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AFRICA
S11
CVJAFRICA • Volume 26, No 2, H3Africa Supplement, March/April 2015
Familial clustering of risk factors for cardiovascular disease
among first-degree relatives of patients with chronic kidney
disease in a sub-Saharan African population
Yemi Raji, Omolara Mabayoje, Taslim Bello
Abstract
Objective:
To determine the prevalence of risk factors for
cardiovascular disease (CVD) in first-degree relatives (FDRs)
of patients with chronic kidney disease (CKD) in a sub-
Saharan African population.
Methods:
This was a cross-sectional survey of 460 subjects
(230 FDRs of patients with CKD and 230 healthy controls).
Anthropometrics and blood pressures were measured. Spot
urine and fasting venous blood samples were obtained for
biochemical analysis.
Results:
The prevalence of hypertension, diabetes melli-
tus, obesity and dyslipidaemia were significantly higher in
FDRs of patients with CKD compared with the controls:
56 (24.3%) vs 29 (12.6%),
p
=
0.01; 20 (8.7%) vs 6 (2.6%),
p
=
0.01; 40 (17.4%) vs 24 (10.4%),
p
=
0.03 and 171 (74.3%) vs
138 (60.0%),
p
=
0.01, respectively. Hypertension (OR, 1.65),
dyslipidaemia (OR, 1.72) and albuminuria (OR, 1.61) were
independently associated with being a FDR of patients with
CKD.
Conclusion:
In this sub-Saharan African population, risk
factors for CVD were more prevalent in the FDRs of patients
with CKD than in healthy controls.
Keywords:
cardiovascular disease, chronic kidney disease, first-
degree relatives, risk factors, sub-Saharan Africa
Cardiovasc J Afr
2015;
26
: S11–S14
www.cvja.co.zaDOI:
10.5830/CVJA-2015-041
Cardiovascular disease (CVD) is receiving global attention
because of its rising prevalence and its resultant high morbidity
and mortality rate and the huge economic burden. It was
responsible for one-third of global deaths in 2005 and it is
projected that it will account for three-quarters of the deaths
worldwide by 2030.
1-3
In sub-Saharan Africa, a region undergoing
an epidemiological transition,
2,4
recent reports have suggested
that CVD may be the leading cause of death.
3,5
CVD is particularly prevalent among patients with chronic
kidney disease (CKD). In fact, patients with CKD are more
likely to die from cardiovascular diseases than from progression
of renal disease.
6
The risk of cardiovascular death in patients
with end-stage renal disease (ESRD) is 10 to 100 times that in
the healthy population,
6,7
and many researchers consider CKD
an independent risk factor for CVD in view of the changes in the
cardiovascular system associated with CKD, such as endothelial
dysfunction, arterial stiffening, left ventricular hypertrophy
(LVH), and vascular calcification.
8
It has been suggested that the higher prevalence of
cardiovascular disease seen in patients with CKD may in part
be as a result of risk factors for CVD being more prevalent in
those individuals. Evidence suggests that both traditional and
non-traditional cardiovascular risk factors are more common
among patients with CKD than in the general population.
9,10
Relatives of patients withCKDare themselves at increased risk
of developing CKD.
11
This increased risk has been hypothesised
to be due to shared genetic and environmental factors.
12
Most
of these shared factors are cardiovascular risk factors, such as
hypertension, diabetes, obesity and dyslipidaemia.
11,13
Inserra
et al.
reported a high prevalence of common CVD risk factors
among 810 first-degree relatives (FDRs) of patients with CKD;
with hypertension being present in 41.8%, overweight or obesity
in 62.1%, hypercholesterolaemia in 42.9%, hyperglycaemia in
5.2%, and cigarette smoking in 34.8%.
13
Tsai
et al.
and Wei
et al.
both reported the prevalence of CVD risk factors to be
significantly higher in FDRs of patients with CKD compared to
healthy and spousal controls.
14,15
FDRs of patients with CKD are not only at increased risk of
developing CKD but are also at increased risk of experiencing
an adverse cardiovascular event. Because many of the CVD
risk factors are modifiable, identifying individuals with a higher
prevalence of these risk factors would be a cost effective way
of reducing the burden of cardiovascular disease, especially in
resource-poor settings.
16-18
FDRs of patients with CKD appear
to be one such group.
There is a paucity of data, however, on the prevalence of CVD
risk factors in FDRs of patients with CKD from sub-Saharan
Africa. The aim of this study was to determine the prevalence
of CVD risk factors in a sub-Saharan African population of
FDRs of patients with CKD and compare it with a cohort of
individuals with no family history of CKD.
Methods
This was a cross-sectional study of a cohort of 460 subjects
(230 FDRs of patients with CKD and 230 age- and gender-
matched controls with no personal or family history of CKD)
carried out between January and June 2011. The FDRs were
parents, siblings or offspring of 106 consecutively presenting
and consenting patients with CKD who were receiving care
Nephrology Unit, Department of Medicine, College of
Medicine, University of Ibadan, Ibadan, Nigeria
Yemi Raji, MB ChB,
yemyrajj@yahoo.comNephrology Unit, Department of Medicine, College of
Medicine, University of Lagos, Idi-Araba, Lagos, Nigeria
Omolara Mabayoje, MB ChB
Taslim Bello, MB ChB