Cushing's Syndrome is a rare disease resulting from prolonged exposure to high levels of circulating cortisol. Clinical manifestations are variable but many patients present a metabolic syndrome (abdominal obesity, insulin resistance, dyslipidemia, hypertension). With regard to the liver, experimental data have shown that excess cortisol leads in an increase in lipogenesis and a reduction in the oxidation of fatty acids. This, in association with an accumulation of visceral adipose tissue and deregulation of adipokines, may contribute to the development of hepatic steatosis in animals. However, few data is available in humans with only one study of 50 patients with Cushing's syndrome estimating the prevalence of hepatic steatosis at 20%.
NAFLD (Non-Alcoholic Fatty Liver Disease), is defined as the presence of hepatic steatosis in the absence of secondary causes of intrahepatic fat accumulation. It is a heterogeneous disease ranging from simple liver steatosis, whose prognosis is generally considered to be benign, to inflammation (NASH, Non-Alcoholic Steato-Hepatitis) which may progress to fibrosis, cirrhosis and an increased risk of hepatocellular carcinoma. The prognosis for NAFLD is mainly related to the severity of hepatic fibrosis.
In Cushing's syndrome, normalization of cortisol production is the most effective strategy to improve co-morbidities associated with hypercortisolism. However, some of these complications, especially the metabolic co morbidities, could not be completely reversible and no data is available about resolution of hepatic steatosis.