Nonalcoholic Fatty Liver in Lean Individuals: Clinicobiochemical Correlates of Histopathology in 157 Liver Biopsies from Healthy Liver Donors

Abstract

Generally diagnosis of non-alcoholic fatty disease is made on imaging, however, mild steatosis is difficult to diagnose on imaging. Liver biopsy is the procedure of choice but is not carried out as it is an invasive procedure. We describe our experience of 157 liver biopsies in living liver donors with normal body mass index (BMI) <23kg/M2 (lean). The study was conducted at a tertiary care center in north India. Data of lean living donors who underwent a liver biopsy before donation were analyzed. Data are presented as percentage, mean, or median (25-75 interquartile range). Of 718 donors who had a liver biopsy before donation, 157 (21.8%) donors were lean (BMI<23kg/M2). Seventy-eight percent of lean donors had no or only one metabolic risk factor. Fifty-three (33.7%) of lean donors had nonalcoholic fatty liver (NAFL) in liver biopsy. When donors with NAFL were compared to donors with normal histology, donors with NAFL had significantly higher aspartate transaminase (26.6±7.5 versus 23.7±5.4, p=0.007), alanine transaminase (33.4±11.7 versus 27.8±10.7, p=0.003), and gamma glutamyl transpeptidase [25 (16-40.5) versus 18 (14-23), p=0.003]. Only triglycerides (TGs) were statistically different among metabolic factors in lean NAFL and normal histology groups, 97 (70-161) versus 86 (62.5-114.7), p=0.043. A total of 30% donors in the lean NAFL group had TGs >150mg/dl as compared with 12.5% in the normal histology group, p=0.009. Other metabolic risk factors were not statistically different. One third of lean donors had NAFL. Among all metabolic risk factors, only higher TGs levels showed a significant association with NAFL.