[Angiotensinogen gene T174M polymorphism: opposite relationships with essential hypertension and obesity in a homogeneous population from Majorca (Baleric Islands, Spain)].
Numerous association studies have been performed to evaluate the relationship between the angiotensinogen gene and the essential hypertension, but their results are conflicting. The conflicting results may be explained by methodological reasons, particularly genetic differences in the population samples, phenotypic differences in the hypertensive populations analyzed, lack of appropriate control for other hypertension risk factors in some studies, or limited statistical power among many studies. Furthermore, hypertension is a public health issue of great relevance in Baleric Islands (Spain). For these reasons we performed an association study about the relationship between the M235T, T174M and G-6A diallelic polymorphisms of the angiotensinogen gene and hypertension in a population from Majorca (Balearic Islands), in which a considerable homogeneity with respect to ethnicity and environmental factors could be documented. This population was composed of 109 patients and 107 controls. Alleles of the angiotensinogen gene were determined by PCR and restriction site polymorphism analysis. The different genotypes were tested for association with dependent variables by univariate and multivariate logistic regression analysis. In the univariate analysis we found no evidence of association between the angiotensinogen gene genotypes and hypertension. This lack of association was independent of obesity, familial history of hypertension and diabetes for the genotypes of the polymorphisms M235T and G-6A; however, in the multivariate analysis the T174T174 genotype showed an almost significant positive association with hypertension [OR = 2.76 (95% confidence interval: 1.00-7.65, p = 0.05)]. The T174T174 genotype also showed a significant negative association with obesity [OR = 0.41 (95% confidence interval: 0.18-0.90, p = 0.03)] that remained after adjustment by sex, hypertension and diabetes [OR = 0.26 (95% confidence interval: 0.10-0.65, p = 0.004)]. Our results: a) are in contrast with the results from most previous studies that found a relationship of the T174M polymorphism with hypertension, as in those studies the M174 allele was responsible for the association; b) emphasize the need for rigorous control for obsesity in the studies of association between the angiotensinogen gene and hypertension; c) underscore the importance and the utility of using concrete populations to carry out studies on the genetic dissection of hypertension.
Marco
J
J
Servicio de Nefrología, Hospital Universitario Son Dureta, Palma de Mallorca.
Zabay
J M
JM
García-Marco
M A
MA
Gomez
G
G
Mulet
J M
JM
Munar
M A
MA
Soler
J
J
Viader
C
C
D000328:Adult; D000368:Aged; D000808:Angiotensinogen / Q000235:genetics*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000235:genetics*; D011110:Polymorphism, Genetic; D013030:Spain
D000808:Angiotensinogen