Re: Non-alcoholic fatty liver disease and risk of incident acute myocardial infarction and stroke: findings from matched cohort study of 18 million European adults
Dr Alexander and colleagues  reported non-alcoholic fatty liver disease and risk of incident acute myocardial infarction and stroke. We think the conclusion of this original manuscript is new. However, there are some points to discuss about this paper.
Firstly, baseline characteristics of patients need to be expanded. We think statin administration should be included. The authors have collected statin use information. However, we do not find that statin use was calculated in the statistics. Indeed,the New England Journal of Medicine also stresses lipid management for the prevention of atherosclerotic cardiovascular disease (including AMI and stroke) .
Secondly, compared with previous studies, the authors have analyzed fewer risk factors. We think the authors should extract as many risk factors as possible. We wonder why the authors have extracted fewer risk factors than previous studies .
Thirdly, we think it should be clarified how to make a match. It is very important. However, we cannot find how they performed the match. We think it should be clarified in detail.
Finally, in this passage,
“In the four databases we identified people with a diagnosis of NAFLD (including non-alcoholic steatohepatitis (NASH)) before 1 January 2016. Owing to differences in coding terminology, recording of NASH diagnoses as distinct from NAFLD diagnoses was only possible in Spain (SIDIAP) and the UK (THIN). In the main analyses in these databases, people with NAFLD and NASH were grouped together, as was also the case in IPCI and HSD owing to the coding (ICPC Dutch codes and ICD-9 do not have distinctive codes for NAFLD and NASH). We carried out sensitivity analyses in SIDIAP and THIN excluding participants with NASH.”
the authors have performed sensitivity analysis in SIDIAP and THIN, and they excluded NASH. However, we have to remember that there were participants with NASH in IPCI and HSD. Therefore, we think it is not important to perform sensitivity analyses in SIDIAP and THIN.
1 Alexander M, Loomis AK, van der Lei J, Duarte-Salles T, Prieto-Alhambra D, Ansell D, Pasqua A, Lapi F, Rijnbeek P, Mosseveld M, Avillach P, Egger P, Dhalwani NN, Kendrick S, Celis-Morales C, Waterworth DM, Alazawi W, Sattar N.Non-alcoholic fatty liver disease and risk of incident acute myocardial infarction and stroke: findings from matched cohort study of 18 million European adults.BMJ. 2019 Oct 8;367:l5367. doi: 10.1136/bmj.l5367.
2 Michos ED, McEvoy JW, Blumenthal RS.Lipid Management for the Prevention of Atherosclerotic Cardiovascular Disease.N Engl J Med. 2019 Oct 17;381(16):1557-1567. doi: 10.1056/NEJMra1806939.
3 Bhatia LS, Curzen NP, Calder PC, Byrne CD.Non-alcoholic fatty liver disease: a new and important cardiovascular risk factor?Eur Heart J. 2012 May;33(10):1190-200. doi: 10.1093/eurheartj/ehr453.
Competing interests: No competing interests