CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 4, July/August 2014
AFRICA
153
Cardiovascular Topics
Ambulatory blood pressure profiles in a subset of
HIV-positive patients pre and post antiretroviral therapy
Megan Borkum, Nicola Wearne, Athlet Alfred, Joel A Dave, Naomi S Levitt, Brian Rayner
Abstract
Objectives:
Human immunodeficiency virus (HIV) and
antiretroviral therapy (ART) are associated with renal disease
and increased cardiovascular risk. The relationship between
HIV and ambulatory blood pressure (ABP) non-dipping
status, a risk factor for cardiovascular events and target-
organ damage, has never been assessed in South Africa.
Study objectives were to establish the prevalence of chronic
kidney disease, and assess the ABP profile in asymptomatic
HIV-positive clinic out-patients.
Methods:
This was a prospective cohort study. Office blood
pressure (BP), urinary microalbumin–creatinine ratio, urine
dipsticks, serum creatinine and estimated glomerular filtra-
tion rate (eGFR) were measured at baseline and six months
after ART initiation. A subset of HIV-positive subjects and
an HIV-negative control group underwent 24-hour ABP
monitoring.
Results:
No patient had an eGFR
<
60 ml/min, three patients
(4.7%) had microalbuminuria and one had macroalbuminu-
ria. Mean office systolic BP was 111
±
14 mmHg at baseline
and increased by 5 mmHg to 116
±
14 mmHg (
p
=
0.05) at six
months. This increase was not confirmed by ABP monitoring.
In the HIV-positive and -negative patients, the prevalences of
non-dipping were 80 and 52.9%, respectively (
p
=
0.05, odds
ratio
=
3.56, 95% CI: 0.96–13.13). No relationship between
dipping status and ART usage was found.
Conclusion:
The prevalence of chronic kidney disease (CKD)
was lower than anticipated. HIV infection was associated
with an ambulatory non-dipping status, which suggests an
underlying dysregulation of the cardiovascular system. In the
short term, ART does not seem to improve loss of circadian
rhythm.
Keywords:
human immunodeficiency virus, antiretroviral thera-
py, microalbuminuria, chronic kidney disease, ambulatory blood
pressure, non-dipping
Submitted 6/10/13, accepted 3/5/14
Cardiovasc J Afr
2014; 25: 153–157
DOI: 10.5830/CVJA-2014-029
South Africa has 5.6 million people living with HIV/AIDS and
has the largest antiretroviral therapy (ART) programme globally,
with more than two million people accessing ART.
1
Although
ART has significantly decreased the mortality rate from HIV
infection, these individuals are now living longer and are at
risk of developing metabolic (dyslipidaemia, lipodystrophy,
dysglycaemia), cardiovascular and renal complications from
ART and chronic exposure to HIV infection.
2-7
Chronic HIV and ART are associated with increased risk of
developing hypertension.
8
In studies of HIV-positive patients in
high-income countries, hypertension prevalence ranges from 13
to 34%.
9,10
However, data from low- and middle-income countries
remain sparse.
Nocturnal blood pressure (BP) is superior to daytime or office
BP as a predictor of cardiovascular disease.
11
Non-dipping is
defined as an abnormal diurnal rhythm manifested by a blunted
nocturnal decline in systolic BP (SBP).
11
It is associated with
more severe hypertensive target-organ damage (left ventricular
hypertrophy, microalbuminuria and cerebrovascular disease)
and is also a predictor of increased cardiovascular risk, both in
hypertensive and normotensive populations.
11
Studies from high-income countries have shown an increased
prevalence of non-dipping with HIV infection.
9,12
However, the
participants in these studies were largely white, middle-aged
males. Since the majority of subjects with HIV infection in
sub-Saharan Africa are young black females, it is not known
whether the same relationship between dipping status and HIV
infection would be found. In addition, there are data showing
that black HIV-negative individuals have less nocturnal dipping
compared to their white counterparts.
5,13,14
Therefore, the aims of this study were to document the
prevalence of chronic kidney disease (CKD) and hypertension
at baseline (ART naïve) in a healthy HIV-positive cohort, and to
assess changes in these parameters after six months on ART. The
characteristics of ambulatory blood pressure (ABP) in a subset
of patients were to be recorded and compared to a control group
of HIV-negative patients.
Department of Medicine, University of Cape Town, Cape
Town, South Africa
Megan Borkum, MD,
Athlet Alfred, MD
Department of Nephrology and Hypertension, University of
Cape Town, Cape Town, South Africa
Nicola Wearne, MD
Brian Rayner, MD
Division of Diabetic Medicine and Endocrinology,
University of Cape Town, Cape Town, South Africa
Joel A Dave, MD
Naomi S Levitt, MD
