Aldosterone synthase alleles and cardiovascular phenotype in young adults

Abstract

The C(-344)T promoter polymorphism of the human aldosterone synthase (CYP11B2) gene has been associated with hypertension and cardiac hypertrophy, but there were contrasting data. We analysed the genotype/phenotype associations between this polymorphism and cardiovascular variables in a young adult population, where interactions among genes, gene-environment, and acquired ageing-related organ damage are reduced. Anthropometric measurements, blood pressure, heart rate, left ventricular variables (by echocardiography), and carotid artery wall intimal-media thickness (by high-resolution sonography and digitalized morphometry) were taken in 420 white Caucasian students (mean age 23.5 years, s.d. 2.5 years). CYP11B2 alleles were detected by genomic polymerase chain reaction followed by digestion. Taking into account the three possible models of inheritance, we found no differences in the considered variables, except for an independent effect of the C(-344) allele on SBP in males (TT 125.6 (1.6), TC 128.4 (1.2) and CC 130.5 (2.2), mmHg, media (ES), P=0.03), and on interventricular septum thickness in diastole in females (CC 6.98 (0.12) vs TT 6.87 (0.09) and TC 6.87 (0.07), mmHg, P<0.01), in the codominant model. In conclusion, the CYP11B2 C(-344)T polymorphism appears to have a slight role in the cardiovascular phenotype of young healthy adults, even if these genotype/phenotype relationships might change with ageing.

Full text

ORIGINAL ARTICLE
Aldosterone synthase alleles and
cardiovascular phenotype in young adults
R Sarzani
1
, F Salvi
1
, P Dessı
´-Fulgheri
1
, R Catalini
1
, D Mazzara
1
, G Cola
1
, N Siragusa
1
,
D Spagnolo
1
, P Ercolani
1
, R Gesuita
2
, F Carle
2
and A Rappelli
1
1
Institute of Clinical Medicine, University of Ancona, Ancona, Italy;
2
Department of Epidemiology,
Biostatistics, and Medical Information Technology, University of Ancona, Ancona, Italy
The C(344)T promoter polymorphism of the human
aldosterone synthase (CYP11B2) gene has been asso-
ciated with hypertension and cardiac hypertrophy, but
there were contrasting data. We analysed the genotype/
phenotype associations between this polymorphism
and cardiovascular variables in a young adult popula-
tion, where interactions among genes, gene–environ-
ment, and acquired ageing-related organ damage are
reduced. Anthropometric measurements, blood pres-
sure, heart rate, left ventricular variables (by echocar-
diography), and carotid artery wall intimal–media
thickness (by high-resolution sonography and digita-
lized morphometry) were taken in 420 white Caucasian
students (mean age 23.5 years, s.d. 2.5 years). CYP11B2
alleles were detected by genomic polymerase chain
reaction followed by digestion. Taking into account the
three possible models of inheritance, we found no
differences in the considered variables, except for an
independent effect of the C(344) allele on SBP in males
(TT 125.6 (1.6), TC 128.4 (1.2) and CC 130.5 (2.2), mmHg,
media (ES), P¼0.03), and on interventricular septum
thickness in diastole in females (CC 6.98 (0.12) vs TT
6.87 (0.09) and TC 6.87 (0.07), mmHg, Po0.01), in the
codominant model. In conclusion, the CYP11B2
C(344)T polymorphism appears to have a slight role
in the cardiovascular phenotype of young healthy
adults, even if these genotype/phenotype relationships
might change with ageing.
Journal of Human Hypertension (2003) 17, 859–864.
doi:10.1038/sj.jhh.1001619
Keywords: young; aldosterone synthase; alleles; blood pressure; cardiac hypertrophy
Introduction
Aldosterone is a key hormone in BP regulation and
cardiovascular disease. The aldosterone synthase
gene (CYP11B2) C(344)T promoter polymorphism
was originally associated with left ventricular size
and mass in young healthy adults, as reported by
Kupari et al.
1
Indeed, the C(344) allele was
strongly and independently associated with in-
creased left ventricular diameters and mass. A
subsequent study on a larger but older population
failed to confirm the association between C(344)T
polymorphism and BP, cardiac measurements, and
aldosterone levels.
2
Further contradictory results
came from another paper that described both a
linkage study on hypertensive sibships and a case–
control study.
3
These studies, based on older
populations than Kupari’s,
1
failed in finding a
linkage of hypertension with CYP11B2 alleles, but
found a positive association of the T(344) allele
with hypertension.
3
Finally, a recent study found
that the CC genotype was associated with early
eccentric left ventricular hypertrophy in young mild
hypertensives.
4
These contrasting findings might depend on
multiple factors, including age of the studied
populations. Indeed, multiple genetic and acquired
factors can interact and overlap with ageing, making
the results of the association and linkage studies
contradictory, depending both on the duration of the
gene–environment interaction and on age-depen-
dent gene expression.
It is conceivable to hypothesize that the poten-
tially unfavourable early effects of the CYP11B2
C(344) or T(344) allele might affect the cardio-
vascular phenotype of young adults. A young adult
population is likely to represent a good model for
studying the effects of a single gene on cardiovas-
cular phenotype. The multiple and complex inter-
actions among genes, gene–environment, and
acquired ageing-related organ damage (eg renal
failure) are all limited in young subjects. Despite
this, different levels of BP and cardiac dimensions
are already measurable even at this young age,
depending on gender and family history.
5,6
We
therefore decided to investigate the associations of
Received 17 April 2003; revised 21 June 2003; accepted 3 July
2003
Correspondence: Professor R Sarzani, Clinica di Medicina
Interna, Polo Ospedaliero-Universitario, Via Conca, 60020
Torrette of Ancona, Italy.
E-mail: sarzani@unian.it
Journal of Human Hypertension (2003) 17, 859– 864
&
2003 Nature Publishing Group All rights reserved 0950-9240/03
$25.00
www.nature.com/jhh

C(344)T polymorphism with clinical, cardiac, and
arterial wall variables in a large population of
healthy young adults to look for an independent
genotype/phenotype relationship.
Materials and methods
Population and clinical evaluation
By a posted advertisement in the Medical School of
the University of Ancona, located in the town of
Ancona in east-central Italy, we recruited 434 young
white Caucasians (mean age 23.5 years, s.d. 2.5
years) without previously diagnosed cardiovascular
diseases; each subject gave a written informed
consent and institutional approval was obtained as
previously described.
6
Briefly, anthropometric, SBP,
DBP, and heart rate (HR) measurements were taken;
family history for hypertension, smoking habits, and
physical activity were carefully evaluated by a
questionnaire filled with the assistance of a physi-
cian. A total of 14 subjects were excluded from
further analysis because of significant valvulopathy,
cardiac diseases, or assumption of drugs interfering
with BP or cardiac structure (eg oestroprogestins),
or, in one case, loss of blood sample. Among the 420
subjects studied, 43 had a SBP X140 mmHg and/or
DBP X90 mmHg, but were not classified as hyper-
tensives because BP measurements were made in a
single visit.
Echocardiographic and echovascular measurements
Left ventricular dimensions were measured by
echocardiography (3.5 MHz probe, SIGMA iris 440,
Kontron Instruments, France) after superVHS re-
cording. The left ventricular mass (LVM) was
calculated (M-mode tracings under two-dimensional
control, left parasternal short axis view, mean of
three cardiac cycles) using the formula of Devereux
7
(Penn convention) (which has been validated for use
in individuals with normal hearts), and indexed
either by body surface area or by height
2.7
.
8
The left
ventricular diastolic function was evaluated using
PW Doppler from the apical four-chamber view:
transmitral Doppler flow was obtained with a 4 mm
sample volume placed on the tips of mitral leaflets,
calculating (mean of three cardiac cycles) early
diastolic velocity peak (Epk) and integral (IntE),
atrial systolic velocity peak (Apk) and integral
(IntA), isovolumic relaxation time (IRT) and early
filling deceleration time (DT) adjusted by the HR at
the moment of the examination. The reliability of
echocardiographic measurements in our centre was
assessed in a previous study.
9
The far and near carotid arterial walls were
evaluated by high-resolution sonography using a
Biosound 2000 II SA system with an 8 MHz
transducer (Biosound Inc., Indianapolis, IN, USA)
at the level of distal common carotid, bifurcation,
and the first centimetre of the proximal internal
carotid of both sides according to the protocol of a
multicentric international study in which we have
been a referral centre.
10
After superVHS/NTSC
recording, a total of 12 intimal–medial thickness
(IMT) measurements were obtained for each subject
with the help of a software for morphometric
analysis (KS-100-SW, Carl Zeiss, Hallbergmoos,
Germany) and the mean of the maximum IMT of
the four far walls of the carotid bifurcations and
distal common carotid arteries (CBM-max), mean of
the maximum IMT at 12 different sites (M-max), and
overall mean maximum IMT (T-max) have been used
for statistical analysis. The reliability of ultrasonic
measurements of IMT in our centre was also
assessed in the study reported above.
10
DNA extraction and genotyping
Genomic DNA was extracted from whole blood
using the Gnome Whole Blood kit (BIO 101, Vista,
CA, USA). CYP11B2 C(344)T polymorphism was
evaluated by polymerase chain reaction (PCR) using
the ‘Ready to Go’ PCR kit (Amersham Pharmacia
Biotech, Milan, Italy) with the primers previously
described,
1
and enzymatic digestion by HaeIII (New
England Biolabs), followed by electrophoresis in 4%
NuSieve (FMC BioProducts, Rockland, ME, USA)
agarose gel. A photographic record of genotypes was
made after ethidium bromide staining.
Statistical analysis
The present study is a post hoc genetic analysis of
an already phenotyped population.
6
The Hardy–
Weinberg equilibrium for the distribution of
CYP11B2 genotypes in the study population was
assessed using the w
2
test.
Analysis of covariance was performed to verify
the effect of sex and BMI on the following variables:
SBP, DBP, HR for clinical variables, left ventricular
diastolic diameter (LVDD), interventricular septum
thickness in diastole (IVSD), posterior wall thick-
ness in diastole (PWD), LVM, IntE/IntA, Epk/Apk,
DT for cardiovascular variables, and M-max, T-max
and CBM-max for IMT measurements.
The effect of CYP11B2 genotypes on clinical,
cardiac, and IMT measurements were investigated
according to three genetic models: the codominant
model in which each genotype was considered
separately; the C-recessive model in which geno-
types TT and TC were pooled and compared with
CC; the C-dominant model in which genotype TT
was compared with TC and CC pooled genotypes.
The ANOVA adjusted for covariates (body mass
index (BMI) for clinical variables, BMI and BP for
cardiac variables, pulse pressure (DBP) for IMT
measurements) was used to evaluate the effect of
CYP11B2 genotypes on clinical, cardiac, and IMT
measurements in each genetic model.
CYP11B2 and young cardiovascular phenotype
R Sarzani et al
860
Journal of Human Hypertension

The power of ANOVA models was estimated for
each dependent variable adjusted for covariates
considering actual sample size and sample variance,
with a significant level equal to 5% and an effect
size of independent variable equal to 5% (ie for SBP,
an effect size of 5% means that the model is able to
show a mean difference equal to 3 mmHg among
genotype groups, if this difference is really due to
the effect of genotype on SBP, adjusted for covari-
ates).
11
Power analysis was performed for males and
females separately.
All the analysis related to the genetic models were
performed separately according to sex; the results of
analysis of variance were expressed as adjusted
means and standard errors (s.e.). A level of sig-
nificance equal to 0.05 was used to assess statistical
significance. The Statistical Analysis System (SAS
8.2, Sas Institute Inc., Cary; NC, USA) was used for
all statistical analyses.
Results
The characteristics of the subjects studied, and the
echocardiographic and echovascular measurements
are reported in Tables 1 and 2, respectively. The BMI
means, as well as the means of most of the
cardiovascular variables, were significantly different
between genders, the females having significantly
lower BMI, BP, cardiac dimensions, LVM, and IMT
(Tables 1 and 2).
CYP11B2 genotypes were 126 TT (30%), 223 TC
(53%), and 71 CC (17%), according to the Hardy–
Weinberg equilibrium (P¼0.10).
Statistical analysis according to a C- and a T-
dominant model did not show any independent
significant association between the CYP11B2
C(344)T polymorphism and the considered vari-
ables (data not shown).
On the contrary, when the codominant model was
considered, a positive and independent effect of the
CYP11B2 C(344)T polymorphism on SBP was
found in males (Table 3), even if comparisons
among groups do not allow us to explain the main
effect,
12
and on IVSD in females (Table 4). No
significant associations of CYP11B2 genotypes with
echocardiographic variables in males were found in
the codominant model (Table 4) and no significant
differences among genotypes were observed on
echovascular variables either in males or females
(data not shown).
For males, the power of ANOVA models was of
90% for all the variables; for females, the power of
ANOVA models was 88% for both clinical and
echocardiographic variables, while it was 93% for
echovascular variables. The study power supports
the results reported above.
Discussion
Allelic variants of many candidate genes for hyper-
tension have been associated with hypertension and
cardiovascular phenotype in both case–control and
linkage studies.
1,4,13–15
These associations might be
influenced by multiple gene–environment interac-
tions, age-dependent gene expression changes, and
selection criteria of cases and controls.
On the contrary, a young adult population, in
which these confounding factors are reduced or
absent, represents a good model to study the effects
of a single allelic variant on the cardiovascular
phenotype. Even at this young age, indeed, different
levels of BP and cardiac dimensions are measurable,
Table 1 Main characteristics of the subjects (n=420)
Males (n=218) Females (n=202) P
Age (years) 24.0 (2.6) 22.9 (2.2) o0.001
a
BMI (kg/m
2
) 23.7 (2.6) 21.8 (2.9) o0.001
a
SBP (mmHg) 128.2 (13.0) 116.7 (11.8) o0.001
a
DBP (mmHg) 79.9 (8.9) 73.3 (7.7) o0.001
a
DBP (mmHg) 48.4 (12.0) 43.4 (9.8) o0.001
a
HR (bpm) 75.8 (11.4) 78.3 (11.1) 0.02
a
Family history of hypertension (n, %)
No 139 (67.2) 123 (62.1) 0.29
b
Yes 68 (32.9) 75 (37.9)
CYP11B2 genotypes (n, %)
T(344)T 61 (28.0) 65 (32.2)
T(344)C 120 (55.0) 103 (51.0) 0.63
b
C(344)C 37 (17.0) 34 (16.8)
BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; DBP, pulse pressure; HR, heart rate. Values are as means and
s.d., except for family history and genotypes that are reported as number of subjects and (percentage). A positive family history of hypertension
was defined as the presence of at least one first-degree relative with high blood pressure that required treatment.
a
t-test for independent samples.
b
w
2
test.
CYP11B2 and young cardiovascular phenotype
R Sarzani et al
861
Journal of Human Hypertension

depending on gender, family history of hyperten-
sion, and genetic variants.
5,6,16,17
When the sex and BMI effects on clinical, cardiac,
and IMT variables were investigated, we found that
BMI was able to affect SBP and DBP levels. HR was
affected neither by BMI nor by gender. Both sex and
BMI influenced LVDD. IVSD, LVM, and PWD were
affected by BMI. There was no any significant effect
either of sex or of BMI on IntE/IntA, Epk/Apk, and
DT. Finally, regarding IMT measurements, we found
that BMI affected M-max (Sarzani et al
6
and data not
shown). Thus, in our young population BMI is a key
factor in the modulation of cardiovascular pheno-
type even at this young age.
In our study, we investigated the association of the
biallelic C(344)T CYP11B2 polymorphism with
BP, cardiac variables, and IMT of the carotid arteries,
and we found a significant effect of C(344) allele
on SBP (males, Table 3). A similar effect of the
C(344) allele was also observed on IVSD (females,
Table 4).
These results are interesting because the studied
population was free of the ageing-dependent organ
changes present in hypertensive adults. Indeed, in
Table 2 Echocardiographic and echovascular variables of the subjects
Males (n=218) Females (n=202) P
a
Echocardiographic variables
LVDD (mm) 51.7 (3.9) 46.5 (3.4) o0.001
IVSD (mm) 7.7 (0.8) 6.9 (0.8) o0.001
PWD (mm) 7.8 (0.8) 6.9 (0.7) o0.001
RWT 0.3 (0.03) 0.3 (0.03) 0.16
LVMi (g/m
2
) 93.3 (16.2) 79.1 (13.3) o0.001
LVM/h
2.7
(g/m
2.7
) 38.5 (7.5) 34.7 (7.0) o0.001
IntE/IntA 1.6 (0.4) 1.7 (0.4) 0.29
Epk/Apk 1.7 (0.4) 1.7 (0.5) 0.23
IRT (ms) 77.9 (0.78) 76.4 (0.81) 0.18
DT (ms) 138.3 (21.0) 136.1 (20.2) 0.28
Males (n=217) Females (n=198) P
Echovascular variables
M-max (mm) 0.51 (0.06) 0.49 (0.06) o0.001
CBM-max (mm) 0.57 (0.07) 0.53 (0.07) o0.001
T-max (mm) 0.69 (0.11) 0.65 (0.12) o0.001
LVDD, left ventricular diastolic diameter; IVSD, interventricular septum thickness in diastole; PWD, posterior wall thickness in diastole; RWT,
relative wall thickness calculated as (PWD+IVSD)/LVDD; LVMi, left ventricular mass indexed by body surface area; LVM/h
2.7
, left ventricular mass
indexed by m
2.7
; IntE/IntA, integral of early diastolic and atrial systolic velocity peak ratio; Epk/Apk, early diastolic and atrial systolic velocity
peak ratio; IRT, isovolumetric relaxation time; DT, deceleration time; M-max, mean of the maximum carotid artery wall intimal–medial thickness
(IMT) at 12 different sites; CBM-max, mean of the maximum IMT of the four far walls of the carotid bifurcation and distal common carotid arteries;
T-max, overall maximum IMT. Values are as mean and s.d.
a
t-test for independent samples.
Table 3 Clinical variables by CYP11B2 genotypes (codominant hypothesis)
Significance of model TT TC CC P
n=61 n=120 n=37
Males
SBP (mmHg) o0.01 125.6 (1.6) 128.4 (1.2) 130.5 (2.2) 0.03
DBP (mmHg) o0.01 78.2 (1.1) 79.8 (0.8) 82.4 (1.5) 0.62
DBP (mmHg) 0.08 47.4 (1.5) 48.6 (1.1) 48.1 (2) F
HR (bpm) 0.29 76.5 (1.5) 75 (1) 76.9 (1.9) F
n=65 n=168 n=34
Females
SBP (mmHg) 0.17 116.6 (1.5) 116.6 (1.2) 116.7 (2) F
DBP (mmHg) 0.34 73.7 (1) 72.5 (0.8) 74.4 (1.3) F
DBP (mmHg) 0.46 42.9 (1.2) 44.1 (1) 42.4 (1.7) F
HR (bpm) 0.83 78.5 (1.4) 77.7 (1.1) 80 (1.9) F
Abbreviations are as in Table 1. Results of analysis of variance, adjusted mean, and s.e. Values were adjusted for BMI. When the ANOVA adjusted
for the covariates (model) was not significant, P-values of CYP11B2 genotype’s effect was not reported in the far right column.
CYP11B2 and young cardiovascular phenotype
R Sarzani et al
862
Journal of Human Hypertension

older populations it may be difficult to separate the
effect of C(344)T polymorphism from the effects of
ageing-related changes due to overlapping risk
factors. Studies of coronary artery disease indicate
that genetic determination in young individuals is
much stronger than in old individuals,
18
probably
because of increasing participation of nongenetic
factors in disease aetiology with ageing. Therefore, it
is important to consider that the role of inheritance
in determining susceptibility to hypertension may
also decline with age.
19
Nevertheless, it is also important to note that no
significant effect of C(344)T was found in the other
BP, cardiac, and IMT considered variables and the
study power supports these results. Moreover,
sitting BP measurements were taken three times
but in a single visit,
6
and SBP, that is positively
associated with C allele in males, might be espe-
cially sensitive to the measurement itself. An
interpretation is that this polymorphism has a slight
(if any) role in determining the cardiovascular
phenotype in young adults. Increasing evidence
suggests that susceptibility to hypertension-related
organ damage might be separate and different from
the inheritance of susceptibility to hypertension.
19
Indeed, it is possible that the most common
polymorphisms of the renin–angiotensin–aldoster-
one system studied so far have very little effect
(if any) on BP and its consequences, as also
suggested by our results
6
and those of another recent
study.
20
Studies that analysed older populations (affected
sibships, cross-sectional, and case–control studies)
produced widely contradictory data
2,3
even if, over-
all, the T(344) allele appears to be the ‘unfavour-
able’ one.
3
Population biases (criteria used to select
patients and controls or differences in age, environ-
mental, and ethnic/genetic background), lack of
statistical power, epistatic interactions,
13,14
and,
finally, publication bias toward positive association
have been indicated as possible causes of these
contradictory results.
Finally, from the biological and functional point
of view, the C(344) allele was suggested to have a
reduced transcription
1
compared with the T(344)
allele which, accordingly, has been associated with
higher aldosterone levels.
21
Our hypothesis is that a
slight resetting of the renin–angiotensin system
(chronic, low-level up-regulation, even without
significant plasmatic differences), secondary to
inherited reduced C(344)C CYP11B2 gene tran-
scription, might be present. This would induce, in
the long term, aldosterone-independent higher BP
and cardiac changes by an increased activity of
angiotensin II on arteries, peripheral nervous sys-
tem, and cardiac tissue, even in young subjects.
22
In older populations, increased visceral adiposity,
acting as an independent source of angiotensinogen
Table 4 Echocardiographic variables by CYP11B2 genotypes (codominant hypothesis)
Significance of model TT TC CC P
n=61 n=120 n=37
Males
LVDD (mm) 0.04 51.5 (0.5) 51.8 (0.4) 52 (0.7) 0.84
IVSD (mm) o0.01 7.85 (0.11) 7.66 (0.07) 7.69 (0.14) 0.30
PWD (mm) o0.01 7.84 (0.1) 7.81 (0.07) 7.75 (0.13) 0.37
RWT 0.52 0.31 (0) 0.3 (0) 0.3 (0.01) F
LVMi (g/m
2
)
a
0.38 93.7 (2.5) 94.5 (1.8) 93.5 (3.2) F
LVM/h
2.7
(g/m
2,7
)
a
0.06 38.5 (1.0) 38.4 (0.7) 39.1 (1.2) F
IntE/IntA 0.03 1.58 (0.05) 1.64 (0.03) 1.61 (0.06) 0.27
Epk/Apk 0.01 1.64 (0.05) 1.73 (0.04) 1.65 (0.07) 0.2
IRT (ms) 0.12 78.2 (1.4) 77.7 (1.0) 78.1 (1.7) F
DT (ms)
b
o0.01 135.2 (2.6) 141.0 (1.8) 134.9 (3.4) 0.1
n=65 n=103 n=34
Females
LVDD (mm) o0.01 46.3 (0.4) 46.3 (0.3) 47.4 (0.5) 0.11
IVSD (mm) o0.01 6.87 (0.09) 6.87 (0.07) 6.98 (0.12) o0.01
PWD (mm) o0.01 6.9 (0.08) 6.86 (0.07) 7.03 (0.12) 0.2
RWT 0.4 0.3 (0) 0.3 (0) 0.3 (0.01) F
LVMi (g/m
2
)
a
0.43 77.6 (1.7) 78.5 (1.3) 82.5 (2.3) F
LVM/h
2.7
(g/m
2.7
)
a
0.45 33.8 (0.9) 34.7 (0.7) 36.0 (1.2) F
IntE/IntA o0.01 1.66 (0.05) 1.68 (0.04) 1.59 (0.07) 0.35
Epk/Apk 0.1 1.73 (0.06) 1.76 (0.05) 1.72 (0.08) F
IRT (ms) 0.04 76.3 (1.4) 76.9 (1.2) 75.0 (2.0) 0.70
DT (ms)
b
o0.01 132.4 (2.4) 138.3 (1.9) 136.7 (3.3) 0.16
Abbreviations are as in Table 2. Results of analysis of variance, adjusted mean, and s.e.; values adjusted for BP and BMI.
a
Adjusted for BP only.
b
Adjusted for BP and for HR at the moment of echocardiography.
When the ANOVA adjusted for the covariates (model) was not significant, P-values of CYP11B2 genotype’s effect was not reported in the far right
column.
CYP11B2 and young cardiovascular phenotype
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863
Journal of Human Hypertension

and angiotensin II, might facilitate CYP11B2 tran-
scription in the presence of the T(344) allele,
determining increased aldosterone levels and its
cardiovascular consequences.
21
Our hypothesis is
that the association between the C(344)T alleles
and BP might change with age, similar to the age-
dependent association of other candidate genes as
shown for b
2
-adrenergic receptor alleles.
23
The association between the C(344)T poly-
morphism and the cardiovascular phenotype in
young and in older hypertensive patients needs to
be further investigated with specifically designed
studies to assess the hypothesis of an age-dependent
change of the role of aldosterone synthase alleles on
cardiovascular phenotype.
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