AK LE PAGE1,2, D SIVANTHANAN1, K POLKINGHORNE2,3, L JOHNSTONE1,2
1Monash Children’s Hospital, VIC; 2Monash University, VIC; 3Monash Medical Centre, VIC
Aim: To evaluate the association between evidence based targets of haemoglobin (Hb), phosphate and calcium in young (age <25yrs) dialysis patients with demographic and clinical variables, and explore the impact of these categories on time to transplant and survival on dialysis.
Background: Hb and phosphate are associated with mortality on dialysis in adult patients. Whether these relationships hold in young patients with less comorbidities is unclear. Off-target indices may also be associated with transplantation delay given postulated links to nonadherence.
Methods: All incident young Australian dialysis patients (N=789) within ANZDATA from 2003 to 2015 were assessed. First reported uncorrected calcium, haemoglobin (Hb) and phosphate at 3-15 months were categorised according to evidence based targets Multivariate Cox models with age stratification were developed to examine associations between categories with time to transplant and mortality.
Results: Low calcium and phosphate were significantly more common in those with diabetic kidney disease (42.9%, 30.8% respectively) compared with glomerulonephritis (14.66%, 15%). High phosphate was associated with older age, and high calcium with younger age. Hb>120 was more common in regional/remote (25.2% versus 19% cities) or low socioeconomic postcodes (27.3% lowest SES, 13.9% highest SES).
Time to transplant did not associate with Hb, phosphate or calcium categories in the multivariate analysis. Mortality was significantly associated with Hb>120 for those starting dialysis at 20-25 years (HR 4.1 95%CI 1.64-10.1). Low calcium was associated with mortality for the 15-20 year age group (HR 12.4 95%CI 1.7-91).
Conclusions: Age, remoteness, SES, race, and ESKD cause were associated with off-target calcium, phosphate and Hb. These indices did not associate with time to transplant, however high Hb was associated with increased mortality on dialysis.