Factors associated to serum paraoxonase 1 activity in patients with cardiovascular disease

ABSTRACT Objectives: Paraoxonase 1 (PON1) is an enzyme that has antioxidant potential, which confers a protective effect against the atherosclerotic process. However, studies associating genetics, dietary patterns and PON1 activity in individuals with cardiovascular disease (CVD) are scarce. Thus, the aim of the current study was to evaluate the influence of dietary factors on serum PON1 in CVD patients. Subjects and methods: Cross-sectional, sub-study of the BALANCE Program Trial. All patients aged 45 years or older and had evidence of established atherosclerotic disease in the preceding 10 years. Body weight, height, waist circumference, blood pressure, lipid profile and fasting glucose were collected. Food intake was assessed with 24-h dietary recall. Data was analyzed using SAS University Edition and a P value ≤ 0.05 was considered statistically significant. Sample was divided into three groups, according to the PON1 T(-107)C genotype (CC, CT and TT) and serum PON1 activity (Low, Medium, High). Results: There were no genotype differences for major factors. However, the systolic blood pressure was lower for CT individuals (p<0.05). Intake of cholesterol, saturated fatty acids (SFA) and monounsaturated fatty acids (MUFAS) was higher in patients with lower PON1 activity. Lipid ingestion tended to be higher in patients with lower PON1 activity (p=0.08). In the multivariate logistic regression model, SFA intake (P=0.03), genotype (P=0.09), gender (P=0.04), age (P=0.07) and carbohydrate intake (P=0.16) contributed the most to the serum PON1 activity. Conclusion: Based on these findings, nutritional guidance for these patients becomes essential, since dietary components interact with serum PON1 activity more than genotype.

The effect of paraoxonase 1 (PON1) gene polymorphisms T(-107)C and L55M and diet composition on serum PON1 activity in women

ABSTRACT Objective: The aim of this study was to evaluate the serum activity of PON1 in women according to SNPs L55M and T-107C and diet composition. Materials and methods: Blood and serum samples from 26 women were used. DNA extraction, PCR and digestion with restriction enzymes of the PCR fragment were performed for genotyping the PON1 SNPs T-107C and L55M. Serum PON1 activity was measured in a single time point. Patients completed the semi-quantitative food frequency questionnaire and diet composition was estimated. Results: Genotypic distribution for L55M SNP was 56% for the LL genotype, 32% for LM and 12% for MM; for the PON1 C(-107)T SNP it was 28% for the TT genotype, 41% for CT and 31% for CC. Individuals with C and L alleles had higher serum PON1 activity. Combining the two SNPs, we observed that individuals carrying the LL and CC genotypes had twice the activity of carriers of the TT and MM genotypes. Considering food intake, no significant difference was observed between genotypes and intake levels. Conclusion: PON1 T(-107)C and L55M SNPs exert a strong effect on serum PON1 activity in an additive manner and are more important than diet to predict serum PON1 activity.

Association Between PON1 (L55M and Q192R) Genetic Polymorphism and Recurrent Pregnancy Loss in North Indian Women Exposed to Pesticides / Associação entre o polimorfismo genético PON1 (L55M e Q192R) e a perda recorrente de gravidez emmulheres do norte da Índia expostas a pesticidas

Abstract Objective The aim of the present study was to examine the relation between the PON1 polymorphisms and recurrent pregnancy loss (RPL). Methods In a cross-sectional study, blood samples were collected from 100 females. DNA was extracted and PON1 genotypes were determined by polymerase chain reaction (PCR) amplification. Results Regarding PON1 L55M, the mutated allele (M) frequency was found in 70.5% in RPL and in 53.5% in controls; theMallele was significantly associated with an increased risk of RPL (adjusted odds ratio [ORadj]=2.07; 95% confidence interval [CI]; p<0.001). However, regarding PON1 Q192R, the R mutated allele frequency was found in 28.5% in RPL and in 33% in controls. The R allele did not show any risk for RPL (ORadj 0.81; 95%CI; p=0.329). Conclusion The present study suggests that there is an effect of genetic polymorphism on RPL and provides additional evidence that combines with the growing information about the ways in which certain PON1 genotypes can affect the development of the fetus in the uterus.

Resumo Objetivo O objetivo deste estudo foi examinar a relação entre os polimorfismos PON1 e perda recorrente de gravidez PRG. Métodos Em um estudo transversal, foramcoletadas amostras de sangue de 100 mulheres. O DNA foi extraído e os genótipos PON1 foram determinados por amplificação por PCR. Resultados Com relação ao PON1 L55M, a frequência do alelo mutado (M) foi encontrada em 70,5% no PRG e em 53,5% nos controles; o alelo M foi significativamente associado a um risco aumentado de PRG (odds radio ajustado [ORadj] =2,07; intervalo de confiança [IC] 95%; p<0,001). No entanto, em relação ao PON1 Q192R, a frequência do alelo mutado R foi encontrada em 28,5% no PRG e em 33% nos controles. O alelo R não mostrou qualquer risco para PRG (ORadj 0,81; IC 95; p=0,329). Conclusão O presente estudo sugere que há um efeito do polimorfismo genético sobre PRG e fornece evidências adicionais que se combinam com as informações crescentes sobre asmaneiras pelas quais certos genótipos PON1 podemafetar o desenvolvimento do feto no útero.

Influence of nutritional factors and the PON1 C(-107)T polymorphism on paraoxonase-1 activity in childhood / Influência de fatores nutricionais e do polimorfismo PON1 C(-107)T sobre a atividade da Paraoxonase 1 na infância

Abstract Objective: The cardioprotective enzyme paraoxonase-1 (PON1) suffers an important influence from genetic polymorphisms and nutritional factors. The aim of this study was to investigate the influence of diet, nutritional status, and the C(-107)T polymorphism on PON1 arylesterase activity in children. Methods: This was a cross-sectional study with 97 children, aged between 5 and 8 years, of both genders, from a pediatric outpatient clinic in southern Brazil. A sociodemographic, behavioral, and food consumption questionnaire was applied, and anthropometric measurements and laboratory blood samples were taken. PON1 arylesterase activity was measured by phenol extinction (U/mL), and DNA extraction and analysis of the PON1 C(-107)T polymorphism were performed. The Hardy-Weinberg equilibrium was tested with the chi-squared test and linear regression was used to estimate PON1 activity according to four adjustment models, with an acceptable error of 5%. Results: In the sample, the male gender accounted for 50.5%, 39.2% were 6 years of age, 54.5% had normal weight, and 51.5% had PON1 activity below the median (90.0, 15-30 U/mL). Genotype frequency was 54.6% (53/97), 31.0% (30/97), and 14.4% (14/97), respectively, for CT, CC, and TT, consistent with the Hardy-Weinberg equilibrium (p = 0.22). In the regression analysis, the model that included sociodemographic variables as well as frequency of consumption of fruits, vegetables, legumes, dairy products, and beans estimated a variability of 14.8% in PON1 activity combined with the PON1 C(-107)T polymorphism. Conclusions: During childhood, a good-quality diet with greater inclusion of healthy foods was important to predict the activity of the cardioprotective enzyme PON1 combined with the C(-107)T polymorphism of the PON1 gene.

Resumo Objetivo: A enzima cardioprotetora Paraoxonase 1 (PON1) sofre importante influência de polimorfismos genéticos e fatores nutricionais. O objetivo deste estudo foi investigar a influência da alimentação, do estado nutricional e do polimorfismo C(-107)T sobre a atividade arilesterase da PON1 em crianças. Métodos: Estudo transversal com 97 crianças entre 5 e 8 anos, de ambos os sexos, de um ambulatório de pediatria no sul do Brasil. Realizou-se questionário sociodemográfico, de comportamento e de consumo alimentar, medidas antropométricas e coleta de sangue em laboratório. A atividade arilesterase da PON1 foi mensurada pela extinção de fenol (U/mL), realizada extração do DNA e análise do polimorfismo PON1 C(-107)T. O equilíbrio de Hardy-Weinberg foi testado com qui-quadrado e usada regressão linear para estimar a atividade da PON1 segundo quatro modelos de ajuste, erro aceitável de 5%. Resultados: Na amostra o sexo masculino representou 50,5%, 39,2% tinham 6 anos, 54,5% eram eutróficos e 51,5% tinha atividade da PON1 inferior à mediana (90,0;15-30 U/ml). A frequência dos genótipos foi 54,6% (53/97), 31,0% (30/97) e 14,4% (14/97), respectivamente, para CT, CC e TT, estiveram em equilíbrio de Hardy-Weinberg (p = 0,22). Na análise de regressão o modelo que incluiu variáveis sociodemográficas, de frequência do consumo de frutas, verduras, legumes, laticínios e feijões estimou uma variabilidade de 14,8% na atividade da PON1 combinada ao polimorfismo PON1 C(-107)T. Conclusões: Na infância uma alimentação de boa qualidade, com maior participação de alimentos saudáveis foi importante para predizer a atividade da enzima cardioprotetora PON1 combinada ao polimorfismo C(-107)T do gene da PON1.

Paraoxonase 1 serum activity in women: the effects of menopause, the C(-107)T polymorphism and food intake

ABSTRACT Objective The aims of this study were to investigate changes in serum paraoxonase 1 (PON1) activity in women at the pre and postmenopausal stages and its association with the PON1 C(-107)T polymorphism and food intake profile. Subjects and methods A cross-sectional study with female patients aged between 35 and 59 years old was conducted. Women were divided into two groups: premenopausal (n = 40) and postmenopausal (n = 36). Women enrolled in the study had serum PON1, total cholesterol, HDL, LDL, glucose and HbA1c, as well as the BMI measured. Additionally, women were genotyped for the PON1 T(-107)C polymorphism and the food intake profile was obtained through interview. Results Glucose (p = 0.03), HbA1c (p = 0.002) and total cholesterol (p = 0.002)concentrations were higher in post than premenopausal women, however PON1 activity was not different (p > 0.05). Carriers of the C allele had higher PON1 activity (CC: 88.9 ± 6.5 U/mL and CT: 79.9 ± 4.7 U/mL) than women of the TT genotype (66.6 ± 5.9 U/mL) (p < 0.05). However, the model predicting PON1 activity was slightly better when genotype, total fat and cholesterol content in the diet were all included. Conclusion In sum, we observed that the PON1 C(-107)T genotype was the major regulator of PON1 activity, and menopause had no effect on PON1 activity. The lipid and glycemic profile were altered in postmenopausal women.

Paraoxonase-1 polymorphisms and cerebral ischemic stroke: a pilot study in mexican patients / Caracterización polimórfica de la paraoxonasa-1 en el infarto cerebral aterotrombótico de una poblacion mexicana: estudio piloto

Abstract Background: The serum paraoxonase-1 (PON1) associated to HDL presents two common polymorphisms in the positions 192 and 55. These polymorphisms are considered determinant of the capacity of HDL to protect LDL from their oxidative modification. In this context, the PON1 genotype has been associated with cardiovascular diseases, including stroke. Objective: To determine the allelic and genotypic frequencies of PON1 L55M and Q192R as well as the enzymatic activities of PON1 in subjects with and without atherothrombotic stroke. Methods: There were included 28 people with atherothrombotic stroke and 29 without stroke. The genotyping was carried out by PCR-RFLP and the phenotyping by measurement of the activities of paraoxonase and arylesterase in serum. Results: For the polymorphism Q192R, the allelic frequencies (Q/R) were 0.46/0.54 and 0.48/0.52 (p= 0.843) for the control group and the group with stroke, respectively. While for the polymorphism L55M, the allelic frequencies (L/M) were 0.81/0.19 for the control group, and 0.78/0.22 for the group with stroke (p= 0.610). The activity levels of paraoxonase were not significantly different between the control and stroke groups (450 vs. 348 UI/mL, p= 0.093) While the activity levels of arylesterase were significantly different between the studied groups (90 vs. 70 UI/mL, p= 0.001); however, upon adjustment by multiple linear regression, it was not longer significant. Conclusion: The polymorphisms Q192R and L55M, and the paraoxonase activity of PON1 are not risk factors for atherothrombotic stroke according to the results of this study.

Resumen Introducción: La paraoxonasa-1 (PON1) sérica asociada a las HDL presenta dos polimorfismos comunes en las posiciones 192 y 55. Estos polimorfismos se consideran determinantes para la capacidad de las HDL de proteger a las LDL de su modificación oxidativa. En este contexto, el genotipo de PON1 se ha asociado con enfermedades cerebrovasculares, que incluyen el infarto cerebral. Objetivo: Determinar las frecuencias alélicas y genotípicas de PON1-L55M y PON1- Q192R, así como las actividades enzimáticas de PON1 en sujetos con y sin infarto cerebral aterotrombótico. Métodos: Se incluyeron 28 personas con infarto cerebral aterotrombótico y 29 sin infarto. Las genotipificaciones se realizaron mediante PCR-RFLP y las fenotipificaciones mediante la medición de las actividades paraoxonasa y arilesterasa en suero. Resultados: Para el polimorfismo Q192R, las frecuencias alélicas (Q/R) fueron 0.46/0.54 y 0.48/0.52 (p= 0.843) para el grupo control y el grupo con infarto, respectivamente. Mientras que para el polimorfismo L55M, las frecuencias alélicas (L/M) fueron 0.81/0.19 para el grupo control y 0.78/0.22 para el grupo con infarto (p= 0.610). Los niveles de actividad paraoxonasa no fueron significativamente diferentes entre los grupos control y con infarto (450 vs. 348 Ul/mL, p= 0.093). Mientras que los niveles de actividad arilesterasa fueron significativamente diferentes entre los grupos estudiados (90 vs. 70 Ul/mL, p= 0.001), sin embargo, al ajustarla por regresión lineal múltiple, dejo de ser significativa. Conclusión: Los polimorfismos Q192R y L55M, y la actividad paraoxonasa de la PON1 no son factores de riesgo para el infarto cerebral aterotrombótico en este estudio.

Decreased platelet responsiveness to clopidogrel correlates with CYP2C19 and PON1 polymorphisms in atherosclerotic patients

Clopidogrel and aspirin are the most commonly used medications worldwide for dual antiplatelet therapy after percutaneous coronary intervention. However, clopidogrel hyporesponsiveness related to gene polymorphisms is a concern. Populations with higher degrees of genetic admixture may have increased prevalence of clopidogrel hyporesponsiveness. To assess this, we genotyped CYP2C19, ABCB1, and PON1 in 187 patients who underwent percutaneous coronary intervention. Race was self-defined by patients. We also performed light transmission aggregometry with adenosine diphosphate (ADP) and arachidonic acid during dual antiplatelet therapy. We found a significant difference for presence of the CYP2C19*2 polymorphism between white and non-white patients. Although 7% of patients had platelet resistance to clopidogrel, this did not correlate with any of the tested genetic polymorphisms. We did not find platelet resistance to aspirin in this cohort. Multivariate analysis showed that patients with PON1 and CYP2C19 polymorphisms had higher light transmission after ADP aggregometry than patients with native alleles. There was no preponderance of any race in patients with higher light transmission aggregometry. In brief, PON1 and CYP2C19 polymorphisms were associated with lower clopidogrel responsiveness in this sample. Despite differences in CYP2C19 polymorphisms across white and non-white patients, genetic admixture by itself was not able to identify clopidogrel hyporesponsiveness.

Paraoxonase 1 gene polymorphisms and enzyme activities in coronary artery disease and its relationship to serum lipids and glycemia / Polimorfismos en el gen de la paraoxonasa 1 y sus actividades enzimáticas en la enfermedad coronaria. Su relación con el perfil lipídico y la glucemia

Abstract Objectives Oxidative stress and inflammation are important processes in development of atherosclerosis. Paraoxonase 1 (PON1) is a bioscavenger enzyme associated with inflammation and oxidative stress. We evaluate the association of two single nucleotide polymorphisms in PON1 gene, and enzyme activities with lipid profile and glycemia. Methods This case-control study consisted of 126 patients with coronary artery disease (CAD) and 203 healthy controls. PON Q192R and L55M polymorphisms were detected by real-time PCR. Paraoxonase and arylesterase activities were determined spectrophotometrically. Blood glucose, cholesterol, triglycerides, HDL, and LDL were measured. Results PON1 QR192 polymorphism had a major effect on paraoxonase but no effect on arylesterase serum activities. Paraoxonase activity was higher in RR genotype and lowest in QQ genotype. Paraoxonase and arylesterase activities were higher in LL and lower in MM genotypes of PON1 LM55 polymorphism. RQ and LM variants showed intermediate activities between respective homozygous. Elevated concentrations of triglycerides in cases correlate with QQ variant or the presence of M allele. Glucose levels were elevated in cases with QQ variant or with the presence of M allele. Cholesterol and LDL did not show variations in control and cases with any variant of both polymorphisms. HDL is lower in cases with respect to controls independently of genotypes. All differences were significant with p < 0.05. Conclusions Our results confirm the relationship between variations in PON1 activities and lipid metabolism, and showed that genetically programmed low PON1 activities would have certain responsibility in the increase in glycemia and concomitantly the aggravation of atherosclerotic disease.

Resumen Objetivos La enzima paraoxonasa 1 (PON1), está asociada con el estrés oxidativo y la inflamación, procesos importantes en el desarrollo de la aterosclerosis. Evaluamos la asociación de 2 polimorfismos de un solo nucleótido en el gen PON1 y sus actividades enzimáticas con el perfil lipídico y la glucemia. Métodos Estudio caso-control en 126 pacientes con enfermedad coronaria y 203 controles sanos. Los polimorfismos PON Q192R y L55M fueron detectados por PCR en tiempo real y las actividades de paraoxonasa y arilesterasa por espectrofotometría. Se midieron glucemia, colesterol, triglicéridos, HDL y LDL. Resultados El polimorfismo PON1 QR192 afectó la actividad de paraoxonasa pero no la de arilesterasa. La actividad de paraoxonasa fue mayor en el genotipo RR y menor en QQ. Ambas actividades fueron mayores en el genotipo LL y menores en MM del polimorfismo PON1 LM55. Las variantes RQ y LM mostraron actividades intermedias entre los respectivos homocigotos. Concentraciones elevadas de triglicéridos en los casos correlacionaron con la variante QQ o la presencia del alelo M. Los niveles de glucosa fueron elevados en los casos QQ o con la presencia del alelo M. El colesterol y el LDL no variaron ni en los casos ni en los controles con ambos polimorfismos. El HDL fue menor en los casos respecto de los controles, independientemente del genotipo. Conclusiones Los resultados confirman la relación entre las variaciones en las actividades de PON1 y el metabolismo lipídico y mostraron que las bajas actividades de PON1 genéticamente programadas tendrían cierta responsabilidad en el aumento de la glucemia y, concomitantemente, en la agravación de la enfermedad aterosclerótica.

Paraoxonase 1 (PON1) Q192R genotypes and their interaction with smoking strongly increase atherogenicity and the Framingham risk score

ABSTRACT Objective Paraoxonase 1 (PON1) polymorphisms are associated with an increased susceptibility to cardiovascular disease. PON1 Q192R polymorphism (rs662) partially determine PON1 hydrolytic activity and protect against oxidation of LDL and HDL. This study aimed to delineate the association of PON1 status (functional 192 genotype and plasma activity levels) and atherogenicity in urbans residents aged 40 years or more. Materials and methods Anthropometric data, lipid profiles, the atherogenic index of the plasma (AIP) and Framingham score risk were measured. Three kinetic assays were conducted to assay PON1 status using phenylacetate and 4-(chloromethyl)phenyl acetate as substrates. Results Smoking per se did not significantly impact the AIP but the interaction PON1 genotype by smoking significantly increased the AIP. In subjects with the RR genotype smoking increased the AIP index from (estimated mean ± SEM) -0.038 ± 0.039 to 0.224 ± 0.094. The QR genotype increased the Framingham risk index by around 1.3 points. Smoking by RR genotype carriers significantly increased the Framingham risk score (17.23 ± 2.04) as compared to smoking (13.00 ± 1.06) and non-smoking (7.79 ± 0.70) by QQ+QR genotype carriers. The interaction RR genotype by smoking was a more important predictor (odds ratio = 7.90) of an increased Framingham risk score (> 20) than smoking per se (odds ratio = 2.73). The interaction smoking by RR genotype carriers significantly increased triglycerides and lowered HDL cholesterol. Conclusion Smoking per se has no (AIP) or a mild (Framingham risk score) effect on atherogenicity, while the interaction smoking by PON1 RR genotype has a clinically highly significant impact on atherogenicity.

p.Q192R SNP of PON1 seems not to be Associated with Carotid Atherosclerosis Risk Factors in an Asymptomatic and Normolipidemic Brazilian Population Sample / O SNP p.Q192R da PON1 não Parece Associar-se a Fatores de Risco para a Aterosclerose Carotídea em Amostra de População Brasileira Normolipidêmica e Assintomática

Evidences suggest that paraoxonase 1 (PON1) confers important antioxidant and anti-inflammatory properties when associated with high-density lipoprotein (HDL).

Effectiveness of Limberg and Karydakis flap in recurrent pilonidal sinus disease

OBJECTIVE: Sacrococcygeal pilonidal sinus is common in young men and may recur over time after surgery. We investigated whether a factor exists that can aid in the determination of the preferred technique between the early Limberg flap and Karydakis flap techniques for treating recurrent pilonidal sinus. MATERIALS AND METHODS: This prospective and randomized study enrolled 71 patients with recurrent pilonidal sinus in whom the Limberg flap or Karydakis flap techniques were applied for reconstruction after excision. Patients were divided into two groups as follows: 37 patients were treated with the Limberg flap technique and 34 patients were treated with the Karydakis flap technique. Fluid collection, wound infection, flap edema, hematoma, partial wound separation, return to daily activities, pain score, complete healing time, painless seating and patient satisfaction were compared between the groups. ClinicalTrial.gov: NCT02287935. RESULTS: The development rates of total fluid collection, wound infection, flap edema, hematoma, and partial wound separation were 9.8%, 16%, 7%, 15% and 4.2%, respectively; total flap necrosis was not observed in any patient (p<0.001). During the average follow-up of 28 months, no patients (0%) developed recurrent disease. The two groups differed with respect to early surgical complications (p<0.001). CONCLUSION: In this study, use of the Limberg flap was associated with lower complication rates, shorter length of hospital stay, early return to work, low pain score, high patient satisfaction and better complete healing duration. Therefore, we recommend the Limberg flap for treatment of recurrent pilonidal sinus. .

Paraoxonase1, its Q192R polymorphism and HDL-cholesterol in relation to intensive cardiac care unit stay in ischemic heart disease.

AIMS AND OBJECTIVES: The present study was evaluated the atheroprotective potential of paraoxonase1 (PON1) and its Q192R polymorphism, to determine whether this polymorphism, which is responsible for differential PON1 activity plays any role in the pathogenesis, severity and extent of coronary artery disease (CAD). MATERIALS AND METHODS: This hospital‑based cross‑sectional study investigated 60 diagnosed cases of CAD and 60 age and gender matched controls. All were assessed for serum PON1 activity, PON1 Q192R polymorphism and for classical cardiovascular risk factors. Individual serum phenotyping for PON1 Q192R polymorphism was determined by double substrate hydrolysis assay. Severity of CAD was assessed by the length of intensive cardiac care unit (ICCU) stay. RESULTS: Serum PON1 activity is significantly reduced in cases of CAD (92.6 ± 31.13 IU/L when compared with controls (105.26 ± 32.53 IU/L). Furthermore, serum arylesterase activity is reduced in CAD patients (90.31 ± 23.26 kU) when compared with the control subjects (101.61 ± 28.68 kU). Serum PON1 and arylesterase activities are significantly negatively correlated with the length of ICCU stay (r = −393 and r = −374 respectively). There is no significant difference in the occurrence of CAD and length of ICCU stay among the PON1 phenotypes (P = 0.92). Logistic regression analysis after adjustment of established risk factors revealed no significant association between CAD risk and PON1 Q192R polymorphism (odds ratios: 1.179 [95% confidence intervals: 0.507‑2.744], P = 0.702). SUMMARY AND CONCLUSIONS: The current study demonstrates that the activity of the PON1 enzyme may be more important factor than the PON1 Q192R polymorphism in the severity and extent of CAD.

Paraoxonase 1 status in keratoconus: a preliminary study of activity and polymorphism / Estatus de la paraoxonasa 1 en el queratocono: estudio preliminar de actividad y polimorfismo

OBJECTIVE: To determine the activity of paraoxonase 1 (PON1) in keratoconus in a Malaysian population in comparison with non-keratoconic subjects. METHODS: Clinical eye examinations were performed on patients with keratoconus and non-keratoconic subjects after questionnaires were completed. Blood samples were collected and subjected to spectrophotometry analysis of paraoxonase and diazoxonase activities for the determination of the status of PON1 of every individual. RESULTS: Of the 11 keratoconic patients and 55 non-keratoconic control samples collected, eight patients of Indian ethnicity were keratoconic (73%), whereas 33 non-Indians were non-keratoconic (60%; p = 0.047). Paraoxonase activity was lower in Indians compared to the non-Indians ie Malays and Chinese (p = 0.008). Keratoconic subjects had a lower paraoxonase activity compared to non-keratoconics (p = 0.038). CONCLUSIONS: The reduced paraoxonase activity in keratoconic patients suggests that the keratoconic corneas were more susceptible to oxidative stress. Reduced paraoxonase activity and keratoconus status appears to be associated with ethnicity.

OBJETIVO: Determinar la actividad de paraoxonasa 1 (Pon 1) en el queratocono en una población malaya, en comparación con sujetos no queratocónicos. MÉTODOS: Se realizaron exámenes clínicos oculares a pacientes con queratocono y a sujetos no queratocónicos luego que los mismos respondieran a los cuestionarios. Se recogieron muestras de sangre, que fueron entonces sometidas a análisis espectrofotométrico en relación con las actividades de la paraoxonasa y la diazoxonasa para la determinación del estatus de la paraoxonasa 1 de cada individuo. RESULTADOS: De los 11 pacientes queratocónicos y las 55 muestras de control no queratocónicas recogidas, 8 pacientes de etnicidad india fueron queratocónicos (73%), mientras que 33 no indios fueron no queratocónicos (60%; p = 0.047). La actividad de la paraoxonasa fue más baja en los indios en comparación con los no indios, es decir, los malayos y los chinos (p = 0.008). Los sujetos queratocónicos tenían una actividad de la paraoxonasa más baja, comparada con los no queratocónicos (p = 0.038). CONCLUSIONES: La actividad de la paraoxonasa reducida en los pacientes queratocónicos sugiere que las córneas queratocónicas son más susceptibles al estrés oxidativo. La actividad de la paraoxonasa reducida y el estatus del queratocono parecen estar asociados con la etnicidad.

Association of Paraoxonase 1 (PON1) polymorphisms with osteoporotic fracture risk in postmenopausal Korean women

There is increasing evidence of a biochemical link between lipid oxidation and bone metabolism. Paraoxonase 1 (PON1) prevents the oxidation of low-density lipoprotein (LDL) and metabolizes biologically active phospholipids in oxidized LDLs. Here, we performed association analyses of genetic variation in PON1 to ascertain its contribution to osteoporotic fractures (OFs) and bone mineral density (BMD). We directly sequenced the PON1 gene in 24 Korean individuals and identified 26 sequence variants. A large population of Korean postmenopausal women (n = 1,329) was then genotyped for eight selected PON1 polymorphisms. BMD at the lumbar spine and femoral neck was measured using dual-energy X-ray absorptiometry. Lateral thoracolumbar (T4-L4) radiographs were obtained for vertebral fracture assessment, and the occurrence of non-vertebral fractures (i.e., wrist, hip, forearm, humerus, rib, and pelvis) was examined using self-reported data. Multivariate analyses showed that none of the polymorphisms was associated with BMD at either site. However, +5989A>G and +26080T>C polymorphisms were significantly associated with non-vertebral and vertebral fractures, respectively, after adjustment for covariates. Specifically, the minor allele of +5989A>G exerted a highly protective effect against non-vertebral fractures (OR = 0.59, P = 0.036), whereas the minor allele of +26080T>C was associated with increased susceptibility to vertebral fractures (OR = 1.73, P = 0.020). When the risk for any OFs (i.e., vertebral or non-vertebral) was considered, the statistical significance of both polymorphisms persisted (P = 0.002-0.010). These results suggest that PON1 polymorphisms could be one of useful genetic markers for OF risk in postmenopausal women.

Paraoxonase gene Q192R & L55M polymorphisms in Indians with acute myocardial infarction & association with oxidized low density lipoprotein.

Background & objectives: Paraoxonase (PON) is an HDL associated ester hydrolase with an ability to retard LDL oxidation in vitro by preventing lipid peroxide generation. The population variability in enzyme activity is attributed to polymorphisms in paraoxonase gene. For example, polymorphism at codon 192 and 55 of the paraoxonase gene has been reported to be associated with coronary heart disease (CAD) and diabetes among different ethnic groups. The present study looks at PON192 and 55 polymorphism among hospitalized Asian Indian patients with myocardial infarction (MI) and their association with circulating oxidized LDL and antioxidant status. Methods: One hundred and twenty four consecutive patients of acute myocardial infarction and 221 age-matched controls were recruited for the study. Oxidized LDL was measured in serum by ELISA and total antioxidant levels by the 2,2’-azino-bis-(3 ethyl benzothiozoline-6-sulfonate) (ABTS) method. Other known cardiovascular risk factors, apolipoprotein B, apolipoproteinA1, lipoprotein(a), hsCRP and homocysteine were also measured. Paraoxonase gene polymorphism at codon 192 and 55 were analyzed by PCR-RFLP. Results: Patients with MI had significantly higher oxidized LDL (P<0.05) and lower total antioxidant capacity (P<0.001) as compared to controls. Oxidized LDL correlated with total cholesterol, LDL and Apo B in patients. B allele frequency of the codon 192 polymorphism in paraoxonase gene was higher in cases as compared to controls and odds ratio of developing the MI with BB genotype versus AA genotype was 2.37, (P=0.044). Codon 55 polymorphism in paraoxonase gene was not associated with CAD. There was no difference in oxidized LDL between the different genotypes of PON192 and PON55. Interpretation & conclusions: Although PON192 polymorphism was associated with CAD, no correlation of PON192 or 55 polymorphism was found with oxidized LDL suggesting that presence of other antioxidant factors may be of equal importance in preventing LDL oxidation.

Paraoxonases : Structure, gene polymorphism & role in coronary artery disease.

Paraoxonases (PONs) i.e. PON1, PON2, PON3 are basically lactonases. Of these, PON1 in addition has an efficient esterase activity and can hydrolyze organophosphates. The PONs prevent low density lipoprotein cholesterol (LDL-C) from peroxidation, thereby preventing atherosclerosis. The PON1 is exclusively associated with high density lipoprotein cholesterol (HDL-C) and its antioxidant activity is largely attributed to PON1 located on it. At present, PON1 status i.e. its activity and concentration, is considered to be more important than polymorphism alone, in prevention of coronary artery disease (CAD). Its activity has been found to be affected by a number of pharmacological agents, diet and other factors, thereby becoming a promising target for pharmacological intervention. The PON2 prevents cell mediated lipid peroxidation. However, little is known about the role of PON3. This review describes the structure, gene polymorphism, and factors affecting the activity of PONs, and their role in prevention of CAD.

Paraoxonase 1 gene polymorphisms contribute to coronary artery disease risk among north Indians.

Background: Polymorphisms in paraoxonase 1 (PON1) coding for PON1 enzyme have been studied as genetic markers of coronary artery disease (CAD). PON1 Q192R and PON1 L55M polymorphisms have been analyzed extensively, but data on association and role of these polymorphisms in the etiology of CAD are conflicting. In this study, we tested the genetic association between PON1 Q192R and PON1 L55M polymorphisms and CAD among north Indians. Materials and Methods: Two hundred eighty-five angiographically proven patients with coronary artery disease and 200 sex-matched and ethnically matched controls were genotyped for 2 PON1 polymorphisms by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Genotype/ allele frequencies were compared in patients and controls using the chi-square test. Results: At PON1-192 locus, there were significant differences between patients and controls (P< 0.05), leading to significant odds ratios for RR genotype (OR= 1.92, CI: 1.19-3.10) and *R allele (OR= 1.30, CI: 1.00-1.70). These odds ratios were higher in the sub-sample of smokers (2.84 and 1.45, respectively). Binary logistic regression analysis also confirmed that *R allele carriers (QR and RR) have a higher risk of CAD (OR= 3.54, CI: 1.67-5.53). PON1-55 locus did not show significant differences between patients and controls, but LL genotype and *L allele were significant risk factors in the nonsmoker group. RL haplotype was also significantly associated with CAD risk (OR= 1.44, CI: 1.08-1.93). Conclusions: PON1-192R allele and RR genotype are significantly associated with CAD patients from the north Indian population (Uttar Pradesh). This association was stronger in smokers, supporting the conclusion that an interaction between PON1 activity and smoking augments CAD risk. Further studies with larger sample size are warranted to confirm these associations in different Indian populations.

Paraoxonase Gene Polymorphism in South-western Korean Population

Paraoxonase (PON) has anti-atherogenic activity. Considering the important role of polymorphism in the genetic susceptibility to cardiovascular disease and the variability of its allele frequencies in different ethnic groups, the distribution of genotypes and allele frequencies of PON1M55L, PON1Q192R, PON2A148G, and PON2S311C polymorphisms was analyzed in a total 988 South-western Koreans and determined their effects on lipid parameters. The genotype distribution of PON1 at position 55 was LL=0.886, LM=0.114; and at position 192 was QQ=0.406, QR=0.594. The frequencies of the PON1 55L allele and the PON1 192R allele were similar to those seen in Chinese populations and Western populations, respectively. The genetic distribution of PON2 at position 148 was AA=0.619, AG=0.345, GG=0.035; and at position 311 was CC=0.035, SC=0.345, SS=0.619. The frequencies of the PON2 148G and 311S alleles were similar to those seen in Chinese populations. The concentrations of LDL and ApoB were significantly different between the PON2A148G (P<0.05) and PON2 S311C polymorphisms (P<0.01). PON polymorphisms and allele frequencies were described in Koreans living south-western part of Korea. These ethnic variations are considered important in the interpretation of diseases associated with PON polymorphisms.

impact of the genetic polymorphism of paraoxonase gene [PON1] on the incidence of coronary vascular disease in Saudi population

Cardiovascular diseases as being one of the major causes of morbidity and mortality drags attention for the study of their pathogenesis which seems multifactorial including habitual/ environmental and genetic causes. The major cause for atherosclerosis is deposition of oxidized lipoproteins in the blood vessel. Paraoxonase [PON1], an enzyme tightly linked to HDL plays an important role in decreasing the susceptibility of LDL-cholesterol for oxidation, thus minimizing atherosclerotic changes in the blood vessels. Paraoxonase activity in the serum alone is not a determining factor for this role. This function is also controlled and affected by many polymorphisms occurring in the PON1 gene, The aim of this study was to evaluate the effect of one of this genetic polymorphism [at position 192] on cardiovascular diseases in Saudi population. This study included 169 subjects [100 cases and 69 controls]. For all participants in the study paraoxonase activity, lipid profile, Apo A-l and genetic polymorphism was done. The percentage distribution of this genetic polymorphism differs in Saudi population than those observed in previous studies as in Mexican population and is more similar to those in Japanese population. There was no significant difference in the genetic distribution between control and CVD groups. The activity of paraoxonase was lower in the CVD group compared to the control; also there was no significant correlation between this genetic polymorphism and the lipid composition of the blood. PON1 activities toward paraoxon are lower in subjects with CVD than in control subjects regardless of the PON1 genotype although the PON1 activity is much lower in RR genotype than QQ genotype