Background: Hyperinsulinemia has been associated with hepatic fat deposition and ensuing insulin resistance. It is unknown if treatment with exogenous insulin in patients with type 2 diabetes, who are most prone to hepatic fat accumulation, would promote the occurrence or worsening of nonalcoholic fatty liver disease.
Methods: Patients with treatment-naive type 2 diabetes (N = 16) were treated with insulin and metformin for a 3-month lead-in period, then assigned triple oral therapy (metformin, glyburide, and pioglitazone) or continued treatment with insulin and metformin. Hepatic triglyceride content (HTC)—measured by magnetic resonance spectroscopy, serum lipids, glucose, liver function tests, and inflammatory and thrombotic biomarkers were followed for a median of 31 months.
Results: The 45% decline in HTC during the lead-in period persisted through the follow-up period with no difference between treatment groups at the end of the study (5.26 ± 4.21% in the triple oral therapy vs 7.47 ± 7.40% for insulin/metformin), whereas glycemic control was comparable.
Conclusions: Improvements in HTC with initial insulin/metformin therapy persisted through the median 31-month follow-up period regardless of the treatment. More importantly, insulin-based treatment did not appear to promote or worsen nonalcoholic fatty liver disease.