Serum prealbumin is higher in peritoneal dialysis than in hemodialysis: a meta-analysis.

BACKGROUND

Although not widely appreciated, the reported concentration of serum prealbumin, like that of serum cholesterol, tends to be higher in patients on peritoneal dialysis (PD) than on hemodialysis (HD), despite the substantial loss of protein during PD.

METHODS

The mean difference in serum prealbumin was quantified by meta-analysis of the mean differences found in six cohorts with both PD and HD patients (set 1; N = 639) using a fixed-effects model, and meta-analysis of the mean prealbumin values reported in 23 cohorts of unselected dialysis patients on a single modality (set 2; 9 PD cohorts, 14 HD cohorts; N = 12,256) using a mixed model. For comparison, the mean difference in serum albumin concentration between PD and HD also was estimated in sets 1 and 2 using the same methods.

RESULTS

In set 1, the mean prealbumin difference (PD-HD) in the individual cohorts ranged from 3.6 to 14.7 mg/dL (P < 0.05 in five cohorts), and the weighted mean difference was 5.4 mg/dL (95% CI, 3.8 to 7.0 mg/dL). In set 2, weighted mean prealbumin was 8.1 mg/dL (95% CI, 5.2 to 10.9 mg/dL) higher in PD than in HD in the entire data set, and 6.9 mg/dL (95% CI, 5.2 to 8.6 mg/dL) higher in a sensitivity analysis that excluded two outlying HD studies. By contrast, weighted mean serum albumin concentration was significantly lower in PD than in HD in both sets 1 and 2; the mean difference was 0.25 g/dL (95% CI, 0.14 to 0.36 g/dL) in set 1 and 0.28 g/dL (95% CI, 0.14 to 0.42 g/dL) in set 2.

CONCLUSIONS

Serum prealbumin level is approximately 6 mg/dL higher in PD than HD, perhaps due to the stimulation of hepatic synthesis by PD albumin loss, while serum albumin is approximately 0.3 g/dL lower in PD. Different reference ranges and clinical targets (such as, K/DOQI guidelines) are needed for PD and for HD.