Effects of Low Protein Formula on Renal Function, Oxidative Stress and Antioxidant Capacities in CKD Patients

Chronic renal disease is now the tenth leading cause of mortality Taiwan. It is worth to study the effect of low protein formula on the retardation of failing renal function, decrease plasma homocysteine and oxidative stress and further increase antioxidant capacities in patients with chronic kidney disease. The purpose of this study is going to investigate the effects of protein formula on renal function, homocysteine , oxidative stress and antioxidant capacities in patients with chronic kidney disease. One hundred and twenty patients with end stage renal disease (stage 2\~4) who meet the inclusion criteria will be recruited from Taichung General Veterans Hospital, Taichung. Participant patients will be blinded and randomly assigned to either the placebo (n = 60) or low protein formula (n = 60) for 12 weeks. Data on demography, anthropometry and medical history will be collected, and fasting blood samples and 24 h urine samples will be obtained at week 0, 12 and 24 during intervention period. The levels of hematological, plasma and erythrocyte PLP, plasma pyridoxal and 4-pyridoxic acid, serum and erythrocyte folate, serum vitamin B-12, homocysteine, lipid peroxidation indicators, glutathione, total antioxidant capacity and antioxidant enzymatic will be measured. Twenty-four hour urine volume will be recorded and urine creatinine and urea nitrogen will be analyzed. Creatinine clearance rate will be measured. Hopefully, the results of this study could provide more pictures on beneficial effects of low protein formula on renal function, plasma homocysteine, oxidative stress and antioxidant capacities in patients with chronic kidney disease.

Chronic renal disease is now the tenth leading cause of mortality Taiwan. It is worth to study the effect of low protein formula on the retardation of failing renal function, decrease plasma homocysteine and oxidative stress and further increase antioxidant capacities in patients with chronic kidney disease. The purpose of this study is going to investigate the effects of protein formula on renal function, homocysteine , oxidative stress and antioxidant capacities in patients with chronic kidney disease. This protocol is designed as a hospital-based blinded randomized placebo-controlled intervention trial. One hundred and twenty patients with end stage renal disease who meet the inclusion criteria will be recruited from Taichung General Veterans Hospital, Taichung. Participant patients will be blinded and randomly assigned to either the placebo (n = 60) or low protein formula (n = 60) for 12 weeks. Data on demography, anthropometry and medical history will be collected, and fasting blood samples and 24 h urine samples will be obtained at week 0, 12 and 24 during intervention period. The levels of hematological (red blood cell, hemoglobin, albumin, creatinine, urea nitrogen, total cholesterol, triglyceride, high and low density lipoprotein), plasma and erythrocyte PLP, plasma pyridoxal and 4-pyridoxic acid, serum and erythrocyte folate, serum vitamin B-12, homocysteine, lipid peroxidation indicators (serum malondialdehyde and oxidized low density lipoprotein), glutathione, total antioxidant capacity and antioxidant enzymatic activities (superoxide dismutase, glutathione peroxidase, glutathione S-transferase, glutathione reductase) will be measured. Twenty-four hour urine volume will be recorded and urine creatinine and urea nitrogen will be analyzed. Creatinine clearance rate will be measured. Hopefully, the results of this study could provide more pictures on beneficial effects of low protein formula on renal function, plasma homocysteine, oxidative stress and antioxidant capacities in patients with chronic kidney disease.

Eligibility Criteria:
Inclusion Criteria:

1) Diagnosed as stage 2 \~ 3 chronic kidney disease

Exclusion Criteria:

1. clinical unstable (i.e., systolic blood pressure \< 90 mmHg, mean arterial blood pressure \< 65 mmHg, fatal arrhythmia or the requirement of vasopressor to maintain blood pressure) or unconscious at any point during the study.
2. chronic diseases (i.e. liver disease, gastrointestinal diseases, alcoholism, cancer); or 3) being in pregnant or lactation.