Prospective study of cardiovascular disease and Its risk factors in populations with rheumatoid arthritis that are at different stages of the epidemiological transition
Date
2017
Authors
Solomon, Ahmed
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Rheumatoid arthritis (RA) increases the risk of particularly atherosclerotic cardiovascular
disease in developed populations. The sub-Saharan black African population is currently at
an earlier epidemiological health transition stage. Consequently, black Africans experience
a markedly reduced risk of atherosclerotic cardiovascular disease.
The main objectives of this thesis were to determine whether (1) the atherosclerotic
cardiovascular risk burden is reduced in black compared to other African patients with RA;
(2) RA impacts on cardiovascular risk factor profiles and ultrasound determined carotid
intima-media thickness among black Africans and (3) the atherosclerosis burden and its
association with traditional and non-traditional risk factors differ in black compared to white
Africans with RA.
Black compared to other Africans with RA had more prevalent hypertension and obesity but
smoked and consumed alcohol less frequently. However, the overall traditional and nontraditional
atherosclerotic cardiovascular risk burden was as large in black as in other
Africans with RA.
RA was not independently associated with unfavourable traditional and non-traditional
atherosclerotic risk factors including systemic inflammation among black Africans. Carotid
intima-media thickness was similar in black RA and non-RA Africans.
The carotid intima-media thickness and plaque prevalence were as large in black
compared to white African patients with RA. Blood pressure, dyslipidemia, Framingham
score, systemic inflammation and extraarticular manifestations were associated with
atherosclerosis in white but not black African RA patients. The Arthritis Impact
Measurement Scales tension score was consistently related to atherosclerosis in black but
not white African patients with RA.
Black African RA women experienced a markedly larger adiposity burden than their
white counterparts. However, body mass index was associated with carotid intima-media
thickness and waist-to-hip ratio with plaque in white but not black women with RA.
The US National Cholesterol Education Program Adult Treatment Panel III metabolic
syndrome was identified in 30.8% of black compared to 9.7% of white African women with
RA (p = 0.009). In white African RA women, the metabolic syndrome definition was
associated with carotid intima-media thickness and the triglyceride criterion and number of
metabolic syndrome criteria were associated with plaque. In black African RA women, only
the blood pressure criterion was associated with carotid intima-media thickness, which
represents mostly age and blood pressure induced hypertrophy of medial cells rather than
atherosclerosis.
Reduced estimated glomerular filtration rate was found in 49.1% of black compared
30.6% of white African patients with RA (p=0.004). In Receiver Operating Characteristic
curve analysis, eight of nine evaluated estimated glomerular filtration rate equations were
associated with carotid artery plaque to a clinically useful extent for cardiovascular risk
stratification in black but not white African patients with RA. By contrast, estimated
glomerular filtration rate was related to the endothelial activation markers of monocyte
chemoattractant protein-1 and angiopoietin 2 in white but not black African patients with
RA.
In conclusion, the overall cardiovascular risk factor and atherosclerosis burden are currently
as large in black compared to white African patients with RA. Modifiable traditional risk
factors and disease characteristics were consistently unrelated to atherosclerosis in black
African patients with RA. Impaired kidney function comprised the only routinely available
cardiovascular risk factor that was useful in identifying black African RA patients with high
risk atherosclerosis.Systematic vascular imaging and possibly the use of novel cardiovascular
risk biomarkers may be required for adequate cardiovascular risk stratification among black
African patients with RA.
Description
A thesis submitted to the Faculty of Health Sciences,
University of the Witwatersrand, Johannesburg
for the degree of Doctor of Philosophy
Johannesburg 2016.
Keywords
Citation
Solomon, Ahmed (2017) A prospective study of cardiovascular disease and its risk factors in populations with rheumatoid arthritis that are at different stages of the epidemiological transition, University of the Witwatersrand, Johannesburg, https://hdl.handle.net/10539/25520