PATHOBIOLOGY AND FUNCTIONAL STATUS OF LONG-TERM HEMODIALYSIS-PATIENTS

There may be cumulative 'metabolic scars' after a decade or more of lo ng-term hemodialysis. We studied 39 patients who have been on maintena nce hemodialysis for 10-24 years to determine their functional status and pathobiology. The 39 long-term (greater than or equal to 10 years) patients were compared with a control cohort of 37 age, gender-, race -, and renal-diagnosis-matched patients on hemodialysis for less than or equal to 3 years. The functional status was measured using a modifi ed Karnofsky scale, and the employment status was noted as well. Detai ls of hospitalizations and intercurrent infections requiring outpatien t oral or intravenous antibiotic therapy during the preceding year wer e obtained. Comorbid medical conditions were documented, and basic lab oratory tests were performed. The mean age of the long-term patients w as 51.8 +/- (SE) 1.9 years, and the mean age of the control group was 51.5 +/- 2.4 years (p = 0.92). Three times weekly hemodialysis prescri ptions were similar in both groups (long-term: 3.5 +/- 0.02 h, control : 3.4 +/- 0.02 h; p = 0.27). The mean modified Karnofsky scores were e quivalent in both groups. Also the rates of employment were poor and e quivalent in both groups. The rate of hospitalizations during the prec eding year was higher among the long-term patients (0.92 +/- 0.19/pati ent year) than in the control patients (0.51 +/- 0.15/patient year; p = 0.09). The long-term patients had more intercurrent infections (1.23 +/- 0.21) than the controls (0.68 +/- 0.16; p = 0.04). Comorbid medic al conditions were more prevalent in the long-term patients as reflect ed by their comorbidity index of 1.6 +/- 0.2 versus a comorbidity inde x of 0.7 +/- 0.16 for the control patients (p = 0.007). Mean postdialy sis weight and serum albumin and serum creatinine concentrations were equivalent in both groups. Of all the measured laboratory indices, onl y the hematocrit differed significantly between the two groups (long-t erm patients: 29 +/- 0.79%, controls: 26.6 +/- 0.69%; p = 0.02), altho ugh both groups received equivalent three times weekly doses of recomb inant human erythropoietin. We conclude that patients on maintenance h emodialysis for 10 years or more have more intercurrent infections as well as more comorbid medical conditions than freshly started (1-3 yea rs) hemodialysis patients. Also there is a clinically significant incr eased risk of hospitalization among the long-term patients. However, n utritional status, level of physical activity, and rate of employment in the long-term patients were equivalent to that of freshly started h emodialysis patients.