Predictive factors of non-treatment and non-persistence to osteoporosis medication after fragility hip fractures at 3 years after discharge: a multicentre, prospective cohort study in the northern Kyushu district of Japan.

We examined osteoporosis medication use and factors affecting persistence in 497 patients with fragility hip fractures. Only 25.5% of patients received continuous medication for 3 years, and 44.1% of patients received no treatment. Low Barthel index at discharge was a risk factor for both non-treatment and non-persistence to osteoporosis medication. PURPOSE: Fragility hip fractures (FHF) caused by osteoporosis decrease the quality of life and worsen life expectancy. Use of osteoporosis medication may be an efficient method in the prevention of secondary FHF. However, previous studies have reported low rates of osteoporosis medication and persistence after FHF. This study aimed to evaluate osteoporosis medication use and factors affecting persistence in patients with FHF in the northern Kyushu area of Japan. METHODS: A total of 497 FHF patients aged ≥ 60 years with a 3-year follow-up were included. We prospectively collected data from questionnaires sent every 6 months regarding compliance with osteoporosis medication. We compared baseline characteristics among three groups: no treatment (NT), no persistence (NP), and persistence (P), and conducted multivariable regression models to determine covariates associated with non-treatment (NT vs. NP/P) and non-persistence (NP vs. P). RESULTS: There were 219 (44.1%), 151 (30.4%), and 127 (25.5%) patients in the NT, NP, and P groups, respectively. Factors associated with non-treatment were male sex, chronic kidney disease, no previous osteoporosis treatment, and low Barthel index (BI) at discharge. The only factor associated with non-persistence was a low BI at discharge. Factors associated with a low BI at discharge were male sex, older age, trochanteric fracture, and surgical delay. CONCLUSION: Low BI at discharge is a risk factor for both non-treatment and non-persistence to osteoporosis medication. Therefore, appropriate interventions to improve BI may result in persistence to osteoporosis medication.

Predictive factors of mortality of patients with fragility hip fractures at 1 year after discharge: A multicenter, retrospective study in the northern Kyushu district of Japan.

PURPOSE: Fragility hip fractures (FHFs) are associated with a high risk of mortality, but the relative contribution of various factors remains controversial. This study aimed to evaluate predictive factors of mortality at 1 year after discharge in Japan. METHODS: A total of 497 patients aged 60 years or older who sustained FHFs during follow-up were included in this study. Expected variables were finally assessed using multivariable Cox proportional hazards models. RESULTS: The 1-year mortality rate was 9.1% (95% confidence interval: 6.8-12.0%, n = 45). Log-rank test revealed that previous fractures (p = 0.003), Barthel index (BI) at discharge (p = 0.011), and place-to-discharge (p = 0.004) were significantly associated with mortality for male patients. Meanwhile, body mass index (BMI; p = 0.023), total Charlson comorbidity index (TCCI; p = 0.005), smoking (p = 0.007), length of hospital stay (LOS; p = 0.009), and BI (p = 0.004) were the counterparts for females. By multivariate analyses, previous vertebral fractures (hazard ratio (HR) 3.33; p = 0.044), and BI <30 (HR 5.42, p = 0.013) were the predictive variables of mortality for male patients. BMI <18.5 kg/m2 (HR 2.70, p = 0.023), TCCI ≥5 (HR 2.61, p = 0.032), smoking history (HR 3.59, p = 0.018), LOS <14 days (HR 13.9; p = 0.007), and BI <30 (HR 2.76; p = 0.049) were the counterparts for females. CONCLUSIONS: Previous vertebral fractures and BI <30 were the predictive variables of mortality for male patients, and BMI <18.5 kg/m2, TCCI ≥5, smoking history, LOS <14 days, and BI <30 were those for females. Decreased BI is one of the independent and preventable risk factors. A comprehensive therapeutic approach should be considered to prevent deterioration of activities of daily living and a higher risk of mortality.

Characteristics of patients with fragility hip fractures in the northern Kyushu district in Japan: a multicenter prospective registry based on an electronic data capture system.

Osteoporosis has become a worldwide public health problem, in part due to the fact that it increases the risk of fragility hip fractures (FHFs). The epidemiological assessment of FHFs is critical for their prevention; however, datasets for FHFs in Japan remain scarce. This was a multicenter, prospective, observational study in the northern district of Kyushu Island. Inclusion criteria were age > 60 years with a diagnosis of FHF and acquisition of clinical data by an electronic data capture system. Of 1294 registered patients, 1146 enrolled in the study. Nearly one third of patients (31.8%) had a history of previous fragility fractures. The percentage of patients receiving osteoporosis treatment on admission was 21.5%. Almost all patients underwent surgical treatment (99.1%), though fewer than 30% had surgery within 48 h after hospitalization. Bone mineral density (BMD) was evaluated during hospitalization in only 50.4% of patients. The rate of osteoporosis treatment increased from 21.5% on admission to 39.3% during hospitalization. The main reasons that prescribers did not administer osteoporosis treatment during hospitalization were forgetfulness (28.4%) and clinical judgment (13.6%). Age and female ratio were significantly higher in patients with previous FHFs than in those without. There was a significant difference in the rate of osteoporosis treatment or L-spine BMD values in patients with or without previous FHFs on admission. In conclusion, this study confirmed that the evaluation and treatment of osteoporosis and FHFs is still suboptimal in Japan, even in urban districts.

Single-step affinity purification of recombinant proteins using the silica-binding Si-tag as a fusion partner.

We previously reported that a silica-binding protein, designated Si-tag, can be used as a fusion tag to immobilize functional proteins on silica surfaces. In this study, by taking advantage of the strong affinity of Si-tag for silica, we developed a single-step purification method for Si-tagged fusion proteins. We utilized unmodified bare silica particles as a specific adsorbent and a high concentration of MgCl(2) solution as an elution buffer. A fusion protein of Si-tag and immunoglobulin-binding staphylococcal protein A, designated Si-tagged protein A, was recovered with a purity of 87+/-3% and yield of 84+/-4% from a crude extract of recombinant Escherichia coli. The simplicity of our method enables rapid, cost-effective purification of Si-tagged fusion proteins. We also discuss the mechanism of binding and dissociation of Si-tag and silica surfaces, and we suggest that the unusual basicity and disordered structure of the Si-tag polypeptide play important roles in the binding to silica.

Oriented immobilization of antibodies on a silicon wafer using Si-tagged protein A.

We previously reported a silica-binding protein, designated Si-tag, which can be used to immobilize proteins on silica surfaces. Here, we constructed a fusion protein of Si-tag and immunoglobulin-binding staphylococcal protein A for oriented immobilization of antibodies on a silicon wafer whose surface is oxidized to silicon dioxide (silica). The fusion protein, Si-tagged protein A, strongly bound to the silica surface with a dissociation constant of 0.31 nM. Time-of-flight secondary ion mass spectrometry analysis of the silicon wafer coated with Si-tagged protein A, combined with principal component analysis and mutual information, demonstrated that protein A is localized on the outermost surface of the bound protein layer. Immunoglobulin G (IgG) was immobilized both on the silicon wafer coated with Si-tagged protein A and, as a control, directly on the intact silicon wafer via physical adsorption. The silicon wafer coated with Si-tagged protein A bound 30-70% more IgG than the uncoated silicon wafer, whereas the antigen-binding activity was 4- to 5-fold higher for the former, indicating that IgG was functionally immobilized on the silicon wafer via Si-tagged protein A in an oriented manner.