Urine headspace analysis with field asymmetric ion mobility spectrometry for detection of chronic kidney disease.

Electronic noses (eNoses) are an emerging class of experimental diagnostic tools. They are based on the detection of volatile organic compounds. Urine is used as sample medium in several publications but neither the effect of chronic kidney disease (CKD) on the analysis nor the potential to detect CKD has been explored. Materials & methods: We utilized an eNose based on field asymmetric ion mobility spectrometry (FAIMS) technology to classify urine samples from CKD patients and controls. Results: We were able to differentiate extremes of kidney function with an accuracy of 81.4%. Conclusion: In this preliminary study, applying eNose technology we were able to distinguish the patients with impaired kidney function from those with normal kidney function.

Valvular calcification and its relationship to atherosclerosis in chronic kidney disease.

BACKGROUND AND AIM OF THE STUDY: Cardiovascular calcification is a common complication in patients with chronic kidney disease (CKD). The study aim was to identify the characteristics and risk factors of valvular calcification, and its relationship to atherosclerosis, in CKD. METHODS: In this cross-sectional study, a total of 135 patients with CKD (mean age 52 +/- 11 years) included 58 pre-dialysis patients, 36 dialysis patients, and 41 renal transplant recipients. A control group of 58 subjects was also examined. The characteristics of valvular calcification were assessed using transthoracic echocardiography. RESULTS: The combined prevalences of mitral or aortic valve calcification were 31% in pre-dialysis patients, 50% in dialysis patients, 29% in renal transplant recipients, and 12% in controls (p = 0.001). The prevalences of mitral annular calcification were 17%, 31%, 27% and 2%, respectively (p = 0.001). In multivariate analysis, the risk factors for valvular calcification in CKD were age, duration of dialysis treatment and interleukin-6 level. Mitral annular calcification proved to be five-fold more common in diabetic patients than among non-diabetics. A close association between valvular calcification and patients with or without increased carotid intima-media thickness (44% versus 15%, p < 0.001), carotid plaque (77% versus 49%, p = 0.002), calcified carotid plaque (65% versus 26%, p = 0.001), coronary artery disease (40% versus 15%, p = 0.003) and peripheral arterial disease (46% versus 9%, p < 0.001) was found. CONCLUSION: Valvular calcification is common in CKD, and is closely associated with findings of intimal arterial disease. The presence of inflammation and the duration of dialysis treatment contribute to this complication. Diabetes is also a prominent risk factor for mitral annular calcification in CKD.

Peripheral vascular disease in diabetic peritoneal dialysis patients.

In the present article, we review current knowledge of the epidemiology, diagnosis, and treatment of peripheral vascular disease in patients with end-stage renal disease. The main focus is placed on diabetic patients receiving peritoneal dialysis, but studies on patients receiving hemodialysis are also reviewed, because most reports involve this patient group, and the number of reports on peripheral vascular disease in PD patients alone is limited.

Comparison of calcium phosphate product values using measurement of plasma total calcium and serum ionized calcium.

Calcium phosphate product (Ca x Pi) is a clinically relevant tool to estimate the cardiovascular risk of patients with renal failure. In reports, mostly total serum calcium has been used. As measurement of serum ionized calcium has some benefits and is being used increasingly, we estimated the respective levels of calcium phosphate product using both total (t-Ca x Pi) and ionized calcium (ion-Ca x Pi). Fifty-eight healthy individuals and 180 hemodialysis (HD) patients from 2 centers were studied. Diagnostic accuracies for corresponding values of the t-Ca x Pi and ion-Ca x Pi were calculated using a GraphROC program. Of HD patients, 64% had t-Ca x Pi <4.4 mmol(2)/L(2) regarded as a desirable goal, and 10% had values over 5.6 mmol(2)/L(2) associated with a high cardiovascular risk. Based on GraphROC analysis, t-Ca x Pi of 4.4 mmol(2)/L(2) corresponded to a value of 2.2 mmol(2)/L(2) of ion-Ca x Pi and, respectively, t-Ca x Pi of 5.6 mmol(2)/L(2) corresponded 2.8 mmol(2)/L(2) of ion-Ca x Pi. Owing to the good agreement between the results in the 2 centers, these values for risk levels can be used in both centers. When measurement of ionized calcium is used, Ca x Pi values of 2.2 and 2.8 mmol(2)/L(2) can be used instead of generally used values of 4.4 and 5.6 mmol(2)/L(2) with total calcium.

Prediction of coronary artery disease by transesophageal echocardiographic detection of thoracic aortic plaque in patients with chronic kidney disease.

BACKGROUND/AIMS: Our aim was to examine the significance of thoracic aortic plaque detected by transesophageal echocardiography (TEE) in the prediction of coronary artery disease (CAD) in patients with chronic kidney disease (CKD). METHODS: We examined 118 patients (mean age 52 +/- 12 years) with CKD and followed them for a mean of 3.4 +/- 0.8 years. The study group included 52 predialysis patients with moderate to severe CKD (plasma creatinine > or = 200 micromol/l), 32 patients on dialysis treatment, and 34 renal transplant recipients. At baseline, TEE was performed to evaluate thoracic aortic atherosclerosis. CAD was defined by a history of a documented myocardial infarction, a coronary angiogram or a post-mortem autopsy finding showing significant occlusive CAD by the end of the follow-up period. RESULTS: CAD was documented in 31 (26%) of the 118 study patients. The presence of thoracic aortic plaque had a sensitivity of 100% and a specificity of 37% for CAD and the positive and negative predictive values were 36 and 100%, respectively. In the subset of 36 patients with morphological findings of coronary arteries by angiogram or autopsy, the presence of large thoracic aortic plaques (> or = 3 mm in diameter) had a 73% sensitivity and 90% specificity for significant coronary artery stenosis. The positive and negative predictive values were 95 and 56%, respectively. CONCLUSION: TEE may be used for detecting high-risk patients with CKD; the absence of thoracic aortic plaque predicted the absence of CAD, and the presence of large aortic plaques predicted significant coronary artery stenosis.

Homocysteine and carotid atherosclerosis in chronic renal failure--the confounding effect of renal function.

Since total homocysteine (tHcy) level is markedly elevated in patients with chronic renal failure (CRF), it has been presented as a potential factor contributing to the high risk of cardiovascular disease (CVD) in CRF. Our aim was to examine the significance of elevated tHcy level and other cardiovascular risk factors for carotid atherosclerosis in patients with CRF. In this cross-sectional study, 135 study patients with CRF (52 +/- 11 years) included 58 patients with moderate to severe predialysis CRF, 36 dialysis patients and 41 renal transplant recipients. In addition, 58 control subjects were examined. The association of tHcy level and classic risk factors for atherosclerosis with common carotid artery intima-media thickness (IMT) or carotid artery plaque score was examined. We found no association between tHcy and carotid IMT or a high carotid plaque score in the CRF patient groups. No consistent association was found between elevated tHcy and coronary artery disease, cerebrovascular disease or peripheral arterial disease. Renal function, described as creatinine clearance, was the strongest determinant for tHcy level. Significant predictors of carotid atherosclerosis were age, duration of hypertension and elevated low-density lipoprotein cholesterol level. In conclusion, the present study shows no apparent association between tHcy level and atheromatous carotid findings in patients with CRF. However, because of the changing renal function in the course of renal disease, the strong confounding effect of renal function may not be adequately controlled for the analysis of the significance of elevated tHcy level for CVD in patients with CRF.

Carotid atherosclerosis in chronic renal failure-the central role of increased plaque burden.

Studies on carotid artery atherosclerosis have been performed in order to understand the high risk for cardiovascular disease in chronic renal failure (CRF). The purpose of this study was to evaluate the extent and nature of carotid artery atherosclerosis in patients with CRF. Of the 135 patients with CRF (52 +/- 11 years), 58 had moderate to severe predialysis CRF (PR), 36 were on dialysis treatment (DI), and 41 were renal transplant recipients (TR). In addition, 58 control subjects (CO) were examined. Common carotid artery intima-media thickness (IMT), plaque prevalence, plaque score, and stiffness index beta were determined. Furthermore, plaque calcification and internal carotid artery stenoses were classified. Plaque prevalence (PR 64%, DI 61%, TR 51%, CO 28%; P < 0.001) and plaque score (PR 3.3 +/- 4.3, DI 3.0 +/- 3.4, TR 2.5 +/- 3.2, CO 0.8 +/- 1.7 mm; P < 0.001) were significantly greater in the CRF patient groups compared to the controls, whereas no difference in IMT was noted between the study groups. The prevalences of plaque calcification and internal carotid artery stenoses were higher among the CRF patient groups. In addition, the stiffness index beta was higher in the CRF patient groups. The present study shows that the characteristic alterations of the carotid arteries in CRF include increased plaque burden, calcification and increased arterial stiffness.

Risk factors for aortic atherosclerosis determined by transesophageal echocardiography in patients with CRF.

BACKGROUND: The significance of various risk factors for cardiovascular disease (CVD) in the pathogenesis of atherosclerosis in patients with chronic renal failure (CRF) is, to a great deal, unresolved. The high risk for CVD in patients with CRF may be caused by the high prevalence of recognized risk factors for CVD or by factors characteristic of CRF in these patients. In this prospective cross-sectional study, we examined risk factors for thoracic aortic atherosclerosis in a population of patients with CRF consisting of predialysis and dialysis patients, as well as renal transplant recipients. METHODS: Of 118 patients, 52 patients had moderate to severe predialysis CRF, 32 patients were on dialysis treatment, and 34 patients were renal transplant recipients. Mean age was 52 +/- 12 years, and 35 patients (30%) had diabetes. Multiplane transesophageal echocardiography (TEE) was performed using local anesthesia. RESULTS: Large aortic plaques (LAPs; > or = 3.0 mm in diameter) were found in 39 patients (33%). In univariate analysis, age, duration of hypertension, pulse pressure, low diastolic blood pressure, elevated fibrinogen level, C-reactive protein level, total cholesterol level, low-density lipoprotein cholesterol level, and duration of dialysis or a functioning renal transplant were significantly associated (P < 0.05) with LAP. In multivariate analysis, age, duration of hypertension, and total cholesterol level were associated with LAP. CONCLUSION: Results of the present TEE study suggest that in addition to duration of hypertension and renal disease, hypercholesterolemia has a role in the pathogenesis of atherosclerosis in patients with CRF.

The prevalence of peripheral arterial disease and medial arterial calcification in patients with chronic renal failure: requirements for diagnostics.

BACKGROUND: Knowledge of the prevalence of peripheral arterial disease (PAD) in patients with chronic renal failure (CRF) is limited because of a lack of uniformity in disease definition and recognition. Furthermore, little is known of the prevalence of medial arterial calcification (MAC) in patients with CRF. Our goal is to study the prevalence of PAD and MAC defined by ankle brachial index (ABI) or toe brachial index (TBI) measurements in a Finnish population of patients with CRF consisting of predialysis and dialysis patients, as well as renal transplant recipients. METHODS: We examined 136 patients with CRF and 59 control subjects. Fifty-nine of the patients with CRF had moderate to severe predialysis CRF, 36 patients were on dialysis treatment, and 41 were renal transplant recipients. Mean age of patients was 51.9 +/- 11.5 years, and 39 patients (29%) had diabetes. ABI and TBI were measured by means of photoplethysmography. The definition of PAD required an ABI value of 0.90 or less, a TBI value of 0.60 or less, or a previous positive lower-extremity angiogram result. ABI values of 1.3 or greater or incompressible arteries at ankle level indicated MAC. The presence of claudication was determined by an interview. RESULTS: Prevalences of PAD on this study were 22.0% in patients with predialysis CRF, 30.6% in patients on dialysis treatment, 14.6% in renal transplant recipients, and 1.7% in the control group (P = 0.001). Prevalences of MAC were 23.7%, 41.7%, 23.1%, and 3.4% (P < 0.001), respectively. Only 9 patients had claudication, and 6 of those patients had PAD. CONCLUSION: Both asymptomatic PAD and MAC are common in patients with CRF. Therefore, we recommend the use of both ABI and TBI measurements in the evaluation of PAD in patients with CRF.