Touching some firm ground in the epidemiology of NASH.

Anyone trying to understand the burden of disease of NAFLD in our societies might feel like they are trapped in a labyrinth, under a dim light. A labyrinth, because there are many ways to look for NAFLD and not just one straightforward diagnostic method. Under a dim light, because all these imperfect procedures and tests do not allow us to see far enough, given their limited sensitivity and specificity. Yet, for all these uncertainties, the sense of facing a real problem is overwhelmingly present. Just as it should be when you are trapped in a labyrinth. Because of the absence of a simple and readily available marker of NAFLD, data from the general population has been slow to emerge. The report from Armstrong et al. in this issue of the Journal of Hepatology is therefore an important addition to the literature. The authors studied NAFLD in the setting of a large, primary care practice in the UK. This is a step closer to the general population although not yet as close as screening for NAFLD in factory workers [1] or through City Hall records [2]. The overall design was to identify individuals with increased liver function tests, but without a past history of liver disease, known alcohol-related health problems, past or present intravenous drug use or current symptoms of liver disease. Increased LFTs were therefore diagnosed in asymptomatic individuals with a low risk of liver disease. But this does not mean that those individuals were otherwise healthy. Most of them had chronic health problems which actually prompted testing for LFTs. In fact 40% of participating individuals were obese, 43% had arterial hypertension, and 24% had type 2 diabetes (Table 2), all conditions epidemiologically associated with NAFLD. While this is far from the endof-spectrum seen in tertiary referral centers, it still concerns a population enriched with risk factors for NAFLD, albeit less so than reports from specialized academic centers. With these entry criteria, 1118 individuals were included. The strength of the study is that almost all of them underwent a thorough work-up including ultrasound and specialized hepatological tests, to diagnose the underlying liver disease. The results come as a surprise to anyone that first learnedwhat causes liver disease, a bare 20 years ago. In today’s clinical landscape, 26% of these cases are related to NAFLD, 25% to alcohol consumption, and 45% have no clear cause, while all classical causes of