Association of eGFR slope with all-cause mortality, macrovascular and microvascular outcomes in people with type 2 diabetes and early-stage chronic kidney disease

Abstract

Aims: The association of estimated glomerular filtration rate (eGFR) slope with progression of complications in people with type 2 diabetes (T2D) and early-stage chronic kidney disease (CKD) is less clear.

Methods: We identified 115,139 T2D participants without decreased eGFR (>60 mL/min/1.73 m²) between 2008 and 2015 from the electronic database of the Hong Kong Hospital Authority. eGFR slope calculated by linear-mixed effects model using 3-year eGFR measurements was categorized into quintiles. With Quintile 3 of eGFR slope as the reference group, we used Cox proportional or cause-specific models to investigate the association between eGFR slope and all-cause mortality, macrovascular and microvascular complications, as appropriate.

Results: Over a median follow-up of 7.8 years, fastest eGFR declines (Quintile 1 with median eGFR slope: -4.32 mL/min/1.73 m²/year) were associated with increased risk of all adverse outcomes (adjusted hazard ratio [aHR] 1.36 to 2.97, all P < 0.0001), compared with less steep eGFR declines (Quintile 3: -1.08 mL/min/1.73 m²/year). Substantial eGFR increases (Quintile 5: 1.34 mL/min/1.73 m²/year) were associated with decreased risk of CKD and ≥ 40 % decline in eGFR (aHR [95 % CI] 0.65 [0.63, 0.67] and 0.85 [0.82, 0.89], respectively) and higher risk of death, CVD, DR and DN (aHR [95 % CI] 1.48 [1.40, 1.56], 1.19 [1.14, 1.25], 1.07 [1.004, 1.15] and 1.62 [1.37, 1.91], respectively).

Conclusions: In a cohort of T2D people without decreased eGFR, accelerated declines and increases in eGFR were associated with all-cause mortality, macrovascular and microvascular complications, supporting the potential prognostic utility of eGFR slope in T2D people with early-stage CKD.

Keywords: Cardiovascular disease; Chronic kidney disease; Diabetes complications; Dynamic change; Type 2 diabetes; eGFR slope.