Aortic Stiffness and its Relationship to Kidney Disease, Brain Structure, and Cognition.
the aging population, chronic kidney disease and cognitive impairment are highly
prevalent and account for a significant portion of medical problems and health care
costs. Unfortunately, the disease mechanisms are not well understood. Aortic stiffness
increases with age and results in transmittance of increased pressures to the
microvasculature of both organs. Aortic stiffness ... read morehas been linked to both diseases, but
prior studies have shown mixed results or were performed in select populations. We
hypothesized that higher aortic stiffness would be associated with lower kidney
function, lower kidney function would be associated with changes in brain structure and
impaired cognition, and these latter associations would be attenuated by adjustment for
aortic stiffness. We conducted a cross sectional study utilizing data from a subset of
the Age, Gene/Environment, Susceptibility-Reykjavik Study, a large community-based
prospective cohort study of cardiovascular disease in Iceland. We used linear or
logistic regression as appropriate to assess the associations between aortic stiffness
[carotid femoral pulse wave velocity (CFPWV) and carotid pulse pressure (CPP)] and
kidney function and damage [estimated glomerular filtration rate (eGFR) and urine
albumin to creatinine ratio (ACR)] as well as eGFR and ACR and brain structure and
cognition. Sequential sets of multivariable models were performed adjusting for
demographics and cardiovascular risk factors. We included 940 patients (mean age 75.8
years, mean eGFR 68 ml/min/1.73m2, median UACR 3 mg/g). Age was strongly related to
eGFR, ACR, CFPWV, and CPP. Although CFPWV was associated with eGFR [β (SE)=0.08
(0.02), p-value<0.001] and ACR [β (SE)=-0.009 (0.002), p-value<0.001], the
association was attenuated after adjusting for age and blood pressure. In those patients
with CPP greater than 80 mmHg, CPP was associated with eGFR [β (SE)=-0.22 (0.09),
p-value=0.011], but the relationship became nonsignificant after adjustment for
cardiovascular disease risk factors. CPP was significantly related to ACR in fully
adjusted models [β (SE)=0.006 (0.003), p-value=0.013]. ACR was significantly
associated with all measures of brain structure; effect was minimally attenuated after
adjustment for aortic stiffness. In summary, aortic stiffness was not strongly related
to eGFR but higher CPP was related to albuminuria. Albuminuria was more strongly
associated than eGFR with brain structure but neither were related to cognition. There
was no consistent change in effect size after adjustment for aortic stiffness.
Adjustment for age attenuated all
Thesis (M.S.)--Tufts University, 2014.
Submitted to the Dept. of Clinical & Translational Science.
Advisor: Andrew Levey.
Committee: Lesley Inker, and Farzad Noubary.
Keywords: Epidemiology, and Health sciences.read less