Serum 25-hydroxy vitamin D concentrations are more deficient/insufficient in peritoneal dialysis than haemodialysis patients in a sunny climate

Outcomes of elderly peritoneal dialysis patients: 65-74 years old versus ≥ 75 years old

OBJECTIVE

To analyze the clinical data of elderly patients with peritoneal dialysis (PD) and compare patient and technique survival rates between Group 1 (65-74 years old) and Group 2 (≥75 years old).

METHODS

This retrospective study enrolled 296 elderly patients (≥65 years old) on maintenance PD who were admitted to the Peritoneal Dialysis Center of the Second Hospital of Soochow University. The patients were categorized by outcome into ongoing PD, changed to hemodialysis, renal recovery dialysis stopped, or death groups. The patients were divided into Group 1 (65-74 years old) and Group 2 (≥75 years old). Patient survival and technique survival rates were calculated by the Kaplan-Meier method. Factors associated with patient survival were analyzed using the Cox regression model.

RESULTS

There were 176 (59.5%) subjects in Group 1 and 120 (40.5%) subjects in Group 2. The primary causes of death were cardiovascular events, peritonitis, and other infections. The patient survival rates at 1, 3, and 5 years were 91.2%, 68.0%, and 51.3% in Group 1 and 76.8%, 37.5%, and 17.6% in Group 2 (p < 0.001, HR 0.387, 95% CI 0.282-0.530). There was no statistically significant difference in the technique survival rate between the two groups (p = 0.54).

CONCLUSION

The elderly PD patients in this cohort mostly died from cardiovascular events, with a higher patient survival rate in Group 1 and similar technique survival in both groups. Older age, lower prealbumin, higher creatinine, not being on activated vitamin D, and high Charlson's comorbidity index (CCI) score were independent risk factors for death.

Effects of parathyroid hormone and vitamin D supplementation on stroke among patients receiving peritoneal dialysis

BACKGROUND

Continuous ambulatory peritoneal dialysis (CAPD) patients have a high incidence of stroke and commonly have increased parathyroid hormone levels and vitamin D insufficiency. We seek to investigate the incidence of stroke and the role of parathyroid hormone and vitamin D supplementation in stroke risk among CAPD patients.

METHODS

This study employed a retrospective design. We enrolled a Chinese cohort of 980 CAPD patients who were routinely followed in our department. The demographic and clinical data were recorded at the time of initial CAPD and during follow-up. The included patients were separated into non-stroke and stroke groups. The effects of parathyroid hormone and vitamin D supplementation on stroke in CAPD patients was evaluated. The primary endpoint is defined as the first occurrence of stroke, and composite endpoint events are defined as death or switch to hemodialysis during follow-up.

RESULTS

A total of 757 eligible CAPD patients with a mean follow-up time of 54.7 (standard deviation, 33) months were included in the study. The median incidence of stroke among our CAPD patients was 18.9 (interquartile range, 15.7-22.1) per 1000 person-years. A significant nonlinear correlation between baseline iPTH and hazard of stroke (p-value of linear association = 0.2 and nonlinear association = 0.002) was observed in our univariate Cox regression analysis, and low baseline iPTH levels (≤150 pg/ml) were associated with an increased cumulative hazard of stroke. Multivariate Cox regression analysis indicated a significant interaction effect between age and iPTH after adjusting for other confounders. Vitamin D supplementation during follow-up was a predictive factor for stroke in our cohort.

CONCLUSIONS

CAPD patients suffered a high risk of stroke, and lower iPTH levels were significantly correlated with an increased risk of stroke. Nevertheless, vitamin D supplementation may reduce the risk of stroke in these patients.

Relative importance of the determinants of serum levels of 25-hydroxy vitamin D in patients with chronic kidney disease

INTRODUCTION

The cause of vitamin D deficiency in chronic kidney disease (CKD) is probably multi-factorial; however, the relative importance of each potential determinant is uncertain.

AIMS

To determine factors associated with serum levels of 25-hydroxy vitamin D (25OHD) and their relative importance in a cohort of pre-dialysis CKD patients.

MATERIAL AND METHODS

Incident patients admitted to a CKD outpatient clinic were included. Those who were receiving vitamin D supplements or anticonvulsants were excluded. In addition to demographic and clinical data, information about outdoor physical activity, season of blood collection, prescription of statins, anti-angiotensin drugs and xanthine-oxidase inhibitors were included as potential determinants. Johnson's relative weights analysis was used to estimate the relative importance of each potential determinant and the results were expressed as percentage contribution to multiple R.

RESULTS

The study group consisted of 397 patients, 30 of whom were excluded. The mean serum level of 25OHD was 13.7±7.4ng/ml, and 81% of patients had serum levels lower than 20ng/ml. By multiple linear regression and relative weights analyses, the best determinants of low serum 25OHD levels and their relative importance were: higher proteinuria (28.5%), old age (21.4%), low physical activity (19.4%), female gender (19.3%) and low serum bicarbonate levels (11.4%).

CONCLUSIONS

Proteinuria and age are the determinants with the highest relative importance for predicting 25OHD levels in CKD patients.

Vitamin D Status Is an Independent Risk Factor for Global Cognitive Impairment in Peritoneal Dialysis Patients

Objective

Vitamin D (VD) deficiency is an independent risk factor for cognitive impairment (CI) in the general population, but VD status in peritoneal dialysis (PD) patients has not been investigated. In this study, we aimed to investigate the relationship between serum VD levels and global and specific cognitive functions in PD patients.

Design and Setting

Cross-sectional study, simultaneously conducted at two PD centers.

Patients

Clinically stable patients (n = 273) undergoing PD for at least 3 months were enrolled over a period of one year.

Main outcome Measures

Demographic and comorbidity data were recorded, and routine biochemical parameters and serum 25-hydroxyvitamin D (25(OH) D) levels of overnight fasted patients were determined. Global cognitive function was assessed by the Modified Mini-Mental State Examination (3MS) score; executive function, by the trail making tests (Trails A and B); and immediate memory, delayed memory, and language ability by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) sub-tests.

Results

In the univariate analysis, serum 25(OH) D levels significantly correlated with 3MS scores (r = -0.139; P = 0.02), and Trail A (r = -0.188; P = 0.002) and B (r = -0.154; P = 0.01) completion times. In the multivariate analysis, 25(OH) D was found to be independently associated with global CI, but not with executive dysfunction. Serum 25(OH) D could not predict scores of immediate/delayed memory and language ability.

Conclusions

VD deficiency is highly prevalent in PD patients and is an independent risk factor for global CI in this patient cohort.