Applying the new ALT upper limit of normal (≤19 U/L) reduced the proportion of obese women with normal ALT from 72.5% to 36.9%, but diagnostic utility for NASH remained poor.
Cross-Sectional (n=233)
Does the proposed new normal range for serum ALT (≤19 U/L) improve the diagnostic utility for NAFLD and NASH in women with class II/III obesity compared to the old standard (≤30 U/L)?
Lowering the upper limit of normal for ALT to 19 U/L in obese women increases the detection of fatty liver but has poor diagnostic utility for identifying NASH, potentially leading to unnecessary healthcare expenditures.
Absolute Event Rate: 36.9% vs 72.5%
The upper limit of normal for ALT activity has been recommended to be lowered to 19 U/L) demonstrated an increased prevalence of FL (36%) and IPF (11.6%) but a 23.8% decrease in the prevalence of NASH as compared with the old standard. The sensitivity and specificity for NASH were 42% and 80% (ALT > 30 U/L) compared with 74% and 42% (ALT > 19 U/L). In conclusion, a significant increase in the prevalence of FL and IPF is detected in subjects with elevated ALT levels with the application of the new standard. However, the diagnostic utility for ALT to identify NASH or IPF remains poor, and significant healthcare expenditures may be incurred if this standard is adopted.
Kunde et al. (2005) conducted a cross-sectional in Nonalcoholic fatty liver disease (NAFLD) (n=233). New ALT standard (ULN ≤ 19 U/L) vs. Old ALT standard (ULN ≤ 30 U/L) was evaluated on Proportion of patients classified as having normal ALT levels. Applying the new ALT upper limit of normal (≤19 U/L) reduced the proportion of obese women with normal ALT from 72.5% to 36.9%, but diagnostic utility for NASH remained poor.