Prevalence Rate of Proteinuria and Metabolic Acidosis Among Kidney Transplant Recipients in a Tertiary Teaching Hospital and Its Relationship to Dietary Intake

BACKGROUND: Proteinuria and metabolic acidosis adversely affect long term renal allograft outcome and are highly prevalent in reported studies. The role of dietary intake in influencing proteinuria and metabolic acidosis remained uncertain. This study aims to determine the prevalence rate of proteinuria and metabolic acidosis among kidney transplant recipients (KTRs) and to study their relationship with dietary intake.

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.