Modest longitudinal decline in renal function in early stages of kidney disease is associated with stiffening of the arteries, which is a risk for stroke and dementia, according to a University of Maine-led research team.
Worsening of kidney function is associated with higher pulse wave velocity (PWV) values and, by inference, higher levels of arterial stiffness in the heart and brain, says team leader Merrill Elias, UMaine professor of psychology and cooperating professor in the Graduate School of Biomedical Sciences and Engineering.
“[E]ven modest associations constitute unacceptable risks at a population level and become major associations in late-stage renal disease,” he says. “Effective management of multiple cardiovascular disease risk factors associated with renal disease could be a way for successful early intervention.”
PWV, which is a measure of arterial stiffness, is the velocity of a pressure wave created when blood returns to the heart from the periphery of the vascular system. A fast return indicates greater stiffness in arteries; a slower return indicates arteries are flexible. PWV is a relatively new technology; Elias calls it the gold standard measure of arterial stiffness.
A strength of this study, says Elias, is that researchers related decline in renal functioning over four to five years to PWV. The study involved 482 community-based men and women with a mean age of nearly 61 years. They had normal blood pressure and arterial hypertension and investigators were unaware of the participants’ kidney disease status during data collection. Those with diabetes, other hypertension-related risk factors or diseases detected at various stages of the study were referred to their physicians for active treatment.
The findings, which were observed with controls for demographic factors, heart rate, mean arterial pressure and other potential confounders, are the most recent in a 38-year Maine-Syracuse Longitudinal Study that examines cardiovascular risk factors in relation to cognitive performance.
Elias and Syracuse University physician David H.P. Streeten began the longitudinal study in 1975. In previous studies, researchers found mild to moderate kidney disease was related to a drop in cognitive functioning, abstract reasoning and verbal memory, and that PWV was higher in those with the lowest cognitive performance.
Thus, says Elias, early detection of mild to moderate kidney disease is an important public health concern.
Elias, a psychologist and cardiovascular epidemiologist, and Michael Robbins, a UMaine colleague and psychologist, conducted the study with support from the National Institutes of Health (NIH) and National Heart, Lung, and Blood Institute (NHLBI). UMaine colleague Gregory Dore; as well as Adam Davey, a developmental psychologist, and Avrum Gillespie, a nephrologist, both from Temple University; and Walter Abhayaratna, a cardiologist from Australian National University, also participated in this latest study.
“Deterioration in Renal Function is Associated With Increased Arterial Stiffness” was initially published online in September in the American Journal of Hypertension.
Contact: Beth Staples, 207.581.3777