Liver and pancreas: 'Castor and Pollux' regarding the relationship between hepatic steatosis and pancreas exocrine insufficiency.

Background: Pancreatic exocrine insufficiency (PEI) is found in 30-50% of diabetes mellitus (DM). Insulin resistance is triggering factor in both DM and nonalcoholic fatty liver disease (NAFLD). Therefore, we aimed to investigate frequency of PEI in NAFLD, and relationship of fecal pancreatic elastase (PE) levels with liver histology and pancreatic fat.

Methods: Ninety-seven biopsy proven NAFLD patients and 50 controls were enrolled. Pancreas exocrine functions were measured by PE. Magnetic resonance imaging-estimated proton density fat fraction (MRI-PDFF) was used to quantify fat.

Results: NAFLD patients had significantly lower PE levels than controls (297 [204-517] vs. 500 [298-678] μg/g, p < 0.01). PEI (PE < 200 μg/g) ratio of NAFLD patients (22.7%, n = 22) was higher than PEI ratio of controls (6%, n = 3) (p = 0.011). Among diabetic (n = 35) NAFLD patients, 9 (25.7%) exhibited PEI, compared to 13 (21%) of non-diabetics. There was no significant difference in patients with and without DM in terms of PEI (p = 0.592). Among NASH (n = 68) patients 16 (23.5%) exhibited PEI, compared to (20.7%) of non-NASH (p = 0.76). Multiple analysis revealed NAFLD as a predictor of PEI independent of age, sex and DM (OR = 4.892, p = 0,021). Mean pancreas MRI-PDFF was significantly higher in diabetics (13.7% ± 3.6% vs. 8.7% ± 5.1%, p = 0.001). There was no significant pancreas MRI-PDFF difference between NASH and non-NASH (P = 0.95). Mean pancreas MRI-PDFF was significantly higher in patients with PEI (13.7% ± 3.4% vs. 8.9% ± 5.2%, P < 0.01).

Conclusion: This is the first study demonstrating the high frequency of PEI in NAFLD independent of DM. Moreover, increasing pancreatic steatosis appears to be associated with higher frequency of PEI in NAFLD.