A synergistic association of ACE I/D and eNOS G894T gene variants with the progression of immunoglobulin A nephropathy - a pilot study.

BACKGROUND: Individual variability in the natural history and response to therapy of immunoglobulin A nephropathy (IgAN) suggests a complex multifactorial pathogenesis. We investigated whether single nucleotide polymorphisms (SNPs) involved in the non-immunologic progression of renal disease are related with disease progression. METHODS: This is a pilot historic cohort study of 64 Caucasian patients with biopsy-proven IgAN and a median follow-up of 70 months. Three SNPs of the renin-angiotensin system genes (angiotensin I converting enzyme insertion/deletion (ACE I/D), angiotensinogen (AGT) M235T, and angiotensin II type 1 receptor (AT(1)R) 1166A/C), 2 of the endothelial nitric oxide synthase (eNOS), 4a/b and G894T, and 1 of the bradykinin 1 receptor, G-699C, were genotyped. The primary outcome was 'kidney survival' defined as a 30% decrease of baseline creatinine clearance; annualized decrease of glomerular filtration rate was also calculated. RESULTS: Proteinuria, histological lesions, and mean arterial pressure were related to an unfavorable outcome. The simultaneous presence of the DD and GG variants of the ACE and eNOS genes was related to an unfavorable outcome as compared with other combinations [hazard ratio ranging from 4.7 (95% CI 1.52-14.33) to 8.4 (95% CI 2.45-29.10)] after controlling for proteinuria, mean arterial pressure and baseline histological lesions. CONCLUSION: This study suggests that in our population with IgAN, an interaction between ACE and eNOS polymorphisms may be a prognostic factor for renal function deterioration.

Peroxisome proliferator-activated receptor-gamma2-Pro12Ala and endothelial nitric oxide synthase-4a/bgene polymorphisms are associated with essential hypertension.

OBJECTIVE: Peroxisome proliferator-activated receptor-gamma2 (PPARgamma2) belongs to the family of the nuclear hormone receptors and has been recently implicated in vascular biology. PPARgamma2(Pro12Ala) gene polymorphism is associated with obesity, body mass index and diabetes mellitus. The endothelial nitric oxide synthase (eNOS) (4a/b) gene polymorphism contributes to coronary heart disease and hypertension risk. We tested whether both polymorphic variants were associated with hypertension risk, and their inter-relationship with plasma homocysteine. DESIGN: A case-control study was conducted selecting 235 subjects with arterial hypertension and 223 normotensive matched controls. METHODS: Genotyping for the PPARgamma2(Pro12Ala) and the eNOS(4a/b) were performed by mutagenically separated polymerase chain reaction and by polymerase chain reaction. Glucose, lipid profile, plasma creatinine, homocysteine and microalbuminuria were measured. RESULTS We found a significant contribution of the PPARgamma2(Pro12Ala) and eNOS(4a/b) gene polymorphisms to hypertensive risk in our population (odds ratio, 1.9 and 1.6, respectively), confirmed by multiple logistic regression analysis. Those subjects with normal plasma homocysteine values had an increased hypertensive risk with an odds ratio of 2.6 for the PP genotype of the PPARgamma2 gene and an odds ratio of 1.8 for the a allele of the eNOS gene. CONCLUSIONS: Both analyzed polymorphisms were associated in a synergistic manner with hypertension. This effect manifested only in those subjects with normal homocysteine plasma values. Our findings suggest complex genotype-environmental interactions on hypertensive risk.

[The involvement of the renin-angiotensin system gene polymorphisms in coronary heart disease]. / Relevancia de los polimorfismos génicos del sistema renina-angiotensina en la enfermedad coronaria.

INTRODUCTION AND OBJECTIVES: Previous studies angiotensin-converting enzyme gene insertion/deletion polymorphism ACE (I/D), angiotensinogen gene polymorphism, and angiotensin II AT1 receptor polymorphism in relation to coronary heart disease controversial results. This study was designed to analyze the association between these gene polymorphisms and the first coronary event in individuals residing on Grand Canary Island, Spain. PATIENTS AND METHOD: Case-control study. Case subjects (n = 304) were recruited at the first coronary event; age-matched controls (n = 315) were randomly selected from the Grand Canary population. Participants were examined for the usual risk factors. Blood samples were obtained for biochemical analyses and DNA extraction. Genotyping was performed by PCR and restriction analysis. RESULTS: Neither ACE (I/D) nor AT1 receptor polymorphism was associated with coronary heart disease, whereas the frequency distribution of AGT M235T genotypes among patients and control subjects (TT: 29% and 19%; MT: 48% and 50%; MM: 22% and 31%, respectively) was statistically different (p = 0.003). Multiple logistic regression analysis identified the TT genotype of the angiotensinogen gene (OR = 1.9; 95% CI 1.1-3.4), diabetes (OR = 4.4; 95% CI 2.0-9.4) and hypertension (OR = 2.1; 95% CI 1.3-3.3) as risk factors predicting the coronary event. CONCLUSIONS: Our results provide no evidence of an association between ACE (I/D) or AT1 receptor polymorphism and coronary heart disease. However, homozygosity for the T allele of the angiotensinogen gene, diabetes and hypertension independently place individuals at higher risk of experiencing a coronary event on Grand Canary Island.