The practical utility of non-invasive indices in metabolic hepatic steatosis

Metabolic hepatic steatosis (metHS) is the most frequent cause of chronic liver disease in our environment. The "gold standard" for its diagnosis continues to be liver biopsy, but this is an invasive technique, is not risk-free, and has great interobserver variability, so noninvasive diagnostic methods are necessary.

To determine the diagnostic accuracy of non-invasive methods based on clinical and analytical data compared to liver biopsy, and to analyse their concordance with each other in the overall cohort and in subpopulations at risk of metHS.

Prospective observational study of 245 patients aged 19-80 years diagnosed with metHS by liver biopsy. Steatosis indices were calculated: FLI (Fatty Liver Index), LAP (Liver Accumulation Product), HSI-(Hepatitis Score Index) and fibrosis indices: Non-alcoholic fatty liver disease fibrosis score (NFS), fibrosis-4 index (FIB-4) and Hepamet Fibrosis Score (HFS).

The non-invasive steatosis indices showed high sensitivity, and those of fibrosis, high specificity. To assess steatosis, FLI was the most sensitive index in all subpopulations (89-97%), except in women. To assess fibrosis, HFS offers maximum sensitivity in diabetics (86.7%) and is the index with the highest negative predictive value overall. The COR curves for non-invasive indices in steatosis and fibrosis compared to liver biopsy showed greater areas under the curve for the fibrosis indices, with NFS and HFS offering greater diagnostic accuracy (area > 0.8, p < 0.05). HFS also offers high diagnostic sensitivity in the diabetic population.

Non-invasive indices of steatosis are more sensitive and those of fibrosis more specific than liver biopsy. NFS and HFS offer the highest diagnostic accuracy, with HFS having the highest negative predictive value.