Patients with NAFLD have more visceral fat, reduced muscle mass

Issue: December 2012

BOSTON — Nonalcoholic fatty liver disease is associated with greater visceral fat and diminished muscle mass and correlates directly with severe illness, according to data presented at The Liver Meeting.

Researchers used computed tomography (CT) and dual energy X-ray absorptiometry (DEXA) to evaluate the lean body and fat mass of 38 patients. They compared DEXA measurements of fat and lean mass between 61 patients with nonalcoholic steatohepatitis (NASH) and 19 patients with steatosis. The psoas muscle area and visceral fat mass of healthy controls (n=57) also was compared with that of 74 patients with nonalcoholic fatty liver disease (NAFLD), including 19 with steatosis, 42 with NASH and 13 with cirrhosis.

“Increased visceral fat mass is nearly universal in nonalcoholic fatty liver disease,” the researchers wrote. “Loss of muscle mass has been recognized in states of insulin resistance. Since the severity of NAFLD correlates with that of insulin resistance, we hypothesized that skeletal muscle loss occurs in NAFLD and correlates with the histological severity of disease.”

DEXA-measured axial muscle mass and whole body lean and whole body fat mass correlated with CT measurements of psoas muscle area and visceral fat mass (P<.001), as did visceral fat mass measured by CT and trunk and whole body fat measured by DEXA.

Patients with NAFLD had significantly higher whole body and trunk fat compared with controls. Both trunk (18.1 ± 6.7 kg among NASH patients compared with 20.8 ± 6.2 kg for steatosis) and whole body fat (35.4 ± 2.3 kg compared with 43.8 ± 7.0 kg) were greater among patients with NASH than those with steatosis (P<.05 for both comparisons). Investigators observed no significant difference between patients with NASH or steatosis in limb, trunk or whole lean body mass.

Psoas muscle area was greater in controls and patients with steatosis than in patients with NASH and those with cirrhosis (29.4 ± 7.5 cm2, controls; 30.4 ± 9.9 cm2, steatosis vs. 26.5 ± 8.5 cm2, NASH; 22.2 ± 6.4 cm2, cirrhosis). Researchers noted an inverse correlation between psoas muscle area and lobular inflammation and fibrosis. Controls and cirrhotic patients had less visceral fat mass (57.8 ± 7.4 mm3, controls; 61.5 ± 6.4 mm3,cirrhosis) than those with NASH (75.6 ± 8.4 mm3) or steatosis (72.8 ± 4.2 mm3).

“With the skeletal muscle loss that we have demonstrated in steatosis and NASH subjects, we think that this is a possibility for a new target of intervention in patients with NAFLD,” researcher Cynthia Tsien, MD, clinical associate at University of Toronto, told Healio.com. “If we can reduce the loss of muscle mass in these patients, we can possibly improve insulin resistance and halt the progression of the worsening of NAFLD from steatosis to NASH to cirrhosis.”

Disclosure: Researcher Arthur J. McCullough reports serving on advisory committees and/or review panels for Amylin, Norgine and Merck.

For more information:

Tsien C. #1466: Severity of non-alcoholic fatty liver disease related to reduced skeletal muscle mass. Presented at: The Liver Meeting 2012; Nov. 9-13, Boston.