Prevalence and Correlates of Probable Nonalcoholic Steatohepatitis (NASH) in Pars Cohort Study.

Background: Studies on the prevalence of nonalcoholic steatohepatitis (NASH) and the factors associated with its high prevalence among Iranian people are limited. This study evaluated the prevalence of NASH and its associated factors among Iranian adults using Pars Cohort Study (PCS) data.

Methods: This cross-sectional study was conducted based on PCS, which includes 40-75-year-old adults from the Valashahr area. NASH was defined as alanine aminotransferase (ALT) higher than 40 U/L without evidence of hepatitis B or C infections. The prevalence of NASH and its associations with basic and demographic characteristics, socioeconomic characteristics, medical history, gastrointestinal symptoms, and laboratory tests were evaluated.

Results: Overall, 8734 patients, including 3917 men (44.8%), were enrolled in this study. The mean age of participants was 52.62 years (SD=9.68), and 605 individuals had NASH (6.9%). In the regression analysis, in contrast to female gender (OR=0.31, 95% CI=0.249‒0.386, P<0.001) and age (OR=0.951, 95% CI=0.941‒0.962, P<0.001), history of heart disease (OR=1.499, 95% CI=1.146‒1.962, P=0.003), history of diabetes (OR=1.523, 95% CI=1.162‒1.995, P=0.002), hypertension (OR=1.241, 95% CI=1.023‒1.506, P=0.029), being overweight or obese (OR=2.192, 95% CI=1.755‒2.737, P<0.001), being in the richest or second richest wealth index quantiles (OR=1.315, 95% CI=1.107‒1.156, P=0.002), and increased waist circumference (OR=1.409, 95% CI=1.107‒1.793, P<0.005) were independently associated with a higher risk of having NASH.

Conclusion: In this study, we determined the prevalence of NASH and found male gender, younger age, history of heart disease, history of diabetes, hypertension, socioeconomic status, and obesity as possible factors associated with a higher risk of NASH among Iranians.