated with an increased probability of sac regression (OR 2.47; 95% CI 1.29-4.72; p = 0.006). Persistent type II endoleak was associated with significantly lower probability of sac regression in univariate and multivariate analysis after adjustment for age, hypertension, sex, smoking and dyslipidaemia (OR 0.26; 95% CI 0.10-0.66; p = 0.004). Higher age was a significant predictor of sac regression in multivariate analysis after adjustment for hypertension, sex, smoking and dyslipidaemia (OR 1.07; 95% CI 1.02-1.14; p = 0.012). No difference was found between patient subgroups with and without sac regression in all-cause mortality during follow-up. Conclusions: Higher preprocedural fibrinogen, absence of persistent type II endoleak and higher age were predictive factors of aneurysm sac regression post-EVAR.

Association of JAG1 gene polymorphism with systemic blood pressure in patients with obstructive sleep apnea: a prospective cohort study.

AIM: To assess the effects of single nucleotide polymorphisms (SNPs) on blood pressure control in patients with obstructive sleep apnea (OSA). METHODS: This prospective observational cohort study, conducted between 2004 and 2014, examined the associations of SNPs of JAG1, GUCY1A3-GUCY1B3, SH2B3, and NPR3-C5orf23 genes with systolic and diastolic blood pressure (SBP, DBP) in 1179 adults evaluated for OSA with overnight polysomnography. Genotyping was performed by unlabeled probe melting analysis. RESULTS: The patients were predominantly male (69.6%, mean age 52±11 years, apnea-hypopnea index 34±31 episodes/h). Only JAG1 genotype was associated with SBP and DBP: compared with AA homozygotes, G allele carriers (pooled GG and AG genotype) had significantly higher morning SBP (132±19 vs 129±18 mm Hg; P=0.009) and morning and evening DBP (85±11 vs 83±10 mm Hg, P=0.004; 86±10 vs 84±10 mm Hg, P=0.012, respectively); the differences remained significant after the correction for multiple SNPs testing. In multivariate analyses, oxygen desaturation index and JAG1 genotype independently predicted morning SBP (P=0.001, P=0.003, respectively) and DBP (P<0.001, P=0.005, respectively), and evening SBP (P=0.019, P=0.048, respectively) and DBP (P=0.018, P=0.018, respectively). CONCLUSION: This is the first replication study of the SNPs recently linked to arterial hypertension in general population by genome-wide association studies. Our findings suggest that JAG1 genotype is related to blood pressure control in OSA: G allele was associated with higher morning and evening SBP and DBP.

Risk allele of gene variant rs6584389 is associated with increased intima-media thickness in patients with type 2 diabetes.

BACKGROUND: Genome-wide association studies identified several gene variants associated with peripheral arterial disease (PAD). Among them, rs6584389 A>C was significantly associated with PAD defined by decreased ankle-brachial index (ABI). The aim of this study was to investigate whether the rs6584389 variant is also associated with the earlier stages of atherosclerosis assessed by intima-media thickness (IMT) or pulse-wave velocity (PWV) in clinically asymptomatic subjects with type 2 diabetes (T2DM), a group of patients with a high cardiovascular risk. PATIENTS AND METHODS: In total, 111 patients with T2DM (56 females, 55 males) with a mean age 63.0 ± 9.1 years were consecutively included in the study. IMT was measured by ultrasound using 7 MHz linear transducer. PWV was measured using a piezoelectric method. Genotyping for rs6584389 was performed by PCR-HRMA method. RESULTS: The carriers of the risk C-allele of rs6584389 variant had significantly higher mean left-side IMT (AA: 0.67 ± 0.12, AC 0.77 ± 0.21, CC 0.78 ± 0.22 mm; p = 0.04). In multiple linear regression analysis, rs6586389 genotype was significantly associated with all measured IMT parameters. The presence of each risk C-allele predicted an increase in left-side IMT by 0.056 mm (p = 0.017), right-side IMT by 0.053 mm (p = 0.039), average IMT by 0.054 mm (p = 0.023), and maximal IMT by 0.058 mm (p = 0.021). Age and HbA1c levels were also significantly associated with increased IMT in all multivariate models. CONCLUSIONS: Gene variant rs6584389 A>C near to PAX2 gene was associated with increased carotid IMT in patients with type 2 diabetes independently of the other main risk factors for atherosclerosis.

A pharmacogenetic association between a variation in calpain 10 (CAPN10) gene and the response to metformin treatment in patients with type 2 diabetes.

PURPOSE: The aim of the present study was to investigate possible associations of the single-nucleotide variants in six genes encoding the key molecules mediating the metformin pharmacodynamic effect with the response to treatment with metformin in patients with type 2 diabetes. METHODS: One hundred forty-eight drug-naïve patients with type 2 diabetes were included in the study. PRKAA1 rs249429, STK11 rs741765, PCK1 rs4810083, PPARGC1A rs10213440, HNF1A rs11086926, and CAPN10 rs3792269 variants were genotyped. The outcomes of the study were treatment success defined by achieving HbA1c <7 % and absolute reduction in HbAlc after 6-month metformin therapy. The relationships between genotypes and outcomes were evaluated in multivariate logistic and linear models. The level of statistical significance after Bonferroni correction was predefined as p<0.0083. RESULTS: The minor G-allele of CAPN10 rs3792269 A>G polymorphism was significantly associated with less treatment success with an odds ratio of 0.27 (95 % CI 0.12-0.62, p=0.002) per variant allele. When the reduction in HbA1c was analyzed as a quantitative trait, G-allele was nominally associated with a smaller reduction in HbA1c (per allele ß=-0.26, 95 % CI -0.50 to -0.02, p=0.032). The reduction in HbA1c in minor allele carriers (24 % of study population) was smaller by 0.3 % in comparison with the major allele homozygotes. CONCLUSIONS: The present study provides the first observation of an association between a variant in CAPN10 gene and the response to metformin therapy in patients with type 2 diabetes. This observation needs to be replicated in further studies in different populations.

Closed tube method for rapid screening of IL28B polymorphisms involved in response to hepatitis C treatment.

BACKGROUND & AIM: Hepatitis C is a liver disease caused by the hepatitis C virus. Interferon and ribavirin combination therapy has been a standard treatment of chronic hepatitis C. But only about 50% of patients have positive response to treatment and achieve so called sustained virological response. Recent studies indicate association of several single nucleotide polymorphisms near IL28B gene and response of hepatitis C patients to combined interferon/ribavirin treatment. In this study, rapid, specific and cost-effective small amplicon genotyping method for the two clinically important polymorphisms, rs12979860 C > T and rs8099917 T > G, near the IL28B gene is described. METHODS: The distribution of genotypes of 181 HCV-uninfected Slovak Caucasians was analyzed using this novel method, based on a real-time melting analysis of the small amplicon. RESULTS AND CONCLUSIONS: The frequency of wild-type (TT) homozygotes for rs8099917 was 66.30%, frequency of heterozygotes (TG) was 30.94% and we found only 2.76% subjects homozygous for risk G allele (allelic frequencies: T = 81.77%, G = 18.23%) were found. The frequency of wild-type genotype (CC) for rs12979860 was 49.72%, frequencies of heterozygous (CT) and risk-allele homozygous genotypes (TT) were 39.78% and 10.50%, respectively (allele frequencies: C = 69.61%, T = 30.39%). Statistically significant differences in the distribution of the alleles between the men and the women were not found. The novel method developed in our laboratory proved to be simple and highly customizable.

Positive association between calcium channel blocker treatment and persistent type II endoleak.

BACKGROUND: Type II endoleaks are the most common complication occurring after endovascular abdominal aortic aneurysm repair (EVAR). The aims of our study were to evaluate the impact of persistent type II endoleak on sac dynamics post-EVAR, and to study the association between non-anatomical factors including polymorphisms associated with abdominal aortic aneurysm (AAA) and persistent type II endoleak. METHODS: The cohort comprises 210 patients undergoing EVAR between January 2010 and December 2018. A persistent type II endoleak was defined as any type II endoleak lasting longer than six months and included also a type II endoleak diagnosed after six months or more post-EVAR during the 36-month follow-up period confirmed with CT-angiography. Anteroposterior AAA maximum diameter and AAA volume were measured pre-EVAR and 36 months post-EVAR using CT-angiographic pictures. Sac progression was defined as at least 5 mm increase, sac regression as at least 5 mm decrease in the sac diameter in relation to the preprocedural diameter. Sociodemographic information, comorbidities, treatment, laboratory parameters, selected anatomical and genetic factors were all analyzed to determine their impact on persistent type II endoleak. The adjustments included age, hypertension, diabetes mellitus, dyslipidemia, sex, smoking in multivariate analyses. When postprocedural diameter and volume were evaluated, adjustments included also preprocedural diameter/volume. RESULTS: After exclusion, 178 patients with mean age 72.4±7.60 years remained for analysis. Persistent type II endoleak was found in 27.5% of patients (N.=49) and 2.94-times increased risk of sac progression in multivariate analysis (P=0.033). In multivariate analysis, AAA diameter in patients with persistent type II endoleak was 4.31 mm greater than in patients without (B=4.31; P=0.014); and its presence was also associated with 22.0 cm3 greater sac volume (B=22.0; P=0.034) compared to patients without persistent type II endoleak. Treatment with calcium channel blockers increased risk of persistent type II endoleak 2.11-times in multivariate analysis (OR=2.11; 95% CI: 1.05-4.25; P=0.037). No association between persistent type II endoleak and selected polymorphisms associated with AAA and other observed factors were found. CONCLUSIONS: Risk of persistent type II endoleak was more than doubled in patients taking calcium channel blockers. Patients with persistent type II endoleak had greater anteroposterior sac diameter and sac volume compared to patients without persistent type II endoleak.

Effect of NAT2 gene polymorphism on bladder cancer risk in Slovak population.

N-acetyltransferase 2 (NAT2) is phase II enzyme with major roles in catalyzing the detoxification of aromatic amines, which are known risk factors for bladder cancer, and are ubiquitously present in the environment. We assessed the association between common polymorphisms in NAT2 gene and the risk of bladder cancer in 90 Slovak patients and 274 ethnicity-matched healthy controls. Effect modifications by smoking, age and gender were also evaluated. Overall, NAT2 slow acetylation was associated with significantly increased risk of bladder cancer (OR = 1.90; 95% CI, 1.15-3.16). In stratified analyses by age and gender, the elevated risk conferred by slow acetylator genotype was evident in older individuals (OR = 3.55; 95% CI, 1.77-7.35) and males (OR = 4.65; 95% CI, 1.68-16.10), with further increasing in NAT2*5B/*6A genotype carriers. Smoking was confirmed to be important risk factor, moreover, the risk was markedly increased in smokers with NAT2 slow acetylator genotype, and NAT2*5B/*6A carriers especially. In summary, these findings are consistent with previous literature suggesting that individual susceptibility to bladder cancer may be modulated by NAT2 polymorphisms, particularly in interaction with relevant environmental exposures such as smoking.

Variation in KCNQ1 is associated with therapeutic response to sulphonylureas.

BACKGROUND: We aimed to analyse quantitative effects of treatment with sulphonylurea in addition to metformin on parameters of glycemic control in relation to KCNQ1 genotypes, and to identify factors predictive for the response to sulphonylurea treatment. MATERIAL/METHODS: Effect of 6-month sulphonylurea therapy in addition to metformin on glycemic control according to KCNQ1 genotypes was evaluated in 87 patients with type 2 diabetes who failed to achieve glycemic control on metformin monotherapy. KCNQ1 rs163184 (T>G) polymorphism was determined by real-time PCR with melting analysis of unlabeled probe. RESULTS: The reduction in fasting plasma glucose (ΔFPG) after 6-month sulphonylurea therapy significantly differed among 3 KCNQ1 genotype groups (ANOVA, p=0.017). In a recessive genetic model, carriers of the T-allele (TT+TG) achieved significantly lower FPG levels in comparison with patients with the GG genotype (6.95 ± 0.13 vs. 7.50 ± 0.21 mmol/L, p=0.033). Consequently, ΔFPG was significantly higher in the TT+TG group compared to the GG group (1.58 ± 0.13 vs. 1.04 ± 0.18 mmol/L, p=0.016). In multiple linear regression analysis KCNQ1 genotype (p=0.016) and baseline FPG (p<0.001) were the only significant independent predictors of ΔFPG (R2=0.48). CONCLUSIONS: Our results suggest that the magnitude of FPG reduction after 6-month sulphonylurea treatment in addition to metformin in patients with type 2 diabetes is related to the variation in KCNQ1. The FPG response to sulphonylureas was significantly lower in carriers of the risk GG genotype.

Genetic variants associated with glycemic response to treatment with dipeptidylpeptidase 4 inhibitors.

Aim: We examined associations of eight SNPs in/near seven candidate genes with glycemic response to 6 month treatment with DPP4 inhibitors. Patients & methods: 206 patients with type 2 diabetes (116 men and 90 women) were treated with sitagliptin or vildagliptin (both 100 mg/day) in combination with metformin or metformin/sulphonylurea over 6 months, and the reduction in glycated hemoglobin (HbA1c) was measured. Results: Rs6923761 in GLP1R was significantly associated with a reduction in HbA1c (adjusted p = 0.006). Homozygotes for the minor A allele had smaller reduction in HbA1c by 0.4% (4 mmol/mol) than the G allele carriers (p = 0.016). Conclusion: The missense variant rs6923761 in the GLP1R gene was associated with a smaller glycemic response to 6 month gliptin therapy in diabetic patients of central European origin.

Beta2-adrenergic receptor haplotype and bronchodilator response to salbutamol in patients with acute exacerbations of COPD.

BACKGROUND: The role of the beta2-adrenergic receptor (ADRB2) genotype in patients with chronic obstructive pulmonary disease (COPD) is unclear. In patients with acute exacerbations of COPD (AECOPD), we assessed the role of ADRB2 haplotypes in morning lung function and in the bronchodilator response to salbutamol. MATERIAL/METHODS: In 107 patients with AECOPD, polymorphisms in the amino acid position 16 (Arg16/Gly16) and 27 (Gln27/Glu27) of the ADRB2 gene were assessed by allele-specific polymerase chain reaction, identifying 31 subjects with the Gly16/Glu27-negative and 76 with the Gly16/Glu27-positive ADRB2 haplotype. Pulmonary function and bronchodilator response to salbutamol were assessed using bodyplethysmography. RESULTS: Forced expiratory volume in 1 second (FEV1) and peak expiratory flow (PEF) were significantly higher in the Gly16/Glu27-negative compared to the Gly16/Glu27-positive haplotype group at baseline (49.7+/-2.9% vs 42.4+/-1.8% predicted, P=0.037; 44.0+/-2.2% vs 36.4+/-1.6% predicted, P=0.008, respectively). FEV1, PEF, and forced vital capacity (FVC) increased from baseline to after salbutamol treatment in both the Gly16/Glu27-negative and the Gly16/Glu27-positive ADRB2 haplotype groups (P<0.001 for all comparisons). Values for FEV1 and PEF after administration of the bronchodilator were significantly higher in the Gly16/Glu27-negative haplotype group compared with the Gly16/Glu27-positive haplotype group (P=0.030 and P=0.034, respectively). No differences were observed in DeltaFEV1, DeltaPEF, or DeltaFVC after bronchodilation between the 2 ADRB2 haplotype groups (12.2+/-1.8% vs 14.5+/-1.5% predicted, P=0.393; 12.2+/-3.3% vs 20.8+/-3.2% predicted, P=0.117; 9.1+/-2.3% vs 10.4+/-1.9% predicted, P=0.707, respectively). CONCLUSIONS: The present findings suggest that the ADBR2 gene haplotypes may affect the severity of obstructive ventilatory impairment but not the immediate response to salbutamol during AECOPD.

Glutathione S-transferase and microsomal epoxide hydrolase gene polymorphisms and risk of chronic obstructive pulmonary disease in Slovak population.

AIM: To determine the risk of chronic obstructive pulmonary disease (COPD) associated with polymorphisms in the glutathione S-transferase (GST) M1, GST T1, and microsomal epoxide hydrolase (EPHX1) genes in a cohort of Slovak population. METHODS: Two hundred and seventeen patients with the diagnosis of COPD and 160 control subjects were enrolled in the study. Blood samples were collected from all subjects and the DNA from peripheral blood lymphocytes was used for subsequent genotyping assays, using polymerase chain reaction and restriction fragment-length polymorphism methods. RESULTS: In an unadjusted model, an increased risk for COPD was observed in subjects with EPHX1 His113-His113 genotype (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.20-4.69; P=0.008), compared with the carriers of the Tyr113 allele. However, after the adjustments for age, sex, and smoking status, the risk was not significant (adjusted OR, 1.79; 95% CI, 0.91-3.53; P=0.093). In a combined analysis of gene polymorphisms, the genotype combination EPHX1 His113-His113/GSTM1 null significantly increased the risk of COPD in both, unadjusted (OR, 5.08; 95% CI, 1.70-20.43; P=0.001) and adjusted model (OR, 4.87; 95% CI, 1.57-15.13; P=0.006). CONCLUSION: Although none of the tested gene polymorphisms was significantly related to an increased risk of COPD alone, our results suggest that the homozygous exon 3 mutant variant of EPHX1 gene in the combination with GSTM1 null genotype is a significant predictor of increased susceptibility to COPD in the Slovak population. The findings of the present study emphasize the importance of detoxifying and antioxidant pathways in the pathogenesis of COPD.

Influence of PAHs in ambient air on chromosomal aberrations in exposed subjects: international study - EXPAH.

The aim of this study was to determine the influence of carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) in complex mixtures in ambient air on DNA damage (chromosomal aberrations) in occupationally exposed subjects measured as percent of aberrant cells (% AB.C.). There were in total 203 exposed subjects and 150 respective controls in the whole project, allocated in three different European cities - Kosice (Slovakia), Prague (Czech Republic) and Sofia (Bulgaria). The studied population from Kosice (Slovakia) consisted of 106 subjects. From these 51 were exposed policemen and 55 were controls. The Czech population comprised 52 exposed policemen and 50 controls. In Bulgaria, there were two equally numerous exposed groups: 50 policemen and 50 professional bus drivers together with 45 controls. According to personal monitoring, policemen and bus drivers in the Bulgarian capital Sofia were exposed to the highest levels of c-PAHs amongst the exposed subject groups in the cities (45.3+/-25.9ng/m(3) in policemen resp. 36.1+/-31.6ng/m(3) in bus drivers in Sofia, 26.8+/-39.8ng/m(3) for policemen in Kosice and 11.9+/-11.2ng/m(3) for policemen in Prague), compared to the respective controls (24.9+/-17.7ng/m(3) for controls in Sofia, 7.9+/-3.8ng/m(3) for controls in Kosice and 6.2+/-3.6ng/m(3) for controls in Prague). We observed the following frequency of % AB.C. scored by conventional method: 2.60+/-2.64 in exposed policemen and 2.14+/-1.61 in controls in Kosice (p=n.s.); 2.33+/-1.53 in exposed policemen and 1.94+/-1.28 in controls in Prague (p=n.s.); 3.04+/-1.64 in exposed policemen, respectively, 3.60+/-1.63 in exposed bus drivers and 1.79+/-0.77 in the control group in Sofia (p<0.05, respectively, p<0.05). According to data from multiple regression analysis, and group comparison of smokers versus nonsmokers in Sofia also cigarette smoking (p=0.055) and the age (p=0.020) seem to play an important role within the aberrant cell formation in addition to the occupational c-PAHs exposure (p=0.000). Smoking status was the modifying factor for % AB.C. in Kosice (p=0.020) after multiple regression approach was employed. In summary, we can say that subjects occupationally exposed to higher levels of c-PAHs in ambient air in Sofia are at greater genotoxic risk compared to those working indoors.

Chromosomal aberrations by fluorescence in situ hybridization (FISH)--Biomarker of exposure to carcinogenic PAHs.

The fluorescence in situ hybridization (FISH) technique with whole chromosome painting for chromosomes #1 and #4 was used to study the impact of air pollution containing higher concentrations of carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) in three European cities, Prague (Czech Republic), Kosice (Slovakia) and Sofia (Bulgaria). In each site were followed an exposed group, who were police officers or bus drivers who work usually through busy streets for at least 8h, and a reference group, who spent more than 90% of their daily time indoors. In Prague, a significant increase was observed in percentage of aberrant cells (% AB.C.) in the police officers compared to the reference group (0.33+/-0.25 versus 0.24+/-0.18, p<0.05). In Kosice, the exposed group differed from reference in the endpoints F(G)/100 1.52+/-1.18 versus 1.12+/-1.30, p<0.05; % AB.C. 0.30+/-0.19 versus 0.21+/-0.20, p<0.05; t/1000 3.91+/-3.18 versus 2.84+/-3.10, p<0.05. In Sofia were followed two exposed groups: police officers and bus drivers. All FISH endpoints were significantly higher in police officers compared to reference group (F(G)/100 1.60+/-0.99 versus 0.82+/-0.79, p<0.01; % AB.C. 0.25+/-0.14 versus 0.13+/-0.13, p<0.01; t/1000 4.19+/-2.65 versus 2.13+/-2.05, p<0.05; rcp 1.46+/-1.07 versus 0.70+/-0.76, p<0.05). In bus drivers compared to reference there was an increase in % AB.C. (0.25+/-0.18 versus 0.13+/-0.13, p<0.05). This is the first study when FISH method was used to analyze the impact of environmental air pollution. According to the original hypothesis it is expected that the most important group of chemicals responsible for the biological activity of air pollution represent c-PAHs.

Air pollution by carcinogenic PAHs and plasma levels of p53 and p21(WAF1) proteins.

We analyzed the effect of exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) in ambient air on the plasma levels of p53 and p21(WAF1) proteins among city policemen, bus drivers and controls in three European cities: Prague (Czech Republic), Kosice (Slovakia) and Sofia (Bulgaria). p53 and p21(WAF1) proteins are key regulators of the cell cycle and are accepted as universal markers of genotoxic stress and DNA damage. In total 204 exposed subjects (100 smokers, 104 nonsmokers) and 152 controls (54 smokers, 98 nonsmokers) were analyzed. Personal exposure to c-PAHs was evaluated using personal samplers during the working shift. The levels of p53 and p21(WAF1) proteins were assessed by ELISA assay. There were no differences between the levels of either protein between exposed and controls, or smokers and nonsmokers, in any city. However, we observed significant differences in p53 plasma levels in all subjects regardless of the exposure status between the individual cities (median values: 5, 31, 234pg/ml, p<0.001, for Prague, Kosice and Sofia, respectively). The levels correspond to the differences in exposure levels to c-PAHs and benzo[a]pyrene (B[a]P) in the individual cities. A multiple linear regression analysis confirmed that c-PAHs exposure is a variable significantly affecting levels of both proteins in all locations. When all subjects were divided into the group exposed to below-median levels of c-PAHs and the group exposed to above-median levels of c-PAHs we found significantly higher p53, as well as p21(WAF1) levels in the above-median exposure group (p53, 167pg/ml versus 25pg/ml, p<0.001; p21(WAF1), 2690pg/ml versus 2600pg/ml, p<0.05). Among all subjects p53 plasma levels were positively correlated with p21(WAF1) levels, exposure to B[a]P, c-PAHs and levels of total DNA adducts; for p21(WAF1) levels we observed the positive correlation with cotinine, c-PAHs exposure, total and B[a]P-like DNA adduct levels. In conclusion our results suggest that p53 and p21(WAF1) proteins plasma levels may be useful biomarkers of c-PAHs environmental exposure.

KCNQ1 gene polymorphism is associated with glycaemic response to treatment with DPP-4 inhibitors.

AIMS: Only afew gene variants were associated with the response to dipeptidylpeptidase-4 inhibitors (DPP4I). KCNQ1 gene variants were previously related both to type 2 diabetes (T2D) and incretin effect. We hypothesized that T2D related KCNQ1 variants would be associated with smaller glucose-lowering effect of DDP4I. METHODS: We performed a retrospective study in 137 Caucasian subjects with T2D who were followed for 6months after initiation of DPP4I treatment. Genotyping for KCNQ1 rs163184 and rs151290 was performed using PCR-HRMA and PCR-RFLP methods, respectively. The main clinical outcome was reduction in HbA1c (ΔHbA1c) after 6-month DPP4I treatment. RESULTS: KCNQ1 rs163184 T>G variant was associated with the response to DPP4I treatment in genetic additive model (ß=-0.30, p=0.022). For each G allele in the rs163184 genotype, we observed a 0.3% (3.3mmol/mol) less reduction in HbA1c during treatment with a DPP4I. Both the GG homozygotes and G-allele carriers had significantly smaller HbA1c reduction in comparison with the TT homozygotes. CONCLUSIONS: KCNQ1 rs163184 T>G variant was associated with a reduced glycaemic response to DPP4I. The difference of 0.6% (6.5mmol/mol) in HbA1c reduction between the TT and GG homozygotes might be of clinical significance if replicated in further studies.

Single nucleotide polymorphisms in the intergenic region between metformin transporter OCT2 and OCT3 coding genes are associated with short-term response to metformin monotherapy in type 2 diabetes mellitus patients.

OBJECTIVES: High variability in clinical response to metformin is often observed in type 2 diabetes (T2D) patients, and it highlights the need for identification of genetic components affecting the efficiency of metformin therapy. Aim of this observational study is to evaluate the role of tagSNPs (tagging single nucleotide polymorphisms) from genomic regions coding for six metformin transporter genes with respect to the short-term efficiency. DESIGN: 102 tagSNPs in 6 genes coding for metformin transporters were genotyped in the group of 102 T2D patients treated with metformin for 3 months. METHODS: Most significant hits were analyzed in the group of 131 T2D patients from Slovakia. Pharmacokinetic study in 25 healthy nondiabetic volunteers was conducted to investigate the effects of identified polymorphisms. RESULTS: In the discovery group of 102 patients, minor alleles of rs3119309, rs7757336 and rs2481030 were significantly nominally associated with metformin inefficiency (P = 1.9 × 10-6 to 8.1 × 10-6). Effects of rs2481030 and rs7757336 did not replicate in the group of 131 T2DM patients from Slovakia alone, whereas rs7757336 was significantly associated with a reduced metformin response in combined group. In pharmacokinetic study, group of individuals harboring risk alleles of rs7757336 and rs2481030 displayed significantly reduced AUC∞ of metformin in plasma. CONCLUSIONS: For the first time, we have identified an association between the lack of metformin response and SNPs rs3119309 and rs7757336 located in the 5' flanking region of the genes coding for Organic cation transporter 2 and rs2481030 located in the 5' flanking region of Organic cation transporter 3 that was supported by the results of a pharmacokinetic study on 25 healthy volunteers.

Variation in the glucose transporter gene SLC2A2 is associated with glycemic response to metformin.

Metformin is the first-line antidiabetic drug with over 100 million users worldwide, yet its mechanism of action remains unclear. Here the Metformin Genetics (MetGen) Consortium reports a three-stage genome-wide association study (GWAS), consisting of 13,123 participants of different ancestries. The C allele of rs8192675 in the intron of SLC2A2, which encodes the facilitated glucose transporter GLUT2, was associated with a 0.17% (P = 6.6 × 10(-14)) greater metformin-induced reduction in hemoglobin A1c (HbA1c) in 10,577 participants of European ancestry. rs8192675 was the top cis expression quantitative trait locus (cis-eQTL) for SLC2A2 in 1,226 human liver samples, suggesting a key role for hepatic GLUT2 in regulation of metformin action. Among obese individuals, C-allele homozygotes at rs8192675 had a 0.33% (3.6 mmol/mol) greater absolute HbA1c reduction than T-allele homozygotes. This was about half the effect seen with the addition of a DPP-4 inhibitor, and equated to a dose difference of 550 mg of metformin, suggesting rs8192675 as a potential biomarker for stratified medicine.

PPARGC1A and PPARG genotyping: beginner's guide to genotyping with unlabeled probes.

Amplicon melting and genotyping with unlabeled probes has become wide spread technique for SNP genotyping. In both methods PCR is performed with new generation of double-strand DNA binding dyes. Nucleic acid melting generates distinct melting curves that can be used to identify the presence of sequence variation within the amplicon. Unlabeled probes are inexpensive and provide the sequence specificity. This chapter provides comprehensive instructions about design of primers and probes and evaluation of their quality. Chapter also contains useful advices on how to perform DNA purification, optimize PCR conditions, how to prepare working solutions, and how to interpret the data of melting analysis.

Association between TCF7L2 Genotype and Glycemic Control in Diabetic Patients Treated with Gliclazide.

Previous studies showed associations between variants in TCF7L2 gene and the therapeutic response to sulfonylureas. All sulfonylureas stimulate insulin secretion by the closure of ATP-sensitive potassium (KATP) channel. The aim of the present study was to compare TCF7L2 genotype specific effect of gliclazide binding to KATP channel A-site (Group 1) with sulfonylureas binding to AB-site (Group 2). A total of 101 patients were treated with sulfonylureas for 6 months as an add-on therapy to the previous metformin treatment. TCF7L2 rs7903146 C/T genotype was identified by real-time PCR with subsequent melting curve analysis. Analyses using the dominant genetic model showed significantly higher effect of gliclazide in the CC genotype group in comparison with combined CT + TT genotype group (1.32 ± 0.15% versus 0.73 ± 0.11%, P (adj) = 0.005). No significant difference in ΔHbA1c between the patients with CC genotype and the T-allele carriers was observed in Group 2. In the multivariate analysis, only the TCF7L2 genotype (P = 0.006) and the baseline HbA1c (P < 0.001) were significant predictors of ΔHbA1c. After introducing an interaction term between the TCF7L2 genotype and the sulfonylurea type into multivariate model, the interaction became a significant predictor (P = 0.023) of ΔHbA1c. The results indicate significantly higher difference in ΔHbA1c among the TCF7L2 genotypes in patients treated with gliclazide than in patients treated with glimepiride, glibenclamide, or glipizide.