C-344T polymorphism of the aldosterone synthase gene and blood pressure in the elderly: a population-based study.
OBJECTIVE
Whether the C-344T polymorphism of the aldosterone synthase gene is important for blood pressure control remains controversial. It has been proposed that an association between this polymorphism and blood pressure might be evident in elderly subjects. The aim of the present study was to test this hypothesis in an epidemiological context.


METHODS
A cross-sectional epidemiological evaluation of a highly homogeneous unselected general population of elderly Caucasians.


METHODS
Lifestyle, medical history, anthropometrics, skinfold thickness, supine blood pressure, heart rate and biochemical measures were recorded in 437 subjects aged > or = 65 years living in a secluded valley. All were genotyped for C-344T allele status and underwent measurements of plasma aldosterone and renin.


RESULTS
The C-344T genotypic frequency did not deviate from Hardy-Weinberg equilibrium. The aldosterone to renin ratio was 19% lower in the CC than in the TT genotype. Systolic blood pressure was significantly lower in subjects with the CC genotype, higher in the TT (+9.6 mmHg versus CC) and intermediate in the CT (+7.9 mmHg versus CC). Adjustment for age, gender, smoking and antihypertensive treatment did not affect this association. Diastolic blood pressure did not differ across genotypes. A significant increase of systolic blood pressure with increasing age and with increasing skinfold thickness was observed in the TT homozygotes but not in the C-carriers.


CONCLUSIONS
These data support the concept that the C-344T polymorphism plays a role in controlling systolic blood pressure and the age-related increase in systolic blood pressure in response to age and to body fat, possibly through differences in modulation of aldosterone synthesis.
Casiglia
Edoardo
E
Department of Clinical and Experimental Medicine, University of Padova, Italy. edoardo.casiglia@unipd.it
Tikhonoff
Valérie
V
Mazza
Alberto
A
Rynkiewicz
Andrzej
A
Limon
Janusz
J
Caffi
Sandro
S
Guglielmi
Francesco
F
Martini
Bortolo
B
Basso
Giancarlo
G
Winnicki
Mikolaj
M
Pessina
Achille C
AC
Somers
Virend K
VK
D000368:Aged; D001794:Blood Pressure / Q000235:genetics*; D003430:Cross-Sectional Studies; D019405:Cytochrome P-450 CYP11B2 / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006339:Heart Rate / Q000235:genetics; D006801:Humans; D008297:Male; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics*; D044465:White People / Q000235:genetics
D019405:Cytochrome P-450 CYP11B2