Glomerular filtration rate change and outcomes in type 2 diabetes.

Objectives: To assess the relationship between relative estimated glomerular filtration rate (eGFR) change and outcomes in patients with type 2 diabetes (T2D).

Study Design: This retrospective cohort study utilized administrative claims (Humana Research Database) for patients with T2D aged 65 to 89 years, enrolled in a Medicare Advantage plan, with an initial eGFR of 25 to 89 mL/min/1.73m2 in 2008 to 2017, and a second eGFR measurement within 3 to 24 months after the identification date.

Methods: The primary exposure was relative decline in eGFR of 40% or more in a 2-year period. Outcomes included end-stage kidney disease (ESKD) or kidney failure, a composite cardiovascular (CV) outcome, and all-cause mortality assessed with multivariable adjusted survival models. Days out of the home and all-cause total costs were assessed using multivariable adjusted generalized linear models.

Results: A total of 288,170 patients were included. The adjusted HR for ESKD or kidney failure was 4.38 (95% CI, 3.99-4.81) in patients with 40% or greater decline versus those with a decline of less than 40%. The adjusted HR was 1.67 (95% CI, 1.53-1.82) for the composite CV outcome and 1.98 (95% CI, 1.87-2.10) for all-cause mortality. Patients with a 40% or greater relative decline had 2.23 times higher all-cause total per patient per month costs ($1910 difference) and 1.82 times higher odds of 7 or more days out of the home versus those with less than 40% relative eGFR decline.

Conclusions: Our results indicate that a relative eGFR decline of 40% or greater is associated with an increased risk of ESKD or kidney failure, CV outcomes and all-cause mortality, and increased health care resource utilization and costs.