Several studies have shown that in contrast to osteoporosis (OP), osteoarthritis (OA) is characterized by high bone mineral density (BMD). Bone strength not only depends on mineral content as determined by dual X-ray absorptiometry (DXA), but also on bone microarchitecture. We studied intertrochanteric bone from normal controls and OA and OP patients by bone histomorphometry (BHM) and microcomputed tomography (ŽCT) as well as DXA in order to first, test the differences between OA and OP comparing both groups to healthy controls, second, to assess variations between three different skeletal sites in controls and third, to determine the level of agreement between microCT, BHM, and DXA. Analysis was performed on 115 samples from OA and OP patients, and controls. We found significant differences between OA and OP samples in structural parameters and in the osteoid fraction (p(0.05). The majority of the intra-skeletal differences were shown between lumbar spine andfemoral head samples (p(0.05). Significant agreements were found between microCT and BHM and DXA (r=0.32-0.45, p(0.05). Our findings suggest differences in intertrochanteric bone between OA and OP, the age-related intra-skeletal variations and a correlation between microscopic and macroscopic bone evaluation methods.
COBISS.SI-ID: 3393137
Osteoporosis treatment is generally quite successful, however, interindividual differences can be observed. Genetic factors represent one possible cause of this variability and have already been examined for bisphosphonates, HRT and raloxifene. Only one small, negative study was published recently on teriparatide PGx, while there are, as yet, no reports on PGx of other approved antiosteoporotic drugs.The efficacy of treatment is commonly assessed by an increase in bone mineral density or a decrease in biochemical markers of bone turnover, CTx and P1NP, but these changes are imperfect surrogates for antifracture efficacy, making pharmacogenomic studies difficult. In our opinion, the potential of pharmacogenomics to improve osteoporosis management has yet to be unraveled, as polymorphisms in only a few candidate genes have been studied and there are conflicting results for some drugs and a small number or lack of studies for the rest of the drugs. Currently, several options are available for the treatment of osteoporosis and there is evidence for interindividual differences in treatment efficacy and adverse drug reactions.
COBISS.SI-ID: 3448177
The role of bone marrow adipocytes in bone tissue is not yet understood. Adipocytes express enzymes for metabolism of free fatty acids and adipokines such as adiponectin, which have been shown to exert different effects on bone cells. Our aim was to find out whether triglyceride (TG) metabolism in bone tissue is associated with osteoblast and osteoclast differentiation by gene expression analysis of lipoprotein lipase (LPL), hormone sensitive lipase (HSL), fatty acid synthase (FASN), adiponectin, RUNX2, RANK, RANKL and OPG. Bone tissue was obtained from patients undergoing hip arthroplasty due to osteoporosis (OP) (50) or osteoarthritis (OA) (48) or from healthy autopsy controls (14). Lower bone mineral density and microstructural parameters were observed in OP compared to OA. The FASN expression did not differ between groups suggesting similar de novo lipogenesis. Lower LPL and HSL in OP suggest lower FFA release and uptake in OP bone tissue. Adiponectin expression was lower in OP than in OA and a trend was seen for controls. These results suggest OP bone has lower TG metabolism than OA and normal bone. In OP bone, lower osteoblastogenesis and higher osteoclast formation were observed and correlation analysis suggests adiponectin, LPL and HSL are associated with higher osteoblastogenesis and lower osteoclastogenesis. This study gives insights into TG metabolism in the human bone microenvironment. We conclude that OP bone tissue exhibits lower osteoblastogenesis, higher osteoclastogenesis and lower TG metabolism compared to OA or healthy controls.
COBISS.SI-ID: 3433585