"The most interesting finding of our research is that regression of fatty liver is associated with reduced risk of subclinical carotid atherosclerosis compared to persistent fatty liver," said Dr. Geum-Youn Gwak from Sungkyunkwan University School of Medicine in Seoul.
"So, if somebody has fatty liver at one point, he or she should try hard to resolve fatty liver. Otherwise, it is highly likely that he or she would get cardiovascular disease one day," Dr. Gwak told Reuters Health by email.
NAFLD is associated with metabolic syndrome, diabetes, and cardiovascular disease morbidity and mortality, and several studies have shown that fatty liver is associated with markers of subclinical atherosclerosis.
Dr. Gwak's team conducted a retrospective longitudinal study of 8,020 men to assess the independent association of NAFLD with the development of subclinical carotid atherosclerosis identified by ultrasound, as defined by the development of an abnormally increased carotid intima-media thickness (CIMT) or of carotid plaque.
At baseline, 39.7% of the men had NAFLD, and 17.6% of these showed regression of NAFLD during follow-up. Nearly a quarter of men (23.1%) without NAFLD at baseline had developed it by the end of follow-up, which lasted a median of 3.3 years.
The three-year cumulative incidence of subclinical carotid atherosclerosis was 14.3%, the researchers report in Gastroenterology, online June 6.
The risk of developing carotid atherosclerosis was 23% higher among men with persistent NAFLD than among those without the condition (p<0.001). This association persisted after adjusting for smoking, alcohol use, body mass index, and weight change but disappeared after adjustment for metabolic variables.
This suggests that metabolic factors mediate the association between NAFLD and the development of carotid atherosclerosis, the researchers note.
Men whose NAFLD regressed had an 18% lower risk of carotid atherosclerosis, compared with men who had persistent NAFLD (p<0.013).
Other factors associated with the development of carotid atherosclerosis included higher baseline NAFLD fibrosis score and baseline or persistent elevations of alanine aminotransferase (ALT) or gamma-glutamyltransferase (GGT).
"Once fatty liver is successfully resolved, the cardiovascular disease risk becomes similar to those without fatty liver at baseline," Dr. Gwak concluded. "That's the key message that physicians should deliver to their fatty liver patients."