High peritoneal KT/V and peritonitis rates are associated with peritoneal calcification

Prognosis and factors related to severe secondary hyperparathyroidism in long-term peritoneal dialysis patients

Secondary hyperparathyroidism (SHPT) can progress to severe SHPT (sSHPT), which affects the survival rate and quality of life of patients. This retrospective cohort study investigated risk factors for sSHPT and the association between SHPT and mortality (all-cause and infection-related) among 771 clinically stable patients (421 male patients; mean age, 51.2 years; median dialysis vintage, 28.3 months) who underwent >3 months of regular peritoneal dialysis (PD) between January 2013 and March 2021. The sSHPT and non-sSHPT groups comprised 75 (9.7%) (median progression, 35 months) and 696 patients, respectively. sSHPT was defined as a serum intact parathyroid hormone (PTH) level >800 pg/mL observed three times after active vitamin D pulse therapy. The influence of sSHPT on the prognosis of and risk factors for sSHPT progression were evaluated using logistic and Cox regression analyses. After adjusting for confounding factors, higher (each 100-pg/mL increase) baseline PTH levels (95% confidence interval (CI) 1.206-1.649, p < .001), longer (each 1-year increase) dialysis vintages (95% CI 1.013-1.060, p = .002), higher concomitant diabetes rates (95% CI 1.375-10.374, p = .010), and lower (each 1-absolute unit decrease) Kt/V values (95% CI 0.859-0.984, p = .015) were independent risk factors for progression to sSHPT in patients on PD. During follow-up, 211 deaths occurred (sSHPT group, n = 35; non-sSHPT group, n = 176). The sSHPT group had significantly higher infection-related mortality rates than the non-sSHPT group (12.0% vs. 4.3%; p < .05), and sSHPT was associated with increased infection-related mortality. In conclusion, patients with sSHPT are at higher risk for death and infection-related mortality than patients without sSHPT.

Renal hyperparathyroidism- a risk factor in the development of encapsulating peritoneal sclerosis

Background

Encapsulating peritoneal sclerosis (EPS) is a rare complication of prolonged peritoneal dialysis (PD) exposure, characterised by peritoneal thickening, calcification, and fibrosis ultimately presenting with life-threatening bowel obstruction. The presence or role of peritoneal calcification in the pathogenesis of EPS is poorly characterised. We hypothesise that significantly aberrant bone mineral metabolism in patients on PD can cause peritoneal calcification which may trigger the development of EPS. We compared the temporal evolution of bone mineral markers during PD in EPS patients with non-EPS long-term PD controls.

Methods

Linear mixed model and logistic regression analysis were used to compare four-monthly serum levels of calcium, phosphate, parathyroid hormone, and alkaline phosphatase (ALP) over the duration of PD exposure in 46 EPS and 46 controls (PD, non-EPS) patients.

Results

EPS patients had higher mean calcium (2.51 vs. 2.41 mmol/L) and ALP (248.00 vs. 111.13 IU/L) levels compared with controls (p=0.01 and p<0.001 respectively, maximum likelihood estimation). Logistic regression analysis demonstrated that high serum calcium and phosphate levels during PD were associated with a 4.5 and 2.9 fold increase in the risk of developing EPS respectively.

Conclusion

High levels of calcium and phosphate in patients on PD were identified to be risk factors for EPS development. Possible reasons for this may be an imbalance of pro-calcifying factors and calcification inhibitors promoting peritoneal calcification which increases peritoneal stiffness. Mechanical alterations may trigger, unregulated fibrosis and subsequent development of EPS. Improved management of secondary hyperparathyroidism during PD may ultimately diminish the EPS risk.

A Fast Decline of Residual Renal Function in the First Year is a Predictor for Early Withdrawal from Peritoneal Dialysis in Non-Diabetic Patients

BACKGROUND/AIMS

Little is known about the relationship between residual renal function (RRF) decline in early period and survival in non-diabetic peritoneal dialysis (PD) patients.

METHODS

A total of 567 non-diabetic patients who began PD from January 1, 2005 to June 30, 2013 was investigated. The rate of RRF decline was determined by the "slope of the trend equation" of serial RRFs. A composite end-point of all-cause mortality and conversion to hemodialysis (HD) was used, survival status was censored on June 30, 2016.

RESULTS

The median of "the slope of RRF decline equation" was 0.308 (0.001-2.111) ml/min/1.73 m2/ month. In the median follow-up period of 43 months (range 12 to 120 months), 65 (11.5%) patients died, 90 (15.9%) patients converted to HD and 171 (30.2%) patients received kidney transplantation. Multivariate linear regression showed male, high baseline RRF, high baseline peritoneal Kt/V urea, low serum albumin and low uric acid were independently associated with the rate of RRF decline in the first year of PD. Multivariate Cox models revealed that RRF decline in the first year remained a predictor for composite end-point (HR, 2.74, 95% CI, 1.53 to 4.90, P=0.001). The patients were divided into high RRF decline group (> 0.308ml/ min/1.73m2/month) and low RRF decline group (≤0.308 ml/min/1.73m2/month). In the first three years of PD, the rate of end-point events was higher in high RRF decline group (23.2%) than that in low RRF decline group (11.0%) (P< 0.001). There were 189 patients in low RRF decline group and 171 patients in high RRF decline group maintaining PD for more than 3 years, in a median follow-up of 54 months (range 37 to 120 months), the survival rate was 30.9% in high RRF decline group and 46.4% in low RRF decline group (P=0.883). In high RRF decline group, there were 92 patients reaching composited end-point and 112 patients maintaining PD; multivariate Cox model showed high peritoneal Kt/V urea after 1 year of PD and high albumin level were protective factors (HR, 0.29, 95% CI, 0.13 to 0.61, P= 0.001; HR, 0.94, 95% CI, 0.90-0.99, P=0.022, respectively), while fast RRF decline remained risk factor for composite end-point (HR, 3.28, 95% CI,1.48-7.31, P=0.004).

CONCLUSION

A faster RRF decline in the first year was a predictor for all-cause mortality and conversion to HD in non-diabetic PD patients, mainly in the first three year. For patients with faster RRF decline, increasing PD dose was effective to improve survival.

Enhancement of Interface Characteristics of Neural Probe Based on Graphene, ZnO Nanowires, and Conducting Polymer PEDOT

In the growing field of brain-machine interface (BMI), the interface between electrodes and neural tissues plays an important role in the recording and stimulation of neural signals. To minimize tissue damage while retaining high sensitivity, a flexible and a smaller electrode with low impedance is required. However, it is a major challenge to reduce electrode size while retaining the conductive characteristics of the electrode. In addition, the mechanical mismatch between stiff electrodes and soft tissues creates damaging reactive tissue responses. Here, we demonstrate a neural probe structure based on graphene, ZnO nanowires, and conducting polymer that provides flexibility and low impedance performance. A hybrid Au and graphene structure was utilized to achieve both flexibility and good conductivity. Using ZnO nanowires to increase the effective surface area drastically decreased the impedance value and enhanced the signal-to-noise ratio (SNR). A poly[3,4-ethylenedioxythiophene] (PEDOT) coating on the neural probe improved the electrical characteristics of the electrode while providing better biocompatibility. In vivo neural signal recordings showed that our neural probe can detect clearer signals.

Serum Alkaline Phosphatase Levels Predict Infection-Related Mortality and Hospitalization in Peritoneal Dialysis Patients

BACKGROUND

Serum alkaline phosphatase (ALP) levels have been reported to be associated with all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients. However, it is unclear whether serum ALP levels predict infection-related clinical outcomes in PD patients. The aim of this study was to determine the relationships between serum ALP levels, infection-related mortality and hospitalization in PD patients.

METHODS

PD patients from the Clinical Research Center registry for end-stage renal disease, a multicenter prospective observational cohort study in Korea, were included in the present study. Patients were categorized into three groups by serum ALP tertiles as follows: Tertile 1, ALP <78 U/L; Tertile 2, ALP = 78-155 U/L; Tertile 3, ALP >155 U/L. Tertile 1 was used as the reference category. The primary outcomes were infection-related mortality and hospitalization.

RESULTS

A total of 1,455 PD patients were included. The median follow-up period was 32 months. The most common cause of infection-related mortality and hospitalization was PD-related peritonitis. Multivariate Cox regression analyses showed that patients in the highest tertiles of serum ALP levels were at higher risk of infection-related mortality (HR 2.29, 95% CI, 1.42-5.21, P = 0.008) after adjustment for clinical variables. Higher tertiles of serum ALP levels were associated with higher risk of infection-related hospitalization (Tertile 2: HR 1.56, 95% CI, 1.18-2.19, P = 0.009, tertile 3: HR 1.34, 95% CI, 1.03-2.62, P = 0.031).

CONCLUSIONS

Our data showed that elevated serum ALP levels were independently associated with a higher risk of infection-related mortality and hospitalization in PD patients.

Prevalence of chronic kidney disease-mineral and bone disorder in incident peritoneal dialysis patients and its association with short-term outcomes

INTRODUCTION

A complex relationship exists between chronic kidney disease-mineral and bone disorder (CKD-MBD) and adverse outcomes among dialysis patients. This study aimed to report the prevalence of CKD-MBD and examine the impact of achieving target CKD-MBD parameters on morbidity and mortality one year after peritoneal dialysis (PD) initiation.

METHODS

In this retrospective cohort study, patients electively initiated on PD were followed up for one year. Laboratory parameters were collected and the prevalence of CKD-MBD 4-6 months after PD initiation was determined based on the Kidney Disease Outcomes Quality Initiative (KDOQI) and Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Linear regression and Cox proportional hazards model were used to evaluate the effects of achieving CKD-MBD targets 4-6 months after PD initiation on hospitalisation, the incidence of peritonitis or exit-site infections (ESIs), and mortality at one year.

RESULTS

The prevalence of CKD-MBD among the 86 patients in this study was 86.0% (KDOQI) and 54.7% (KDIGO). There was no significant difference in hospitalisation duration between patients who achieved targets and those who did not. Patients who failed to meet all the KDIGO CKD-MBD or calcium serum targets had a higher incidence of peritonitis or ESI. A trend toward shorter time to death was observed among patients who failed to meet the KDIGO phosphorus serum targets.

CONCLUSION

There was moderate (KDIGO) to high prevalence (KDOQI) of CKD-MBD among the patients. Achievement of all the KDIGO CKD-MBD or calcium serum targets was associated with reduced peritonitis or ESI, while achievement of the KDIGO phosphorus serum targets was associated with improved survival.

Massive peritoneal cavity calcification in the course of advanced ovarian cancer: a case report

Ovarian cancer usually does not give any clinical signs until it reaches a large size. This condition is often associated with the occurrence of metastases within the peritoneal cavity, pelvic and abdominal cavities. Ovarian cancer can spread by intraperitoneal implantation, by way of the lymphatic system, and also through the systemic circulation. Even when the tumor reaches a large size, the symptoms are not specific and may resemble other ailments. Therefore, ovarian cancer is detected in most cases only in the third and fourth level of advancement. Peritoneal calcification occurs in many diseases. The degree of calcium deposits is usually small and does not give clinical symptoms. In the reported case, computed tomography of the abdomen showed numerous scattered peritoneal calcifications of irregular shape as well as massive calcification in the uterus and appendages. In the detection of changes associated with calcification, multidetectory computed tomography shows a very high sensitivity. It makes the precise location and assessment of the extent of changes possible.