Serum osteoprotegerin levels are associated with increased aortic calcification in dialysis patients

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in dialysis (D) patients. Vascular calcification (VC) represents one of the major risk factors involved in the pathogenesis of CVD in this population. Osteoprotegerin (OPG) is a bone regulating protein modulating the genesis and activity of osteoclasts, but its role in VC pathogenesis in D patients has not been clarified so far. The present study aimed to evaluate OPG serum levels and their association with aortic calcification in D patients. A total of 92 D patients (72 on haemodialysis -HD- and 20 on peritoneal dialysis -PD-), aged 67.811.4 years, were assessed for biochemical markers of bone metabolism and OPG. Subsequently, D patients were scored for aortic calcification (AoC) by spinal lateral X-ray (L1-L4). AoC was diagnosed by radiographic detection of calcified deposits in the abdominal aorta (Witterman JC et al, Lancet 1994). D patients were divided in 4 groups, considering AoC length: group I (AoC = 0 cm), II (AoC = 0.1-5 cm), III (AoC = 5.1-10 cm), IV (AoC >10.0 cm). Results are summarized in the table. Patients without AoC are significantly younger. AoC were associated with higher serum PTH levels, but not with serum calcium and phosphate levels. Furthermore, serum OPG levels associate with increased AoC in this population. In conclusion, serum OPG levels determination could have a potential role in the biologic follow-up of D patients.