Comparison of Blood Pressure Control and Left Ventricular Hypertrophy in Patients on Continuous Ambulatory Peritoneal Dialysis (CAPD) and Automated Peritoneal Dialysis (APD)

A comparative analysis of ambulatory BP profile and arterial stiffness between CAPD and APD

Prior studies have associated automated peritoneal dialysis (APD) with less effective volume and blood pressure (BP) control as compared with continuous ambulatory peritoneal dialysis (CAPD). Our study aimed to compare the volume status, ambulatory BP profile and severity of arterial stiffness between patients treated with CAPD versus APD. In a case-control design, 28 CAPD patients were matched in 1:1 ratio with 28 controls receiving APD for age, gender and diabetic status. Body composition was assessed with the method of bioimpendence spectroscopy. Twenty-four hours ambulatory BP monitoring with the Mobil-O-Graph device (IEM, Germany) was performed to determine peripheral and central hemodynamic parameters, heart rate-adjusted augmentation index (AIx75) and pulse wave velocity (PWV). Standardized office BP, antihypertensive medication use and extracellular-to-total body water ratio did not differ between CAPD and APD groups. Twenty-four hours brachial systolic BP (129.0 ± 17.3 vs. 128.1 ± 14.2 mmHg, P = 0.83) and 24-h aortic systolic BP (116.9 ± 16.4 vs. 116.4 ± 11.6 mmHg, P = 0.87) were similar in patients treated with CAPD versus APD. Similarly, there was no significant difference between PD modalities in severity of arterial stiffness, as assessed with 24-h AIx75 (24.8 ± 8.9 vs. 22.5 ± 9.1, P = 0.36) and 24-h PWV (9.1 ± 2.4 vs. 8.8 ± 2.1 m/s, P = 0.61). The present study suggests that there is no difference in peripheral and central hemodynamic parameters as well as in the severity of arterial stiffness between CAPD and APD. However, these observations should be interpreted within the context of clinical characteristics of patients included in this case-control study. The comparative effectiveness of these 2 PD modalities warrants further investigation in larger longitudinal studies.

APD or CAPD: one glove does not fit all

The use of Automated Peritoneal Dialysis (APD) in its various forms has increased over the past few years mainly in developed countries. This could be attributed to improved cycler design, apparent lifestyle benefits and the ability to achieve adequacy and ultrafiltration targets. However, the dilemma of choosing the superior modality between APD and Continuous Ambulatory Peritoneal Dialysis (CAPD) has not yet been resolved. When it comes to fast transporters and assisted PD, APD is certainly considered the most suitable Peritoneal Dialysis (PD) modality. Improved patients’ compliance, lower intraperitoneal pressure and possibly lower incidence of peritonitis have been also associated with APD. However, concerns regarding increased cost, a more rapid decline in residual renal function, inadequate sodium removal and disturbed sleep are APD’s setbacks. Besides APD superiority over CAPD in fast transporters, the other medical advantages of APD still remain controversial. In any case, APD should be readily available for all patients starting PD and the most important indication for its implementation remains patient’s choice.

Equivalent Fall Risk in Elderly Patients on Hemodialysis and Peritoneal Dialysis

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BACKGROUND

Accidental falls are common in the hemodialysis (HD) population. The high fall rate has been attributed to a combination of aging, kidney disease-related morbidity, and HD treatment-related hazards. We hypothesized that patients maintained on peritoneal dialysis (PD) would have fewer falls than those on chronic HD. The objective of this study was to compare the falls risk between cohorts of elderly patients maintained on HD and PD, using prospective data from a large academic dialysis facility. ♦

METHODS

Patients aged 65 years or over on chronic in-hospital HD and PD at the University Health Network were recruited. Patients were followed biweekly, and falls occurring within the first year recorded. Fall risk between the 2 groups was compared using both crude and adjusted Poisson lognormal random effects modeling. ♦

RESULTS

Out of 258 potential patients, 236 were recruited, assessed at baseline, and followed biweekly for falls. Of 74 PD patients, 40 (54%) experienced 86 falls while 76 out of 162 (47%) HD patients experienced a total of 305 falls (crude fall rate 1.25 vs 1.60 respectively, odds ratio [OR] falls in PD patients 0.78, 95% confidence interval [CI] 0.61 - 0.92, p = 0.04). After adjustment for differences in comorbidity, number of medications, and other demographic differences, PD patients were no less likely to experience accidental falls than HD patients (OR 1.63, 95% CI 0.88 - 3.04, p = 0.1). ♦

CONCLUSIONS

We conclude that accidental falls are equally common in the PD population and the HD population. These data argue against post-HD hypotension as the sole contributor to the high fall risk in the dialysis population.

Left ventricular hypertrophy and blood pressure control in automated and continuous ambulatory peritoneal dialysis patients

Hypertension, non-dipper blood pressure (BP) pattern and decrease in daily urine output have been associated with left ventricular hypertrophy (LVH) in peritoneal dialysis (PD) patients. However, there is lack of data regarding the impact of different PD regimens on these factors. We aimed to investigate the impact of circadian rhythm of BP on LVH in end-stage renal disease patients using automated peritoneal dialysis (APD) or continuous ambulatory peritoneal dialysis (CAPD) modalities. Twenty APD (7 men, 13 women) and 28 CAPD (16 men, 12 women) patients were included into the study. 24-h ambulatory blood pressure monitoring (ABPM) and transthoracic echocardiography besides routine blood examinations were performed. Two groups were compared with each other for ABPM measurements, BP loads, dipping patterns, left ventricular mass index (LVMI) and daily urine output. Mean systolic and diastolic BP measurements, BP loads, LVMI, residual renal function (RRF) and percentage of non-dippers were found to be similar for the two groups. There were positive correlations of LVMI with BP measurements and BP loads. LVMI was found to be significantly higher in diastolic non-dippers compared to dippers (140.4 ± 35.3 vs 114.5 ± 29.7, respectively, P = 0.02). RRF and BP were found to be independent predictors of LVMI. Non-dipping BP pattern was a frequent finding among all PD patients without an inter-group difference. Additionally, higher BP measurements, decrease in daily urine output and non-dipper diastolic BP pattern were associated with LVMI. In order to avoid LVH, besides correction of anemia and volume control, circadian BP variability and diastolic dipping should also be taken into consideration in PD patients.

Cardiac, Inflammatory and Metabolic Parameters: Hemodialysis versus Peritoneal Dialysis

INTRODUCTION

Mortality in dialysis patients is higher than in the general population, and cardiovascular disease represents the leading cause of death. Hypertension and volume overload are important risk factors for the development of left ventricular hypertrophy (LVH) in hemodialysis (HD) and peritoneal dialysis (PD) patients. Other factors are mainly represented by hyperparathyroidism, vascular calcification, arterial stiffness and inflammation. The aim of this study was to compare blood pressure (BP) and metabolic parameters with cardiovascular changes [cardiothoracic ratio (CTR), aortic arch calcification (AAC) and LV mass index (LVMI)] between PD and HD patients.

MATERIALS AND METHODS

45 patients (23 HD and 22 PD patients) were enrolled. BP measurements, echocardiography and chest X-ray were performed in each patient to determine the LVMI and to evaluate the CTR and AAC. Inflammatory indexes, intact parathyroid hormone (iPTH) and arterial blood gas analysis were also evaluated.

RESULTS

LVMI was higher in PD than HD patients (139 ŷ 19 vs. 104 ŷ 22; p = 0.04). In PD patients, a significant correlation between iPTH, C-reactive protein and the presence of LVH was observed (r = 0.70, p = 0.04; r = 0.70, p = 0.03, respectively). The CTR was increased in PD patients as compared to HD patients, while no significant differences in cardiac calcifications were determined.

CONCLUSIONS

Our data indicate that HD patients present more effective BP control than PD patients. Adequate fluid and metabolic control are necessary to assess the adequacy of BP, which is strongly correlated with the increase in LVMI and with the increased CTR in dialysis patients. PD is a home therapy and allows a better quality of life, but PD patients may present a further increased cardiovascular risk if not adequately monitored.

The "Pulse Time Index of Norm" highly correlates with the left ventricular mass index in patients with arterial hypertension

BACKGROUND

Arterial stiffness, as measured by the pulse wave velocity (PWV), is recommended for routine use in clinical practice as an important parameter for the evaluation of cardiovascular risk.1 New 24-hour monitors (eg, with Vasotens technology; Petr Telegin Company, Nizhny Novgorod, Russian Federation) provide single PWV measurements as well as several PWV measurements over a period of 24 hours.2 Such 24-hour pulse wave analysis led to the development of the novel Pulse Time Index of Norm (PTIN), which is defined as the percentage of a 24-hour period during which the PWV does not exceed the 10 m/second PWV threshold. The aim of this study is to test the new PTIN for correlation with the left ventricular mass index (LVMI).

METHODS

Oscillometrically generated waveform files (n=137) used for clinical research studies were reanalyzed using the new 2013 version of the Vasotens technology program, which enables PTIN calculations.

RESULTS

A good correlation (r=-0.72) between the PTIN and the LVMI was shown, which was significantly above the blood pressure load (r=0.41).

CONCLUSION

The PTIN generated by the Vasotens technology can be recommended as an indicator of end organ damage via hypertension.

Blood pressure profile in continuous ambulatory peritoneal dialysis patients

BACKGROUND

Cardiovascular mortality is the leading cause of death in end stage renal disease. Despite being on continuous ambulatory peritoneal dialysis (CAPD), blood pressure (BP) remains poorly controlled. A higher pulse pressure and non dipping are associated with increased cardiovascular mortality. We studied BP control and the prevalence of non dipping in CAPD patients.

METHODS

All patients undergoing CAPD at our institution who met the inclusion criteria were recruited. We compared BP control and dipping status in diabetic and non diabetic patients on CAPD. We also determined whether BP and peritoneal membrane permeability were associated.

RESULTS

Forty six patients with a mean age 45 ± 13 years were enrolled. Diabetic patients were older (mean age 54 ± 13 vs. 40 ± 11 yrs, p <0.001), had a lower mean diastolic BP (80 ± 14 vs. 90 ± 14 mmHg, p = 0.025) and a higher mean pulse pressure (59 ± 17 vs. 49 ± 14 mmHg, p = 0.035). They were also non dippers (n = 15 vs. n = 1, p = 0.007). The low and low average transporters tended to have a higher systolic BP (p = 0.054) and a higher pulse pressure (p = 0.058). On multivariate analysis, age was the main predictor of pulse pressure.

CONCLUSION

Despite being on chronic maintenance PD, BP was not well controlled. Diabetic patients had a higher pulse pressure and were non dippers thereby increasing their cardiovascular risk. We should therefore optimize BP control and aim to restore the nocturnal dip in these patients.