Association between polymorphisms of the VKORC1 and CYP2C9 genes and warfarin maintenance dose in Peruvian patients.

AIMS: The aim of this study was to investigate the association between VKORC1 and CYP2C9 genes polymorphisms and the maintenance dose of warfarin in Peruvian patients. METHODS: An observational study was conducted on outpatients from the Hospital Grau ESSALUD in Lima, Peru. The participants were selected using nonprobabilistic convenience sampling. Inclusion criteria required patients to have been on anticoagulation therapy for >3 months, maintain stable doses of warfarin (consistent dose for at least 3 outpatient visits), and maintain an international normalized ratio within the therapeutic range of 2.5-3.5. DNA samples were obtained from peripheral blood for gene analysis. RESULTS: Seventy patients (mean age of 69.6 ± 13.4 years, 45.7% female) were included in the study. The average weekly warfarin dose was 31.6 ± 15.2 mg. The genotypic frequencies of VKORC1 were as follows: 7.1% (95% confidence interval, 2.4-15.9) for AA; 44.3% (32.4-56.7) for GA; and 48.6% (36.4-60.8) for GG. No deviation from the Hardy-Weinberg equilibrium was observed in the variants studied (P = .56). The mean weekly warfarin doses for AA, GA and GG genotypes were 16.5 ± 2.9, 26.5 ± 9.5 and 37.9 ± 17.1 mg, respectively (P < .001). The genotypic frequencies of CYP2C9 were as follows: 82.8% (72.0-90.8) for CC (*1/*1); 4.3% (1.0-12.0) for CT (*1/*2); and 12.9% (6.1-23.0) for TT (*2/*2). We did not find a significant association between the CYP2C9 gene polymorphism and the dose of warfarin. CONCLUSIONS: The AA genotype of the VKORC1 gene was associated with a lower maintenance dose of warfarin in Peruvian patients.

Angiotensin-Converting Enzyme (ACE) genetic variation and longevity in Peruvian older people: a cross-sectional study.

Background: Some studies have suggested that the insertion(I)/deletion(D) polymorphism of the Angiotensin-Converting Enzyme (ACE) gene may be associated with human longevity, especially in centenarians. However, this association is still controversial. Besides, there have been no studies in Peruvians.Aim: To describe the age distribution of the ACE polymorphism in a convenience sample of Peruvian older people.Subjects and methods: This was a cross-sectional study in 104 Geriatric Day Hospital patients in Lima, Perú. The ACE polymorphism was determined in all patients. For the purpose of association with age, the sample was divided into four categories: young (< 65), youngest-old (65-74), middle-old (75-84) and oldest-old (85 or more).Results: The distribution of genotype frequencies was consistent with a population in Hardy-Weinberg equilibrium (p = 0.62). The number (%) of D/D, I/D and I/I genotypes in the young was 2 (14.3%), 3 (21.4%) and 9 (64.3%), respectively; in youngest-old: 4 (11.4%), 15 (42.9%) and 16 (45.7%); in middle-old: 6 (12.2%), 20 (40.8%) and 23 (46.9%); and in oldest-old: 0 (0.0%), 4 (66.7%) and 2 (33.3%). A chi-square analysis showed no significant differences in genotype distribution between age groups (p = 0.647).Conclusion: No significant age differences were found in the distribution of the ACE polymorphism in this sample. Further studies with greater statistical power are recommended.