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 17 beta 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.