YKL-40 is elevated in patients with peripheral arterial disease and diabetes or pre-diabetes.

OBJECTIVE: YKL-40 is secreted by macrophages in atherosclerotic lesions and involved in plaque rupture. YKL-40 is elevated in coronary artery disease, and predicts cardiovascular mortality. Experimental in vivo and in vitro data suggest a role of YKL-40 in tissue remodeling. A disease modulating potency of YKL-40 was not investigated in peripheral arterial disease (PAD).

METHODS: We measured YKL-40 in 460 subjects: 316 PAD: 71 normal glucose metabolism (PAD-NGM), 90 pre-diabetes (PAD-PREDM) and 155 diabetes (PAD-DM); 20 diabetes with atherosclerosis but without PAD (AS-DM); 85 diabetes without macro-vascular complications (DM) and 39 healthy controls (CO).

RESULTS: YKL-40 is higher in PAD vs. CO (median [25-75 percentile]: 103 [69-159] vs. 43 [30-80]ng/ml; p<0.001). In addition, YKL-40 is elevated in DM (p<0.001), PAD-NGM (p=0.001), PAD-PREDM (p<0.001), PAD-DM (p<0.001) and AS-DM (p=0.002) compared to CO. Among PAD, YKL-40 is increased in PAD-PREDM (p=0.001) and PAD-DM (p=0.01) vs. PAD-NGM. By multivariate regression YKL-40 is significantly associated with age (beta=0.272), triglycerides (beta=0.216), aspartate-amino-transferase (beta=0.177) and c-reactive-protein (beta=0.178). Underpinning its role YKL-40 was found to be associated with micro-/macroalbuminuria (p=0.014/p=008)--a strong remodeling inducer. In addition, YKL-40 was elevated in existence of mediasclerosis (p=0.008), a remodeling process.

CONCLUSION: We are first to show that YKL-40 is higher in subjects with peripheral arterial disease. YKL-40 was higher in PAD patients with pre-/diabetes. In addition, YKL-40 was associated with the "severity" of generalized atherosclerosis estimated by affected vascular beds. All our findings point towards a role of YKL-40 in the progression/prognosis of patients with PAD and concomitant diabetes.