The association of low-grade albuminuria with incident non-alcoholic fatty liver disease and non-invasive markers of liver fibrosis by glycaemia status

Background & aim: Low-grade albuminuria, as an early marker of endothelial dysfunction and kidney damage, has been recognized as a risk factor for metabolic disorders. Epidemiological studies manifesting the association of low-grade albuminuria with the risk of incident NAFLD and fibrosis were not available. We aimed to investigate the association of low-grade albuminuria with incident NAFLD and fibrosis by glycaemia status.

Methods: A prospective population-based study was performed in 3308 participants without NAFLD at recruitment. Baseline urinary albumin excretion was obtained by a first-voided early morning spot urine sample. At follow-up visit, incident NAFLD was diagnosed by hepatic ultrasound after excluding alcohol abuse and other cause of hepatic diseases. Fatty liver index (FLI) was employed to reflect liver fat content. Liver fibrosis was evaluated by NAFLD fibrosis score (NFS), fibrosis-4 score (FIB-4) and Hepamet fibrosis score (HFS) respectively.

Results: After 4.3 years of follow-up, 622 (18.8%) were detected as incident NAFLD. Participants with low-grade albuminuria imposed a 40.4% [1.404 (1.112-1.772)] greater risk on incident NAFLD, and 52.0% [1.520 (1.141-2.026)], 87.4% [1.874 (1.291-2.720)] and 40.4% [1.404 (1.038-1.898)] higher risks on newly onset higher values of FLI, NFS and FIB-4 respectively. The effect of low-grade albuminuria was stronger in the subgroup of non-diabetic population.

Conclusions: Low-grade albuminuria was independently associated with incident NAFLD and a higher probability of fibrosis, especially among non-diabetic individuals.