CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 7, August 2012
392
AFRICA
Patients with poor education (
<
six years of formal education)
were more likely to have lower lipid levels. The effect of urban
upbringing versus migration (typically rural to urban) on
dyslipidaemia in this cohort was not apparent; Soweto origin was
not related to high TC and LDL-C or low HDL-C levels.
However the effect of ethnicity on dyslipidaemia was apparent:
compared to patients of African descent, white European, mixed-
ancestry and Indian patients were two-, three- and four-fold
more likely to have high TC levels, respectively. These lipid
gradients, ranked across ethnicities, persisted for high LDL-C
and high TG levels in age-, gender- and BMI-adjusted models;
white European (OR 1.58, 95% CI: 0.92–2.69;
p
=
0.10),
mixed-ancestry (OR 2.57, 95% CI: 1.50–4.39;
p
=
0.001) and
Indian (OR 4.33 95% CI: 2.75–6.83;
p
<
0.0001) patients were
all more likely to have high TG levels compared to patients of
African descent. Ethnicity was not associated with low HDL-C
levels (Table 2). While current smokers were 1.5-fold more
likely to have low HDL-C levels (OR 1.47, 95% CI: 1.17–1.85,
p
=
0.001), diabetes co-morbidity was not associated with low
HDL-C (
p
=
0.3).
CRP was only measured in a limited number of patients.
However, subgroup analysis showed that serum CRP was
strongly associated with low HDL-C: in age- and gender-
adjusted models, patients in the medium- (OR 3.17, 95%
CI: 1.10–9.12;
p
=
0.03) and high-risk CRP groups (OR 5.58,
95% CI: 2.34–13.31;
p
<
0.001) were more likely to have low
HDL-C levels compared to the low-risk reference group (i.e.
those with a CRP of 1.0 mg/l). There was no association between
200
150
100
50
0
1.0
3.0
7.0
9.0
11.0
5.0
African descent
White European
Mixed ancestry
Indian
Frequency
Plasma cholesterol (mmol/l)
300
200
100
0
.00
1.00
3.00
4.00
2.00
Frequency
Plasma HDL (mmol/l)
250
200
150
50
0
.00
2.00
6.00
8.00
4.00
African descent
White European
Mixed ancestry
Indian
Frequency
Plasma LDL (mmol/l)
100
300
200
0
.01
2.01
6.01
4.01
African descent
White European
Mixed ancestry
Indian
Frequency
Plasma triglycerides (mmol/l)
100
African descent
White European
Mixed ancestry
Indian
Fig. 1. Frequency distribution of lipid levels according to ethnicity. Lipid levels (mmol/l): mean (
±
standard deviation)
in A, B and C. Median (inter-quartile range) for triglycerides (D). TC
=
total cholesterol; LDL
=
low-density lipoprotein
cholesterol; HDL
=
high-density lipoprotein cholesterol.
