Peripheral Arterial Disease Predicts Overall and Cardiovascular Mortality in Peritoneal Dialysis Patients

Serum osteoprotegerin level is positively associated with peripheral artery disease in patients with peritoneal dialysis

Osteoprotegerin (OPG) is a potential biomarker of cardiovascular disease complications and severity. Peripheral arterial disease (PAD) is associated with an increased risk of death in patients on peritoneal dialysis (PD). Therefore, this study aimed to evaluate the relationship between serum OPG levels and PAD by measuring the ankle-brachial index (ABI) of patients on PD. A commercial enzyme-linked immunosorbent assay kit was used to measure OPG values. Left or right ABI values of <0.9 were categorized as the low ABI group. Among 70 patients on PD, 13 (18.6%) were categorized in the low ABI group. Patients in the low ABI group had higher prevalence of diabetes mellitus (p = .044) and higher serum C-reactive protein (CRP) (p < .001) and OPG levels (p < .001) but lower creatinine (p = .013) and peritoneal Kt/V (p = .048) levels than those in the normal ABI group. Results of multivariable logistic regression analysis revealed that OPG [adjusted odds ratio (aOR) 1.027, 95% confidence interval (CI) 1.010-1.045, p = .002] and CRP (aOR 1.102, 95% CI 1.006-1.207, p = .037) levels were independent predictors of PAD in patients on PD. OPG can also be used to predict PAD development with the area under the receiver operating characteristic curve of 0.823 (95% CI: 0.714-0.904, p < .001) in patients on PD. Therefore, serum OPG and CRP levels can be considered as risk factors for PAD development in patients on PD.

Increased prevalence of peripheral arterial disease in patients with obese sarcopenia undergoing hemodialysis

Background peripheral arterial disease (PAD) is a common complication in patients undergoing dialysis, which reduces the quality of life and increases the risk of mortality. Recent literature has documented an association between increased visceral fat (VF) content and a proatherogenic factors in end-stage renal disease. The present study investigated the prevalence of PAD in patients undergoing hemodialysis. PAD was determined as an ankle-brachial index <0.9. Additionally, VF content was determined using multiple frequency bioelectrical impendence analysis. The nutritional status of the patients was evaluated by subjective global assessment and endothelial function was measured by ultrasonographic brachial artery flow-mediated dilatation. Patients divided into two groups (malnourished and non-malnourished) with two further subgroups in each (high VF and low VF content). The prevalence of PAD was identified to be significantly higher in patients with a high VF mass compared with a low VF mass in non-malnourished patients. PAD was significantly more common in malnourished patients compared with non-malnourished patients (P<0.01). The presence of PAD in patients undergoing hemodialysis was identified to be significantly correlated with age, diabetes mellitus (DM) status VF content, malnutrition, serum albumin level, diastolic blood pressure and log C-reactive protein levels. Furthermore, logistic regression analysis determined that age, DM, VF content and malnutrition were significant independent risk factors for PAD in patients undergoing hemodialysis. In conclusion, the results of the present study indicated that obesity and malnutrition act synergistically to increase the risk of PAD in patients undergoing dialysis.

Abdominal Aortic Calcifications Predict Survival in Peritoneal Dialysis Patients

BACKGROUND

Peripheral arterial disease and vascular calcifications contribute significantly to the outcome of dialysis patients. The aim of this study was to evaluate the prognostic role of severity of abdominal aortic calcifications and peripheral arterial disease on outcome of peritoneal dialysis (PD) patients using methods easily available in everyday clinical practice.

METHODS

We enrolled 249 PD patients (mean age 61 years, 67% male) in this prospective, observational, multicenter study from 2009 to 2013. The abdominal aortic calcification score (AACS) was assessed using lateral lumbar X ray, and the ankle-brachial index (ABI) using a Doppler device.

RESULTS

The median AACS was 11 (range 0 - 24). In 58% of the patients, all 4 segments of the abdominal aorta showed deposits, while 19% of patients had no visible deposits (AACS 0). Ankle-brachial index was normal in 49%, low (< 0.9) in 17%, and high (> 1.3) in 34% of patients. Altogether 91 patients (37%) died during the median follow-up of 46 months. Only 2 patients (5%) with AACS 0 died compared with 50% of the patients with AACS ≥ 7 (p < 0.001). The adjusted hazard ratio for all-cause mortality was 4.85 (95% confidence interval [CI] 1.94 - 24.46) for aortic calcification (AACS ≥ 7), 2.14 for diabetes (yes/no), 0.93 for albumin (per 1 g/L), and 1.04 for age (per year). A low or high ABI were not independently associated with mortality.

CONCLUSIONS

Severe aortic calcification was a strong predictor of all-cause mortality in PD patients. The evaluation of aortic calcifications by lateral X ray is a simple method that allows the identification of high-risk patients.

Prognostic significance of ankle brachial pressure index: A systematic review and meta-analysis

Purpose To synthesize and quantify the excess risk of morbidity and mortality in individuals with low ankle-brachial pressure index. Methods Electronic databases were searched to identify studies investigating morbidity and mortality outcomes in individuals undergoing ankle-brachial pressure index measurement. Meta-analysis of the outcomes was performed using fixed- or random-effects models. Uncertainties related to varying follow-up periods among the studies were resolved by meta-analysis of time-to-event outcomes. Results Forty-three observational cohort studies, enrolling 94,254 participants, were selected. A low ankle-brachial pressure index (<0.9) was associated with a significant risk of all-cause mortality (risk ratio: 2.52, 95% CI 2.26-2.82, P < 0.00001); cardiovascular mortality (risk ratio: 2.94, 95% CI 2.72-3.18, P < 0.00001); cerebrovascular event (risk ratio: 2.17, 95% CI 1.90-2.47, P < 0.00001); myocardial infarction (risk ratio: 2.28, 95% CI 2.07-2.51, P < 0.00001); fatal myocardial infarction (risk ratio: 2.81, 95% CI 2.33-3.40, P < 0.00001); fatal stroke (risk ratio: 2.28, 95% CI 1.80-2.89, P < 0.00001); and the composite of myocardial infarction, stroke, and death (risk ratio: 2.29, 95% CI 1.87-2.81, P < 0.00001). Similar findings resulted from analyses of individuals with asymptomatic PAD, individuals with cardiovascular or cerebrovascular co-morbidity, and patients with diabetes. Conclusions A low ankle-brachial pressure index is associated with an increased risk of subsequent cardiovascular and cerebrovascular morbidity and mortality. Randomised controlled trials are required to investigate the effectiveness of screening for PAD in asymptomatic and undiagnosed individuals and to evaluate benefits of early treatment of screen-detected PAD.

The association of very-low-density lipoprotein with ankle-brachial index in peritoneal dialysis patients with controlled serum low-density lipoprotein cholesterol level

Background

Peripheral artery disease (PAD) represents atherosclerotic disease and is a risk factor for death in peritoneal dialysis (PD) patients, who tend to show an atherogenic lipid profile. In this study, we investigated the relationship between lipid profile and ankle-brachial index (ABI) as an index of atherosclerosis in PD patients with controlled serum low-density lipoprotein (LDL) cholesterol level.

Methods

Thirty-five PD patients, whose serum LDL cholesterol level was controlled at less than 120mg/dl, were enrolled in this cross-sectional study in Japan. The proportions of cholesterol level to total cholesterol level (cholesterol proportion) in 20 lipoprotein fractions and the mean size of lipoprotein particles were measured using an improved method, namely, high-performance gel permeation chromatography. Multivariate linear regression analysis was adjusted for diabetes mellitus and cardiovascular and/or cerebrovascular diseases.

Results

The mean (standard deviation) age was 61.6 (10.5) years; PD vintage, 38.5 (28.1) months; ABI, 1.07 (0.22). A low ABI (0.9 or lower) was observed in 7 patients (low-ABI group). The low-ABI group showed significantly higher cholesterol proportions in the chylomicron fraction and large very-low-density lipoproteins (VLDLs) (Fractions 3–5) than the high-ABI group (ABI>0.9). Adjusted multivariate linear regression analysis showed that ABI was negatively associated with serum VLDL cholesterol level (parameter estimate=-0.00566, p=0.0074); the cholesterol proportions in large VLDLs (Fraction 4, parameter estimate=-3.82, p=0.038; Fraction 5, parameter estimate=-3.62, p=0.0039) and medium VLDL (Fraction 6, parameter estimate=-3.25, p=0.014); and the size of VLDL particles (parameter estimate=-0.0352, p=0.032).

Conclusions

This study showed that the characteristics of VLDL particles were associated with ABI among PD patients. Lowering serum VLDL level may be an effective therapy against atherosclerosis in PD patients after the control of serum LDL cholesterol level.