CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 8, September 2013
332
AFRICA
of hypertension and obesity, only 9.7% of black patients had
clinically overt CVD.
Asian patients had the highest rates of CVD (51.5%) among
all ethnic groups studied and also the highest reported rate of a
family history of premature CVD (44%). Diabetes was highly
prevalent at 44.4% while the hypertension prevalence of 64.6%
was similar to that observed in Caucasian patients. Mixed-
ancestry patients had the highest smoking rates (18%) while the
diabetes and hypertension prevalences were 50.8 and 89.3%,
respectively. CVD was documented in 49.2% of mixed-ancestry
patients.
CVD was almost twice as common in men (49.9%) than
women (26.3%). DM was more common in men than women
(45.7 vs 36.7%), while obesity was more frequent in women
(46.8 compared with 35.7%). Additionally, using the 2011 ESC
criteria, 73.5% of patients (83.9% men and 66.0% of women)
were classified as very high risk for CV complications [defined
as having CVD, DM and/or an ESC systematic coronary risk
evaluation (SCORE) risk of
≥
10% on chronic statin therapy].
Lipid-modifying regimens and statin potency
Prior to enrollment in DYSIS, patients had been treated with
various lipid-lowering therapies. The most commonly prescribed
statin was simvastatin (64.6%), followed by atorvastatin (22.2%),
rosuvastatin (10.9%), pravastatin (1.6%), fluvastatin (0.6%) and
lovastatin (0.2%). Other lipid-lowering agents were used by only
2% of patients, including ezetimibe (1.2%), fibrates (0.9%) and
bile acid sequestrants (0.2%).
The most frequently used statin dose potency was 3 (equivalent
to 20 mg simvastatin per day) for both very high-risk patients
(40.2%) and non-very high-risk patients (47.6%), while the
second most-frequent dose potency was 2 (equivalent to 10 mg
simvastatin per day) in 32.4 and 25.6% of very high-risk patients
and non-very high-risk patients, respectively (Fig. 1). While a
statin dose potency of 3 was most frequently used in Caucasian,
Asian and mixed-ethnicity patients, a dose potency of 2 was most
common in black patients.
Lipid abnormalities
Data on the frequency of lipid abnormalities, including
sub-analyses by CVD risk level, are provided in Tables 2 and 3.
Among all patients (
n
=
1 029), 50.3% had LDL-C levels not at
goal. We defined ‘not at LDL-C goal’ as LDL-C
≥
1.8 mmol/l
and LDL-C reduction of
<
50% for patients with CVD, DM and/
or a SCORE risk of
≥
10% (very high risk), and as
≥
2.5 mmol/l
and
≥
3 mmol/l for patients with a SCORE risk of 5 to 9% (high
risk) and 1 to 4% (moderate risk), respectively. Elevated TG
levels (defined as
>
1.7 mmol/l) were seen in 45.3% of patients,
and 33.7% had low HDL-C levels (defined as
<
1.0 mmol/l for
men and
<
1.2 mmol/l for women).
TABLE 1. PATIENT CHARACTERISTICS, RISK CATEGORIESAND 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.
