Arterial wave reflections and kidney function decline among persons with preserved estimated glomerular filtration rate: The Multi-Ethnic Study of Atherosclerosis

Differences in arterial wave reflections have been associated with increased risk for heart failure and mortality. Whether these measures are also associated with kidney function decline is not well established. Reflection magnitude (RM, defined as the ratio of the backward wave [P_b] to that of the forward wave [P_f]), augmentation index (AIx), and pulse pressure amplification (PPA) were derived from radial tonometry measures among 5232 participants free of cardiovascular disease who were enrolled in the Multiethnic Study of Atherosclerosis. Kidney function was estimated by creatinine and cystatin C measurements, as well as albumin-to-creatinine ratio. We evaluated the associations of P_b, P_f, RM, AIx, and PPA with annualized estimated glomerular filtration rate (eGFR) change and rapid kidney function decline over 5 years, using generalized linear mixed models and logistic regression, respectively. Of the study participants, 48% were male, mean age was 62 years, mean eGFR and median albumin-to-creatinine ratio at baseline were 84 mL/min/1.73 m² and 5.3 mg/g, respectively. In demographically adjusted models, both P_b and P_f had similarly strong associations with kidney function decline; compared to those in the lowest tertiles, the persons in the highest tertiles of P_b and P_f had a 1.01 and 0.99 mL/min/1.73 m²/year faster eGFR decline, respectively (P <.05). However, these associations were attenuated after adjustment for systolic blood pressure. We found no significant associations between RM, AIx, or PPA and kidney function decline. In conclusion, the reflected and forward wave components were similarly associated with kidney function decline, and these associations were explained by differences in systolic blood pressure.