Age differences in associations of serum alkaline phosphatase and mortality among peritoneal dialysis patients

Covariates were age, sex, diabetes mellitus, CVD, 24-h urine output, hemoglobin, serum albumin levels, neutrophil to lymphocyte ratio (N/L), serum alanine aminotransferase (ALT), albumin-corrected calcium, serum phosphorus, as well as intact parathyroid hormone (iPTH), and medication use, including vitamin D analogs and phosphate binders. The elderly patients had higher serum ALP levels and N/L, but lower 24-h urine output, diastolic blood pressure (DBP), serum albumin, phosphorus, iPTH, blood nitrogen (BUN), serum creatinine and uric acid (UA) levels than the younger patients. See PDF] After adjusting for demographics, comorbid diseases, 24-h urine output, liver function, nutrition, inflammation, bone metabolism parameters, and medication use, we found that each 10 U/L higher ALP level was associated with a 5.6% higher hazard (95% CI, 1.03–1.09; P < 0.001) for all-cause mortality in overall patients using Cox proportional hazards model (data not shown). After adjustment for age, gender, comorbid diseases, 24-h urine output, hemoglobin level, serum albumin level, N/L, iPTH level, albumin-corrected calcium level, serum phosphorus level, vitamin D analog use and phosphate binder use, there was no significant association between ALP levels and all-cause mortality in the elderly group (HR: 1.04, 95% CI: 0.99–1.10; P = 0.101).Table 1 Associations between continuous and quartiles of serum ALP and all-cause mortality in younger and elderly patients [Figure omitted.