Springer Science and Business Media LLC

Rheumatoid arthritis (RA) is an inflammatory disorder characterized by progressive joint destruction. Recent studies have demonstrated that osteoclasts are responsible for bone destruction in RA. Receptor activator of nuclear factor kappa B ligand (RANKL), an osteoclast differentiation factor, belongs to the tumor necrosis factor superfamily and plays a critical role in osteoclast differentiation. RANKL is highly expressed in the synovial tissues in patients with RA and is involved in osteoclast development and thus bone destruction in RA. Denosumab, a specific antibody to human RANKL, efficiently suppressed the progression of bone destruction in patients with RA in a randomized controlled study and is considered a putative therapeutic option for RA.

It has been reported that many elderly people have low serum levels of 25-hydroxyvitamin D [25(OH)D] and that serum 25(OH)D levels may have a relationship with cognitive function. The aim of this study was to examine the relationship between serum 25(OH)D levels and cognitive function in a Japanese population. This cross-sectional study was performed as a part of the Project in Sado for Total Health (PROST). The PROST study evaluated cognitive state and serum vitamin D level from June 2011 to November 2013 for 740 patients (431 men and 309 women). The Mini-Mental State Examination-Japanese version (MMSE-J) and serum 25(OH)D level measurements were used as assessment tools. Cognitive impairment was defined using MMSE-J ≤ 23 as a cutoff. Multiple logistic regression analyses were performed to calculate the odds ratios (ORs) for low MMSE-J scores. The average subject age was 68.1 years, the average MMSE- J score was 25.9, and the average 25(OH)D level was 24.6 ng/mL. Significant ORs for cognitive impairment were observed for both high age and low serum 25(OH)D. The adjusted OR for the lowest versus highest serum 25(OH)D quartiles was 2.70 (95% confidence interval 1.38–5.28, P = 0.0110). Low serum 25(OH)D levels were independently associated with a higher prevalence of cognitive impairment.

The effect of 1α-hydroxyvitamin D3 (1α(OH)D3) on the metabolic bone disorders developed in gastrectomized rats were investigated biochemically and histomorphologically. 1α(OH)D3 was suspended in 0.2 % Triton-X-100 aqueous solution after dissolving in a very small amount of ethanol, was given orally to the rats for 10 weeks. The sham operated animals and the gastrectomy control animals received the vehicle alone. Gastrectomy was followed by the development of the metabolic bone disorders after 10 weeks of observation. This was characterized by reduction in ash content of the femur and histologically by a disappearance of the trabecular bone in tibial metaphysis. Decrease Ca absorption from the intestines was demonstrated by a radiotracer technique. Biochemical studies showed significant decreases in serum 25(OH)D concentration in gastrectomized rats. These findings suggest that gastrectomy partially impairs intestinal absorption of calcium and results in a negative calcium balance, which may contribute to the development of bone metabolic disorders in rats. The administration of 1α(OH)D3 increased dose-dependently serum calcium and Ca absorption from the intestine and prevented the development of bone metabolic disorders histomorphologically.

Femur stiffness, for example axial and bending stiffness, integrates both geometric and material information of the bone, and thus can be an effective indicator of bone strength and hip fracture risk. Femur stiffness is ideally measured from quantitative computed tomography (QCT), but QCT is not recommended for routine clinical use due to the public concern about exposure to high-dosage radiation. Dual energy X-ray absorptiometry (DXA) is currently the primary imaging modality in clinic. However, DXA is two-dimensional and it is not clear whether DXA-estimated stiffness has adequate accuracy to replace its QCT counterpart for clinical application. This study investigated the accuracy of femur stiffness (axial and bending) estimated from CTXA (computed tomography X-ray absorptiometry) and DXA against those directly measured from QCT. Proximal-femur QCT and DXA from 67 subjects were acquired. For each femur, the QCT dataset was projected into CTXA using CTXA-Hip (Mindways Software, Inc., USA). Femur stiffness at the femoral neck and intertrochanter were then calculated from QCT, CTXA and DXA, respectively, and different elasticity-density relationships were considered in the calculation. Pearson correlations between QCT and CTXA/DXA measured stiffness were studied. The results showed that there were strong correlations between QCT and CTXA derived stiffness, although the correlations were affected by the adopted elasticity-density relationship. Correlations between QCT and DXA derived stiffness were much less strong, mainly caused by the inconsistence of femur orientation in QCT projection and in DXA positioning. Our preliminary clinical study showed that femur stiffness had slightly better performance than femur geometry in discrimination of hip fracture cases from controls.

Primary hyperparathyroidism is characterized by hypercalcemia with loss of bone mass. After parathyroidectomy, hypocalcemia may develop in some patients due to unregulated bone mineralization. Preoperative administration of bisphosphonates, potent inhibitors of osteoclast activity, may prevent postoperative hypocalcemia after parathyroidectomy. We retrospectively reviewed medical records to investigate the effect of bisphosphonate pretreatment on serum calcium level changes after parathyroidectomy. Twenty-three patients with a diagnosis of primary hyperparathyroidism underwent parathyroidectomy between April 1997 and August 2002. Clinical and laboratory data were collected before and after the operation. These patients were divided into two groups; those showing hungry bone syndrome (n = 9) and those not (n = 14). None of the 9 patients with hungry bone syndrome had received bisphosphonate pretreatment. Of the 14 patients without hungry bone syndrome, 6 had received bisphosphonate pretreatment (P < 0.05). Furthermore, preoperative calcium concentration was not related to the occurrence of hypo-calcemia in those without bisphosphonate pretreatment. In conclusion, administration of bisphosphonates in primary hyperparathyroidism can prevent the occurrence of hungry bone syndrome after parathyroidectomy.

Quantitative ultrasound (QUS) is used for prediction for risks of osteoporotic fractures at various skeletal sites, irrespective of weight-bearing or non-weight-bearing skeletons. In the current study, we investigated the correlation between calcaneal QUS measurements (BUA, VOS, and Soundness) and volumetric trabecular, cortical, and its integral bone mineral density (tBMD, cBMD, and iBMD) using peripheral quantitative computed tomography (pQCT) of the weight-bearing distal tibia and non-weight-bearing distal radius in 198 healthy Chinese women between 40 and 62 years of age. Results showed that BUA, VOS, and Soundness measured by calcaneal QUS were significantly correlated with tBMD, cBMD, and iBMD of both distal tibia and distal radius (r = 0.210–0.447; all P < 0.01). The correlation coefficients of all the individual parameters between calcaneus and distal tibia were correspondingly higher (r = 0.214–0.447; all P < 0.01) than that of distal radius (r = 0.210–0.368; all P < 0.01). QUS Soundness showed the highest correlation (r = 0.447; P < 0.01) with tBMD of distal tibia when comparing with all other parameters between these two measurement devices. Stronger “within-device” correlations (r = 0.640–0.764; all P < 0.01) were found in pQCT measurements between distal tibia and radius. In addition, the largest and significant age-related decline was found in tBMD of the distal radius measured by pQCT and Soundness of the QUS measurement in the postmenopausal group. In conclusion, heel QUS measurement demonstrated slightly better correlation with trabecular bone of the weight-bearing skeleton than that of the non-weight-bearing skeleton measured by pQCT.