Association of TNF-α and lipoprotein lipase gene expression with renal impairment in non-diabetic patients with metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) is recognized as a systemic metabolic disorder associated with chronic kidney disease (CKD), though the underlying mechanisms remain unclear. This cross-sectional study investigated the association between tumor necrosis factor-α (TNF-α), lipoprotein lipase (LPL) gene expression, and renal impairment in 237 non-diabetic patients with MAFLD, stratified by CKD status. Clinical characteristics, biochemistries, serum TNF-α levels, LPL gene expression, and transient elastography findings were assessed. Multivariable logistic regression evaluated independent associations with CKD after adjusting for metabolic confounders. Patients with CKD exhibited significantly higher body mass index, waist circumference, liver stiffness, serum TNF-α, and adverse lipid profiles, alongside significantly lower LPL gene expression than those without CKD. TNF-α was inversely correlated with both estimated glomerular filtration rate and LPL gene expression. However, the association between TNF-α and CKD lost statistical significance after adjusting for metabolic confounders, whereas reduced LPL gene expression remained independently associated with CKD. These findings support an association between inflammation, altered lipid metabolism, and renal impairment in non-diabetic MAFLD. The inverse relationship between TNF-α and LPL gene expression suggests a biological link requiring confirmation in prospective, mechanistic studies.