CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 2, March/April 2010
AFRICA
93
Cardiovascular Topics
Blood pressure response to an exercise treadmill test,
and echocardiographic left ventricular geometry in
Nigerian normotensive diabetics
EA AJAYI, MO BALOGUN, OA AKINTOMIDE, RA ADEBAYO, OE AJAYI, RT IKEM, SA OGUNYEMI, AT OYEDEJI
Summary
Objectives:
This study evaluated normotensive diabetic
patients’ blood pressure response to graded exercise and their
echocardiographic pattern of left ventricular geometry.
Methods:
A descriptive, cross-sectional, hospital-based study
was carried out on 30 normotensive type 2 diabetic patients
and 34 controls, aged 30 to 60 years. The outcome measures
were to determine the exercise-related variable, blood pres-
sure response, and left ventricular geometry by means of
echocardiography.
Results:
Nineteen (29.7%) and 11 (17.2%) normotensive
diabetic subjects had normal left ventricular geometry and
concentric left ventricular remodelling, respectively. None
of the subjects had concentric or eccentric left ventricu-
lar hypertrophy. On this basis, the normotensive diabetic
subjects were divided to two groups: G1 (normal) and G2
(concentric left ventricular remodelling). The groups had
comparable mean age, body mass index (BMI), fasting blood
glucose (FBG) and two-hour post-prandial blood glucose
values, and heart rate, systolic (SBP) and diastolic blood
pressure (DBP) at rest. G2 patients had higher mean dura-
tion of diabetes than G1 subjects (69.0
±
9.48 vs 18.7
±
8.7
months;
p
=
0.007). Peak systolic blood pressure was signifi-
cantly higher in G2 than G1 subjects (213.6
±
20.1 vs 200.0
±
15.3 mmHg;
p
=
0.04). Although there was no statistically
significant difference in the left ventricular (LV) mass index
between the groups, G2 patients had significantly higher
relative wall thicknesses than G1 patients (0.53
±
0.03 vs 0.41
±
0.04;
p
<
0.001).
Conclusion:
Normotensive diabetic subjects with concentric
left ventricular remodelling have increased blood pressure
reactivity to exercise. It is probable, as suggested in earlier
studies, that increased blood pressure reactivity to exercise is
an indicator of target-organ damage, particularly in normo-
tensive diabetics.
Keywords:
diabetes, exercise, blood pressure response, left
ventricular geometry
Submitted 9/9/09, accepted 4/10/09
Cardiovasc J Afr
2010;
21
: 93–96
Stress increases blood pressure, and variable individual blood
pressure responses have been evaluated with regard to prediction
of new-onset hypertension, target-organ damage and incident
cardiovascular disease or death.
1
The significance of blood
pressure reactivity to exercise has been evaluated, with variable
results, in studies on the association between the blood pres-
sure response to exercise and either left ventricular mass or left
ventricular geometry in hypertensive patients.
2,3
The exaggerated
exercise blood pressure (BP) values in these hypertensive adults
have been attributed to impaired endothelial vasodilator func-
tion.
4
Arterial stiffness is also related to type 2 diabetes,
5
mainly due
to an impaired endothelial vasodilator function, which
in turn is
associated with increased afterload,
5
leading to an elevated systo-
lic blood pressure (SBP).
6
These processes consequently lead
to structural alterations in the diabetic heart. In normotensive
diabetic patients, early and asymptomatic functional and struc-
tural abnormalities may alter the normal response to exercise,
as already observed in elderly
7
and non-diabetic hypertensive
patients.
3
However, not much is known about the relationship
between blood pressure response to exercise and sub-clinical
cardiac end-organ damage in normotensive diabetics, particu-
larly in Nigeria.
In light of the above, we set out to investigate the relationship
between blood pressure response to graded exercise in normo-
tensive diabetics and their echocardiographic pattern of left
ventricular geometry, as evidence of cardiac end-organ damage.
Methods
Thirty normotensive type 2 diabetic subjects (male
=
15; female
=
15) and 34 normal controls (male
=
17; female
=
17) aged
30 to 60 years were recruited through the medical out-patient
department of Obafemi Awolowo University Teaching Hospitals
complex (OAUTHC), Ile Ife, Nigeria. Ethical clearance for the
study was approved by the Ethics and Research Committee of
the Hospital in conformity with ethical guidelines of the 1975
Department of Internal Medicine, University Teaching
Hospital, Ado Ekiti, Nigeria
EA AJAYI, FWACP,
,
Department of Medicine, Obafemi Awolowo University
Teaching Hospital, Ile Ife, Nigeria
MO BALOGUN, FWACP, FMCP
OA AKINTOMIDE, FWACP
RA ADEBAYO, FWACP
OE AJAYI
RT IKEM, FMCP
SA OGUNYEMI, FMCP
AT OYEDEJI, FMCP
