Association between Plasma Follistatin-like Protein 1 Levels and the Presence and Severity of Coronary Artery Disease

Follistatin-like protein 1 (FSTL1) is a secreted glycoprotein known for its role in inflammation. However, plasma FSTL1 levels in patients with coronary artery disease (CAD) have not been fully elucidated. Thus, in this study, we investigated the plasma FSTL1 levels of 350 patients who underwent elective coronary angiography. The severity of CAD was represented as the numbers of > 50% stenotic vessels and segments and the severity score. CAD was detected in 196 patients, of whom 84 had 1-vessel disease (1-VD), 62 had 2-VD, and 50 had 3-VD. Plasma high-sensitivity C-reactive protein (hsCRP) levels were higher in patients with CAD than in those without CAD (median 0.56 versus 0.44 mg/L, P < 0.01). Notably, plasma FSTL1 levels were higher in patients with CAD than in those without CAD (median 4.05 versus 3.47 ng/mL, P < 0.02). A stepwise increase in FSTL1 levels was found depending on the number of > 50% stenotic vessels: 3.47 in CAD (−), 3.74 in 1-VD, 4.42 in 2-VD, and 4.65 ng/mL in 3-VD (P < 0.05). FSTL1 levels also correlated with the number of > 50% stenotic segments and the severity score (r = 0.14 and r = 0.15, respectively, P < 0.005) and hsCRP levels (r = 0.10, P < 0.05). In the multivariate analysis, FSTL1 levels were an independent factor associated with CAD. The odds ratio for CAD was 1.61 (95% CI = 1.01-2.58) for high FSTL1 level of > 3.6 ng/mL (P < 0.05). In conclusion, plasma FSTL1 levels in patients with CAD were found to be high and associated with the presence and severity of CAD, thus, suggesting that FSTL1 may play a role in the progression of coronary atherosclerosis.