Abstract
Introduction: End-stage renal disease (ESRD) is one of the most common diseases, which affects
many aspects of patients’ lives. The measurement of exercise capacity through peak oxygen
uptake is an important factor in predicting mortality and survival in patients with ESRD.
Objectives: In the current study, we aimed to examine the relationship between phosphorus level
and VO2
uptake in renal transplant candidates receiving hemodialysis.
Patients and Methods: Thirty renal transplant candidates on hemodialysis were evaluated through
spirometry and exercise tests. Then, the results were compared according to the inclusion criteria
of age, gender, and phosphorus level.
Results: All of cases were male with the mean age of 37.93±10.48 years (range; 20-55 years). Mean
VO2
max was 23.46±8.22 mL/kg/min (range; 6.88 to 43.44 mL/kg/min). The mean phosphorus
level was 6±2.3 mg/dL (range; 2-10.6 mg/dL) since eight patients had high levels of phosphorus
(more than 5.5 mg/dL). In patients with low phosphorus level an abnormal VO2
max was detected
(P=0.027). Furthermore, Fisher’s exact test reflected a significant association between higher levels
of phosphorus with normal VO2
max (P=0.029).
Conclusion: In hemodialysis, decreased blood phosphorus is a predisposing factor for reduced
exercise capacity, while hypophosphatemia may lower VO2
max through reducing energy of skeletal
muscles. The relationship between phosphorus level and VO2
max may be related to morbidity in
hemodialysis patients. Hence, treatment modalities reducing serum levels of phosphorus should be
conducted with caution in some patients.