non-alcoholic fatty liver disease is the most common cause of abnormal liver chemistries throughout the world, with purported incidence of 15-40% (16% in the recent NHANES3 data), often associated with obesity, metabolic syndrome, diabetes, dyslipidemia. we certainly see more NAFLD in patients with increased ALT than hepatitis C at the health center, which is also quite common. recent article found that weight loss was associated with reversal of NAFLD (see http://dx.doi.org/10.1016/j.jhep.2013.04.013#sthash.DTEHzjif.dpuf). in brief:
–154 pts with NAFLD in community-based study in Hong Kong identified by increased ALT (median 43) and negative viral serologies/ANA, randomized to diet (dietician-led individual education weekly x 4 months, then monthly for 8 months, focusing on exercise and reducing calorie intake) vs control, assessing intrahepatic triglyceride content (IHTG) by proton-magnetic resonance spectroscopy at start and end of study (following ALT levels is a less reliable indicator of NAFLD activity). primary outcome was remission of NAFLD, as evidenced by IHTG <5% (average initial IHTG was 12%, overall a group with pretty mild NAFLD). average BMI = 25.
–results: NAFLD remitted in 64% of patients in intervention group vs 20% of controls. body weight dec 5.6 vs 0.6 kg, but of those who lost >10% of body weight, 97% had remission of NAFLD. 41% of those with wt loss of 3-5% also achieved remission. of parameters assessed, only weight reduction significantly correlated with NAFLD remission. intervention group also had decreased in ALT and LDL-cholesterol
so, NAFLD is very common, recent studies have suggested that the long-term outcome is pretty much the same as with hepatitis C infection in terms of progression to cirrhosis/hepatoma, but in this community-based study there was significant remission with aggressive weight loss. one caveat is that though it seems that IHTG is a more reliable indicator of NAFLD than ALT, it does not reveal important histologic data (eg necroinflammation) which can only be assessed by biopsy and seems to be more associated with adverse hepatic outcomes. this study was done in hong kong, so although the average BMI was not so high compared to our standards, asian people tend to have more metabolic syndrome at lower waist circumference/BMI than westerners. but, the bottom line in this community-based study is that diet/exercise really seems to lead to remission of NAFLD in large % of people who are successful with weight loss, in a dose response relationship.