Our prospective cohort study will include 150 men (75 patients requiring surgery for CAD and a control group without coronary heart disease). The primary endpoints are the differences between the two groups in serum levels of OPG and RANKL, markers of bone metabolism (osteocalcin [OC], crosslaps [CTX], tartrate resistant acid phosphatase (TRAP5b), 25(OH) vitamin D [Vit D], 1.25(OH) vitamin D, parathormone [iPTH], endocrine parameters related to vascular damage (e.g. aldosterone, renin and cortisol) and bone mineral density. Metabolomic based biomarkers will be evaluated to explore the mechanisms behind OPG-RANKL linked CVD damage. In the patients further studies of the mRNA expression of OPG, RANKL, TRAP5b, arginine:glycine amidinotransferase (AGAT) and osteocalcin in bone (sternum sliver) and vascular wall (aorta, internal thoracic artery and the great saphenous vein) will be performed.