AIM:To characterize the histopathologic specifications of non-alcoholic steatohepatitis(NASH)according to age and gender.METHODS:An analytical cross-sectional study was conducted in two private gastroenterology clinics on biopsy proven patients suffering from NASH.Biopsy histopathologic findings as well as demographic and laboratory data of the patients at the time of biopsy were gathered retrospectively from clinical records.The grading and staging of histopathologic findings were performed according to the Brunt method after reevaluation of the slides by a pathologist.Patients were divided into two groups according to age(belowand above 55 years).Mean quantitative grade of all pathologic findings were also calculated according to Brunt scoring values.RESULTS:A total number of 77 NASH patients,consisting of 58 males(75.3%)and 19(24.7%)females with a mean age of 41.99±11.80 years(range,18-70 years),were enrolled.The mean age(48.72±13.99 years vs 39.74±10.16 years,P=0.004)and aspartate aminotransferase level(75.11±29.68 U/L vs 52.78± 25.00 U/L,P=0.002)was significantly higher in female patients.Mean quantitative grade of hepatosteatosis was significantly higher in females(2.00±0.82 vs 1.59 ±0.68,P=0.031)compared to males.Fifty four percent(34/65)of young patients had mild hepatosteatosis (GradeⅠ)while only one patient(11.2%)in the older group had gradeⅠhepatosteatosis.Patients aged≥55 had significantly more severe hepatosteatosis(GradeⅢ) (44.4%vs 9.5%,P=0.007)and the mean quantitative grade of hepatosteatosis was significantly higher among them(2.33±0.71 vs 1.56±0.67,P=0.002).Multivariate analysis after omitting the confounding role of age revealed a higher grade of hepatosteatosis in female patients(P=0.010).CONCLUSION:These findings point toward the possible influence of age in the severity of steatohepatitis,portal and lobar inflammation in patients suffering from NASH while gender independently might contribute to the level of steatohepatitis. AIM: To characterize the histopathologic specifications of non-alcoholic steatohepatitis (NASH) according to age and gender. METHODS: An analytical cross-sectional study was conducted in two private gastroenterology clinics on biopsy proven patients suffering from NASH. Biopsy histopathologic findings as well as demographic and laboratory data of the patients at the time of biopsy were gathered retrospectively from clinical records. The grading and staging of histopathologic findings were performed according to the Brunt method after reevaluation of the slides by a pathologist. Patients were divided into two groups according to age below or above 55 years .Mean quantitative grade of all pathologic findings were also calculated according to Brunt scoring values. RESULTS: A total number of 77 NASH patients, consisting of 58 males (75.3%) and 19 (24.7%) females with a mean age of 41.99 ± 11.80 years (range, 18-70 years), were enrolled. The mean age (48.72 ± 13.99 years vs 39.74 ± 10.16 years, P = 0.004) and asparta te aminotransferase level (75.11 ± 29.68 U / L vs. 52.78 ± 25.00 U / L, P = 0.002) was significantly higher in female patients. Mean quantitative grade of hepatosteatosis was significantly higher in females (2.00 ± 0.82 vs 1.59 ± 0.68, P = 0.031) compared to males. Fifty four percent (34/65) of young patients had mild hepatosteatosis (Grade I) while only one patient (11.2%) in the older group had grade I hepatosteatosis. Patient aged> 55 had significantly more severe severe hepatosteatosis (Grade III) (44.4% vs 9.5%, P = 0.007) and the mean quantitative grade of hepatosteatosis was significantly higher among them (2.33 ± 0.71 vs 1.56 ± 0.67, P = 0.002) .Multivariate analysis after omitting the confounding role of aged revealed a higher grade of hepatosteatosis in female patients (P = 0.010). CONCLUSION: These findings point toward the possible influence of age in the severity of steatohepatitis, portal and lobar inflammation in patients suffering from NASH while gender independently might contribute to the level of steatohepatitis.