Treatment of Non-alcoholic Fatty Liver Disease – Impact on Cardiovascular Disease?
Currently there is no approved pharmacological treatment for NAFLD.12 Metformin and statins do not seem to improve liver histology, at least not in terms of fibrosis.98 Glitazones have a beneficial effect, as well as vitamin E, but not in all patients.99–102 Lifestyle modification (diet and increased physical activity), if successful, improves NAFLD and also Roux-en-Y gastric bypass surgery ameliorates liver histology.11,12,103,104 Although it can be hypothesized that improving NAFLD reduces the risk of CVD, there is currently little data on potential changes in the risk of CVD in relation to the success of NAFLD treatment. Interestingly, two recent studies on the effects of statins on CV events demonstrated a significantly more reduced CV event rate on statin treatment in patients with baseline elevation of liver tests (used as a surrogate marker for the presence of NAFLD), in relation to a significant improvement of liver tests in one study.105,106 The cardioprotective effect of statins was less pronounced in patients with normal liver tests at baseline. Glitazones also improve CV risk, but it is unclear to what extent this can be attributed to their beneficial effect on NAFLD.107–109 Furthermore, as outlined before, it is not clear whether the risk of CVD is increased in all subtypes of NAFLD. Therefore, no evidence-based recommendations can be formulated at present.
Nevertheless, it can be recommended to screen for NAFLD in every patient with risk factors for CVD or with established CVD, as well as to screen for CVD in every patient with NAFLD, and to treat accordingly with lifestyle modification. This recommendation is debated, as there are no data on cost-effectiveness and no pharmacological treatment when NAFLD is diagnosed.12 Metformin is frequently used, as it seems to have beneficial effects on CV risk,110–112 although also debated,113 in patients with insulin resistance. However, as outlined previously, metformin failed to show beneficial effects on liver histology.2,98 Other metabolic factors should be treated according to the corresponding guidelines.