The latest article in our Current Concepts series, Risk of Cardiovascular Disease in Patients with Nonalcoholic Fatty Liver Disease, comes from Drs. Giovanni Targher and Enzo Bonora from the University of Verona, and Dr. Christopher Day from Newcastle University.
Approximately 20 to 30% of adults in the general population in Western countries have nonalcoholic fatty liver disease, and its prevalence increases to 70 to 90% among persons who are obese or have diabetes.
• Is nonalcoholic fatty liver disease associated with cardiovascular disease as a consequence of the shared risk factors?
Patients with nonalcoholic fatty liver disease, both adults and children, typically meet the diagnostic criteria for the metabolic syndrome (i.e., abdominal obesity, hypertension, atherogenic dyslipidemia, and dysglycemia) and therefore have multiple risk factors for cardiovascular disease. The close correlations among nonalcoholic fatty liver disease, abdominal obesity, and insulin resistance make it extremely difficult to distinguish the precise causal relationships underlying the increased risk of cardiovascular disease among patients with nonalcoholic fatty liver disease.
• What is the evidence that nonalcoholic fatty liver disease contributes directly to increased cardiovascular risk?
Nonalcoholic fatty liver disease — especially its necroinflammatory variant, nonalcoholic steatohepatitis — not only is a marker of cardiovascular disease but also may be involved in its pathogenesis. This might occur through the systemic release of proatherogenic mediators from the steatotic or inflamed liver as well as through the contribution of nonalcoholic fatty liver disease itself to insulin resistance and atherogenic dyslipidemia, which are important risk factors for cardiovascular disease.
Morning Report Questions
Q: What is the leading cause of death among patients with nonalcoholic fatty liver disease?
A: Growing evidence suggests that cardiovascular disease is the leading cause of death in patients with advanced nonalcoholic fatty liver disease.
Q: How should patients with nonalcoholic fatty liver disease be managed?
A: Current recommendations are limited to weight reduction by means of diet and exercise and to the treatment of individual components of the metabolic syndrome with the use of therapies that may have beneficial hepatic effects, including bariatric surgery for obesity, insulin sensitizers (metformin and thiazolidinediones ) for type 2 diabetes, and drugs directed at the renin-angiotensin-aldosterone system to control hypertension.
Figure 2. Possible Mechanisms Leading to Cardiovascular Disease in Patients with Nonalcoholic Fatty Liver Disease.