Hepatic steatosis index in acromegaly: Correlation with insulin resistance regardless of the disease control

Abstract

Objective. In acromegaly, both lipotoxicity secondary to GH excess and insulin resistance have a significant impact on the liver. Ultrasonography has shown poor sensitivity in detecting hepatic steatosis and noninvasive methods have been proposed. We evaluated the hepatic steatosis index (HSI), a validated surrogate index of hepatic steatosis, and we correlated it with disease activity and insulin resistance. Design. Thirty-one patients with newly diagnosed acromegaly were studied at diagnosis and after 12 months of treatment with somatostatin receptor ligands. Methods. Glucose and insulin levels, surrogate estimates of insulin sensitivity, and hepatic steatosis through ultrasonography and HSI were evaluated. Results. At diagnosis, ultrasonography documented steatosis in 19 patients (61.2%) while 26 (83.8%) showed high HSI. After 12 months, both GH (p = 0 033) and IGF-1 (p < 0 001) significantly decreased and, overall, 58% of patients were classified as controlled. Ultrasonography documented steatosis in all the same initial 19 patients, while only 14 patients (45.1%) showed high HSI (p < 0 001). A significant reduction in HOMA-IR (p = 0 002) and HSI (p < 0 001) and increased ISI Matsuda (p < 0 001), was documented. The change of HSI from baseline to 12 months was found to be directly correlated with the change of ISI (Rho -0.611; p = 0 004) while no correlation was found with the change of GH or IGF-1 levels and other parameters. Conclusions. In acromegaly, HSI is mainly related with insulin resistance and the reduction of GH and IGF-1 levels, and above all the improvement in insulin sensitivity leads to an improvement of this surrogate index of hepatic steatosis.