Effects of Hemodiafiltration versus Conventional Hemodialysis in Children with ESKD: The HDF, Heart and Height Study

Abstract

Background: Hypertension and cardiovascular disease are common in children undergoing dialysis. Studies suggest that hemodiafiltration (HDF) may reduce cardiovascular mortality in adults, but data for children are scarce.

Methods: The HDF, Heart and Height study is a nonrandomized observational study comparing outcomes on conventional hemodialysis (HD) versus postdilution online HDF in children. Primary outcome measures were annualized changes in carotid intima-media thickness (cIMT) SD score and height SD score.

Results: We enrolled 190 children from 28 centers; 78 on HD and 55 on HDF completed 1-year follow-up. The groups were comparable for age, dialysis vintage, access type, dialysis frequency, blood flow, and residual renal function. At 1 year, cIMT SD score increased significantly in children on HD but remained static in the HDF cohort. On propensity score analysis, HD was associated with a +0.47 higher annualized cIMT SD score compared with HDF. Height SD score increased in HDF but remained static in HD. Mean arterial pressure SD score increased with HD only. Factors associated with higher cIMT and mean arterial pressure SD-scores were HD group, higher ultrafiltration rate, and higher β2-microglobulin. The HDF cohort had lower β2-microglobulin, parathyroid hormone, and high-sensitivity C-reactive protein at 1 year; fewer headaches, dizziness, or cramps; and shorter postdialysis recovery time.

Conclusions: HDF is associated with a lack of progression in vascular measures versus progression with HD, as well as an increase in height not seen in the HD cohort. Patient-related outcomes improved among children on HDF correlating with improved BP control and clearances. Confirmation through randomized trials is required.

Keywords: cardiovascular disease; carotid intima-media thickness; children; growth; hemodiafiltration (HDF); hemodialysis.

Graphical abstract

Figure 1.

Flow chart of study populations, including the number of children who were screened, underwent randomization, and completed 1-year follow-up in the HD and HDF arms.

Figure 2.

At 12 months the cIMT SD score increased in the HD group and remained static in the HDF group. (A) cIMT SD scores at baseline and 12 months for HD and HDF cohorts are shown. cIMT increases significantly from 0 to 12 months in the HD cohort (P=0.02) but remains static in HDF (P=0.89), with a significant difference between groups at 12 months (P=0.009). (B and C) cIMT SD score at baseline and 12 months in incident and prevalent patients on HD and HDF. Data are shown as median and interquartile range. Within-group analyses performed by Wilcoxon matched-pairs signed-rank test (see Supplemental Table 1) and HD versus HDF cohorts compared by Mann–Whitney U test.

Figure 3.

Improved height SD score in HDF compared to HD. The figure shows change in height SD score in the HD and HDF arms at baseline and 1-year follow-up. Data are shown as median and interquartile range. Within-group analyses performed by Wilcoxon matched-pairs signed-rank test and HD versus HDF cohorts compared by Mann–Whitney U test. At 12 months the height SD score in the HDF group was higher than in the HD group (P = 0.04).

Figure 4.

Changes in secondary outcome measures. (A) PWV SD score, (B) 24-hour MAP SD score, and (C) LVMI at baseline and 12 months in the HD and HDF cohorts. PWV SD score, MAP SD score, and LVMI at baseline and 12 months in incident and prevalent patients on HD and HDF. Data are shown as median and interquartile range. Within-group analyses performed by Wilcoxon matched-pairs signed-rank test (see Supplemental Table 1) and HD versus HDF cohorts compared by Mann–Whitney U test.

Figure 5.

Predialysis biochemical measurements in HD and HDF groups at baseline and 12-months follow-up. (A) β2-microglobulin level, (B) hs-CRP (log10 axis), (C) serum albumin levels, (D) serum phosphate levels, (E) serum PTH levels (log10 axis), and (F) serum hemoglobin levels. Data are shown as median and interquartile range. Within group analyses performed by Wilcoxon matched-pairs signed-rank test (see Supplemental Table 2) and HD versus HDF cohorts compared by Mann–Whitney U test.

Figure 6.

Improved patient-related outcome measures on HDF compared to HD. (A) Postdialysis recovery time, (B) physical activity index, and (C) school attendance, (D) Headaches, (E) dizziness, (F) cramps, (G) sleep disturbances, (H) pruritus, and (I) restless legs; individual scales for each measure shown on the figure. Graded on a scale of 1–5 (5 being most severe or frequent). Stacked bar charts showing the percentage of affected children on HD and HDF for each symptom with comparison between groups made by chi-squared test.