An association between time-varying serum alkaline phosphatase concentrations and mortality rate in patients undergoing peritoneal dialysis: a five-year cohort study

Longitudinal study on the change trend of serum alkaline phosphatase and its possible influencing factors in peritoneal dialysis patients

The aim of the study was to analyze the change trend of serum ALP over time and identify factors influencing its levels in peritoneal dialysis patients. Then to investigate the impact of serum ALP changes on calcium and phosphorus metabolism in single peritoneal dialysis center utilizing repeated measurement data. A retrospective cohort study was conducted with a total follow-up duration of 30 months. Serum ALP and other biomarkers, including calcium (Ca), phosphorus (P), 25(OH)D, intact parathyroid hormone (iPTH), albumin(ALB), and hemoglobin(Hb) were measured every 3 months. The generalized estimation equation (GEE) was utilized to analyze the change trend of serum ALP over time, and to assess whether there were differences in changes over time between different genders and different primary disease groups. Additionally, factors influencing serum ALP levels were analyzed, and the impact of serum ALP changes on calcium and phosphorus metabolism was also explored. A total of 34 patients were included in the study. Serum ALP and other indicators were measured repeatedly, with a maximum of 8 times and a minimum of 4 times. The median of serum ALP values at all measurement times for all selected patients was 89 U/L. The GEE analysis revealed that serum ALP gradually increased with time, and patients in diabetes group increased faster than those in non-diabetes group. A positive correlation was observed between serum ALP and dialysis duration, also between serum ALP and hemoglobin. However, variations in serum ALP did not significantly affect serum corrected calcium, phosphorus, or iPTH concentrations. The serum ALP levels of peritoneal dialysis patients increase gradually over time, and the concentrations are influenced by dialysis duration. The changes in serum ALP values do not have a significant impact on serum calcium, phosphorus, and iPTH levels.

Associations between liver function parameters and poor clinical outcomes in peritoneal dialysis patients

Patients with end-stage renal disease (ESRD) have significantly lower survival rates compared with the general population of the same age. Peritoneal dialysis (PD) is an effective treatment for patients with ESRD, but the clinical outcome of PD patients is still not promising. The survival of PD patients is associated with various clinical factors, and exploring some valid risk predictors may be beneficial for this population. In this review, by integrating the latest research, we summarized the association of some common and novel liver function parameters (ALT, AST, ALP, GGT, serum bilirubin, pre-albumin, albumin, albumin-globulin ratio [AGR], serum ferritin, and hyaluronic acid) with clinical outcomes in PD patients. It may contribute to a better understanding of potential risk factors and help to develop strategies to prevent the disease progression.

Risk factors for mortality in patients undergoing peritoneal dialysis: a systematic review and meta-analysis

Aim

Inconsistent investigations of the risk factors for all-cause mortality in patients undergoing peritoneal dialysis (PD) were reported. The present meta-analysis aimed to assess the impact of some clinical characteristics on the risk of mortality in PD patients.

Methods

PubMed and Embase were systematically searched for studies evaluating the risk factors for all-cause mortality in PD patients. Hazard ratio (HR) and 95% confidence interval (CI) were derived using a random-effect or fixed-effect model considering the heterogeneity across studies.

Result

A total of 26 studies were included in this meta-analysis in accordance with the inclusion and exclusion criteria. Age, primary cardiovascular diseases, diabetes mellitus, and high level of alkaline phosphatase showed significant positive associations with elevated risk of all-cause and cardiovascular mortality in PD patients, while hemoglobin acted as a benefit factor. Furthermore, early onset of peritonitis, high peritoneal transport status, elevated body mass index and high-sensitivity C-reactive protein could also considerably increase the risk of all-cause mortality. The absolute serum level of magnesium, potassium, and uric acid required to improve survival in PD patients should be verified further.

Conclusions

Multiple factors could affect the risk of mortality in PD patients.

High alkaline phosphatase and low intact parathyroid hormone associate with worse clinical outcome in peritoneal dialysis patients

OBJECTIVE

Alkaline phosphatase (ALP) is used as a biomarker to monitor the chronic kidney disease-mineral bone disorder (CKD-MBD) and high levels of parathyroid hormone (PTH) that were reported to be related to increased mortality in CKD patients. Therefore, we conducted this longitudinal cohort study to evaluate the relations between ALP and intact PTH (iPTH) and the associations with all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients.

METHODS

In 1276 incident PD patients (median age 50 years, 56% males), baseline serum ALP, iPTH, and metabolic biomarkers potentially linked to CKD-MBD were analyzed in relation to mortality during follow-up period of up to 60 months. All-cause and cardiovascular mortality risk of ALP and iPTH were analyzed with competing-risks regression models with transplantation as competing risk adjusting for all covariates.

RESULTS

After adjustments for confounders by logistic regression model, older age, higher change level to levels of iPTH, S-albumin, calcium, alanine transaminase (ALT), and lower level of phosphorus were associated with higher ALP level (>79 U/L), and female gender, non-diabetes mellitus, younger age, lower calcium, higher ALT, total bilirubin, phosphorus, and ALP were associated with higher iPTH level (>300 pg/mL). During 60 months (median 44 months) of follow-up, the all-cause mortality rate was 16%, and 91 (46%) of the 199 deaths were caused by cardiovascular disease. In competing-risks regression analysis, "high ALP + low iPTH" was independently associated with all-cause and cardiovascular mortality after adjustment for age, gender, presence of diabetes, and cardiovascular disease, the calendar year of recruitment and vitamin D therapy in PD patients. The subhazard ratio (sHR) of group "high ALP + low iPTH" was 1.96 times and 3.35 times higher than sHR of group "low ALP + high iPTH" for all-cause mortality and cardiovascular mortality, respectively.

CONCLUSIONS

The combination of high ALP and low iPTH was independently associated with increased all-cause and cardiovascular mortality in PD patients, suggesting that ALP and iPTH have the potential to predict clinical outcomes and might be useful risk assessment tools in PD patients. Further studies exploring the observed association between combination of ALP with iPTH and mortality are warranted.

Elevated liver enzymes and cardiovascular mortality: a systematic review and dose-response meta-analysis of more than one million participants

Gamma glutamyl transferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) are commonly used liver function markers. We performed a dose-response meta-analysis to investigate the association between liver enzymes and cardiovascular disease (CVD) mortality in prospective cohort studies. We conducted a systematic search up to April 2018 in Medline/PubMed, Scopus, Cochrane, and Embase databases. Combined hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a random-effects model as described by DerSimonian and Laird. Dose-response analysis was also carried out. Twenty-three studies with 1 067 922 participants reported association between GGT and CVD mortality and were included in our analysis. Pooled results showed a significant association between GGT and risk of CVD mortality (HR: 1.62; 95% CI: 1.47-1.78, P=0.001, P-heterogeneity=0.001) and it was HR: 0.87; 95% CI: 0.73-1.07; P=0.221, P-heterogeneity=0.028, for ALT. There was a direct association between baseline levels of ALP and AST/ALT ratio with CVD mortality (HR: 1.45; 95% CI: 1.11-1.89; P=0.005, P-heterogeneity=0.026, and HR: 2.20; 95% CI: 1.60-3.04; P=0.001, P-heterogeneity=0.540, respectively). Pooled results did not show any significant association between AST and the risk of CVD mortality (HR: 1.20; 95% CI: 0.83-1.73; P=0.313, P-heterogeneity=0.024). Moreover, there was a significant nonlinear association between GGT and ALP levels and the risk of CVD mortality (P=0.008 and 0.016, respectively). Our dose-response meta-analysis revealed a direct relationship between GGT and ALP levels and the risk of CVD mortality. High levels of GGT, ALP and AST/ALT were associated with an increased CVD mortality rate.

A turn-on fluorescence assay of alkaline phosphatase activity using a DNA–silver nanocluster probe

A label-free fluorescence assay has been developed for the detection of alkaline phosphatase based on DNA–silver nanocluster probes.

Elevated serum alkaline phosphatase and cardiovascular or all-cause mortality risk in dialysis patients: A meta-analysis

Studies on serum alkaline phosphatase (ALP) and mortality risk in patients with end-stage renal disease (ESRD) undergoing dialysis have yielded conflicting results. This meta-analysis was designed to assess the association of serum ALP levels with cardiovascular or all-cause mortality risk among patients on dialysis. PubMed and Embase databases were searched until March 2017 for studies evaluating the association of serum ALP levels and cardiovascular or all-cause mortality risk in adult patients with ESRD undergoing maintenance hemodialysis or chronic peritoneal dialysis. Twelve studies enrolling 393,200 patients on dialysis were included. Compared with the reference low serum ALP category, pooled adjusted hazard risk (HR) of all-cause mortality was 1.46 (95% confidence interval [CI] 1.30–1.65) for patients on hemodialysis and 1.93 (95% CI 1.71–2.17) for peritoneal patients on dialysis. In addition, elevated serum ALP significantly increased cardiovascular mortality among patients on peritoneal dialysis (HR 2.39; 95% CI 1.23–4.65) but not in patients on hemodialysis (HR 1.08; 95% CI 0.84–1.40). Elevated serum ALP was an independent risk factor for all-cause mortality among patients on hemodialysis or peritoneal dialysis. Further well-designed prospective studies are needed to investigate the association of high serum ALP levels with cardiovascular mortality among patients on dialysis.

Nitrogen-doped Carbon Dots Mediated Fluorescent on-off Assay for Rapid and Highly Sensitive Pyrophosphate and Alkaline Phosphatase Detection

In this report, a novel fluorescent sensing platform using nitrogen-doped carbon dots (N-CDs) as probes for fluorescence signal transmission has been designed for the detection of significant biomolecules pyrophosphate (PPi) and alkaline phosphatase (ALP). The high fluorescent N-CDs could be selectively quenched by Cu2+, and recovered by the addition of PPi because PPi preferentially binds to Cu2+. Once ALP was introduced into the system, ALP can specifically hydrolyze PPi into Pi, the intense fluorescence of N-CDs could be quenched again due to the recombination of the as-released Cu2+ with N-CDs. So, fluorescence of N-CDs is regulated by an ALP-triggered reaction. Based on this strategy, we demonstrated that N-CDs could serve as a very effective fluorescent sensing platform for label-free, sensitive and selective detection of PPi and ALP with low detection limit of 0.16 μM and 0.4 U/L for PPi and ALP, respectively. Moreover, the assay time is just around 0.5 min for PPi and 30 min for ALP. This developed strategy shows remarkable advantages including sensitive, rapid, simple, convenient, and low-cost and so forth. Furthermore, this method was also successfully applied to monitor ALP in human serum, which indicates its great potential for practical applications in biological and clinical diagnosis.