The relationship between urinary albumin excretion, cardiovascular outcomes and total mortality among a large cohort of insulin-treated patients with type 2 diabetes in routine primary care practices.

BACKGROUND

Albuminuria is a recognized diagnostic and prognostic marker of chronic kidney disease and cardiovascular (CV) risk but the well-known relationship between increments in urinary albumin:creatinine ratio (UACR) and CV outcomes and mortality has not been fully explored in insulin-treated patients with type 2 diabetes (T2D) in routine clinical care.

METHODS

We investigated data for insulin users with T2D from UK general practices between 2007 and 2014. The UACR at the time of insulin initiation was measured and categorized as <10, 10- 29, 30-300 and >300 mg/g. Patients were followed up for 5 years or the earliest occurrence of all-cause mortality, non-fatal myocardial infarction or stroke. Cox proportional hazards models were fitted to estimate the risk of a composite of these events.

RESULTS

A total of 12 725 patients with T2D (mean age 58.6 ± 13.8 years, mean haemoglobin A1c 8.7 ± 1.8%) initiating insulin therapy between 2007 and 2014 met the inclusion criteria. Compared with patients whose ACR levels at insulin initiation were <10 mg/g, the adjusted risk of the 3-point composite endpoint was 9, 30 and 98% higher in those with ACR levels between 10-29, 30-300 and >300 mg/g, respectively, after a follow-up period of 5 years. The ACR category on its own did not predict risk of all-cause mortality.

CONCLUSIONS

This study shows that in patients with T2D on insulin therapy, increased urinary ACR is independently associated with an increased risk of major adverse CV events and all-cause mortality.