Title:
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Arterial Stiffness and Chronic Kidney Disease
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Introduction: Chronic kidney disease (CKD) common, particularly in the
elderly, and is linked to an increased risk of cardiovascular disease (CVD). This
is partly explained by joint risk factors such as hypertension and diabetes but
novel risk factors such as arterial stiffness, arterial calcification and endothelial
dysfunction may play a role. Our aims were 1) to prospectively investigate
whether aortic stiffness was linked with rate of decline of renal dysfunction, 2) to
investigate the associations of arterial stiffness in patients with moderate renal
dysfunction, and 3) to investigate whether aortic stiffness was linked with
adverse outcomes. Secondary aims were to explore the links between 24 hour
ambulatory blood pressure (BP) monitoring (24h ABPM), aortic stiffness, and
the novel CV risk factors asymmetric dimethylarginine (ADMA) and Fetuin-A.
Methods: This is an observational study of 133 patients with CKD stages 3-4
(estimated GFR 15-60mUmin). At baseline subjects underwent full assessment
of CV risk, measurement of arterial stiffness, Fetuin-A, ADMA, and 24h ABPM.
Patients were then followed-up with repeat of arterial stiffness measurements 6-
monthly. Change in renal function and clinical events were recorded.
Major results: Renal function is a determinant of aortic stiffness independent of
other well-described factors. Aortic stiffness is closely linked to deterioration in
renal function and predicts cardiovascular events within this cohort. There is a
high prevalence of ambulatory hypotension during 24h ABPM in older patients
with CKD, and a large difference in BP between clinic and home
measurements. The BP difference is associated with aortic stiffness, and is
suggestive of a causal relationship. A rise in BP at night is associated with
increased aortic stiffness, as is the related measure of postural hypotension.
ADMA levels are related to change in renal function, while Fetuin-A is related to
change in aortic stiffness.
Conclusion: In this predominantly elderly cohort of patients with CKD stages 3
and 4, aortic stiffness is associated with baseline and change in renal fundion,
CV risk and BP pattems. This highlights the close links between macro- and
microvascular disease and suggests that knowledge of aortic stiffness may be
crucial in further understanding the pathophysiology and treatment of renal
disease.
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