Abstract

OBJECTIVE: To evaluated osteoprotegerin (OPG), an inhibitor of osteoclastogenesis involved in atherosclerosis, and other novel risk factors as predictive markers of silent myocardial ischemia (SMI).

DESIGN AND METHODS: 465 consecutive diabetic patients with ≥1 additional risk factors were evaluated for SMI using stress myocardial perfusion imaging (MPI). We studied the association of SMI (positive stress-ECG and/or abnormal MPI) with OPG, other novel risk factors (lipoprotein(a), homocysteine, adiponectin, C-reactive protein and fibrinogen) and conventional risk factors (total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides).

RESULTS: 92 patients were diagnosed with SMI. Of the 6 novel markers, OPG was the only one associated with SMI; the relative risk of SMI in patients with OPG values above the 75th percentile was 3.19 (95% CI, 1.99 to 5.18; p<0.001) in comparison to those with OPG below the 75th percentile. In univariate analyses, the other plasma markers significantly associated with SMI were higher triglycerides (p =0.04) and lower HDL-Cholesterol (p =0.02). The association of OPG with SMI remained significant after correcting for other variables associated with SMI at p<0.15 in univariate analysis (RR 3.95; 95% CI 2.21-7.06; p<0.0001) . The association of OPG with SMI was observed in males (p<0.0001), females (p=0.03), in type 1 (0.002) and type 2 (0.0004) diabetic patients, in patients with (0.0004) or without (0.03) nephropathy and in patients without (p<0.0001), but not in those with (p=0.2) peripheral arterial disease.

CONCLUSIONS: OPG measurement, together with other conventional factors, can help to better define the diabetic population with an increased likelihood for SMI.