8626 Associations Between Low Serum Bilirubin Levels and the Progression of Diabetic Kidney Disease in Individuals with Type 2 Diabetes, Including Those in a Normoalbuminuric State

Abstract Disclosure: E. Kim: None. Y. Cho: None. O. Hong: None. K. Jo: None. J. Han: None. S. Moon: None. Objective: This study aimed to investigate the potential correlation between serum bilirubin levels and the progression of diabetic nephropathy, assessing whether low serum bilirubin levels are associated with a decline in renal function, while considering the baseline albumin excretion status. Methods: The longitudinal observation, spanning 11 years, involved 1167 Korean subjects aged 20 years or older, diagnosed with type 2 diabetes mellitus (T2DM), and having a baseline estimated glomerular filtration rate (eGFR) greater than 60 ml/min per 1.73 m2. Albuminuria was assessed by the 24-hour urinary albumin to creatinine excretion rate (ACR) and categorized into normoalbuminuria (ACR <30 mg/g), micro- or macroalbuminuria (ACR >300/g). Cox regression analysis was employed to explore connections between serum bilirubin levels and eGFR decline ≥40%, with adjustments for potential confounding variables. Results: Over a median follow-up of 8.2 years, 128 individuals experienced a decline in eGFR >40%. The hazard ratio (HR) of incident GFR decline was 1.72 (95% CI: 1.04-2.85, P=0.036) in the lowest total bilirubin (TB) tertile compared to the highest TB tertile after multivariable adjustment. When stratified by baseline albuminuria status, low bilirubin levels were significantly associated with eGFR decline, even in the normoalbuminuria group (HR: 2.21, 95% CI: 1.26-3.90, P=0.006), with a gradually increasing risk according to the absence of low TB levels and albuminuria (HR: 2.92, 95% CI: 1.65-5.19, P<0.001), and low TB levels and albuminuria (HR: 3.01, 95% CI: 1.65-5.46, P<0.001). Conclusion: Low serum TB levels are associated with an increased risk of rapid GFR decline in Korean patients with T2DM. Serum bilirubin levels may serve as a prognostic marker for the development and progression of diabetic kidney disease. Presentation: 6/1/2024