Serum levels of soluble receptor activator of nuclear factors-KB ligand [sRANKL], osteoprotegerin [OPG] and bone mineral density in Egyptian osteoporotic elderly women

ABSTRACT

The aim of this study was to determnine the state of the OPG/RANKL system and its possible role in osteoporotic elderly women. The present study included 40 apparently healthy old osteoporotic women aged 64.5 +/- 4.5 years as group I,[GI] and 30 healthy women of matched age as group II [GII]. The two groups were subjected to complete history taking, thorough clinical examination, routine laboratory investigations, measurement of bone formation markers as serum alkaline phosphatase, serum calcium and serum osteocalcin and measurement of bone resorptiomz markers including hydroxyproline in urine, serum OPG and serum RANKL CT Bone Density was done as well. In the current study, non significant differences were noted between the 2 studied groups as regard fasting blood glucose, renal amid hepatic function tests. A significant increase in serum alkaline phosphatase and urinary hydroxyproline and a significant decrease in serum calcium and serum osteocalcin was noted in group I compared to group Ii. Serum levels of RANKL were significantly elevated while serum OPG levels were significantly decreased in osteoporotic women compared to healthy controls. Changes in circulating OPG-RANKL correlates with serum osteocalcin and BMD changes. RANKL is an essential cytokine for the formation and activation of osteoclasts and promotes bone resorption, while OPG antagonizes these effects. Estrogen deficiency tilts the RANKL/OPG balance to favor osteoclastic activation and bone loss. RANKL blockade may emerge as a novel therapeutic option for human bone diseases. Further studies are necessary to elucidate the causes of osteoporosis and low bone mass in old women