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VOLUME 12 NUMBER 1 • JULY 2015
21
SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
Prevalence of dyslipidaemia in statin-treated patients in
South Africa: results of the DYSlipidaemia International
Study (DYSIS)
FREDERICK J RAAL, DIRK J BLOM, SHANIL NAIDOO, PETER BRAMLAGE, PHILIPPE BRUDI
Correspondence to: Frederick J Raal
Carbohydrate and Lipid Metabolism Research Unit, Department of
Medicine, University of the Witwatersrand, Johannesburg, South Africa
e-mail:
frederick.raal@wits.ac.zaDirk J Blom
Division of Lipidology, Department of Medicine, University of Cape Town,
Cape Town, South Africa
Shanil Naidoo
MSD South Africa, Midrand, South Africa
Peter Bramlage
Institut für Pharmakologie und präventive Medizin, Mahlow, Germany
Philippe Brudi
Merck & Co, Inc, Whitehouse Station, NJ, USA
Previously published in
Cardiovasc J Afr
2013;
24
(8): 330–338
S Afr J Diabetes Vasc Dis
2015;
12
: 21–29
Abstract
Introduction and objectives:
Cardiovascular disease (CVD)
is the leading cause of mortality worldwide and increased
levels of low-density lipoprotein cholesterol (LDL-C) are
an important modifiable risk factor. Statins lower LDL-C
levels and have been shown to reduce CVD risk. Despite
the widespread availability of statins, many patients do
not reach the lipid targets recommended by guidelines. We
evaluated lipid goal attainment in statin-treated patients in
South Africa and analysed variables contributing to poor
goal attainment as part of the DYSlipidaemia International
Study (DYSIS).
Methods:
This cross-sectional, observational study enrolled
1 029 consecutive South African patients consulting office-
based physicians. Patients were at least 45 years old, had
to be treated with a stable dose of statins for at least three
months and had been fasting for 12 hours. We evaluated
lipid goal attainment and examined variables associated
with residual dyslipidaemia [abnormal levels of LDL-C, high-
density lipoprotein cholesterol (HDL-C) and/or triglycerides
(TG)].
Results:
We found that 50.3% of the patients overall did not
achieve target LDL-C levels and 73.5% of patients were at
very high cardiovascular risk. In addition, 33.7% had low
levels of HDL-C, while 45.3% had elevated TG levels despite
statin therapy. Asian and mixed-ancestry patients but not
black (vs Caucasian ethnicity), as well as obese individuals
in South Africa were more likely to still have dyslipidaemia
involving all three lipid fractions.
Conclusions:
We observed that many patients in South
Africa experienced persistent dyslipidaemia despite statin
treatment, supporting the concept that there is a need
for more intensive statin therapy or the development of
novel treatment strategies. Measures aimed at combating
obesity and other lifestyle-related risk factors are also vital
for effectively controlling dyslipidaemia and reducing the
burden of CVD.
Keywords:
cardiovascular disease (CVD), dyslipidaemia, lipid
abnormalities, statins, low-density lipoprotein cholesterol (LDL-C)
Cardiovascular disease (CVD) is the leading cause of mortality
worldwide. In 2008, World Health Organisation (WHO) estimates
suggested that 30% (17.3 million) of all deaths worldwide could
be attributed to CVD.
1
(“Cardiovascular diseases (CVDs) Fact sheet
no. 317,” September 2012) In 2008 and 2009, the two most
recent years for which South African data are available, CVD was
responsible for 13.7 and 14.0% of total deaths, respectively.
2-4
However, CVD mortality rates are expected to rise in South Africa
as unhealthy lifestyle trends associated with urbanisation spread
to the countryside, and the population of people surviving life-
threatening infections continues to grow.
5,6
Well-known risk factors for CVD include age, gender,
dyslipidaemia, tobacco smoking, high blood pressure and diabetes
mellitus (DM). Other lifestyle behaviours such as excessive alcohol
consumption, sedentary lifestyle and poor diet with resultant
obesity further contribute to CVD risk.
7,8
The WHO 2008 estimates
indicated that the prevalence of obesity, tobacco smoking and
physical inactivity in South Africa were 31.3 (≥ 20 years old), 14
and 51.1%, respectively.
9
Furthermore, in 2010 the prevalence
of DM was 4.5% for individuals ≥ 15 years old,
10,11
and the WHO
estimated the rate of high blood pressure at 42.2% in 2008.
9
As
the prevalence of these risk factors rise in South Africa,
5
so will the
rate of CVD.
The main effect of statins is to lower LDL-C levels and they
are used extensively in both primary and secondary prevention
of CVD.
12-14
Importantly, several large clinical trials have indicated
that for every 1-mmol/l reduction in LDL-C levels there is a 23%
reduction in CVD risk.
15-18
In a further meta-analysis of studies
comparing high and low statin doses, more intensive lowering of
LDL-C (0.51 mmol/l additional reduction) in the high-dose statin
arm was associated with a further 15% reduction in CVD risk.
19
In the most recently published statin cardiovascular outcomes
trial (JUPITER study: men and women free of overt cardiovascular
disease over the ages of 50 and 60 years, respectively; baseline
LDL-C < 3.37 mmol/l and high-sensitivity C-reactive protein of
2 mg/l or more; randomised to rosuvastatin 20 mg/day or placebo),
statin treatment was associated with a 39% reduction in primary
endpoints (myocardial infarction, stroke, admission to hospital for
unstable angina, arterial revascularisation or CV death) in patients
with at least one risk factor for DM.
20