Treatment with oral active vitamin D is associated with decreased risk of peritonitis and improved survival in patients on peritoneal dialysis

Bone mineral density and related clinical and laboratory factors in peritoneal dialysis patients: Implications for bone health management

BACKGROUND

End-stage renal disease (ESRD) patients often experience accelerated bone turnover, leading to osteoporosis and osteopenia. This study aimed to determine the prevalence of osteoporosis in Peritoneal Dialysis (PD) patients using bone mineral density (BMD) measurements obtained through dual-energy X-ray absorptiometry (DEXA) scan and to explore any possible associations with clinical and biochemical factors.

METHODS

In this cross-sectional study, we enrolled 76 peritoneal dialysis patients from the dialysis center at An-Najah National University Hospital in Nablus, Palestine. We used the DEXA scan to measure BMD at the lumbar spine and hip, with values expressed as T-scores. We conducted a multivariate analysis to explore the relationship between BMD and clinical and biochemical parameters.

RESULTS

Over half (52.6%) of the PD patients had osteoporosis, with a higher prevalence observed among patients with lower BMI (p<0.001). Higher alkaline phosphatase levels were found among osteoporotic patients compared to non-osteoporotic patients (p = 0.045). Vitamin D deficiency was also prevalent in this population, affecting 86.6% of patients. No significant correlation was found between 25 vitamin D levels and BMD. No significant correlation was found between Parathyroid hormone (PTH) levels and BMD.

CONCLUSION

A notable proportion of PD patients experience reduced BMD. Our study found no correlation between vitamin D levels and BMD, but it highlighted the significant vitamin D deficiency in this population. Furthermore, our analysis indicated a positive correlation between BMI and BMD, especially in the femoral neck area. This underscores the significance of addressing bone health in PD patients to mitigate the risk of fractures and improve their overall well-being.

Oral vitamin D supplementation on the prevention of peritoneal dialysis-related peritonitis: A pilot randomised controlled trial

OBJECTIVE

Peritoneal dialysis (PD)-related peritonitis is independently associated with low serum 25-hydroxy vitamin D [25(OH)D] levels. Our objective is to examine the feasibility of conducting a large, randomised controlled trial to determine the effects of vitamin D supplementation on the risk of PD-related peritonitis.

DESIGN

Pilot, prospective, open-label randomised controlled trial.

SETTING

Peking University First Hospital, China.

PARTICIPANTS

Patients receiving PD who had recovered from a recent episode of peritonitis between 30 September 2017 and 28 May 2020.

INTERVENTIONS

Oral natural vitamin D supplementation (2000 IU per day) versus no vitamin D supplementation for 12 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were feasibility (recruitment success, retention, adherence, safety) and fidelity (change in serum 25(OH)D level during follow-up) for a large, randomised controlled trial in the future to determine the effects of vitamin D on PD-related peritonitis. Secondary outcomes were time to peritonitis occurrence and outcome of subsequent peritonitis.

RESULTS

Overall, 60 among 151 patients were recruited (recruitment rate was 39.7%, 95% CI 31.9-47.5%, recruitment rate among eligible patients was 61.9%, 95% CI 52.2-71.5%). Retention and adherence rates were 100.0% (95% CI 100.0-100.0%) and 81.5% (95% CI 66.8-96.1%), respectively. During follow-up, serum 25(OH)D levels increased in the vitamin D (VD) group (from 19.25 ± 10.11 nmol/L to 60.27 ± 23.29 nmol/L after 6 months, p < 0.001, n = 31), and remained higher (p < 0.001) than those in the control group (n = 29). No differences were observed between the two groups with respect to time to subsequent peritonitis (hazard ratio 0.85, 95% CI 0.33-2.17) or any of the peritonitis outcomes. Adverse events were uncommon.

CONCLUSIONS

A randomised controlled trial of the effect of vitamin D supplementation on peritonitis occurrence in patients receiving PD is feasible, safe and results in adequate serum 25(OH)D levels.

Effect of nutritional supplementation on mortality in peritoneal dialysis patients: A meta-analysis

BACKGROUND

Malnutrition is a common clinical problem in peritoneal dialysis (PD) patients and is a predictor of mortality. This work analyzes the effect of nutritional supplementation for PD patients on all-cause and cardiovascular disease (CVD)-related deaths by meta-analysis.

METHODS

A study about nutritional interventions for PD patients on all-cause or CVD-related mortality is included.

RESULTS

Eight studies were included. The results showed that nutritional intervention can reduce all-cause mortality in PD patients (HR, 0.71; 95% confidence interval (CI), 0.64-0.79; p < 0.01). In CVD-related mortality, the results also showed that nutritional interventions significantly reduce CVD-related mortality (HR, 0.75; 95% CI, 0.64-0.87; p < 0.01). In exploratory analysis, vitamin D, folic acid, and high-plant-protein ratio intake have relative advantages.

CONCLUSION

Appropriate nutritional supplementation to PD patients can effectively reduce all-cause and CVD- related mortality in clinical practice, especially for vitamin D, folic acid, sodium supplements, and a high proportion of plant protein.

1,25(OH)2D3 Promotes Macrophage Efferocytosis Partly by Upregulating ASAP2 Transcription via the VDR-Bound Enhancer Region and ASAP2 May Affect Antiviral Immunity

The active form of vitamin D₃, i.e., 1,25(OH)₂D₃, exerts an anti-inflammatory effect on the immune system, especially macrophage-mediated innate immunity. In a previous study, we identified 1,25(OH)₂D₃-responsive and vitamin D receptor (VDR)-bound super-enhancer regions in THP-1 cells. Herein, we examined the transcriptional regulation of ArfGAP with SH3 Domain, Ankyrin Repeat and PH Domain 2 (ASAP2) (encoding a GTPase-activating protein) by 1,25(OH)₂D₃ through the top-ranked VDR-bound super-enhancer region in the first intron of ASAP2 and potential functions of ASAP2 in macrophages. First, we validated the upregulation of ASAP2 by 1,25(OH)₂D₃ in both THP-1 cells and macrophages. Subsequently, we identified three regulatory regions (i.e., the core, 1,25(OH)₂D₃-responsive, and inhibitory regions) in the VDR bound-enhancer of ASAP2. ASAP2 promoted RAC1-activity and macrophage efferocytosis in vitro. Next, we assessed the functions of ASAP2 by mass spectrometry and RNA sequencing analyses. ASAP2 upregulated the expressions of antiviral-associated genes and interacted with SAM and HD domain-containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1). In vivo, vitamin D reduced the number of apoptotic cells in experimental autoimmune encephalomyelitis (EAE) and promoted macrophage efferocytosis in peritonitis without changing the mRNA level of ASAP2. Thus, we could better understand the regulatory mechanism underlying ASAP2 transcription and the function of ASAP2, which may serve as a potential treatment target against inflammatory diseases and virus infections.

The Impact of Preoperative Risk Factors on Peritoneal Dialysis-Related Peritonitis: A Single-Center Prospective Study in Japan

Background and Objectives: Peritoneal dialysis (PD)-related peritonitis is a critical problem. However, preoperative risk factors for PD-related peritonitis have not been established. Thus, we aimed to determine the preoperative risk factors for PD-related peritonitis. Materials and Methods: This is a single-center prospective observational study. All peritonitis episodes during the study period were recorded, and preoperative and intraoperative clinical parameters were compared between patients with and without peritonitis to examine risk factors for PD-related peritonitis. Furthermore, subcutaneous and abdominal fat volumes were evaluated using computed tomography. Results: Among a total of 118 patients, 24 patients developed peritonitis. The proportion of male patients (83% vs. 61%, p = 0.04), body mass index (25 vs. 22 kg/m², p = 0.04), and subcutaneous fat area (120 vs. 102 cm², p = 0.01) were significantly higher and the proportion of patients living with family members (75% vs. 94%, p = 0.02) was significantly lower in the peritonitis group than in the non-peritonitis group. There were no significant differences in age, operation method, surgeon experience, previous abdominal surgery, medical history of diabetic nephropathy, serum albumin level, and renal function between the two groups. Conclusions: Male patients with high subcutaneous fat who are living alone might be at higher risk of PD-related peritonitis. These characteristics might be useful in risk assessment and patient education before PD induction.

Evaluation of modifiable risk factors for peritoneal dialysis-related peritonitis: a single-center retrospective cohort study

Background

Peritoneal dialysis (PD)-related peritonitis risk factors can be categorized as modifiable and uncorrectable. We aimed to identify modifiable risk factors for PD-related peritonitis in our facility to prevent PD-related peritonitis and continue quality improvement.

Methods

This retrospective, observational study included 90 patients who started receiving PD after 2008 and who were continued for over 1 year. Twenty-three patients experienced 40 episodes of peritonitis. Several clinical factors identified at peritonitis onset among patients with a peritonitis history were compared with those identified 1 year after PD initiation among patients without a peritonitis history, and a multivariate analysis was performed. Several serum parameter levels were evaluated as time-average concentrations (TACs; from PD initiation to 1 month before peritonitis onset or to 1 year later). The clinical factors to be investigated were selected based on previous studies.

Results

There were no significant between-group differences in baseline characteristics regarding uncorrectable factors and TAC values for serum parameters. Use of exchange devices was significantly higher (95.7% vs 71.6%; p = 0.054) whereas administration of renin-angiotensin-aldosterone system (RAS) blockers, calcium channel blockers (CCBs), or oral vitamin D was significantly lower (35.0% vs 65.7%, p = 0.002; 55.0% vs 74.6%, p = 0.036; and 55.0% vs 74.6%, p = 0.036, respectively) in the patients with history of peritonitis, although we did not find a factor independently associated with peritonitis in multivariable logistic regression.

Conclusions

Although hypokalemia, hypoalbuminemia, and exchange device use which are considered as risk factors did not affect peritonitis, administration of RAS blockers, CCBs, and oral vitamin D is significantly larger in patients without peritonitis.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

Low serum parathyroid hormone is a risk factor for peritonitis episodes in incident peritoneal dialysis patients: a retrospective study

BACKGROUND

Serum parathyroid hormone (PTH) levels have been reported to be associated with infectious mortality in peritoneal dialysis (PD) patients. Peritonitis is the most common and fatal infectious complication, resulting in technique failure, hospital admission and mortality. Whether PTH is associated with peritonitis episodes remains unclear.

METHODS

We examined the association of PTH levels and peritonitis incidence in a 7-year cohort of 270 incident PD patients who were maintained on dialysis between January 2012 and December 2018 using Cox proportional hazard regression analyses. Patients were categorized into three groups by serum PTH levels as follows: low-PTH group, PTH < 150 pg/mL; middle-PTH group, PTH 150-300 pg/mL; high-PTH group, PTH > 300 pg/mL.

RESULTS

During a median follow-up of 29.5 (interquartile range 16-49) months, the incidence rate of peritonitis was 0.10 episodes per patient-year. Gram-positive organisms were the most common causative microorganisms (36.2%), and higher percentage of Gram-negative organisms was noted in patients with low PTH levels. Low PTH levels were associated with older age, higher eGFR, higher hemoglobin, calcium levels and lower phosphate, alkaline phosphatase levels. After multivariate adjustment, lower PTH levels were identified as an independent risk factor for peritonitis episodes [hazard ratio 1.643, 95% confidence interval 1.014-2.663, P = 0.044].

CONCLUSIONS

Low PTH levels are independently associated with peritonitis in incident PD patients.

Use of vitamin D and infection in patients with chronic kidney disease

ABSTRACT Objective: To evaluate the effectiveness of vitamin D supplementation as protection factor against infection of patients with chronic kidney disease on conservative treatment. Method: Retrospective cohort study carried out between 2013 and 2016 in the Conservative Treatment Outpatient Clinics (Ambulatório de Tratamento Conservador) of the Hypertension and Kidney Hospital (Hospital do Rim e Hipertensão) of the Universidade Federal de São Paulo. Data on sociodemographic factors, comorbidity, infection episodes and use or nonuse of vitamin D supplementation for at least 6 months were collected from medical records. The primary outcomes considered in both groups were: presence or absence of infection anywhere on the body (bloodstream, urinary, respiratory and surgical sites). Results: A total of 263 patients were included and those who received (n=43) vitamin D had 59% less chance of developing infections (OR=0.41; 95%CI; 0.15-0.99), when compared to those who did not receive. Conclusion: Vitamin D supplementation was a protective factor against infections of all causes.

Peritoneal dialysis-related infections recommendations: 2016 update. What is new?

In 2016, the International Society of Peritoneal Dialysis (ISPD) published guidelines that focus on the importance of both prevention and treatment of peritonitis. For once more, the need for annual reporting of peritonitis rates and recording of peritonitis and exit-site infections, isolated microorganism and antimicrobial susceptibilities as a central component of a quality improvement program is highlighted. Data on new antibiotic regimens, techniques for microorganism isolation and peritoneal dialysis solutions are included. Training of both peritoneal dialysis nurses and patients seems to be crucial, while the modifiable risk factors for peritonitis seem to be of great interest. In this article, we record the changes in the last ISPD (2016) guidelines compared to the previous ones published in 2010.

Effects of vitamin D or its analogues on the mortality of patients with chronic kidney disease: an updated systematic review and meta-analysis

The objective of this study was to assess whether vitamin D (VD) treatment alters the overall all-cause and cardiovascular mortalities in a chronic kidney disease (CKD) population. We systematically searched PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials without language restriction, until the publication date of 22 February 2016. All related literatures that compared VD treatment with non-VD treatment and reported the mortality of patients with CKD (including those undergoing dialysis) were identified. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated by using the random- and fixed-effects models. Randomised controlled trials (RCTs) that used the intention-to-treat principle and observational studies (OSs) were analysed separately. For this study, 38 studies involving 223 429 patients (17 RCTs, n=1819 and 21 OSs, n=221610) were included. In the OSs, VD treatment was significantly associated with reductions in both all-cause and cardiovascular mortalities; however, such significant association was not found in the RCTs. The existing RCTs do not provide sufficient or precise evidence that VD supplementation affects the mortality of patients with CKD, although subsets of patients that could potentially benefit from VD treatment can be identified by using the existing data from the RCTs. Nevertheless, large-size RCTs are needed in the future to assess any potential differences in survival prospectively.

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.

Vitamin D and Clinical Outcomes in Dialysis

Most dialysis patients are vitamin D deficient, including deficiencies in both activated vitamin D (1, 25-dihydroxyvitamin D) and the less active 25-hydroxyvitamin D. These and other abnormalities associated with chronic kidney disease (CKD), if they remain untreated, lead to secondary hyperparathyroidism and bone changes, such as osteitis fibrosa cystica. Activated vitamin D has been proven to decrease parathyroid hormone (PTH) levels in dialysis patients and is currently used for this indication. There are multiple other potential "pleotrophic" effects associated with vitamin D therapy. These include associations with lower all-cause and cardiovascular mortality, lower rates of infections and improved glycemic indexes. Meta-analyses of multiple observational studies have shown activated vitamin D therapy to be associated with improved survival. Observational data also suggest fewer infections and better glucose control. There have been no randomized clinical trials powered to evaluate mortality or other clinical outcomes. Small trials of nutritional vitamin D (ergocalciferol and cholecalciferol) showed increases in 25-hydroxyvitamin D levels without hypercalcemia or hyperphosphatemia, even when given in addition to activated vitamin D therapy. While activated vitamin D therapy is associated with improved outcomes, it also leads to higher fibroblast growth factor 23 (FGF-23) levels, which may be detrimental in dialysis patients. Further research is needed to evaluate whether activated or nutritional vitamin D therapy are beneficial in dialysis patients for outcomes other than secondary hyperparathyroidism.

Serum 25-Hydroxyvitamin D Level Could Predict the Risk for Peritoneal Dialysis-Associated Peritonitis

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BACKGROUND

As an immune system regulator, vitamin D is commonly deficient among patients on peritoneal dialysis (PD), which may contribute to their impaired immune function and increased risk for PD-related peritonitis. In this study, we aimed to investigate whether vitamin D deficiency could predict the risk of peritonitis in a prospective cohort of patients on PD. ♦

METHODS

We collected 346 prevalent and incident PD patients from 2 hospitals. Baseline demographic data and clinical characteristics were recorded. Serum 25-hydroxyvitamin D (25[OH]D) was measured at baseline and prior to peritonitis. The mean doses of oral active vitamin D used during the study period were also recorded. The outcome was the occurrence of peritonitis. ♦

RESULTS

The mean age of patients and duration of PD were 58.95 ± 13.67 years and 28.45 (15.04 - 53.37) months, respectively. Baseline 25(OH)D level was 16.15 (12.13 - 21.16) nmol/L, which was closely associated with diabetic status, longer PD duration, malnutrition, and inflammation. Baseline serum 25(OH)D predicted the occurrence of peritonitis independently of active vitamin D supplementation with a hazard ratio (HR) of 0.94 (95% confidence interval [CI] 0.90 - 0.98) after adjusting for recognized confounders (age, gender, dialysis duration, diabetes, albumin, residual renal function, and history of peritonitis). Compared to the low tertile, middle and high 25(OH)D level tertiles were associated with a decreased risk for peritonitis with HRs of 0.54 (95% CI 0.31 - 0.94) and 0.39 (95% CI 0.20 - 0.75), respectively. ♦

CONCLUSIONS

Vitamin D deficiency evaluated by serum 25(OH)D rather than active vitamin D supplementation is closely associated with a higher risk of peritonitis.

Effects of vitamin D on parathyroid hormone and clinical outcomes in peritoneal dialysis: a narrative review

Vitamin D deficiency is very prevalent in dialysis and peritoneal dialysis (PD) patients show lower levels of cholecalciferol (25(OH)D3) than hemodialysis patients. We conducted a systematic narrative review to assess the effects of vitamin D therapy on control of secondary hyperparathyroidism and clinical outcomes induced by vitamin D pleiotropic effects. Medline database was searched for cohort and intervention studies reporting data on vitamin D (all sterols including synthetic analogs) and peritoneal dialysis without language restriction. Two authors independently extracted data. Twenty-nine observational and eleven interventional studies were identified for inclusion (1,036 subjects). PTH levels decreased in twenty-nine studies, increased in one study and remained stable in ten studies. Thirty-three studies analyzed the oral route for vitamin D administration, ten the intraperitoneal, one the subcutaneous and one the intravenous. A significant decrease of peritonitis risk was observed in two studies. Proteinuria decreased in four studies and remained stable in one study. Peritoneal protein loss decreased in one study and was stable in two studies. Studies on the therapeutic effects of vitamin D in PD are limited and describe small population samples. Moreover, vitamin D compounds do not consistently reduce PTH levels. The administration of active vitamin D in PD may have interesting pleiotropic effects such as decreasing proteinuria and peritoneal protein loss. According to these effects, vitamin D could help to preserve residual renal function and ensure efficient peritoneal membrane dialysance.

Low Levels of 25-Hydroxy Vitamin D are Independently Associated with the Risk of Bacterial Infection in Cirrhotic Patients

OBJECTIVES:

Low levels of vitamin D are associated with a higher mortality in cirrhotic patients, but the role of this deficiency is still unknown. The purpose of this study was to assess the levels of vitamin D in cirrhotic patients with and without bacterial infection.

METHODS:

25-hydroxy (25-OH) vitamin D was assessed by immunoassay in 88 patients hospitalized in our hepatology unit.

RESULTS:

The causes of cirrhosis were mainly alcohol (70%), hepatitis C (10%), or both (9%). Infections (n=38) mainly included bacteriemia (21%), urinary tract infections (24%), and spontaneous bacterial peritonitis (29%). A severe deficiency in vitamin D (<10 ng/ml) was observed in 56.8% of patients. Infections were more frequent in patients with a severe deficiency compared with the others (54 vs. 29%, P=0.02). A severe deficiency in vitamin D was a predictive factor of infection (odds ratio=5.44 (1.35–21.97), P=0.017) independently of the Child–Pugh score (odds ratio=2.09 (1.47–2.97) P=0.00004) and the C-reactive protein level (odds ratio=1.03 (1.002–1.052), P=0.03) in a logistic regression also including the alanine amino transferase (not significant). By a Cox regression analysis, only the presence of an infection was significantly associated with mortality (relative risk=3.24 (1.20–8.76), P=0.02) in a model also associating the Child–Pugh score (not significant) and the presence of a severe deficiency in vitamin D (not significant).

CONCLUSIONS:

Low levels of 25-OH vitamin D were independently associated with bacterial infections in cirrhotic patients. The impact of 25-OH vitamin D supplementation on the infection rate and death of cirrhotic patients should be assessed in randomized trials.