First published October 1, 2019 - More info
Background: In this study, we aimed to identify the lipidomic predictors of early type-2 diabetic kidney disease (DKD) progression which are currently undefined DKD progression.
Methods: This longitudinal study included 92 American Indians with type-2 diabetes. Serum lipids (406 from 18 classes) were quantified using mass spectrometry from baseline samples when iothalamate glomerular filtration rate (GFR) was ≥90 mL/min. Affymetrix GeneChip Array was used to measure renal transcript expression. DKD Progression was defined as ≥40% decline in GFR during follow up.
Results: Participants had a mean age of 45±9 years and median urine albumin-creatinine ratio of 43 (interquartile range 11 to 144). The 32 progressors had significantly higher relative abundance of polyunsaturated triacylglycerols (TAG)s and a lower abundance of C16-20 acylcarnitines (AC)s (p<0.001). In a Cox regression model the main effect terms of unsaturated free fatty acids and phosphatidylethanolamines and the interaction terms of C16-20 ACs and short, low-double-bond TAGs by categories of albuminuria independently predicted progression of DKD. Renal expression of acetyl-CoA carboxylase encoding gene (ACACA) correlated with serum diacylglycerols in the glomerular compartment (r=0.36, p=0.006), and with low-double-bond TAGs in the tubulointerstitial compartment (r=0.52, p<0.001).
Conclusion: Collectively, the findings reveal a previously unrecognized link between lipid markers of impaired mitochondrial β-oxidation and enhanced lipogenesis, with DKD progression, in individuals with preserved GFR. Renal acetyl-CoA carboxylase activation accompanies these lipidomic changes and suggests that it may be the underlying mechanism linking lipid abnormalities to DKD progression.
Funding: R24DK082841, K08DK106523, R03DK121941, P30DK089503, P30DK081943, P30DK020572