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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 3, May/June 2018
AFRICA
163
in the study between May 2010 and August 2011. Approval
of the local ethics committee and informed consents of the
participants were obtained accordingly.
A subject was considered treatment adherent when he/she
took her/his prescribed statin regularly on a daily basis. A subject
was considered complient if his/her baseline and post-treatment
measurements were obtained as per the study protocol. Eight
cases (four with compliance problems with follow up, one with
lung cancer and three with non-adherence to medication) were
excluded from the study.
The study was completed with 104 hyperlipidaemic patients,
of whom 50 were assigned to atorvastatin 20 mg per day
and 54 to rosuvastatin 10 mg per day. Patients under the age
of 18 and over the age of 80 years, those with heart failure,
uncontrolled hypertension, endocrine diseases, previous coronary
artery disease, frequent and permanent cardiac dysrhythmia,
malignancy, chronic obstructive pulmonary disease, and chronic
liver, kidney, neurological or psychiatric diseases, which were
likely to produce a compliance problem, were not included in
the study.
Baseline demographic characteristics of the patients were
recorded. Body mass index (BMI) was calculated as body
weight (kg)/height
2
(m). Levels of fasting blood glucose, serum
total cholesterol, high-density lipoprotein (HDL) cholesterol,
low-density lipoprotein (LDL) cholesterol, triglycerides
(TG), urea, creatinine, aspartate transaminase (AST), alanine
transaminase (ALT), creatinine phosphokinase (CPK) and
complete blood counts were measured in all patients after a
12-hour fasting period. In addition, the patients underwent
transthoracic echocardiography.
Lipid levels indicated eligible patients, who were randomly
assigned to receive either rosuvastatin 10 mg/day or atorvastatin
20 mg/day. The patients were followed for one year. Baseline
measurements were repeated at the end of the 12-month
treatment period. Change in LDL level (
Δ
LDL) was defined as
the difference between baseline and post-treatment LDL values.
Endothelial function was measured ultrasonographically
over the brachial artery using echocardiography (Ge-Vivid
7 Pro, General Electric, Florida, USA) with a 12-L probe.
All measurements were performed according to the method
described elsewhere in the literature.
11
Brachial artery basal
Doppler velocity (DV), basal diameter (BD), brachial artery
hyperaemia velocity (HV), and post-flow brachial artery lumen
diameter (hyperaemia diameter
=
HD flow-mediated dilation
response
=
FMDR) were recorded. FMD was calculated from
the following equation:
% FMD
=
FMDR – BD
___________
BD
× 100
Baseline endothelium-independent dilation (EID) was
measured 10 minutes after deflation of the cuff to obtain baseline
conditions and was labelled as pre-nitrate BD. Thereafter, the
patients received 400
μ
g of nitroglycerin sublingually; three to
five minutes later, post-nitrate Doppler, post-nitrate velocity
(NTGV) and post-nitrate arterial diameter (NTGD) were
measured. Lumen diameter was measured three times and the
arithmetic mean was calculated. Post-nitrate arterial diameter
was named nitrate-mediated dilation response (NMDR). EID
was calculated using the following equation:
% EBG
=
NMDR – pre-nitrate BD
____________________
Pre-nitrate BD
× 100
Δ
FMD and
Δ
EID were defined as the difference between
baseline and post-treatment FMD and EID values, respectively.
Statistical analyses
The SPSS (SPSS, Inc, Chicago, IL, USA) program was used
to analyse the data. Mean and standard deviations (SD) were
used for descriptive data. Student’s
t
-test was used to compare
normally distributed quantitative variables, whereas the Mann–
Whitney
U
-test was used to compare independent non-normally
distributed quantitative variables. Moreover, statistical
comparison between continuous dependent variables was done
by paired-samples
t
-test for normally distributed variables,
whereas the Wilcoxon test was used for non-normally distributed
variables. Relationships between the parameters were assessed
with Pearson’s correlation analysis for parametric variables and
by Spearman’s correlation analysis for non-parametric variables.
The results were evaluated with a 95% confidence interval and at
the significance level of
p
<
0.05.
Results
A total of 104 hyperlipidaemic cases were included in the study.
The patients were randomly assigned to either atorvastatin
(group 1,
n
=
50, 48.1%) or rosuvastatin (group 2,
n
=
54,
51.9%) therapy. Of the overall patients, 46 were male (53.7
±
9.7 years) and 58 were female (54.3
±
10.1 years). There was
no statistically significant difference between the two groups in
terms of baseline anthropometric characteristics of the subjects,
haemoglobin, haematocrit, white blood cell count, thrombocyte
count, and urea, creatinine, AST, ALT, CPK, total cholesterol,
TG, HDL and LDL levels.
Mean
Δ
LDL at the end of 12 months was 71.0
±
29.7 mg/
dl (1.84
±
0.77 mmol/l) and percentage
Δ
LDL was 42.2
±
17.6%
(
n
=
104) in the study population.
Δ
LDL was significantly
correlated with
Δ
FMD (
r
=
0.367,
p
<
0.005) and
Δ
EID (
r
=
0.523,
p
<
0.001). Percentage
Δ
LDL was statistically correlated
with
Δ
FMD (
r
=
0.412,
p
<
0.005) and
Δ
EID (
r
=
523,
p
<
0.001).
In the atorvastatin group, a statistically significant reduction
was shown in total cholesterol, LDL and TG levels compared
to baseline values. LDL level showed a 52.5% decrease after 12
months compared to baseline value, whereas no decrease was
observed in HDL level. FMD showed a statistically significant
increase (Table 1).
In the rosuvastatin group, a statistically significant decrease
was found in total cholesterol, LDL and TG levels compared to
baseline values. LDL level showed a 58.5% decrease at the end
of the 12 months compared to baseline value, whereas no change
was observed in HDL levels. While a statistically significant
increase was observed in the brachial artery basal diameter and
hyperaemia diameter compared to baseline values, no change
was observed in the post-nitrate diameter and EID values. FMD
showed a statistically significant increase compared to baseline
(Table 2).
No statistically significant difference was found between
the atorvastatin and rosuvastatin groups in respect of baseline
transthoracic echocardiographic and brachial artery endothelial
function measurements (Table 3). Comparison between the two
groups in terms of their effects on non-invasive ultrasonographic
brachial artery measurements after one year revealed no