Decrease in ankle-brachial index over time and cardiovascular outcomes in patients with hemodialysis

Association of Arterial Stiffness With Chronic Kidney Disease Progression and Mortality

Chronic kidney disease (CKD) is a major public health concern. Despite many potentially life-threatening conditions that can accompany kidney disease, cardiovascular disease (CVD) remains the leading cause of death in these patients. Adjusted-for-age mortality from CVD in patients with end-stage renal disease is 10-30 times higher than in the general population. A decrease in renal function accelerates the development of cardiac pathology. Simultaneous exposure of CVD and CKD plays an important role in the relationship between arterial stiffness (AS) and estimated glomerular filtration rate. But there is a controversy as to whether the AS causes deterioration in kidney function, if renal dysfunction leads to AS, or the relationship is reciprocal. Hence, several studies that recruited high-risk populations reached a conclusion that comorbidities might lead to both AS and decline in kidney function over time. A number of studies have shown that several markers of AS, such as pulse pressure, central and peripheral pressure are associated with the development of CKD. This review takes into account the theoretical background, current status, and future potential of the techniques that measure AS within context of CKD assessment and management.

Change in ankle-brachial index and mortality among individuals with chronic kidney disease: findings from the Chronic Renal Insufficiency Cohort Study

BACKGROUND

Patients with chronic kidney disease (CKD) have an increased risk of peripheral arterial disease (PAD). The ankle-brachial index (ABI), a noninvasive measure of PAD, is a predictor of adverse events among individuals with CKD. In general populations, changes in ABI have been associated with mortality, but this association is not well understood among patients with CKD.

METHODS

We conducted a prospective study of 2920 participants in the Chronic Renal Insufficiency Cohort Study without lower extremity revascularization or amputation at baseline and with at least one follow-up ABI measurement (taken at annual visits) during the first 4 years of follow-up. The ABI was obtained by the standard protocol.

RESULTS

In Cox proportional hazard regression analyses, we found a U-shaped association of average annual change in ABI with all-cause mortality. After adjusting for baseline ABI and other covariates, compared with participants with an average annual change in ABI of 0-<0.02, individuals with an average annual change in ABI <-0.04 or ≥0.04 had multivariable-adjusted hazard ratios (HRs) of 1.81 [95% confidence interval (CI) 1.34-2.44) and 1.42 (95% CI 1.12-1.82) for all-cause mortality, respectively. Compared with the cumulative average ABI of 1.0-<1.4, multivariable-adjusted HRs for those with a cumulative average ABI of <0.9, 0.9-<1.0 and ≥1.4 were 1.93 (95% CI 1.42-2.61), 1.20 (0.90-1.62) and 1.31 (0.94-1.82), respectively.

CONCLUSIONS

This study indicates both larger decreases and increases in average annual changes in ABI (>0.04/year) were associated with higher mortality risk. Monitoring changes in ABI over time may facilitate risk stratification for mortality among individuals with CKD.

Fluid overload, pulse wave velocity, and ratio of brachial pre-ejection period to ejection time in diabetic and non-diabetic chronic kidney disease

Fluid overload is one of the characteristics in chronic kidney disease (CKD). Changes in extracellular fluid volume are associated with progression of diabetic nephropathy. Not only diabetes but also fluid overload is associated with cardiovascular risk factors The aim of the study was to assess the interaction between fluid overload, diabetes, and cardiovascular risk factors, including arterial stiffness and left ventricular function in 480 patients with stages 4–5 CKD. Fluid status was determined by bioimpedance spectroscopy method, Body Composition Monitor. Brachial-ankle pulse wave velocity (baPWV), as a good parameter of arterial stiffness, and brachial pre-ejection period (bPEP)/brachial ejection time (bET), correlated with impaired left ventricular function were measured by ankle-brachial index (ABI)-form device. Of all patients, 207 (43.9%) were diabetic and 240 (50%) had fluid overload. For non-diabetic CKD, fluid overload was associated with being female (β = –2.87, P = 0.003), heart disease (β = 2.69, P = 0.04), high baPWV (β = 0.27, P = 0.04), low hemoglobin (β = –1.10, P<0.001), and low serum albumin (β = –5.21, P<0.001) in multivariate analysis. For diabetic CKD, fluid overload was associated with diuretics use (β = 3.69, P = 0.003), high mean arterial pressure (β = 0.14, P = 0.01), low bPEP/ET (β = –0.19, P = 0.03), low hemoglobin (β = –1.55, P = 0.001), and low serum albumin (β = –9.46, P<0.001). In conclusion, baPWV is associated with fluid overload in non-diabetic CKD and bPEP/bET is associated with fluid overload in diabetic CKD. Early and accurate assessment of these associated cardiovascular risk factors may improve the effects of entire care in late CKD.