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VOLUME 12 NUMBER 2 • NOVEMBER 2015
79
SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
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
Correspondence to: EA Ajayi
Department of Internal Medicine, University Teaching Hospital, Ado Ekiti,
Nigeria
e-mail:
lifecareado@gmail.com,
adekunze@yahoo.comMO Balogun
Department of Medicine, Obafemi Awolowo University Teaching Hospital,
Ile Ife, Nigeria
OA Akintomide
Department of Medicine, Obafemi Awolowo University Teaching Hospital,
Ile Ife, Nigeria
RA Adebayo
FWAP, Department of Medicine, Obafemi Awolowo University Teaching
Hospital, Ile Ife, Nigeria
OE Ajayi
Department of Medicine, Obafemi Awolowo University Teaching Hospital,
Ile Ife, Nigeria
RT Ikem
Department of Medicine, Obafemi Awolowo University Teaching Hospital,
Ile Ife, Nigeria
SA Ogunyemi
Department of Medicine, Obafemi Awolowo University Teaching Hospital,
Ile Ife, Nigeria
AT Oyedeji
Department of Medicine, Obafemi Awolowo University Teaching Hospital,
Ile Ife, Nigeria
Previously published in:
Cardiovasc J Afr
2010;
21
: 93–96
S Afr J Diabetes Vasc Dis
2015;
12
: 79–82
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
pressure 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 ventricular
hypertrophy. On this basis, thenormotensivediabetic 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 duration of diabetes than
G1 subjects (69.0 ± 9.48 vs 18.7 ± 8.7 months;
p
= 0.007). Peak
systolic blood pressure was significantly 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
normotensive diabetics.
Keywords:
diabetes, exercise, blood pressure response, left
ventricular geometry
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 pressure 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 function.
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
systolic blood pressure (SBP).
6
These processes consequently lead
to structural alterations in the diabetic heart. In normotensive
diabetic patients, early and asymptomatic functional and structural
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, particularly in Nigeria.
In light of the above, we set out to investigate the relationship
between blood pressure response to graded exercise in normotensive
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