Non-albuminuric renal impairment in type 2 diabetes and the general population (NEFRON 11)

Abstract

Background: Currently, most diabetic patients with impaired renal function have a urinary albumin excretion in the normal range. The etiology of renal impairment is in this setting is unclear or indeed if it is unique to diabetes.

Methods: This study examines the frequency and predictors of non-albumunuric renal impairment (eGFR <60 ml/min/1.73m²) in a nationally representative cohort of 3893 patients with type 2 diabetes, and compares it to rates observed in the general population from the AusDiab survey (n=11,247).

Results: 23.1% of individuals with type 2 diabetes had an eGFR <60 ml/min/1.73m² (95% CI, 21.8-24.5%), over half (55%) of whom had a urinary albumin excretion persistently in the normal range. This rate of renal impairment was predictably higher than observed in the general population (adjusted odds ratio 1.3; 95% CI 1.1-1.5, p<0.01), but was solely due to CKD associated with albuminuria. By contrast, renal impairment in the absence of albuminuria was less common in those with diabetes than in the general population, independent of gender, ethnicity and duration of diabetes (adjusted odds ratio 0.6; 95% CI 0.5-0.7, p<0.001).

Conclusions: Non-albuminuric renal impairment is not more common in those with diabetes. However, its impact may be more significant. New studies are required to address the pathogenesis, prevention and treatment of non-albuminuric renal disease.