Abstract: Background – Markers of kidney function have been used variably to define stable versus progressive chronic kidney disease (CKD), but quantitative criteria to distinguish these populations are lacking.
Objective – Assessment of 1/creatinine and 1/IDEXX SDMA ® slope cutoffs to distinguish stable versus progressive CKD.
Animals – 113 clinically healthy University staff-owned dogs and 29 male colony dogs with progressive X-linked hereditary nephropathy (XLHN).
Methods – Retrospective analysis combining two prospective observational studies, one tracking kidney function markers in healthy dogs (HD) to a maximum of 3 years, and one tracking kidney function markers in male colony dogs with progressive XLHN to a maximum of 1 year. The minimum slope of 1/creatinine or 1/IDEXX SDMA ® from HD was assigned as the slope cutoff for stable kidney function.
Results – The stable versus progressive slope cutoff was -0.0119 week*dL/mg for 1/creatinine (Figure 1, dashed line) and -0.0007 week*dL/µg for 1/IDEXX SDMA® (Figure 2, dashed line).
Conclusions and clinical importance – In the studied CKD population, progressive dysfunction can be distinguished from stable kidney function by using the slope of 1/creatinine or 1/IDEXX SDMA ®. These criteria may serve to characterize CKD in other cohorts of dogs and to establish guidelines for progression rate in dogs with naturally acquired CKD.