The impact of non-alcoholic fatty liver disease and metabolic syndrome on the progression of coronary artery calcification.

It is unclear whether non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for cardiovascular disease. We examined the independent impact of NAFLD on the progression of the coronary artery calcification (CAC) score, a well-known marker of atherosclerosis progression. We examined 1,173 asymptomatic participants who underwent repeated CAC score measurement during routine health examinations. The subjects were categorised into four groups based on the presence (+) or absence (-) of NAFLD and metabolic syndrome (MetS). The progression of CAC score was defined as either incident CAC in a CAC-free population at baseline or an increase of ≥2.5 units between the baseline and the final square roots of the CAC scores of participants with detectable CAC at baseline. CAC progression was seen in 18.6% (98/526), 28.3% (77/272), 29.1% (30/103) and 32.0% (87/272) of the subjects with NAFLD(-)/MetS(-), NAFLD(+)/MetS(-), NAFLD(-)/MetS(+) and NAFLD(+)/MetS(+), respectively. The subjects with NAFLD(+)/MetS(+) and NAFLD(+)/MetS(-) had a significantly higher risk of CAC progression than those with NAFLD(-)/MetS(-) (multivariate-adjusted odds ratio [OR]: 1.76; 95% confidence interval [CI]: 1.18-2.62 and multivariate-adjusted OR: 1.53, 95% CI: 1.05-2.23, respectively). NAFLD is an independent risk factor for CAC progression, irrespective of the presence of MetS.