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VOLUME 12 NUMBER 1 • JULY 2015
RESEARCH ARTICLE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
The results of these and other studies have resulted in treatment
guidelines recommending progressively lower LDL-C targets.
21-23
However, studies from all over the world have demonstrated
that many patients on lipid-lowering therapy do not reach their
recommended lipid targets.
24-26
The South African Heart Association
(SA Heart) together with the Lipid and Atherosclerosis Society
of Southern Africa (LASSA) therefore recently emphasised that
intensive management of dyslipidaemia could significantly reduce
the South African CVD health burden.
21
The DYSlipidaemia International Study (DYSIS) is a cross-sectional,
observational study that has examined the efficacy of lipid-lowering
therapies in patients from various regions of the world, including
Canada and Europe (11 countries), in order to better characterise
predictive factors for dyslipidaemia and CVD.
24,25
Here, as part of
DYSIS, we have analysed residual dyslipidaemia in statin-treated
South African patients
.
Methods
As part of DYSIS, this epidemiological, observational, cross-sectional
study was conducted in South Africa between 1 November and 9
December 2011. Data for the study were collected in the South
African private healthcare sector by 16 physicians; 50%were primary-
care physicians and 50% were specialised office-based physicians
(e.g. cardiologists).
Prior to study initiation, the relevant local ethical reviewcommittees
approved the study protocol and all patients gave written informed
consent before enrolling in the study. Key eligibility criteria were: (1)
age of at least 45 years, (2) receiving stable statin therapy for at least
3 months, and (3) fasting for at least 12 hours at the time of visit
while on statin therapy. Participating physicians were instructed to
include all eligible and consenting patients consecutively.
Patient demographic, lifestyle and clinical characteristics were
documented. Lipid levels (total cholesterol, LDL-C, HDL-C and
triglycerides) were measured using the CardioChek
®
device (http://
www.cardiocheck.com)at the time of patient enrollment to reliably
collect lipid measurements uniformly at all sites. The LDL-C test
strip provided measures LDL-C directly across a range of 1.29–5.18
mmol/l in about two minutes.
Additionally, the lipid-lowering regimen at the time of the most
recent blood sample was recorded for each patient (in particular,
statin type and daily dose) as well as any information regarding
other lipid-modifying therapies. The potency of different types of
statins was normalised using a calculation that allows benchmarking
against six different simvastatin dose levels (5, 10, 20, 40, 80
Table 1.
Patient characteristics, risk categories and lipid parameters in different ethnic groups
All patients
(
n
= 1 029)
Caucasian
(
n
= 582; 56.6%)
Black
(
n
= 226; 22.0%)
Asian
(
n
= 99; 9.6%)
Mixed ancestry
(
n
= 122; 11.9%)
Age (years) (mean ± SD)
65.4 ± 10.8
69.0 ± 11.0
60.0 ± 8.9
61.8 ± 9.0
60.9 ± 7.4
Family history of premature CHD (%)
26.7
34.0
1.8
44.4
23.0
Current smokers (%)
10.7
11.2
5.3
11.1
18.0
Hypertension (%)
76.8
69.8
93.3
64.6
89.3
Systolic BP (mmHg) (mean ± SD)
134.4 ± 20.0
134.9 ± 20.4
135.2 ± 19.4
129.0 ± 17.1
134.9 ± 20.7
Diastolic BP (mmHg) (mean ± SD)
79.7 ± 11.0
79.6 ± 11.1
79.6 ± 11.5
78.3 ± 9.6
81.2 ± 10.5
Waist circumference (cm) (mean ± SD)
100.7 ± 15.1
99.5 ± 16.5
105.0 ± 13.4
96.1 ± 9.6
101.8 ± 12.5
BMI (kg/m
2
) (mean ± SD)
29.6 ± 6.4
28.6 ± 6.4
32.8 ± 6.5
27.0 ± 4.5
30.4 ± 5.6
BMI > 30 kg/m
2
(%)
42.2
36.8
61.9
22.2
47.5
CVD (%)
36.2
41.1
9.7
51.5
49.2
Diabetes mellitus (%)
40.4
25.6
71.2
44.4
50.8
Metabolic syndrome (IDF) (%)
67.2
59.8
83.2
59.8
78.7
ESC risk level (2011)*
Very high-risk patient (%)
73.5
69.9
77.9
73.7
82.0
High-risk patient (%)
8.9
11.2
4.0
11.1
5.7
Moderate-risk patient (%)
13.5
15.6
11.5
9.1
10.7
Low-risk patient (%)
4.1
3.3
6.6
6.1
1.6
South African guidelines
Very high-risk patient (%)
68.6
61.2
77.9
73.5
82.8
High-risk patient (%)
9.2
11.7
6.2
8.2
3.3
Moderate-risk patient (%)
21.6
26.6
15.9
15.3
13.9
Low-risk patient (%)
0.6
0.5
0.0
3.1
0.0
Lipids (mmol/l) (mean ± SD)
LDL-C
2.3 ± 1.1
2.2 ± 1.0
2.1 ± 1.0
2.6 ± 1.2
2.7 ± 1.1
HDL-C
1.3 ± 0.4
1.3 ± 0.4
1.4 ± 0.4
1.3 ± 0.4
1.3 ± 0.5
Total cholesterol
4.4 ± 1.3
4.4 ± 1.2
4.4 ± 1.4
4.7 ± 1.6
4.7 ± 1.3
Triglycerides [median (IQR)]
1.6 (1.1–2.3)
1.5 (1.1–2.2)
1.7 (1.2–2.4)
1.7 (1.2–2.7)
1.5 (1.1–2.4)
Blood glucose
FBG (mmol/l) [median (IQR)]
4.9 (4.3–6.4)
4.6 (4.2–5.4)
6.2 (4.7–9.0)
5.3 (4.2–7.0)
5.6 (4.7–7.2)
HbA
1c
(%) diabetics [median (IQR)]
7.4 (6.6–8.8)
7.1 (6.0–8.0)
8.2 (6.8–9.9)
7.8 (7.0–8.7)
7.4 (7.0–8.8)
CHD, coronary heart disease; BP, blood pressure; BMI, body mass index; CVD, cardiovascular disease; DM, diabetes mellitus; IDF, International Diabetes
Federation.