Possible factors contributing to similar peritoneal dialysis outcome in patients over 60 years of age and the younger ones.

The aim of studies was a comparison of dialysis adequacy, nutritional parameters, results of the peritoneal equilibration test (PET) and selected standard clinical and laboratory data in peritoneal dialysis (PD) patients with different age, but comparable PD duration and outcome. Two groups of patients were examined: group I (n = 21, 9 F, 12 M) - age 67.7 +/- 4.5 yrs, PD duration 20.1 +/- 12.1 months; group II (n = 21, 9 F, 12 M) - age 42.8 +/- 9.1 yrs, PD duration 20.7 +/- 12.1 months. Parameters of PD adequacy, results of PET, markers of nutrition and standard laboratory measures were determined every 3 months to the end of PD treatment. First obtained values, mean values representing the entire PD course and last values obtained before the end of PD therapy were compared in group I and II. Differences in results obtained at the beginning and at the end of PD therapy were also compared in each group. At the beginning of PD therapy the older patients showed higher total fat mass (TFM) expressed as % of total body mass (TBM), lower lean body mass (LBM), lower serum levels of iron, phosphorus and creatinine as well as lower transferrin saturation. When mean values representing the entire PD course were compared, the older patients showed higher TFM as % of TBM and serum ferritin level, whereas lower values were observed for diastolic blood pressure (DBP), LBM, serum creatinine, phosphorus and iron. At the end of PD therapy TFM as % of TBM and serum ferritin level remained higher in older patients as well as lower both DBP and LBM were maintained. Additionally, serum cholesterol level and residual renal function (RRF) became at the end of PD treatment higher in the older individuals compared to the younger ones. The difference in RRF between the two groups was caused by the decline in RRF in the younger patients with relatively stable values of RRF in the older ones. Nutritional parameters improved in the course of PD only in the younger group. In conclusion, the older patients reach similar PD outcome parameters compared to the younger ones while they show higher TFM as % of TBM, stable RRF and more satisfactory DBP. However, elderly patients show a greater progress in the deterioration of indices of both inflammation and atherosclerosis and therefore are not able to improve nutritional parameters.