29 / 68
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 3, May/June 2015
AFRICA
127
Table 4. Compared to CKD patients with normal Hb levels,
those with SCT showed on average higher uric acid levels (560
±
159 vs 413
±
153 mmol/l;
p
=
0.001) and lower Hb levels (9
±
1.80
vs 10
±
2.20 g/dl;
p
=
0.001).
Multivariate determinants of CKD with a special emphasis
on SCT are presented on Table 5. SCT did not emerge as an
independent determinant of CKD; the main determinants were
hypertension, diabetes, the MetS and anaemia. The presence of
diabetes, hypertension, the MetS and anaemia conferred 2.34-
fold (OR: 2.36 95% CI: 1.150–4.454;
p
=
0.001), 2.16-fold (OR:
2.16 95% CI: 1.202–3.892;
p
=
0.001), 1.69-fold (OR: 1.69 95%
CI: 1.003–2.965;
p
=
0.038) and 3.12-fold (OR: 2.34 95% CI:
1.202–3.892;
p
=
0.001) greater risk for CKD, respectively, in
comparison with patients without these risk factors.
Discussion
The aim of this cross-sectional study was to assess determinants
of CKD with a special emphasis on SCT. Traditional risk factors
in isolation or combined as the MetS emerged as the main
determinants of CKD; however, SCT was not associated with
CKD.
Our finding of increased risk for CKD in the presence of
the MetS agrees with the results of previous reports on the
determinants of CKD. Cheng
et al.
27
found a greater risk of
Table 1. Clinical characteristics of the study population as a
whole and by renal functional status
Variable
n
Whole
group
(
n
=
298)
CKD
–
(
n
=
171)
CKD+
(
n
=
188)
p-
value
Age (years)
359 56
±
15 64
±
10 64
±
10
Gender (%)
359
Males
45
41
48
0.548
Females
55
59
52
FH-SCD (%)
359
6
7
6
0.897
BMI (kg/m
2
)
359 25
±
5
25
±
5
26
±
6 0.341
WC (cm)
359 90
±
14 88
±
12 92
±
16 0.009
SBP (mmHg)
359 143
±
26 136
±
24 151
±
26 0.001
DBP (mmHg)
359 83
±
13 81
±
14 85
±
15 0.001
PP (mmHg)
359 60
±
20 54
±
19 66
±
21 0.001
Causes of CKD 359
HT (%)
39
43
35
0.248
DM (%)
44
37
51
0.010
GN (%)
14
15
13
0.693
Other (%)
3
5
1
0.072
Stages of CKD 359
Stage 3 (%)
40
Stage 4 (%)
38
Stage 5 (%)
21
Data are expressed as mean
±
standard deviation (SD) or relative
frequency (%).
FH-SCD, family history of sickle cell disease; BMI, body mass index;
WC, waist circumference; SBP, systolic blood pressure; DBP, diastolic
blood pressure; PP, pulse pressure; HT, hypertension; DM, diabetes
mellitus; GN, glomerulonephritis; CKD, chronic kidney disease.
Table 2. Biological characteristics of the study population
as a whole and by renal functional status
Variable
n
Whole
group
(
n
=
359)
CKD
–
(
n
=
171)
CKD+
(
n
=
188)
p-
value
Hb (g/dl)
330 11
±
2.40 12
±
2.10 10
±
2.20 0.001
Blood glucose (mg/dl)
350 8.16
±
4.94 8.94
±
4.61 7.50
±
5.16 0.005
TC (mmol/l)
294 5.32
±
2.22 5.14
±
1.73 5.55
±
2.22 0.312
LDL-C (mmol/l)
294 3.04
±
1.65 2.99
±
1.60 3.07
±
1.70 0.662
HDL-C (mmol/l)
294 1.49
±
0.59 1.58
±
0.46 1.39
±
0.67 0.014
TG (mmol/l)
294 1.31
±
0.65 1.22
±
0.54 1.42
±
0.75 0.017
Uric acid (mmol/l)
313 360
±
159 277
±
100 442
±
165 0.001
Creatinine (µmol/l)
359 87
±
44 80
±
24 94
±
54 0.001
eGFR (ml/min/1.73 m²) 359 59
±
46 95
±
39 26
±
20 0.001
Dipstick proteinuria (%) 359
24
24
37
0.001
Data are expressed as mean
±
standard deviation (SD) or relative frequency (%).
Hb, haemoglobin; TC, total cholesterol; LDL-C, low-density lipoprotein
cholesterol; HDL-C, high-density lipoprotein cholesterol; TG, triglycerides;
eGFR, estimated glomerular filtration; CKD, chronic kidney disease.
Table 3. CKD risk factors among the study population
as a whole and by renal functional status
Variable
n
Whole
group
(
n
=
359)
CKD
–
(
n
=
171)
CKD+
(
n
=
188)
p
-value
HbAS (%)
330 19
18
21
0.715
Smoking (%)
359
4
5
3
0.499
Alcohol (%)
359
4
4
4
0.763
Overweigh/obesity (%) 359 29
29
30
0.715
MetS (%)
359 27
24
31
0.007
Anaemia (%)
330 57
42
72
0.001
Elevated PP (%)
359 49
39
60
0.001
Data are expressed as mean
±
standard deviation (SD) or relative
frequency (%).
HbAS, sickle cell trait; MetS, the metabolic syndrome; PP, pulse pressure.
Table 4. Clinical and biological characteristics of CKD
patients by haemoglobin genotype status
Variable
n
HbAA
(
n
=
149)
HbAS
(
n
=
39)
p-
value
Age, years
188 56
±
15
55
±
17 0.808
Gender (%)
188
Males
44
67
0.017
Females
56
33
BMI (kg/m
2
)
188 25
±
5
26
±
6
0.189
WC (cm)
188 88
±
12
89
±
13 0513
SBP (mmHg)
188 150
±
21
158
±
29 0.063
DBP (mmHg)
188 85
±
13
86
±
16 0.550
PP mm Hg
188 64
±
20
71
±
21 0.061
Hb (g/dl)
177 10
±
2.20 09
±
1.80 0.001
Glucose (mmol/l)
181 7.39
±
4.00 7.83
±
2.66 0.613
Uric acid (mmol/l)
157 413
±
153 560
±
159 0.001
TC (mmol/l)
133 5.55
±
2.29 5.68
±
2.32 0.570
LDL-C (mmol/l)
133 3.07
±
1.70 3.12
±
1.75 0.467
HDL-C (mmol/l)
133 1.36
±
0.72 1.49
±
0.43 0.398
TG (mmol/l)
133 1.38
±
0.75 1.52
±
0.79 0.397
Creatinine (µmol/l)
188 530
±
183 707
±
95 0.183
eGFR (ml/min/1.73 m²) 188 26
±
20
23
±
18 0.296
Data are expressed as mean
±
standard deviation (SD) or relative
frequency (%).
BMI, body mass index; WC, waist circumference; SBP, systolic blood
pressure; DBP, diastolic blood pressure; PP, pulse pressure; Hb,
haemoglobin; TC, total cholesterol; LDL-C, low-density lipoprotein
cholesterol; HDL-C, high-density lipoprotein cholesterol; TG, triglyc-
erides; eGFR, estimated glomerular filtration rate.