Benign prostatic hyperplasia associated with white matter hyperintensities in men.

PURPOSE: Benign prostatic hyperplasia (BPH) describes common noncancerous prostate enlargement. BPH is usually associated with lower urinary tract symptoms and an increased risk of cerebrovascular diseases, such as stroke and its recurrence. White matter hyperintensities (WMHs), markers of cerebral injury, increase the risk of stroke, cognitive impairment, dementia, and death. The relationship between BPH and WMHs remains unclear. This study aimed to determine the association between BPH and WMHs. METHODS: A total of 788 male patients from the First Affiliated Hospital of Kunming Medical University from July 2019 to September 2021 were enrolled in this cross-sectional study. BPH was assessed by abdominal ultrasound, and three independent neuroradiologists rated the presence or absence of WMHs. Multiple imputations of chained equations were used to handle missing data. Logistic regression was used to assess the relationship between BPH and WMHs. RESULTS: Patients with BPH presented an increased risk of WMHs with a crude odds ratio (OR) of 2.76 (95% CI, 2.02-3.79) and an adjusted OR of 1.75 (95% CI, 1.24-2.48) after controlling for potential confounding factors in the multivariate logistic regression. CONCLUSION: We found that BPH was closely associated with WMHs in male Chinese individuals.

Electrochemical skin conductance and heart rate variability in patients with non-dialysis chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is very common now and associates with high overall and cardiovascular mortality. Numerous studies have reported that Heart rate variability (HRV) could also be used to detect cardiovascular autonomic dysfunction (CAD). We investigated the association of electrochemical skin conductance (ESC) of EZSCAN results with HRV in non-dialysis CKD patients. METHODS: In a cross-sectional study, we enrolled 248 prevalent non-dialysis CKD patients. Patients underwent a 24-h Holter (CB-2302-A, Bio Instrument, China). A time domain analysis of HRV was performed, and the following parameters were obtained: SDNN, SDANN, rMSSD, pNN50. EZSCAN device (Impeto Medical, Paris, France) measures ESC values of each participants. Mean global skin conductance computed as 0.5 * (reflecting (right + left hand)/2 + (right and left foot)/2). Log transforms data into a normal distribution for statistical analysis. RESULTS: There were 142 males and 106 females included in the present study. Patients' age was 56.6±17.08 years. Logarithm(Log) (global ESC) was independently predicted by age (P<0.01), hypertension history, estimated Glomerular filtration rate (eGFR) and log SDNN (P<0.05). While log SDANN, rMSSD and pNN50 were not independent predictors for log (global ESC). CONCLUSION: Increased global ESC significantly associated with elevated HRV, specifically SDNN in non-dialysis CKD patients. This suggested that global ESC may appear to be an important predictor of CAD, and even could be used as a cardiovascular risk factor in non-dialysis CKD patients.

Glomerular filtration Rate, urine Albumin/ creatinine ratio and current perception threshold in patients with diabetic kidney disease.

BACKGROUND: Diabetic microvascular complications, including diabetic kidney disease (DKD), retinopathy (DR), and neuropathy (DN), were major causes of morbidity and mortality in diabetic patients worldwide. It has been suggested that urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) were not the only indicators of renal function impairment in DKD and that they were also associated with diabetic peripheral neuropathy (DPN) which might affect nerve conduction velocity (NCV). As 30-40% of DPN patients had no subjective symptoms, while current perception threshold (CPT) could detect sensory nerve damage at an early stage. As a result, we aimed to investigate correlation between UACR, eGFR and CPT in DKD patients. METHODS: A total of 273 DKD patients from the First Affiliated Hospital of Kunming Medical University from January 2018 to June 2020 were enrolled to complete the CPT test. CPT values of the bilateral median nerve and superficial and deep peroneal nerves at 2000 Hz, 250 Hz, and 5 Hz were collected. RESULTS: In normoesthesia and hypaesthesia patients with DKD, MDRD-eGFR correlated negatively with TC (r = -0.135, P = 0.037), left superficial peroneal and deep peroneal nerve 2000 Hz CPT (r = -0.205, P = 0.001) and right superficial peroneal and deep peroneal nerve 2000 Hz CPT (r = -0.154, P = 0.017). Besides, left and right superficial peroneal and deep peroneal nerve 2000 Hz CPT correlated with CKD-EPI-eGFR and UACR. Multivariate logistic regression analysis found left superficial peroneal and deep peroneal nerve 2000 Hz CPT was independently associated with both MDRD-eGFR and CKD-EPI-eGFR. CONCLUSION: Decreased MDRD-eGFR and CKD-EPI-eGFR were expected to be a predictor of peripheral nerve injury in normoesthesia and hypaesthesia patients with DKD.

Serum endocan and circadian heart rate variability in non-dialysis stage 5 chronic kidney disease patients.

BACKGROUND: Chronic kidney disease (CKD) is very common now and is associated with high overall and cardiovascular mortality. Numerous studies have reported that elevated heart rate (HR) is a risk factor for cardiovascular mortality. We investigated the link between serum endocan and circadian heart rate variability in non-dialysis stage 5 CKD patients. METHODS: In a cross-sectional study, we enrolled 54 prevalent n non-dialysis stage 5 CKD patients (32 males, aged 48.2 ± 14.92 years). HR was measured with an automatic system. Serum endocan level was analyzed by ELISA. RESULTS: Night/day HR ratio was independently predicted by serum endocan level (P < 0.01) and hypertension history (P < 0.05). Adjusted R2 of the model was 0.222. CONCLUSION: Increased serum endocan is significantly associated with circadian heart rate variability in non-dialysis stage 5 CKD patients. Further investigation is needed to explore the potential benefits of serum endocan lowering therapy in this patient group.

The impact of visit-to-visit systolic blood pressure variability on residual renal function and left ventricular hypertrophy in peritoneal dialysis patients

Background/aim: Blood pressure (BP) variability is more closely associated with adverse outcomes than 'usual' BP in the general population. Residual renal function (RRF) and left ventricular hypertrophy (LVH) are thought to be predictors of poor outcome in dialysis patients. However, only a few studies have focused on BP variation and its link to RRF, LVH, and outcome in peritoneal dialysis (PD) patients. Therefore, we aimed to explore the effect of visit-to-visit BP variability on RRF and LVH in continuous ambulatory PD (CAPD) patients. Materials and methods: We performed an observational study that included all prevalent PD patients between 1 February 2006 and 31 January 2007. All patients underwent BP measurements, pulse wave velocity (PWV), cardiac ultrasound, and biochemical examination during the 1-year observation. Patients were divided into the HBPV group (higher BP variability) and LBPV group (lower BP variability) based on the standard deviation of systolic BP (SBP). Results: There were 70 patients recruited for the final analysis. Patients with HBPV had a higher SBP as compared to patients with LBPV at baseline. Renal Kt/V decreased significantly from 0.50 ± 0.49 to 0.32 ± 0.35 (P < 0.01) in HBPV group (but not in the LBPV group) during follow-up. Patients with HBPV also showed a higher left ventricular mass index (LVMI) and PWV than those with LBPV at the end of follow-up. Conclusion: Our study suggests that BP variability may affect RRF in PD patients. PD patients with HBPV had a faster decline in RRF and higher PWV and LVH.

Sagittal abdominal diameter and Framingham risk score in non-dialysis chronic kidney disease patients.

BACKGROUND: Chronic kidney disease (CKD) is very common now and is associated with high overall and cardiovascular mortality. Numerous studies have reported that abdominal obesity is a risk factor for cardiovascular mortality. We investigated the link between sagittal abdominal diameter (SAD) and Framingham risk score in non-dialysis CKD patients. METHODS: In a cross-sectional study, we enrolled 307 prevalent non-dialysis CKD patients (175 males, aged 50.7 ± 17.04 years). SAD and Framingham risk score were measured. RESULTS: Framingham cardiovascular disease risk score was independently predicted by SAD (P < 0.01), GFR (P < 0.01) and diabetic history (P < 0.05). Adjusted R2 of the model was 0.178. SAD could be independently predicted by BMI (P < 0.01), diabetic history (P < 0.01), GFR (P < 0.01) and age (P < 0.01). Adjusted R2 of the model was 0.409. Using receiver operating characteristic (ROC) curve, a cutoff SAD value of 16.55 cm was determined with sensitivity of 63.7%, specificity of 58.3%. CONCLUSION: Elevated SAD is significantly associated with increased Framingham risk score in non-dialysis CKD patients. SAD can be predicted by patients' BMI, diabetic history, renal function and age. Further investigation is needed to explore the potential benefits of central obesity lowering therapy in this patient group.

Increased night heart rate is associated with worse large artery elasticity in chronic kidney disease patients.

BACKGROUND: Chronic kidney disease (CKD) is associated with high overall and cardiovascular mortality. Numerous studies have reported that increased heart rate is a risk factor for all-cause mortality. We investigated the link between sleep heart rate and artery stiffness in CKD patients. METHODS: In a cross-sectional study, we enrolled 100 prevalent Chinese CKD patients (55 males, aged 52.5 ± 16.40 years). Heart rate was measured with an automatic system. Arterial stiffness was evaluated by using a calibrated tonometer. RESULTS: Large artery elasticity index (LAEI) was positively correlated with body mass index and hemoglobin but negatively associated with age and systolic blood pressure. Furthermore, LAEI was negatively associated with glomerular filtration rate (GFR) and sleep heart rate. In multivariate regression, LAEI was independently predicted by SBP, BMI, age, sleep heart rate, and gender. Adjusted R (2) of the model was 0.486. CONCLUSION: Elevated sleep heart rate is significantly associated with increased arterial stiffness in CKD patients. Further investigation is needed to explore the potential benefits of sleep heart rate lowering therapy in this patient group.

Peripheral arterial disease predicts overall and cardiovascular mortality in peritoneal dialysis patients.

BACKGROUND: Peripheral arterial disease (PAD) is an important manifestation of systemic atherosclerosis and is common among dialysis patients. Cardiovascular disease (CVD) accounts for the leading cause of mortality in dialysis patients, and PAD has been found as a predictor for cardiovascular as well as overall mortality in general population. However, the study on the role of PAD in the prognosis of peritoneal dialysis patients is rather limited. METHODS: Prevalent continuous ambulatory peritoneal dialysis patients over 60 years old were recruited in this study and were followed-up regularly to death or the end of the study. The diagnosis of PAD was based on ankle-brachial pressure index (ABI) < 0.9 or intermittent claudication. Univariate and multivariate Cox proportional hazard models were used to identify the risk factors for cardiovascular and overall mortality. Survival curves were estimated by the Kaplan-Meier method followed by log-rank test to compare the mortality rate between PAD and non-PAD patients. RESULTS: One hundred and seventy-one patients were included and 62 (36%) had PAD complication. In the follow-up of 24.4 (median 34.6) months, 36 deaths were recorded: 19 from PAD group and 17 from non-PAD group. Twenty-one patients died due to CVD: 13 from PAD group and 8 from non-PAD group. The presence of PAD and serum albumin was found independently associated with cardiovascular and overall mortality using Cox proportional hazards model. CONCLUSION: PAD is very common in aged peritoneal dialysis patients and independently associated with both cardiovascular and overall mortality.

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.

Hypertriglyceridemic waist is associated with increased carotid atherosclerosis in chronic kidney disease patients.

BACKGROUND: Patients with chronic kidney disease (CKD) have an unacceptably high risk of death, primarily as a result of cardiovascular disease (CVD). The 'hypertriglyceridemic waist' phenotype has been proposed as a simple and strong predictor of CVD risk. Therefore, we investigated the relationship between the hypertriglyceridemic waist phenotype and carotid atherosclerosis in CKD patients. METHODS: In a cross-sectional study, we enrolled 785 prevalent CKD patients [416 males, aged 44.6 years (21.7-69.4), glomerular filtration rate 52.5 ml/min/1.73 m(2) (5.3-119.4)]. We divided the patients into three groups: group 1: waist circumference >90 cm in men or >85 cm in women and triglycerides ≥2 mmol/l (n = 109); group 3: waist circumference ≤90 cm in men or ≤85 cm in women and triglycerides <2 mmol/l (n = 379), and group 2: the remaining patients (n = 297). Routine biochemical parameters and carotid artery intima-media thickness (IMT) were measured. RESULTS: The prevalence of the hypertriglyceridemic waist phenotypes was 13.8% in the CKD patients. Triglyceride, total cholesterol, HDL-cholesterol and LDL-cholesterol concentrations in group 1 were significantly higher than those in group 3. Carotid artery IMT of the hypertriglyceridemic waist group was the highest. CONCLUSION: The hypertriglyceridemic waist phenotype was associated with worse carotid atherosclerosis in CKD patients. This suggests that the hypertriglyceridemic waist phenotype may be useful for predicting CVD risk in CKD patients.

Peripheral resistance modulates the response to volume overload in peritoneal dialysis patients.

BACKGROUND: Volume overload is thought to be the most important cause of hypertension in peritoneal dialysis (PD) patients. However, there is also evidence that normalization of volume overload is not always accompanied by a drop in blood pressure (BP). In the present study, we hypothesized that dysregulation of peripheral resistance due to endothelial dysfunction would constitute an important determinant of BP response in overhydrated PD patients. METHODS: We performed an observational, prospective cohort study including all prevalent PD patients at the Peking University Third Hospital between 1 June 2006 and 30 November 2006. After baseline measurements, including echocardiography and bioelectrical impedance analysis, patients fulfilling inclusion criteria were reevaluated after 2 months of follow-up. All patients that exhibited significant changes in BP and extracellular water (ECW) between 2 visits were asked to undergo a second ultrasound. These patients were then divided into group A (parallel change between BP and ECW; n = 12) and group B (paradoxical change between BP and ECW; n = 10). RESULTS: The cohort included 22 patients (13 males) with a mean age of 59 +/- 13 years, on dialysis for 23.3 +/- 32.6 months. There were no baseline differences between groups A and B. However, while patients in group A significantly increased their cardiac output, total peripheral resistance remained stable. In group B, cardiac output did not change significantly but total peripheral resistance decreased significantly. CONCLUSION: In PD patients, a significant increase in fluid volume is not necessarily linked to a significant increase in BP. Rather, the change in total peripheral resistance was found to be the most important determinant of the extent to which increased fluid volume affected BP.

Increased dialysate levels of phospholipids containing unsaturated fatty acid are associated with increased peritoneal transport rate.

BACKGROUND: High peritoneal transport status in end-stage renal disease patients receiving peritoneal dialysis was shown to be associated with increased morbidity and mortality. Although the pathogenesis of increased peritoneal transport is still not clear, previous studies have demonstrated that phospholipids (PLs) are present on the peritoneal mesothelium and when added to dialysate can decrease the peritoneal fluid absorption rate and increase peritoneal fluid removal. In the present report, we explored the relationship between peritoneal transport and dialysate loss of endogenous PLs. METHODS: We evaluated 48 prevalent continuous ambulatory peritoneal dialysis patients with high or low peritoneal transport in a cross-sectional study. The 4-hour dwell dialysate PL profile was analyzed by high-performance liquid chromatography coupled with electrospray ionization ion trap mass spectrometry. The patients' peritoneal small solute transport rate was assessed by D/P(Cr) at 4 h and their fluid transport by kinetic modeling. RESULTS: While there were no significant differences between the 2 groups in age, sex, diabetic status and time on dialysis, high transporters had a significantly higher D/P(Cr) and peritoneal fluid absorption rate (K(e)) than low transporters. The PLs in dialysate effluents mainly consisted of PLs containing unsaturated fatty acid, and the concentrations, as well as the amount, of PLs were significantly elevated in the dialysate of high transporters as compared to low transporters. CONCLUSION: Our results showed that dialysate from high transporters exhibited elevated levels of PLs, especially PLs containing unsaturated fatty acid, suggesting a possible loss of peritoneal surface-active PLs in peritoneal dialysis, and this loss may contribute to the alteration in peritoneal transport.

The prevalence of left ventricular hypertrophy in Chinese hemodialysis patients is higher than that in peritoneal dialysis patients.

BACKGROUND: Left ventricular hypertrophy (LVH) is common in dialysis patients, and an independent predictor of mortality. While recent studies have shown no differences in mortality between the two most common dialysis modalities, hemodialysis (HD) and peritoneal dialysis (PD), their impact on LVH is controversial. We thus performed cardiac ultrasound studies in prevalent dialysis patients receiving either HD or PD and compared LVH. METHODS: We included 48 HD and 62 PD patients receiving treatment for at least three months in our dialysis center. All patients underwent echocardiographic examination and blood pressure measurements immediately following therapy. Volume status was assessed by bioelectrical impedance analysis. RESULTS: There was no baseline difference in demographics or comorbidities between HD and PD patients. As expected, extracellular water (ECW) in post-HD patients was significantly lower than that in pre-HD and PD patients, while cardiac output (CO) and systolic blood pressure (SBP) were higher in pre-HD than that in post-HD or PD patients. There was no significant difference in CO or SBP between post-HD and PD patients. Left ventricular mass index (LVMI) was markedly higher in HD patients as compared to PD patients. Thus, the prevalence of LVH according to the Framingham criteria was 68.8% in HD patients and 45.2% in PD patients. Subgroup analysis showed similar results in the patients who had been on single-modality dialysis for at least two years and in the anuric patients. Finally, in a linear regression model (r(2) = 0.364, p < 0.001), SBP, treatment modality (to be in HD), and ECW were all independent predictors of LVMI. CONCLUSIONS: In a cross-sectional analysis of prevalent Chinese patients, we found a higher LVMI and a higher prevalence of LVH in HD than in PD patients. As LVMI was associated with high blood pressure and volume overload, we suggest that in these patients, PD may preserve more physiological hemodynamics even during long-term therapy.

Association between arterial stiffness and peritoneal small solute transport rate.

While cardiovascular disease accounts for 40-50% of the mortality in dialysis patients, and while a high peritoneal transport in continuous ambulatory peritoneal dialysis (CAPD) is an independent predictor of outcome, it is unclear if there are any links. Aortic stiffness has become established as a cardiovascular risk factor. We thus studied pulse wave velocity (PWV) in CAPD patients to explore the possible link between peritoneal small solute transport and aortic stiffness. CAPD patients (n = 76, 27 M/49 F) in our center were included in the present study. Aortic stiffness was assessed by brachial pulse pressure (PP) and carotid-femoral PWV. Patients' peritoneal small solute transport rate was assessed by D/P(cr) at 4 h. Extracellular water over total body water (E/T ratio) was assessed by means of bioimpedance analysis. C-reactive protein was also measured. Carotid-femoral PWV was positively associated with patients' age (r = 0.555; P < 0.01), time on peritoneal dialysis (r = 0.332; P < 0.01), diabetic status (r = 0.319; P < 0.01), D/P(cr) (r = 0.241; P < 0.05), PP (r = 0.475; P < 0.01), and E/T (r = 0.606; P < 0.01). In a multivariate regression analysis, carotid-femoral PWV was independently determined by E/T (P < 0.01), PP (P < 0.01), age (P < 0.01), and D/P(cr) (P < 0.05). D/P(cr), in addition to E/T, age, and PP, was an independent predictor of elevated carotid-femoral PWV in CAPD patients, suggesting that there might be a link between high aortic stiffness and increased peritoneal small solute transport rate.

Pulse wave velocity is associated with metabolic syndrome components in CAPD patients.

BACKGROUND: Overall, the proportion of deaths due to cardiovascular disease (CVD) reached 40-50% in dialysis patients. Pulse wave velocity (PWV) reflects arterial stiffness and may provide an integrated index of vascular status and CVD risk. Individual components of the metabolic syndrome (MetS) are well-established cardiovascular risk factors. Thus we conducted a cross-sectional study in continuous ambulatory peritoneal dialysis (CAPD) patients to explore the association of MetS components with PWV. METHODS: Prevalent CAPD patients (n = 148, 63 M/85 F) were categorized according to the number of traits of the MetS into one of three groups (No MetS, Risk of MetS, MetS). Due to the effect of peritoneal dialysis (PD), waist circumference was not assessed. Aortic stiffness was assessed by carotid-femoral PWV (C-F PWV). RESULTS: Patients' MetS trait numbers were positively associated with C-F PWV (r = 0.301, p < 0.01), pulse pressure (r = 0.256, p < 0.01), systolic blood pressure (r = 0.233, p < 0.01), and serum albumin (r = 0.205, p < 0.05). In a multivariate regression analysis, PWV was independently determined by age (p < 0.01) and MetS score (p = 0.01). Adjusted R(2) of the model was 0.24. CONCLUSION: MetS traits were closely associated with an increased C-F PWV, even after adjustment for confounders. This suggests that commonly recognized MetS criteria are useful also when predicting CVD in CAPD patients.

Ultrafiltration capacity and peritoneal fluid kinetics in continuous ambulatory peritoneal dialysis patients.

Volume control is critical for peritoneal dialysis. Although peritoneal equilibration test (PET) has been used to clarify the peritoneal membrane characteristics, it is not able to adequately predict peritoneal fluid removal and optimize appropriately the dwell time. In the present study, we applied computer simulation and performed a more detailed evaluation of the fluid kinetics in patients with different ultrafiltration (UF) capacity. Patients who used three to four exchanges of 2.27% glucose dialysate per day (poor UF capacity group), and patients who used three to four exchanges of 1.36% glucose dialysate per day (good UF capacity group) to achieve adequate amount of peritoneal fluid removal were included in the present analysis. All included patients were asked to record appropriately their dialysis exchanges for the assessment of their peritoneal fluid transport characteristics. Seventeen continuous ambulatory peritoneal dialysis patients were selected in the present study, nine in poor UF capacity group and eight in good UF capacity group. Patients in poor UF capacity group had significantly higher daily glucose exposure, higher dialysate-to-plasma ratio of creatinine (D/P creatinine) values, and higher peritoneal fluid absorption rate, K(e), as compared to patients with good UF capacity. Our results suggest that patients with poor UF capacity have significant higher peritoneal small solute transport rate, and more importantly, higher peritoneal fluid absorption rate as compared to patients with good UF capacity.

Association between arterial stiffness and peritoneal fluid kinetics.

BACKGROUND: A high peritoneal transport status in continuous ambulatory peritoneal dialysis (CAPD) patients is associated with a markedly increased morbidity and mortality. While the causes are as yet unknown, overall the proportion of deaths due to cardiovascular disease is estimated at 40-50% among dialysis patients. Arterial stiffness has been established as a cardiovascular risk factor, while the links between peritoneal transport status and aortic stiffness have not yet been investigated. METHODS: We included 65 prevalent CAPD patients (24 males/41 females) from our center in a cross-sectional study. Arterial stiffness was assessed by brachial pulse pressure (PP) and carotid-femoral pulse wave velocity (C-F PWV). The patients' peritoneal fluid transport was assessed by kinetic modeling. The patients' peritoneal small solute transport rate was assessed by D/P(cr) at 4 h. Extracellular water to total body water (E/T) ratio was assessed by means of bioimpedance analysis. C-reactive protein was also measured. RESULTS: C-F PWV was positively correlated with patients' age (r = 0.489, p < 0.01), diabetic status (r = 0.327, p < 0.01), peritoneal fluid absorption rate (Ke; r = 0.251, p < 0.05), PP (r = 0.483, p < 0.01), and E/T (r = 0.517, p < 0.01). Multivariate regression analysis showed that C-F PWV was independently related to E/T (p < 0.01), PP (p < 0.01), age (p < 0.05), and Ke (p < 0.05). CONCLUSION: Peritoneal fluid transport (Ke), as well as E/T, age and PP were found to be independent predictors of elevated C-F PWV in CAPD patients, suggesting that there might be a link between high aortic stiffness and increased Ke rate, hypothetically through generalized vasculopathy.

Evaluating peritoneal fluid transport in continuous peritoneal dialysis patients: a practical approach.

BACKGROUND/AIMS: Evaluating the peritoneal fluid kinetics is of clinical importance in peritoneal dialysis treatment. We have previously developed a simple way to evaluate the peritoneal fluid transport characteristics in continuous ambulatory peritoneal dialysis patients which, however, cannot be applied to those patients on a fixed dialysis schedule. Therefore, in the present study, we tested the possibility to vary the peritoneal dwell time and tried to develop a more patient-friendly ultrafiltration (UF) collection protocol. METHODS: The patients' UF volume was recorded for 10 days. All patients recruited were asked to perform their usual dialysis exchanges with, however, a special UF data collection protocol to improve the accuracy of computer simulation: at least one dwell of 2-4 h, one of 4-7 h, and one of more than 7 h. The fluid transport model was applied to the pooled UF volume for fluid kinetics simulation, and the data from the following day's UF records using the same glucose concentration and dwell time were used to evaluate reliability and accuracy of the simulated UF value. RESULTS: Fifty-two chronic peritoneal dialysis patients were included in the present study. All of the UF data could be used in the computer simulation, and there was a significant negative correlation between fluid absorption rate (K(e); see text) and actual UF volume on the following day using a glucose concentration of 1.5% and a dwell time of 4 h (r = -0.336, p < 0.05). The estimated UF values correlated significantly with the actually measured UF values. The variability of the results, expressed by the width between the 95% limits of agreement, fell within -139.2 to 131.9 ml, while the mean difference was -3.7 ml. CONCLUSIONS: Our present study showed that varying the peritoneal dwell time was a patient-friendly UF data collection protocol for continuous ambulatory peritoneal dialysis patients on a fixed dialysis schedule. Applying the fluid transport model and nonlinear least squares regression analysis to pooled UF values might be a good and simple way to predict the peritoneal UF capacity.

Effects of peritoneal resting on peritoneal fluid transport kinetics.

BACKGROUND: Peritoneal resting has been used to restore peritoneal ultrafiltration capacity in peritoneal dialysis patients. Therefore, in the present study, we made a detailed investigation on the effects of peritoneal resting on peritoneal fluid transport characteristics in patients on continuous ambulatory peritoneal dialysis (CAPD). METHODS: A temporary transfer to daytime ambulatory peritoneal dialysis with a nocturnal "empty belly" was applied to let the peritoneal membrane rest overnight in patients with poor ultrafiltration capacity. All included patients were asked to record appropriately their dialysis exchanges for the assessment of peritoneal fluid transport characteristics, which were evaluated before and after peritoneal resting. RESULTS: Seven CAPD patients were included in the present study. There was a significant improvement in peritoneal ultrafiltration capacity as assessed by ultrafiltration volume per gram of glucose load. Patients' daily glucose exposure and dialysate-to-plasma ratio of creatinine were significantly decreased after peritoneal resting. The peritoneal fluid absorption rate was also significantly decreased after peritoneal resting: 1.011 +/- 0.4484 versus 0.625 +/- 0.3833 mL/minute. CONCLUSION: The present study suggests that peritoneal resting can improve CAPD patients' ultrafiltration capacity and decrease the use of hypertonic dialysis solution. The improved ultrafiltration capacity by peritoneal resting was due to decreased membrane solute transport rate and decreased peritoneal fluid absorption rate.

Defining peritoneal dialysis adequacy: Kt/Vurea revisited.

BACKGROUND: Although adequate peritoneal dialysis is not well defined, Kt/Vurea has been used as an index, and various values have been proposed. However, conflicting evidence existed regarding the appropriateness of using Kt/Vurea to define dialysis adequacy and its optimal value. Therefore, the present study performed a theoretical analysis on whether we should use Kt/Vurea to define peritoneal dialysis adequacy and what the optimal value should be. METHODS: The three-pore model was applied to evaluate the transport patterns of different molecular weight solutes and fluid. Optimal Kt/Vurea value was estimated based on urea kinetics and nitrogen balance. RESULTS: The removal pattern of small solute, middle and large molecules, and fluid and sodium are quite different. Depending on the dwell time, higher urea removal does not necessarily mean higher sodium, fluid, and other molecular weight solute removals. To reach nitrogen balance, the dialysis doses and therefore Kt/Vurea values varied with different dietary protein intakes in a patient with a given weight and residual renal function. CONCLUSION: This study shows that Kt/Vurea in peritoneal dialysis cannot represent the removal of other solutes and fluid, indicating that Kt/Vurea alone should not be used as a sole indicator of peritoneal dialysis adequacy. The results also show that optimal Kt/Vurea cannot be a fixed value, but varies according to individual dietary protein intake and tolerable blood urea level.