Wednesday, September 26, 2012

Routinely analyzed parameters may indicate NASH, fibrosis in obese patients

Routinely analyzed parameters may indicate NASH, fibrosis in obese patients

Francque SMA. Clin Gastroenterol Hepatol. 2012;10:1162-1168.
  • September 26, 2012
A scoring system incorporating routine parameters determined the presence and severity of nonalcoholic steatohepatitis and fibrosis in obese patients more accurately than published systems in a recent study.

Researchers performed liver-related tests on 542 overweight or obese patients, including blood analysis, ultrasound, and genetic and aminopyrine breath tests. Liver biopsy was performed on 313 patients within the cohort who showed signs of potential nonalcoholic fatty liver disease (NAFLD). The participants who received biopsies were randomly assigned to design (n=200) and validation cohorts (n=113). Investigators created scoring systems to predict the presence and severity of fibrosis and NAFLD and compared their accuracy to that of various existing systems, including NAFLD liver fat score, FLI, APRI and BARD score.

Nonalcoholic steatohepatitis (NASH) was present in 52.1% of patients, and significant fibrosis was detected in 19.5%. ALT levels greater than 40 U/L, ultrasound steatosis scores and elevated fasting C-peptide levels were associated with NASH. A score designed to diagnose NASH according to these factors was more accurate than all other evaluated systems according to ROC analysis (AUROC=0.854 in the design group and 0.823 in the validation group).

Correlations were observed between NASH severity and these three factors, and researchers also developed a score incorporating them to determine NASH severity, with an R2 of 0.491. Investigators noted correlations between NASH and CK18 and PNPLA3 polymorphism levels, but incorporating these factors did not improve diagnostic accuracy.

Waist circumference and fasting C-peptide and AST levels were predictive of advanced fibrosis in both groups. The scoring system incorporating these factors was found more accurate than other evaluated systems, with an AUROC of 0.811 in the design group and 0.788 in the validation group for the detection of significant fibrosis (R2=0.352 for score).

“We could design and validate scoring systems for NASH and fibrosis on the basis of routine parameters,” the researchers wrote. “Ultrasound significantly adds to the diagnostic accuracy for NASH diagnosis, whereas genetic testing and nonroutine biological tests do not have an added value. Published scores are significantly less accurate. … [However], even our score has a rather unsatisfactory overall accuracy for the diagnosis of fibrosis. … We propose to use the score to exclude the presence of advanced fibrosis. If the score does not exclude advanced fibrosis, a liver biopsy is still necessary to reliably assess liver fibrosis.”

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