Acute effects of dietary phosphorus intake on markers of mineral metabolism in hemodialysis patients: post hoc analysis of a randomized crossover trial.

BACKGROUND: Long-term dietary phosphorus excess influences disturbances in mineral metabolism, but it is unclear how rapidly the mineral metabolism responds to short-term dietary change in dialysis populations. METHODS: This was a post hoc analysis of a randomized crossover trial that evaluated the short-term effects of low-phosphorus diets on mineral parameters in hemodialysis patients. Within a 9-day period, we obtained a total of 4 repeated measurements for each participant regarding dietary intake parameters, including calorie, phosphorus, and calcium intake, and markers of mineral metabolism, including phosphate, calcium, intact parathyroid hormone (iPTH), intact fibroblast growth factor 23 (iFGF23), and C-terminal fibroblast growth factor 23 (cFGF23). The correlations between dietary phosphorus intake and serum mineral parameters were assessed by using mixed-effects models. RESULTS: Thirty-four patients were analyzed. In the fully adjusted model, we found that an increase in dietary phosphorus intake of 100 mg was associated with an increase in serum phosphate of 0.3 mg/dL (95% confidence intervals [CI], 0.2-0.4, p < .001), a decrease in serum calcium of 0.06 mg/dL (95% CI, -0.11 to -0.01, p = .01), an increase in iPTH of 5.4% (95% CI, 1.4-9.3, p = .01), and an increase in iFGF23 of 5.0% (95% CI, 2.0-8.0, p = .001). Dietary phosphorus intake was not related to cFGF23. CONCLUSIONS: Increased dietary phosphorus intake acutely increases serum phosphate, iPTH, and iFGF23 levels and decreases serum calcium levels, highlighting the important role of daily fluctuations of dietary habits in disturbed mineral homeostasis in hemodialysis patients.

Icodextrin Is Associated with a Lower Mortality Rate in Peritoneal Dialysis Patients.

Background:Icodextrin (ICO) improves fluid removal in peritoneal dialysis (PD) patients. However, whether physiological benefits of ICO translate into patient survival remains unclear. We examine the association of ICO and clinical outcomes.Methods:We identified patients who initiated long-term PD from the National Health Insurance Research Database of Taiwan. We matched ICO users with non-users according to propensity score and survival status when ICO was prescribed. We utilized time-dependent analyses to avoid immortal time bias. Additional competing risk models were utilized for the outcomes except for death. The outcomes of interest were time to death, technique failure, peritonitis, major adverse cardiovascular events (MACE), and hospitalization.Results:A total of 4,914 PD patients were enrolled and 2,836 PD patients (57.7%) were identified as ICO users. The ICO users had significantly better overall survival (hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.63 - 0.86), especially among early ICO users (HR 0.64; 95% CI 0.54 - 0.77, p value for interaction: 0.007). The ICO users were associated with higher risk of peritonitis (subdistribution HR 1.22, 95% CI 1.06 - 1.14) and hospitalization (subdistribution HR 1.14, 95% CI 1.05 - 1.24), considering competing risk of death. However, when considering ICO use as a time-varying covariate, ICO users shared similar risks for technique failure, peritonitis, MACE, and hospitalization as non-users. The effect of ICO on mortality was especially prominent among those early users.Conclusions:After adjustments for immortal time biases, ICO users were significantly associated with approximately 20% reduction in mortality, especially among early users.

Risk factors for severe hypocalcemia after parathyroidectomy in prevalent dialysis patients with secondary hyperparathyroidism.

PURPOSE: Hypocalcemia is one of the common complications after parathyroidectomy (PTX). Severe hypocalcemia (SH) can lead to tetany, cardiac arrhythmia and even sudden death. However, predictors for the development of SH in patients with secondary hyperparathyroidism demonstrated in some small-scale studies with a limited sample size remain inconclusive. METHODS: A retrospective chart review of 420 consecutive dialysis patients who underwent PTX during a 12-year period was performed. We checked serum levels of calcium (Ca), phosphorus (P), alkaline phosphatase (ALP) and intact parathyroid hormone (iPTH) for three consecutive days postoperatively. SH was defined as the minimum values of serum calcium lower than 1.875 mmol/L (7.5 mg/dL) within 3 days after operation. RESULTS: The mean (±SD) age of our study population was 53 ± 12 years, and more than half (57 %) were female. SH occurred in 37 % of the patients after PTX. Using a multivariate stepwise logistic regression analysis, lower preoperative levels of Ca (odds ratio 0.69, 95 % CI 0.60-0.79, P < 0.001), higher preoperative levels of iPTH (odds ratio 1.04, 95 % CI 1.00-1.07, P = 0.048), P (odds ratio 2.43, 95 % CI 1.49-3.95, P < 0.001) and ALP (odds ratio 1.08, 95 % CI 1.05-1.11, P < 0.001) were found to be independent predictors of occurrence of SH following PTX. CONCLUSIONS: The readily obtainable preoperative laboratory parameters including Ca, iPTH, P, and ALP will allow identification of a subgroup of patients who are at greater risk for the development of SH following PTX.

Combined alkaline phosphatase and phosphorus levels as a predictor of mortality in maintenance hemodialysis patients.

Hyperphosphatemia-induced vascular calcification and higher alkaline phosphatase (ALP) levels-related high-turnover bone diseases are linked to mortality among patients with chronic kidney disease (CKD). Nonetheless, no large epidemiological study in patients with CKD has been conducted to investigate the interaction and joint effect of hyperphosphatemia and higher ALP levels on mortality.We analyzed 11,912 maintenance hemodialysis patients from January 2005 to December 2010. Unadjusted and adjusted hazard ratios (aHRs) of death were calculated for different categories of serum phosphorus and ALP using the Cox regression model. The modification effect between serum phosphorus and ALP on mortality was determined using an interaction product term.Both hypophosphatemia (<3.0 mg/dL) and hyperphosphatemia (>7.0 mg/dL) were associated with incremental risks of death (aHR: 1.25 [95% confidence intervals (CIs): 1.09-1.44], and 1.15 [95% CI: 1.01-1.31], respectively) compared to the lowest hazard ratio (HR) group (5 mg/dL ≤ phosphorus<6 mg/dL). ALP levels were linearly associated with incremental risks for death (aHR: 1.58 [95% CI: 1.41-1.76] for the category of ALP>150 U/L). In the stratified analysis, patients with combined higher ALP (>150 U/L) and hyperphosphatemia (>7.0 mg/dL) had the greatest mortality risk (aHR: 2.25 [95% CI: 1.69-2.98] compared to the lowest HR group (ALP ≤ 60 U/L and 4 mg/dL ≤ phosphorus<5 mg/dL). Although the effect of hyperphosphatemia on mortality seemed stronger in higher ALP levels, the interaction was not statistically significant (P=0.22).The association between serum phosphorus levels and mortality was not limited to higher ALP levels. Regardless of serum ALP levels, we may control serum phosphorus levels merely toward the normal range. While considering the joint effect of ALP and hyperphosphatemia on mortality, the optimal phosphorus range should be stricter.

Short- and long-term impact of subtotal parathyroidectomy on the achievement of bone and mineral parameters recommended by clinical practice guidelines in dialysis patients: a 12-year single-center experience.

BACKGROUND/AIMS: The short- and long-term impact of parathyroidectomy (PTX) on the parameters of mineral bone disease in dialysis patients with severe secondary hyperparathyroidism (HPT) remains unclear. METHODS: A retrospective chart review of 401 consecutive dialysis patients who underwent subtotal PTX by one surgeon was performed. We checked serum levels of calcium (Ca), phosphorus (P), and intact parathyroid hormone (iPTH) for 3 consecutive days, and then monthly for Ca, P, and tri-monthly for iPTH postoperatively. Patients with available laboratory data within the 1st to 6th postoperative months were included in the short-term follow-up group and those with at least 6 months available data were in the long-term follow-up one. RESULTS: Patients (short-term group, n = 401, and long-term group, n = 94) had severely uncontrolled serum iPTH levels, Ca, P and Ca × P before PTX. In the short-term group, percentages of cases achieving K/DOQI targets for serum Ca, Ca × P, and iPTH and KDIGO ones for serum Ca, P, and iPTH after PTX, significantly improved compared with those before operation (all p < 0.05). In the long-term group (mean follow-up of 43 ± 29 months), the percentage of achieved targets for serum iPTH in both guidelines and for serum Ca and Ca × P in the K/DOQI recommendation also improved postoperatively (all p < 0.05). CONCLUSIONS: Achievements of K/DOQI recommended values for serum Ca, Ca × P, iPTH and KDIGO recommendations for iPTH can be successfully reached by subtotal PTX in medically refractory, secondary HPT in dialysis patients both during short- and long-term follow-ups.

Impact of spiritual and religious activity on quality of sleep in hemodialysis patients.

BACKGROUND: Sleep disorders are common in hemodialysis (HD) patients. This study examined the relationship between quality of sleep (QoS) and religious/spiritual activity in HD patients. METHODS: The study subjects were 861 HD patients from 14 dialysis clinics in Taiwan. QoS and religious/spiritual activity were evaluated by the Pittsburgh Sleep Quality Index (PSQI) questionnaire and the Royal Free Questionnaire respectively. RESULTS: There was no difference in clinical parameters between the good and poor sleepers. Although total scores of religious and spiritual activity did not correlate with global PSQI score, patients who held strong 'spiritual' beliefs reported more problems in 'sleep disturbances', while those who exercised religious beliefs more strongly reported less trouble in 'daytime dysfunction'. CONCLUSION: There is no significant correlation between QoS and religious/spiritual activity globally. However, the spiritual and religious activity did associate with different components of QoS.