Primary Outcome Measures:
- We will assess in our patients how the amount of their protein intake correlates with their muscle mass and arterial stiffness. [ Time Frame: Baseline,6 months,12 months,18 months ] [ Designated as safety issue: No ]
Secondary Outcome Measures:
- Evidence of clinically definite arterial stiffness and cardio vascular disease confirmed by a MRI/BIA test/PWV test [ Time Frame: 18 months ] [ Designated as safety issue: No ]
Biospecimen Description:
We will draw 30 ml of blood four times (months 1, 6, 12 and 18) for plasma/serum/DNA samples.Urine Collection: If patients are making more than ½ cup (200 ml) of urine a day.
Even though the National Kidney Foundation guidelines recommend a dietary protein intake of 1.2 g/kg/d in hemodialysis patients, it remains unclear whether high protein intake has beneficial or harmful nutritional and cardiovascular effects in this population.
We hypothesize that in the dialysis population overall: (1) Protein intake is a major determinant of muscle mass while inflammation, oxidative stress and metabolic acidosis play a lesser role; (2) Malnutrition is not an uremic cardiovascular risk factor hence low protein intake does not cause cardiovascular disease; and (3) In the other extreme, high protein intake is also not a major cause of cardiovascular disease since high serum phosphorus associated with high protein intake can usually be controlled by the use of phosphorus binders in routine clinical practice.
The specific aims of this proposal are to examine in a prospective cohort of hemodialysis patients the longitudinal associations of absolute total protein intake (TPI in g/day) or dietary protein intake normalized to body weight (DPI in g/kg/day) with
- Nutritional status (mid-thigh muscle mass as measured by Magnetic Resonance Imaging ) and functional status (6-min walk) and
- Arterial stiffness (aortic pulse wave velocity) Understanding the relationship between protein intake with body composition (muscle mass) and intermediate CV outcomes (arterial stiffness) in stage V CKD patients in hemodialysis is of great scientific and practical significance