Effects of HRT on liver enzyme levels in women with type 2 diabetes: a randomized placebo-controlled trial.

Background: Increasingly strong links are being recognized between diabetes, insulin resistance and liver fat accumulation [e.g. nonalcoholic fatty liver disease (NAFLD)]. Recent data indicating that hormone replacement therapy (HRT) may lessen diabetes risk is intriguing but explanatory mechanisms are unclear.

Objective: Post hoc investigation of the possibility that HRT may favourably influence liver enzyme levels commonly elevated in patients with diabetes. We examined liver function test data from a 6-month trial of a low-dose continuous combined HRT (1 mg 17beta oestradiol and 0.5 mg norethisterone acetate).

Design: Double-blind, randomized placebo-controlled.

Patients: Fifty women with type 2 diabetes.

Measurements: Liver enzyme levels (AST, ALT, gamma-glutamylytransferase [GGT], and alkaline phosphatase [ALP]).

Results: Forty-five women completed the study with 19/22 in the active group demonstrating compliance as measured by sex hormone changes. Relative to placebo recipients (n = 23), women randomized and compliant to HRT demonstrated significant reductions in ALT [-14 (-23 to -6) U/l, P = 0.002], AST [-9.2 (-14 to -5) U/l, P < 0.001] and ALP [-60.8 (-80 to -42) U/l, P < 0.001]. Circulating concentrations in GGT were also significantly reduced (P = 0.035). All changes were significant using an intention-to-treat analysis.

Conclusion: HRT containing low-dose oestradiol and norethisterone reduces serum concentrations of liver function enzymes, potentially due to a lowering of liver fat accumulation. Better understanding of mechanisms by which this HRT improves liver function tests could help the design of new therapies to treat individuals with NAFLD.