METHODS: We performed a cross-sectional study on KTRs with functioning renal allograft and at least 3 months post transplant. Dietary protein, salt, and dietary acid load were estimated using 24-hour urine collection. Demographic characteristics, concomitant medications, medical history, and laboratory results were obtained from electronic medical records.
RESULTS: A total of 204 KTRs were recruited with median age of 48 years (interquartile range [IQR], 18 years); male to female ratio was 61:39. A total of 79.9% (n = 163) were living related kidney transplants. The median duration after transplant was 71 months (IQR, 131 months), and median eGFR was 65 mL/min/1.73 m2 (IQR, 25 mL/min/1.73 m2). The prevalence rates of proteinuria (defined as ≥ 0.5 g/d) and metabolic acidosis (defined as at least 2 readings of serum bicarbonate ≤ 22 mmol/L in the past 6 months) were 17.7 % and 6.2%, respectively. High dietary protein of > 1.2 g/kg ideal body weight (adjusted odds ratio, 3.13; 95% CI, 1.35-7.28; P = .008) was significantly associated with proteinuria. Dietary protein, salt, and acid load did not correlate with chronic metabolic acidosis.
CONCLUSIONS: The prevalence rate of proteinuria is consistent with published literature, but metabolic acidosis rate is extremely low in our cohort. High protein intake (> 1.2 g/kg ideal body weight) is a risk factor of proteinuria and may have negative impact on KTR outcome.