Fatty Kidney: The Interplay of Lipids and Diabetic Kidney Disease

Diabetic nephropathy and diabetic atherosclerosis often develop together and share similar metabolic disturbances. Lipid abnormalities are common in diabetes, yet their roles in kidney and vascular injury are not fully understood. In diabetic kidney disease, altered lipid uptake, reduced fatty acid oxidation, and accumulation of harmful lipid species contribute to cellular stress, mitochondrial injury, inflammation, and fibrosis. In parallel, disordered lipid handling in the vasculature promotes endothelial dysfunction and atherosclerotic plaque development. However, not all lipid accumulation appears to be detrimental, and some findings suggest adaptive or context-dependent effects, leading to inconsistent results across studies. In this review, we summarize current evidence on lipid metabolism in diabetic nephropathy and atherosclerosis, compare shared and distinct features, and discuss ongoing controversies. We also briefly address the therapeutic relevance of targeting lipid pathways and highlight areas that require further investigation. Compared with prior reviews that mainly discussed fatty kidney as an emerging concept in chronic kidney disease research, this review specifically focuses on diabetic kidney disease and integrates kidney-specific lipid trafficking, kidney–vessel crosstalk, conflicting evidence, and mechanism-based therapeutic implications.