Background: Urine biomarkers such as neutrophil gelatinase associated lipocalin (uNGAL) and gamma-glutamyl transpeptidase (uGGT) may be more sensitive for acute kidney injury caused by telmisartan treatment than increases in serum creatinine (sCr).
Objective: Planned interim analysis of prospective cohort study to determine if urine biomarkers provide evidence of kidney injury not apparent with sCr after telmisartan. Animals: Seven of eleven proteinuric study dogs starting treatment with telmisartan and four of seven control dogs with chronic kidney disease had all samples available at time of interim analysis.
Methods: Urine protein to urine creatinine ratio (uP:uC), uNGAL, uNGAL:uC, uGGT, uGGT:uC, sCr and other parameters were evaluated at baseline (T0) and 3.5m +/- 1m later (T1). Normality was assessed by Shapiro-Wilks. Data was compared within and between groups using a t-test for normally distributed and Man-Whitney U for non-normally distributed data. Correlation between biomarkers and sCr or uP:uC were evaluated using Spearmann correlation. Results There were no significant within-group differences between T0 and T2 (no evidence of adverse telmisartan effect). The study group had lower sCr and higher uP:uC at both time points (p < 0.005). There was significant positive correlation between uP:uC vs. uNGAL:uC (rho = 0.864, p < 0.001) and uGGT:uC (rho = 0.920, p < 0.001) that is not primarily related to urine concentration.
Conclusions: Interim analysis showed greater differences between study and control groups at baseline than expected and no evidence of adverse treatment effect. However, results suggest that proteinuria may be associated with elevated kidney injury biomarker levels.
