Effects of Insulin Glargine and Liraglutide Therapy on Liver Fat as Measured by Magnetic Resonance in Patients With Type 2 Diabetes: A Randomized Trial

OBJECTIVEThis study determined the effects of insulin versus liraglutide therapy on liver fat in patients with type 2 diabetes inadequately controlled with oral agents therapy, including metformin.RESEARCH DESIGN AND METHODSThirty-five patients with type 2 diabetes inadequately controlled on metformin monotherapy or in combination with other oral antidiabetic medications were randomized to receive insulin glargine or liraglutide therapy for 12 weeks. The liver proton density fat fraction (PDFF) was measured by MRS. The mean liver PDFF, the total liver volume, and the total liver fat index were measured by MRI. The Student t test, the Fisher exact test, and repeated-measures ANOVA were used for statistical analysis.RESULTSInsulin treatment was associated with a significant improvement in glycated hemoglobin (7.9% to 7.2% [62.5 to 55.2 mmol/mol], P = 0.005), a trend toward a decrease in MRS-PDFF (12.6% to 9.9%, P = 0.06), and a significant decrease in liver mean MRI-PDFF (13.8% to 10.6%, P = 0.005), liver volume (2,010.6 to 1,858.7 mL, P = 0.01), and the total liver fat index (304.4 vs. 209.3 % mL, P = 0.01). Liraglutide treatment was also associated with a significant improvement in glycated hemoglobin (7.6% to 6.7% [59.8 to 50.2 mmol/mol], P < 0.001) but did not change MRS-PDFF (P = 0.80), liver mean MRI-PDFF (P = 0.15), liver volume (P = 0.30), or the total liver fat index (P = 0.39).CONCLUSIONSThe administration of insulin glargine therapy reduced the liver fat burden in patients with type 2 diabetes. However, the improvements in the liver fat fraction and glycemia control were not significantly different from those in the liraglutide group.