Association between serum albumin and peripheral arterial disease in hypertensive patients

The authors aimed to evaluate the relationship of serum albumin with peripheral arterial disease (PAD) and investigate any possible effect modifiers in hypertensive patients. In the cross-sectional study, a total of 10,900 Chinese hypertensive patients aged ≥18 years were enrolled. The outcome was PAD, defined as an ankle-brachial index (ABI) <0.90 in either leg. The overall mean (SD) serum albumin was 46.8 (4.2) g/L. There were significant inverse associations of serum albumin with PAD (per SD increment; OR: 0.83; 95% CI: 0.72, 0.94). Compared with the lowest tertile (<45.1 g/L), the multivariate-adjusted ORs (95% CI) for participants in the middle tertile (45.1-48.2 g/L) and highest tertile (≥48.2 g/L) of serum albumin were 0.89 (95% CI: 0.67, 1.16) and 0.65 (95% CI: 0.47, 0.90), respectively. Conversely, lower albumin (<48.2 g/L) concentrations were associated with increased odds of PAD (OR: 1.45; 95% CI: 1.08-1.96) compared with higher concentrations. Furthermore, the albumin-PAD association was significantly stronger in males (OR: 2.08; 95% CI: 1.31, 3.30) than in females (OR: 1.06; 95% CI: 0.70, 1.58; p interaction = .024). In conclusion, among Chinese hypertensive adults, lower serum albumin was associated with the prevalence of PAD only in males but not in females.

Association between albumin and C-reactive protein and ankle-brachial index in haemodialysis

AIM

Peripheral artery occlusive disease (PAOD) is associated with increased rates of cardiovascular mortality, morbidity and hospitalization in patients undergoing dialysis. An ankle-brachial index (ABI) less than 0.9 has been used to diagnose PAOD. The aim of this study was to evaluate associations among inflammation, malnutrition and their interactions on the risk of PAOD.

METHODS

Two hundred and twenty-two haemodialysis patients (mean age 61.0 ± 11.7 years, 56.8% men) were enrolled and stratified into four groups according to median values of albumin (3.87 g/dL) and logarithm of C-reactive protein (CRP) (0.48 mg/L). Associations between the study groups and an ABI less than 0.9 were assessed using multiple logistic regression analysis. Receiver operating characteristic curves were constructed to predict an ABI less than 0.9.

RESULTS

A lower level of albumin and higher level of CRP were significantly associated with an ABI less than 0.9 in multivariate analysis (odds ratio, 5.688; 95% confidence interval, 1.369-23.626; P = 0.017) after adjusting for demographic, clinical, biochemical and medication data. The interaction between albumin and CRP in relation to an ABI less than 0.9 was significant in multivariate analysis (odds ratio, 1.797; 95% confidence interval, 1.258-2.568; P = 0.001). The areas under the curve for albumin, CRP and albumin + CRP for the prediction of ABI less than 0.9 were 0.311, 0.654 and 0.733, respectively.

CONCLUSION

Patients undergoing haemodialysis with a lower albumin level and higher CRP level have an increased risk of PAOD. A combination of malnutrition and inflammation may be associated with PAOD in haemodialysis patients.

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.

Comparison of the risk of non-traumatic lower extremity amputation between haemodialysis and peritoneal dialysis patients with end-stage renal disease

AIM

We used insurance claims data of Taiwan to compare the risk of non-traumatic lower extremity amputation between haemodialysis (HD) and peritoneal dialysis (PD) patients.

METHODS

We identified 77 669 HD patients and 10 035 PD patients without prior amputation from 2000 to 2010. Incidence rates and hazard ratios (HRs) of lower extremity amputation, and subsequent 30-day mortality after amputation were evaluated up to 31 December 2011.

RESULTS

There were 2427 and 216 patients undergoing lower extremity amputation during follow-up in the HD and PD groups with incidence rates of 8.35 and 5.79 per 1000 person-years, respectively. Compared with the HD group, the overall adjusted HR of lower extremity amputation for the PD group was 1.27 (95% CI = 1.10-1.46). The impact of diabetes status on the risk of lower extremity amputation interacted with dialysis modality significantly (P < 0.001). Compared with the corresponding HD patients, the PD patients with diabetes had an adjusted HR of 1.44 (95% CI = 1.24-1.67) for amputation, whereas those without diabetes had an adjusted HR of 0.58 (95% CI = 0.36-0.95). The subsequent 30-day mortality rates after amputation were not significantly different between the HD and PD groups (8.45% vs. 9.72%) with an adjusted odds ratio of 1.41 (95% CI = 0.87-2.28, PD versus HD).

CONCLUSION

Compared with corresponding HD patients, the amputation risk is higher for PD patients with diabetes, while the risk is lower for PD patients without diabetes. Dialysis patients have a high 30-day mortality risk after amputation.

ISPD Cardiovascular and Metabolic Guidelines in Adult Peritoneal Dialysis Patients Part II - Management of Various Cardiovascular Complications

Cardiovascular mortality has remained high in patients on peritoneal dialysis (PD) due to the high prevalence of various cardiovascular complications including coronary artery disease, left ventricular hypertrophy and dysfunction, heart failure, arrhythmia (especially atrial fibrillation), cerebrovascular disease, and peripheral arterial disease. In addition, nearly a quarter of PD patients develop sudden cardiac death as the terminal life event. Thus, it is essential to identify effective treatment that may lower cardiovascular mortality and improve survival of PD patients. The International Society for Peritoneal Dialysis (ISPD) commissioned a global workgroup in 2012 to formulate a series of recommendation statements regarding lifestyle modification, assessment and management of various cardiovascular risk factors, and management of the various cardiovascular complications to be published in 2 guideline documents. This publication forms the second part of the guideline documents and includes recommendation statements on the management of various cardiovascular complications in adult chronic PD patients. The documents are intended to serve as a global clinical practice guideline for clinicians who look after PD patients. We also define areas where evidence is clearly deficient and make suggestions for future research in each specific area.

Observational multicenter study to evaluate the prevalence and prognosis of subclinical atheromatosis in a Spanish chronic kidney disease cohort: baseline data from the NEFRONA study

BACKGROUND

Cardiovascular events (CVE) are more prevalent in chronic kidney disease (CKD) than in general population, being the main cause of morbimortality. Specific risk factors related to CKD have been suggested, because traditional factors do not fully explain this increase in cardiovascular disease rates. However, the role of atheromatosis, its pathogenesis and evolution are still unclear. The potential use of diagnostic tests to detect subclinical atheromatosis has to be determined.

METHODS

NEFRONA is a prospective multicenter cohort study. 2445 CKD subjects were enrolled from 81 Spanish hospitals and dialysis clinics, from 2010 to 2012. Eligibility criteria included: 18 to 74 years old, CKD stage 3 or higher, and no previous CVE. 559 non-CKD controls were also recruited. Demographical, clinical and analytical data were collected. Carotid and femoral ultrasounds were performed by a single trained team to measure carotid intima-media thickness (cIMT) and detect atheromatous plaques. Ankle-brachial index (ABI) was measured.

RESULTS

Differences in age, sex and prevalence and control of cardiovascular risk factors were found between controls and CKD patients. These differences are similar to those described in epidemiological studies.No difference was found regarding cIMT between controls and CKD (when subjects with plaques in common carotid arteries were omitted); earlier CKD stages had higher values. CKD patients had a higher rate of atheromatous plaques, with no difference between stages in the unadjusted analysis. A group of patients had plaques in femoral arteries but were plaque-free in carotid arteries, and would have gone underdiagnosed without the femoral study. The percentage of pathologic ABI was higher in CKD, with higher prevalence in more advanced stages, and a higher rate of ABI >1.4 than <0.9, suggesting more vascular calcification.

CONCLUSIONS

NEFRONA is the first large study describing the actual prevalence of subclinical atheromatosis across different CKD stages. There is a very high rate of atheromatous plaques and pathologic ABI in CKD. Prospective data will add important information to the pathogenesis and evolution of atheromatosis in CKD, compared to non-CKD subjects.

Ankle-brachial index and bone turnover in patients on dialysis

An association between atherosclerosis and osteoporosis has been reported in several studies. This association could result from local intraosseous atherosclerosis and ischemia, which is shown by limb osteoporosis in patients with peripheral artery disease (PAD), but also could result from bidirectional communication between the skeleton and blood vessels. Systemic bone disorders and PAD are frequent in ESRD. Here, we investigated the possible interaction of these disorders. For 65 prevalent nondiabetic patients on hemodialysis, we measured ankle-brachial pressure index (ABix) and evaluated mineral and bone disorders with bone histomorphometry. In prevalent patients on hemodialysis, PAD (ABix<0.9 or >1.4/incompressible) was associated with low bone turnover and pronounced osteoblast resistance to parathyroid hormone (PTH), which is indicated by decreased double-labeled surface and osteoblast surface (P<0.001). Higher osteoblast resistance to PTH in patients with PAD was characterized by weaker correlation coefficients (slopes) between serum PTH and double-labeled surface (P=0.02) or osteoblast surface (P=0.03). The correlations between osteoclast number or eroded surface and serum mineral parameters, including PTH, did not differ for subjects with normal ABix and PAD. Common vascular risk factors (dyslipidemia, smoking, and sex) were similar for normal, low, and incompressible ABix. Patients with PAD were older and had high C-reactive protein levels and longer hemodialysis vintage. These results indicate that, in prevalent nondiabetic patients with ESRD, PAD associates with low bone turnover and pronounced osteoblast resistance to PTH.

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.

Peripheral artery disease in peritoneal dialysis and hemodialysis patients: single-center retrospective study in Taiwan

Background

Peripheral artery disease (PAD) is a condition characterized by restricted blood flow to the extremities, and is especially common in the elderly. PAD increases the risk for mortality and morbidity in patients with end-stage renal disease (ESRD), especially those on hemodialysis (HD).

Methods

The records of 484 patients with end-stage renal disease who were on HD or peritoneal dialysis (PD) were reviewed. PAD was diagnosed based on the ankle-brachial pressure index (ABI). Demographic and clinical characteristics were analyzed.

Results

PAD had an overall prevalence of 18.2% and was significantly more common in HD patients (21.8%) than in PD patients (4.8%). Advanced age, diabetes mellitus, smoking, low parathyroid hormone level, elevated serum ferritin, elevated serum glucose, and low serum creatinine levels increased the risk for PAD. PAD was independently associated with advanced age, diabetes mellitus, duration of dialysis, low serum creatinine, and hyperlipidemia. PD patients had a significantly lower prevalence of PAD than HD patients, maybe due to their younger age and lower prevalence of diabetes mellitus in this present study.

Conclusions

The prevalence of PAD was greater in the HD group than the PD group. Most of the risk factors for PAD were specific to HD, and no analyzed factor was significantly associated with PAD in PD patients.

Ankle--brachial index, vascular calcifications and mortality in dialysis patients

BACKGROUND

The ankle-brachial index (ABI) is a noninvasive method to evaluate peripheral artery disease (PAD). ABI <0.9 diagnoses PAD; ABI >1.3 is a false negative caused by noncompressible arteries. The aim of this study is to evaluate the association between ABI with vascular calcifications (VC) and with mortality, in haemodialysis (HD) patients.

METHODS

We studied 219 HD patients (60% male; 20% diabetic). At baseline, ABI was evaluated by a Doppler device. VCs were evaluated by two methods: the abdominal aorta calcification score (AACS) in a lateral plain X-ray of the abdominal aorta and the simple vascular calcification score (SVCS) in plain X-rays of the pelvis and hands. VC were also classified by their anatomical localization in main vessels (aorta and iliac-femoral axis) and in peripheral or distal vessels (pelvic, radial or digital). The cutoff values for the different VC scores in relation with ABI were determined by receiver operating characteristic curve analysis. Biochemical parameters were time averaged for the 6 months preceding ABI evaluation.

RESULTS

An ABI <0.9, an ABI >1.3 or a normal ABI were found, respectively, in 90 (41%), in 42 (19%) and in 87 (40%) patients. AACS ≥6 and SVCS >3 were found, respectively, in 98 (45%) and 95 (43%) patients. The adjusted odds ratio (OR) for having an ABI <0.9 was 2.5 (P = 0.007) for AACS ≥6 and 4.5 (P < 0.001) for iliac-femoral calcification score (CS) ≥2. The adjusted OR for having an ABI >1.3 was 4.2 (P = 0.003) for pelvic CS and 3.7 (P = 0.006) for hand CS ≥2. During an observational period of 28.9 months, all-cause and cardiovascular mortality occurred, respectively, in 50 (23%) and in 29 (13%) patients. Adjusting for age, diabetes, P levels, HD duration and cardiovascular disease at baseline, an ABI <0.9 [hazard ratio (HR) = 3.9, P < 0.001] and an ABI >1.3 (HR = 2.7, P = 0.038) were associated with all-cause mortality; an ABI <0.9 (HR = 7.2, P = 0.002) and an ABI >1.3 (HR = 5.1, P = 0.028) were associated with cardiovascular mortality.

CONCLUSIONS

Both low and high ABI were independent predictors of all-cause and cardiovascular mortality. VC in main arteries were associated with an ABI <0.9. VC in peripheral and distal arteries were associated with an ABI >1.3. ABI is a simple and noninvasive method that allows the identification of high cardiovascular risk patients.

Presence of peripheral arterial disease predicts loss of residual renal function in incident CAPD patients

BACKGROUND

Accelerated cardiovascular disease (CVD), including peripheral arterial disease (PAD), is very common in patients with end-stage renal disease. Residual renal function (RRF) is a strong predictor of patient survival that is suggested to be linked to the degree of CVD. However, the relationship between PAD and decline in RRF has not previously been measured.

METHODS

We studied incident continuous ambulatory peritoneal dialysis patients from Peking University Third Hospital. An ankle brachial index of less than 0.9 was used to diagnose PAD. Residual renal function (RRF) was determined as the mean of 24-hour urea and creatinine clearances (glomerular filtration rate). The Cox proportional hazards model was used to identify factors predicting loss of RRF.

RESULTS

The study included 86 patients (age: 61 ± 14 years; men: 51%), 23 of whom had PAD at baseline. Mean follow-up was 19 months (median: 18 months; range: 6 - 30 months). In univariate analysis, baseline PAD, peritonitis during follow-up, inflammation (C-reactive protein), serum uric acid, Ca×P, and serum phosphate were all significantly associated with a greater-than-50% decrease in RRF during follow-up. In multivariate analysis, only baseline PAD, Ca×P, and peritonitis were independently associated with a decline in RRF.

CONCLUSIONS

Our study suggests that PAD may be a clinically important marker of CVD predicting the loss of RRF. It remains to be determined whether interventions aimed at decreasing PAD may also improve renal vascular status and thus slow the rate of RRF decline.

Surrogate markers of cardiovascular disease in CKD: what's under the hood?

Although clinical cardiovascular outcomes, such as heart attack, stroke, and sudden cardiac death, have a dramatic onset, they result from prolonged exposure to an ever-growing array of risk factors. Several noninvasive procedures are available to assess the cumulative effect of these exposures with the goal of more precisely estimating a person's cardiovascular risk. These include ankle-brachial index, which provides an estimation of obstruction in major-vessel lumen caliber; carotid ultrasound, which evaluates carotid intima-media thickness and plaque, visibly quantifying atherosclerotic burden; aortic pulse wave velocity, which provides a measure of large-artery stiffness; and echocardiography, which measures left ventricular mass, providing a measure of subclinical hypertensive heart disease. In this narrative review, we discuss the role of each of these measures, with a particular emphasis on patients with chronic kidney disease.

Association of peripheral artery disease and long-term mortality in hemodialysis patients

BACKGROUND

Peripheral artery disease (PAD) is a common complication in hemodialysis patients. The ankle-brachial blood pressure index (ABI) has been widely used to screen for subclinical PAD. In the present study, we investigated the association between ABI and long-term (up to 8.8 years) mortality among hemodialysis patients.

METHODS

A total of 86 consecutive patients receiving maintenance hemodialysis who underwent an ABI examination between 2001 and 2003 were retrospectively enrolled in this study. Patients with an ABI of less than 0.9 were considered as having PAD; those with an ABI of more than 0.9 in both legs were considered as being free from PAD. We examined the relationship between mortality and several risk factors.

RESULTS

During the follow-up period, 43 deaths were recorded. In the univariate regression analysis, the mortality hazard ratio (HR) of patients with PAD was 1.67 (95% confidence interval [CI], 1.18-2.28). Other predictive variables for mortality included male gender, age, and diabetes mellitus (P = 0.006, P = 0.024, and P = 0.023, respectively). A multivariate Cox analysis identified PAD and male gender as independent predictors of mortality (P = 0.033 and P = 0.028, respectively). The impact of age and diabetes mellitus on mortality was no longer significant in the multivariate analysis.

CONCLUSION

After a relatively long-term observation period, a multivariate analysis indicated that PAD acted independently of other risk factors, including advanced age and the presence of diabetes mellitus. ABI measurements can be used to identify high-risk hemodialysis patients requiring intensive follow-up care.

Diabetic foot disease in people with advanced nephropathy and those on renal dialysis

Among the spectrum of risk for diabetic foot disease conferred by chronic kidney disease (CKD), end-stage renal disease (ESRD) has emerged as a novel independent risk factor. Apart from the classical triad of neuropathy, infection, and peripheral arterial disease that operate in these individuals, the risk is further compounded by inadequate foot self-care by patients and by dialysis centers not providing onsite foot care, as medical priorities are diverted to the dialysis itself. Consequently, the burden of diabetic foot disease has increased in the CKD and ESRD population as exemplified by high ulceration, amputation, and foot-related mortality rates. Current guidelines on foot care in diabetes should recognize advanced CKD and ESRD/dialysis as a separate risk factor for foot disease to alert professionals and highlight the opportunity for prevention. Recent studies have demonstrated improved foot outcomes when chiropody programs are instituted within dialysis units.

Predicting cardiovascular disease morbidity and mortality in chronic kidney disease in Spain. The rationale and design of NEFRONA: a prospective, multicenter, observational cohort study

Background

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD). Cardiovascular risk assessment in this population is hampered by the failure of traditional risk factors to fully account for the elevated CVD risk (reverse epidemiology effect) and the presence of emerging risk factors specifically related to kidney failure. Therefore, diagnostic tools capable of improving cardiovascular risk assessment beyond traditional risk factors are currently warranted. We present the protocol of a 4-year prospective study aimed to assess the predictive value of non-invasive imaging techniques and biomarkers for CVD events and mortality in patients with CKD.

Methods

From November 2009 to October 2010, 4137 asymptomatic adult patients with stages 2 to 5 CKD will be recruited from nephrology services and dialysis units throughout Spain. During the same period, 843 participants without CKD (control group) will be recruited from lists of primary care physicians, only at baseline. During the follow-up, CVD events and mortality will be recorded from all CKD patients. Clinical and laboratory characteristics will be collected in a medical documentation sheet. Three trained itinerant teams will carry out a carotid ultrasound to assess intima-media thickness and presence of plaques. A composite atherosclerosis score will be constructed based on carotid ultrasound data and measurement of ankle-brachial index. In CKD patients, presence and type of calcifications will be assessed in the wall of carotid, femoral and brachial arteries, and in cardiac valves, by ultrasound. From all participants, blood samples will be collected and stored in a biobank to study novel biomarkers.

Conclusions

The NEFRONA study is the first large, prospective study to examine the predictive value of several non-invasive imaging techniques and novel biomarkers in CKD patients throughout Spain. Hereby, we present the protocol of this study aimed to explore the most effective way in which these tests can be integrated with traditional risk factors to maximize CVD detection in this population.