Relations of Measures of Endothelial Function and Kidney Disease: The Framingham Heart Study

Background: Endothelial dysfunction is prevalent in individuals with end-stage renal disease. Whether endothelial dysfunction is present in patients with moderate chronic kidney disease (CKD) is uncertain. Study Design: Cross-sectional study. Settings & Participants: Brachial reactivity measurements were obtained during the seventh examination cycle in 2,818 (diameter measurements) and 2,256 (flow measurements) Framingham Heart Study Offspring cohort participants (53% women; mean age, 61 ± 9 years). Predictor: Estimated glomerular filtration rate less than 60 mL/min/1.73 m² derived from creatinine- and cystatin C-based estimating equations; microalbuminuria status. Outcome: Brachial reactivity measurements (baseline brachial diameter, flow-mediated dilation, baseline and hyperemic mean flow). Measurements: Linear regression models were used to model brachial measures as a function of CKD and microalbuminuria status. Results: Overall, 7.3% (n = 206) of participants had CKD, and of 2,301 with urinary measurements, 10.0% (n = 230) had microalbuminuria. Brachial reactivity measures did not differ significantly by CKD status in either creatinine- or cystatin C-based equations in either age- and sex- or multivariable-adjusted models. In age- and sex-adjusted models, microalbuminuria was associated with decreased hyperemic mean flow (47.2 ± 1.4 versus 51.4 ± 0.5 mg/g; P = 0.005), but the association was not significant after multivariable adjustment (P = 0.09). Limitations: Predominantly white ambulatory cohort; results may not be generalizable to other ethnic groups or individuals with severe CKD. Conclusions: Endothelial dysfunction was not a major correlate of CKD in our sample.