Serum amyloid a and risk of death and end-stage renal disease in diabetic kidney disease

J Diabetes Complications. Nov-Dec 2016;30(8):1467-1472. doi: 10.1016/j.jdiacomp.2016.07.018. Epub 2016 Jul 27.

Abstract

Aims: To determine if serum levels of serum amyloid A (SAA) predict death and end-stage renal disease in a cohort of people with diabetic kidney disease.

Methods: In a longitudinal cohort study of 135 participants with type 2 diabetes and diabetic kidney disease, serum samples were assayed for SAA. Censored time-to-event analyses in Cox-proportional hazard models were utilized to assess SAA as a predictor of the primary outcome of death and end-stage renal disease.

Results: Participants were 73% Mexican-American (99/135) and 55% men (75/135), with a mean±SD age of 57±7.5years. At baseline, participants had hemoglobin A1c of 8.6±2.3%, systolic blood pressure of 153±27mm Hg, body mass index of 31±9kg/m2, median urine-albumin-to-creatinine ratio of 1861mg/g (interquartile range 720-3912mg/g), and estimated glomerular filtration rate of 55.7±22.3ml/min/1.73m2. Over a median duration of follow-up of 3.5years, 44% (60/135) of participants experienced a primary outcome event. The hazards ratio for the primary outcome was 3.03 (95% CI 1.43-6.40, p=0.003) in the highest (>1.0 μg/ml) compared to the lowest (<0.55 μg/ml) SAA tertile in a model adjusted for urine-albumin-to-creatinine ratio, estimated glomerular filtration rate, age, sex, and race/ethnicity. Addition of SAA as a covariate improved the model C-statistic (Δ c=0.017).

Conclusions: In a longitudinal cohort study of participants with type 2 diabetes and DKD, higher levels of serum SAA predicted higher risk of death and ESRD. SAA is a promising targetable biomarker for DKD.

Keywords: Biomarkers; Chronic kidney disease; Diabetes; Inflammation; Risk-stratification.

MeSH terms

  • Aged
  • California
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / mortality*
  • Diabetic Nephropathies / blood
  • Diabetic Nephropathies / mortality*
  • Disease Progression
  • Female
  • Glomerular Filtration Rate
  • Humans
  • Kidney Failure, Chronic / blood
  • Kidney Failure, Chronic / mortality*
  • Longitudinal Studies
  • Male
  • Mexican Americans
  • Middle Aged
  • Risk Factors
  • Serum Amyloid A Protein / analysis*

Substances

  • Serum Amyloid A Protein