Statins and Abnormal Liver Function Tests: Is There a Correlation?

Background Statins or 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors are one of the most commonly prescribed medications in cardiac patients. Just like any other class of drugs, they have the potential to cause liver injury over time even with judicious use. This drug-induced liver injury (DILI) can be either direct (hepatocellular) or idiosyncratic. As with multiple other hepatic pathologies, DILI may be asymptomatic or clinically silent. Therefore, it is prudent to carry out liver function tests (LFTs) from time to time. LFTs are an inexpensive, noninvasive, and quick first-line investigation to monitor liver status. However, the pattern of liver injury with statin use is not specific and a correlation over time may not be apparent. Aims To evaluate derangement in LFTs over time with respect to statin use and determine if a correlation exists. Methods This was a retrospective observational cohort. All data were collected from the online database of the National Institute of Cardiovascular Diseases (NICVD), Karachi. Patients admitted to the NICVD from July 1, 2018, to December 31, 2018, were eligible for inclusion in the study. Only patients already taking a statin (in any dose) were considered for inclusion. LFTs were recorded from the database at inclusion, post-induction at six and 12 months. Extensive workup was done and great care taken to rule out other diseases that may have affected the LFTs. Results Two hundred and four patients were eventually inducted into the study after a meticulous exclusion process. The male to female ratio was 4:1. The mean duration of statin use before induction into the study was 19.92±14.34 months. Patients were predominantly using only one of two statins, i.e., rosuvastatin 20mg/day or atorvastatin 40 mg/day. Elevations of LFTs were seen with both drugs throughout the study period. These elevations were almost always <2x the upper limit of normal (ULN); greater elevations were seen with atorvastatin 40 mg/day. The derangement in LFTs persisted and improvement was not seen. Conclusions Statins cause dose-dependent borderline elevations of liver function tests over time. These elevations are clinically and statistically insignificant and should not deter physicians from prescribing or continuing statins.