Association of non-alcoholic fatty liver disease with coronary artery calcification progression: a systematic review and meta-analysis

Introduction
Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, which is estimated to affect 20–30% of the adult population in Europe. Several studies have shown an association of NAFLD with multiple cardiovascular risk factors such as abdominal obesity, atherogenic dyslipidaemia, hypertension, insulin resistance, and impaired glucose tolerance. Atherosclerosis is a chronic, progressive, inflammatory disease, which begins early in life and follows a long asymptomatic phase. Coronary artery calcification (CAC) is the radiological confirmation of the presence of atherosclerotic coronary artery disease. The predictive value of CAC for future cardiac events is well established. Also, the progression of CAC is strongly associated with the development of cardiovascular events.
Aim: To assess the association of NAFLD with the progression of subclinical atherosclerotic activity, reflected as the dynamic changes in CAC score over time.

Material and methods
The databases PubMed/Medline/Embase from inception until 31 December 2020 were searched for observational studies investigating NAFLD and CAC progression in adults.

Results
In total, 5 studies were included, 4 of which, including 10,060 patients, provided data regarding the association of NAFLD with the progression of CAC. The analysis showed that NAFLD is associated with significant odds of progression of CAC; OR = 1.5, 95% CI: 1.34–1.68, p = 0.001. No publication bias was detected (Egger’s test p = 0.6). Meta-regression analyses proved that OR toward CAC progression is not significantly influenced by the time of follow-up (coefficient = 0.0083, Z = 1.14, p = 0.25).

Conclusions
NAFLD increases the risk toward CAC progression over time.