9-Month observational Dia-Vacc study of vaccine type influence on SARS-CoV-2 immunity in dialysis and kidney transplant patients

BACKGROUND

SARS-CoV-2mRNA vaccination related seroconversion rates are reduced in dialysis and kidney transplant patients.

METHODS

We evaluated nine months follow up data in our observational Dia-Vacc study exploring specific cellular (interferon-γ release assay) or/and humoral immune responses after 2x SARS-CoV-2mRNA vaccination in 880 participants including healthy medical personnel (125-MP), dialysis patients (595-DP), kidney transplant recipients (111-KTR), and apheresis patients (49-AP) with positive seroconversion (de novo IgA or IgG antibody positivity by ELISA) after eight weeks.

FINDINGS

Nine months after first vaccination, receptor binding domain (RBD) antibodies were still positive in 90 % of MP, 86 % of AP, but only 55 %/48 % of DP/KTR, respectively. Seroconversion remained positive in 100 % of AP and 99·2 % of MP, but 86 %/81 % of DP/KTR, respectively. Compared to MP, DP but not KTR or AP were at risk for a strong RBD decline, while KTR kept lowest RBD values over time. By multivariate analysis, BNT162b2mRNA versus 1273-mRNA vaccine type was an independent risk factor for a strong decline of RBD antibodies. Within the DP group, only time on dialysis was another (inverse) risk factor for the DP group. Compared to humoral immunity, T-cell immunity decline was less prominent.

INTERPRETATION

While seroconverted KTR reach lowest RBD values over time, DP are at specific risk for a strong decline of RBD antibodies after successful SARS-CoV-2mRNA vaccination, which also depends on the vaccine type being used. Therefore, booster vaccinations for DP should be considered earlier compared to normal population.

Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX.

INTRODUCTION

The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD).

METHODS

We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted β-coefficients.

RESULTS

A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination.

CONCLUSION

A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures.

INTRODUCTION

The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors.

METHODS

A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible.

RESULTS

Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed.

CONCLUSIONS

These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

MMF/MPA Is the Main Mediator of a Delayed Humoral Response With Reduced Antibody Decline in Kidney Transplant Recipients After SARS-CoV-2 mRNA Vaccination

Kidney transplant recipients (KTR) show significantly lower seroconversion rates after SARS-CoV-2 mRNA vaccination compared to dialysis patients (DP). Mycophenolate mofetil or mycophenolic acid (MMF/MPA) in particular has been identified as a risk factor for seroconversion failure. While the majority of all KTR worldwide receive MMF/MPA for immunosuppressive therapy, its impact on antibody decline in seroconverted KTR still remains unclear. In an observational study (NCT04799808), we investigated whether 132 seroconverted KTR (anti-spike S1 IgG or IgA positive after 2 vaccinations) show a more rapid antibody decline with MMF/MPA than those without this medication. A total of 2 months after mRNA vaccination, average anti-spike S1 IgG levels of KTR with MMF/MPA were lower than without (p = 0.001), while no differences between these two groups were observed after 6 months (p = 0.366). Similar results were obtained for anti-RBD IgG antibodies (T2 p = 0.003 and T3 p = 0.135). The probability of severe IgG decline with MMF/MPA was three times lower than without (p = 0.003, OR 0.236, 95% CI 0.091-0.609). In the multivariate analysis, neither immunosuppressants, such as calcineurin inhibitors, mTOR inhibitors (mTOR-I; mechanistic target of rapamycin), glucocorticoids, nor vaccine type, sex, or age showed a significant influence on IgG titer decline between 2 and 6 months. For the decision on additional booster vaccinations, we consider immunosurveillance to be needed as an integral part of renal transplant follow-up after SARS-CoV-2 mRNA vaccination. Not only the lack of seroconversion but also the peak and titer decline of the specific IgG and RBD IgG antibody formation after two mRNA vaccinations is significantly influenced by MMF/MPA.

Risk of strong antibody decline in dialysis and transplant patients after SARS-CoV-2mRNA vaccination: Six months data from the observational Dia-Vacc study

Background

Vulnerable dialysis and kidney transplant patients show impaired seroconversion rates compared to medical personnel eight weeks after SARS-CoV-2mRNA vaccination.

Methods

We evaluated six months follow up data in our observational Dia-Vacc study exploring specific cellular (interferon-γ release assay) or/and humoral immune responses after 2x SARS-CoV-2mRNA vaccination in 1205 participants including medical personnel (125 MP), dialysis patients (970 DP) and kidney transplant recipients (110 KTR) with seroconversion (de novo IgA or IgG antibody positivity by ELISA) after eight weeks.

Findings

Six months after vaccination, seroconversion remained positive in 98% of MP, but 91%/87% of DP/KTR (p = 0·005), respectively. Receptor binding domain-IgG (RBD-IgG) antibodies were positive in 98% of MP, but only 68%/57% of DP/KTR (p < 0·001), respectively. Compared to MP, DP and KTR were at risk for a strong IgG or RBD-IgG decline (p < 0·001). Within the DP but not KTR group male gender, peritoneal dialysis, short time on dialysis, BNT162b2mRNA vaccine, immunosuppressive drug use and diabetes mellitus were independent risk factors for a strong decline of IgG or RBD antibodies. The percentage of cellular immunity decline was similar in all groups.

Interpretation

Both vulnerable DP and KTR groups are at risk for a strong decline for IgG and RBD antibodies. In KTR, antibody titres peak at a markedly lower level and accelerated antibody decline is mixed with a delayed/increasing IgG, RBD-IgG, or cellular immune response in a 16% fraction of patients. In both populations, immune monitoring should be used for early timing of additional booster vaccinations.

Funding

This study was funded by the Else Kröner Fresenius Stiftung, Bad Homburg v. d. H., grant number Fördervertrag EKFS 2021_EKSE.27.

Cellular and Humoral Immune Responses After 3 Doses of BNT162b2 mRNA SARS-CoV-2 Vaccine in Kidney Transplant

Supplemental Digital Content is available in the text.

Regional and gender-specific analyses give new perspectives for secular trend in hip fracture incidence

In this study, we found that regional disparity in incidence of hip fractures has converged. Also, annual hip fracture risk ratios between genders have systematically diminished over time.

INTRODUCTION

Several studies have reported secular trends in hip fracture incidence, but knowledge about the possible causes is limited. We studied potential explanations by examining spatio-temporal epidemiology of the fractures and estimating relative risks between genders.

METHODS

This observational study was based on all inpatient hospital discharges in 1972-2018 in Finland. We divided the data by gender, 5-year age groups and Finnish sub-regions and estimated gender and age standardized spatio-temporal rates of hip fractures by using a Bayesian age-period-cohort model.

RESULTS

In 1972, women's hip fracture incidence was 1.2-1.3 times higher in western and coastal Finland compared to eastern and inland areas. Also, women had approximately 1.7 times higher average risk to get a hip fracture compared to men. Today, the hip fracture differences between the areas have converged to insignificant and the relative risk between genders has diminished to 1.2. Age-specific relative risks indicate greater hip fracture risk for younger men and older women, and the women's risk increases beyond the risk of men at age 65 which is ten years later than in the beginning of the study period.

CONCLUSION

Incidence of hip fracture has converged significantly between regions and genders. Especially factors related with socioeconomic development and increased frailty and longevity seem to be important. The hip fracture incidence rate ratio between women and men has systematically decreased in time, and more attention should be paid to hip fracture risk in men in the future.

Humoral and cellular immunity to SARS-CoV-2 vaccination in renal transplant versus dialysis patients: A prospective, multicenter observational study using mRNA-1273 or BNT162b2 mRNA vaccine

Background

Dialysis and kidney transplant patients are vulnerable populations for COVID-19 related disease and mortality.

Methods

We conducted a prospective study exploring the eight week time course of specific cellular (interferon-γ release assay and flow cytometry) or/and humoral immune responses (ELISA) to SARS-CoV-2 boost vaccination in more than 3100 participants including medical personnel, dialysis patients and kidney transplant recipients using mRNA vaccines BNT162b2 or mRNA-1273.

Results

SARS-CoV-2-vaccination induced seroconversion efficacy in dialysis patients was similar to medical personnel (> 95%), but markedly impaired in kidney transplant recipients (42%). T-cellular immunity largely mimicked humoral results. Major risk factors of seroconversion failure were immunosuppressive drug number and type (belatacept, MMF-MPA, calcineurin-inhibitors) as well as vaccine type (BNT162b2 mRNA). Seroconversion rates induced by mRNA-1273 compared to BNT162b2 vaccine were 97% to 88% (p < 0.001) in dialysis and 49% to 26% in transplant patients, respectively. Specific IgG directed against the new binding domain of the spike protein (RDB) were significantly higher in dialysis patients vaccinated by mRNA-1273 (95%) compared to BNT162b2 (85%, p < 0.001). Vaccination appeared safe and highly effective demonstrating an almost complete lack of symptomatic COVID-19 disease after boost vaccination as well as ceased disease incidences during third pandemic wave in dialysis patients.

Conclusion

Dialysis patients exhibit a remarkably high seroconversion rate of 95% after boost vaccination, while humoral response is impaired in the majority of transplant recipients. Immunosuppressive drug number and type as well as vaccine type (BNT162b2) are major determinants of seroconversion failure in both dialysis and transplant patients suggesting immune monitoring and adaption of vaccination protocols.

Obesity is associated with early hip fracture risk in postmenopausal women: a 25-year follow-up

Association of body mass index and hip fracture has been controversial. In this study, women with lowest and highest body weight had the highest fracture incidence. A 25-year follow-up indicated that obesity associates with early hip fracture risk and suggested increasing trend in normal-weight women at a later stage.

INTRODUCTION

Obesity is a pandemic health issue. Its association with hip fracture risk remains controversial. We studied the long-term relationship of body mass index and hip fracture incidence in postmenopausal women.

METHODS

The cohort of 12,715 Finnish women born in 1932-1941 was followed for 25 years, covering ages from 58 up to 83. Fractures and deaths were obtained from national registries. Women were investigated in deciles of BMI as well as in WHO weight categories (normal, overweight, or obese). The follow-up analysis was carried out in two age strata as "early" (58-70 years) and "late" (> 70 years). Body weight information was updated accordingly. Femoral neck BMD was recorded for a subsample (n = 3163). Altogether, 427 hip fractures were observed.

RESULTS

A higher risk of early hip fracture was observed in obese and normal-weight compared with overweight women with hazard ratios (HRs) of 2.3 ((95% CI) 1.4-3.7) and 2.0 (1.3-3.1) while no difference was observed in late hip fracture risk between the three WHO categories (log rank p = 0.14). All-cause mortality during the follow-up was 19.3%. Compared with normal weight women, the obese women had a higher risk of death with an HR of 1.6 (1.4-1.8) and higher baseline BMD (p < 0.001). Faster bone loss was observed in the obese compared with other women (p < 0.001).

CONCLUSION

Obesity associates with earlier hip fracture and higher postfracture mortality. The obese women with low BMD have clearly the highest risk of hip fracture. This combination increases hip fracture risk more than either of the factors alone. After 75 years of age, risk appears to increase more in normal weight women, but this trend is in need of further confirmation.

A new analysis approach for single nephron GFR in intravital microscopy of mice

Background: Intravital microscopy is an emerging technique in life science with applications in kidney research. Longitudinal observation of (patho-)physiological processes in living mice is possible in the smallest functional unit of the kidney, a single nephron (sn). In particular, effects on glomerular filtration rate (GFR) - a key parameter of renal function - can be assessed.

Methods: After intravenous injection of a freely filtered, non-resorbable, fluorescent dye in C57BL/6 mice, a time series was captured by multiphoton microsopy. Filtration was observed from the glomerular capillaries to the proximal tubule (PT) and the tubular signal intensity shift was analyzed to calculate the snGFR.

Results: Previously described methods for snGFR analysis relied on two manually defined measurement points in the PT and the tubular volume was merely estimated in 2D images. We present an extended image processing workflow by adding continuous measurement of intensity along the PT in every frame of the time series using ImageJ. Automatic modelling of actual PT volume in a 3D dataset replaced 2D volume estimation. Subsequent data analysis in R, with a calculation of intensity shifts in every frame and normalization against tubular volume, allowed exact assessment of snGFR by linear regression. Repeated analysis of image data obtained in healthy mice showed a striking increase of reproducibility by reduction of user interaction.

Conclusions: These improvements in image processing and data analysis maximize the reliability of a sophisticated intravital microscopy technique for the precise assessment of snGFR, a highly relevant predictor of kidney function.

Health-Related Quality of Life After Hip and Knee Arthroplasty Operations

Background and objective:

The aim of this study was to investigate the health-related quality of life before and after a hip and a knee arthroplasty operation using a 15D instrument and to compare these scores to the Finnish control population 15D scores.

Methods:

The pre- and post-operative data of 15D were prospective collected from the patients undergoing total hip arthroplasty or total knee arthroplasty at the Kuopio University Hospital. Post-operative data were collected at 6 and 12 months after the operation.

Results:

The mean change of the 15D score after hip arthroplasty was +0.062 and after knee arthroplasty, it was +0.033 at the 12-month follow-up (p < 0.001). Total hip arthroplasty patients of all ages reached the control population 15D scores at the 12-month follow-up. Of the total knee arthroplasty patients, only patients aged >75 years and males aged 55–64 years did reach control population 15D scores at the 12-month follow-up. Patients experienced a statistically significant improvement in mobility, vision, sleeping, usual activities, discomfort and symptoms, distress, and vitality (p < 0.05).

Conclusions:

Successful hip and knee arthroplasty operations improve patients’ health-related quality of life. According to this study, hip arthroplasty improves the health-related quality of life more than knee arthroplasty.

Automating three-dimensional osteoarthritis histopathological grading of human osteochondral tissue using machine learning on contrast-enhanced micro-computed tomography

OBJECTIVE

To develop and validate a machine learning (ML) approach for automatic three-dimensional (3D) histopathological grading of osteochondral samples imaged with contrast-enhanced micro-computed tomography (CEμCT).

DESIGN

A total of 79 osteochondral cores from 24 total knee arthroplasty patients and two asymptomatic donors were imaged using CEμCT with phosphotungstic acid -staining. Volumes-of-interest (VOI) in surface (SZ), deep (DZ) and calcified (CZ) zones were extracted depth-wise and subjected to dimensionally reduced Local Binary Pattern -textural feature analysis. Regularized linear and logistic regression (LR) models were trained zone-wise against the manually assessed semi-quantitative histopathological CEμCT grades (diameter = 2 mm samples). Models were validated using nested leave-one-out cross-validation and an independent test set (4 mm samples). The performance was primarily assessed using Mean Squared Error (MSE) and Average Precision (AP, confidence intervals are given in square brackets).

RESULTS

Highest performance on cross-validation was observed for SZ, both on linear regression (MSE = 0.49, 0.69 and 0.71 for SZ, DZ and CZ, respectively) and LR (AP = 0.9 [0.77-0.99], 0.46 [0.28-0.67] and 0.65 [0.41-0.85] for SZ, DZ and CZ, respectively). The test set evaluations yielded increased MSE on all zones. For LR, the performance was also best for the SZ (AP = 0.85 [0.73-0.93], 0.82 [0.70-0.92] and 0.8 [0.67-0.9], for SZ, DZ and CZ, respectively).

CONCLUSION

We present the first ML-based automatic 3D histopathological osteoarthritis (OA) grading method which also adequately perform on grading unseen data, especially in SZ. After further development, the method could potentially be applied by OA researchers since the grading software and all source codes are publicly available.

A fall in the previous 12 months predicts fracture in the subsequent 5 years in postmenopausal women

PURPOSE

The purpose of this study was to evaluate if a history of falls predicts future postmenopausal fractures and if this prediction variesaccording to frequency, mechanism, and severity of falls and site of fractures.

METHODS

This study used data from OSTPRE prospective cohort. Total study population consisted of 8744 postmenopausal women (mean age 62.2 years) who responded to postal enquiry in 1999 (baseline) and in 2004 (follow-up).

RESULTS

Women were classified by frequency (non/occasional/frequent fallers), mechanism (slip/nonslip), and severity (injurious/ non-injurious) of falls and fractures by site (major osteoporotic/other). A total of 1693 (19.4%) women reported a fall during the preceding 12 months in 1999; 812 a slip fall, 654 a nonslip, 379 an injurious fall, and 1308 a non-injurious fall. A total of 811 women (9.3%) sustained a fracture during the 5-year follow-up period (1999-2004); 431 major osteoporotic fractures and 380 other fractures. Compared with non-fallers, earlier falls predicted subsequent fractures with an OR of 1.41 (95% CI 1.19-1.67, p ≤ 0.001), 1.43 (95% CI 1.14-1.80, p = 0.002) for earlier slip falls, and 1.35 (95% CI 1.04-1.74, p = 0.02) for earlier nonslip falls. Earlier injurious falls predicted future fractures (OR = 1.64, 95% CI 1.21-2.23, p ≤ 0.01), especially other fractures (OR = 1.86, 95% CI 1.24-2.80, p ≤ 0.01), but not major osteoporotic fractures (OR = 1.37, 95% CI 0.89-2.10, p = 0.151). Fracture risk predictions for earlier non-injurious falls was OR = 1.36, 95% CI 1.12-1.64, p = 0.002. These risk patterns remain same after adjustments.

CONCLUSION

History of falls (especially injurious falls) predicts subsequent fractures (mainly other fractures compared with major osteoporotic fractures) inpostmenopausal women. We aimed to investigate if history of falls (frequency, mechanism, and severity) is a predictor of future fractures in postmenopausal women. Our results indicate that history of falls (especially injurious falls) appeared to be an indicator for subsequent fracture overall. Earlier injurious falls were stronger predictors for future other fractures than for typical major osteoporotic fractures.

Near-infrared spectroscopy enables quantitative evaluation of human cartilage biomechanical properties during arthroscopy

OBJECTIVE

To investigate the feasibility of near-infrared (NIR) spectroscopy (NIRS) for evaluation of human articular cartilage biomechanical properties during arthroscopy.

DESIGN

A novel arthroscopic NIRS probe designed in our research group was utilized by an experienced orthopedic surgeon to measure NIR spectra from articular cartilage of human cadaver knee joints (ex vivo, n = 18) at several measurement locations during an arthroscopic surgery. Osteochondral samples (n = 265) were extracted from the measurement sites for reference analysis. NIR spectra were remeasured in a controlled laboratory environment (in vitro), after which the corresponding cartilage thickness and biomechanical properties were determined. Hybrid multivariate regression models based on principal component analysis and linear mixed effects modeling (PCA-LME) were utilized to relate cartilage in vitro spectra and biomechanical properties, as well as to account for the spatial dependency. Additionally, a k-nearest neighbors (kNN) classifier was employed to reject outlying ex vivo NIR spectra resulting from a non-optimal probe-cartilage contact. Model performance was evaluated for both in vitro and ex vivo NIR spectra via Spearman's rank correlation (ρ) and the ratio of performance to interquartile range (RPIQ).

RESULTS

Regression models accurately predicted cartilage thickness and biomechanical properties from in vitro NIR spectra (Model: 0.77 ≤ ρ ≤ 0.87, 2.03 ≤ RPIQ ≤ 3.0; Validation: 0.74 ≤ ρ ≤ 0.84, 1.87 ≤ RPIQ ≤ 2.90). When predicting cartilage properties from ex vivo NIR spectra (0.33 ≤ ρ ≤ 0.57 and 1.02 ≤ RPIQ ≤ 2.14), a kNN classifier enhanced the accuracy of predictions (0.52 ≤ ρ ≤ 0.87 and 1.06 ≤ RPIQ ≤ 1.88).

CONCLUSION

Arthroscopic NIRS could substantially enhance identification of damaged cartilage by enabling quantitative evaluation of cartilage biomechanical properties. The results demonstrate the capacity of NIRS in clinical applications.

Long-term thiazide use and risk of low-energy fractures among persons with Alzheimer's disease-nested case-control study

We investigated the association between thiazide use and the risk of low-energy fractures among community dwellers with Alzheimer's disease. Longer use was associated with a decreased risk of low-energy fractures. This study extends the previous knowledge of reduced fracture risk of thiazides to persons with Alzheimer's disease.

INTRODUCTION

To investigate the association between thiazide use and the risk of low-energy fractures (LEF), and hip fracture among community dwellers with Alzheimer's disease (AD). No prior study has evaluated the effect of thiazides on LEF risk of AD patients.

METHODS

LEF cases were identified from the MEDALZ study, including all community-dwelling persons diagnosed with AD in Finland 2005-2011. During the follow-up from AD diagnoses until the end of 2015, cases with LEF (N = 10,416) and hip fracture (N = 5578) were identified. LEF cases were matched with up to three controls without LEF, according to time since AD diagnosis, age and gender. Thiazide use identified from the Prescription register data was modeled with PRE2DUP method. Current use was defined in 0-30 days' time window before the fracture/matching date, and duration of current use was assessed. The association between thiazide exposure and LEFs was assessed with conditional logistic regression.

RESULTS

Current thiazide use was observed in 10.5% of LEF cases and 12.5% of controls. Current thiazide use was associated with a decreased risk of LEF (adjusted OR [aOR] 0.83, 95% CI 0.77-0.88). In terms of the duration of use, no association was observed with short-term use (< 1 year or 1-3 years), while longer use (> 3 years) was associated with a reduced risk of LEF (aOR 0.77, 95% CI 0.71-0.83) and hip fracture (aOR 0.68, 95% CI 0.60-0.78).

CONCLUSIONS

Our study extends the previous knowledge of reduced fracture risk of thiazides to persons with AD, a population with significantly increased background risk of fractures.

Role of musculoskeletal disorders in falls of postmenopausal women

We aimed to investigate the role of musculoskeletal disorders (MSDs) as risk factors for falls among postmenopausal women. Our results indicate that MSDs are common and are associated with increased falling risk, especially nonslip falls. Excess number of falls due to MSDs is greater than that due to any other disease class.

PURPOSE

Falls are a major public health problem worldwide. The aim of the study was to investigate the role of MSDs as risk factors for falls among postmenopausal women.

METHODS

This cohort study utilized data from a population-based, prospective cohort study (OSTPRE). The study population consisted of 8656 women aged 57-66 years (in 1999) living in Kuopio Province, Eastern Finland, who responded to postal enquiries in 1999 and 2004. Information on MSDs and other morbidities was obtained from the 1999 enquiry and information on falls from the 2004 enquiry. Women were classified as fallers or non-fallers according to their falling events in the preceding 12 months. The fallers were further divided into women with slip and nonslip falls.

RESULTS

Of the study sample, 53.3% reported a MSD and 39.2% reported a fall during the preceding 12 months. MSDs predicted falls (OR = 1.38; 95% CI 1.26-1.50) and the association was stronger for nonslip (OR = 1.56; 95% CI 1.39-1.75) than slip falls (OR 1.22; 95% CI 1.08-1.38) compared to the women without MSDs. The risk of falls increased with increasing number (1, 2, ≥ 3) of MSDs: 1.25 (95%CI 1.13-1.38), 1.48 (95%CI 1.30-1.68), and 1.92 (95%CI 1.60-2.31), respectively. After adjustments, the risk of falling related to MSDs reduced by about 5% (adjusted p < 0.001). The population attributable fraction of falls due to MSDs was 10.3% of all falls, greater than that due to any other disease class.

CONCLUSION

MSDs are common and an important risk factor for falls and especially nonslip falls among postmenopausal women. The number of excess falls due to MSDs in this population group is greater than that due to any other disease class.

Long-term effects of functional impairment on fracture risk and mortality in postmenopausal women

Our findings imply that simple functional tests can predict both hip fracture risk and excess mortality in postmenopausal women. Since the tests characterize general functional capacity (one-legged stance, squatting down, and grip strength), these simple measures should have clinical utility in the assessment of women at risk of falls and fragility fracture.

INTRODUCTION

Functional impairment is associated with the risk of fall, which is the leading cause of hip fracture. We aimed to determine how clinical assessments of functional impairment predict long-term hip fracture and mortality.

METHODS

A population-based prospective cohort involved 2815 Caucasian women with the average baseline age of 59.1 years. The mean follow-up time in 1994-2014 was 18.3 years. Three functional tests and their combinations assessed at baseline were treated as dichotomous risk factors: (1) inability to squat down and touch the floor (SQ), (2) inability to stand on one leg for 10 s (SOL), and (3) having grip strength (GS) within the lowest quartile (≤ 58 kPa, mean 45.6 kPa). Bone mineral density (BMD) at the proximal femur was measured by DXA. Fractures and deaths were verified from registries. Hazard ratios were determined by using Cox proportional models. Age, body mass index (BMI), and BMD were included as covariates for fracture risk estimates. Age, BMI, and smoking were used for mortality.

RESULTS

Altogether, 650 (23.1%) women had 718 follow-up fractures, including 86 hip fractures. The mortality during the follow-up was 16.8% (n = 473). Half of the women (56.8%, n = 1600) had none of the impairments and were regarded as the referent group. Overall, women with any of the three impairments (43.2%, n = 1215) had higher risks of any fracture, hip fracture, and death, with hazard ratios (HR) of 1.3 ((95% CI) 1.0-1.5, p < 0.01), 2.4 (1.5-3.4, p < 0.001), and 1.5 (1.3-1.8, p < 0.001), respectively. The strongest single predictor for hip fracture was failing to achieve a one-leg stand for 10 s (prevalence 7.1%, n = 200), followed by inability to squat down (27.0%, n = 759) and weak grip strength (24.4%, n = 688), with their respective HRs of 4.3 (2.3-8.0, p < 0.001), 3.1 (2.0-5.0, p < 0.001), and 2.0 (1.2-3.4, p < 0.001). In addition, age, lower BMD, BMI, and smoking were significant covariates.

CONCLUSIONS

These findings suggest that functional tests provide long-term prediction of fracture and death in postmenopausal women. Whether reversal of these impairments is associated with a reduction in adverse outcomes is an area for future trials.

Pulse-echo ultrasound method for detection of post-menopausal women with osteoporotic BMD

We lack effective diagnostics of osteoporosis at the primary health care level. An ultrasound device was used to identify subjects in the osteoporotic range as defined by DXA. A case finding strategy combining ultrasound results with DXA measurements for patients with intermediate ultrasound results is presented.

INTRODUCTION

We lack effective screening and diagnostics of osteoporosis at primary health care. In this study, a pulse-echo ultrasound (US) method is investigated for osteoporosis screening.

METHODS

A total of 1091 Caucasian women (aged 50-80 years) were recruited for the study and measured with US in the tibia and radius. This method measures cortical thickness and provides an estimate of bone mineral density (BMD) and density index (DI). BMD assessment of the hip was available for 988 women. A total of 888 women had one or more risk factors for osteoporosis (OP _susp ), and 100 women were classified healthy. Previously determined thresholds for the DI were evaluated for assessment of efficacy of the technique to detect hip BMD at osteoporotic range (T-score at or below - 2.5).

RESULTS

In the OP _susp group, the application of thresholds for the DI showed that approximately 32% of the subjects would require an additional DXA measurement. The multi-site ultrasound (US) measurement-based DI showed 93.7% sensitivity and 81.6% specificity, whereas the corresponding values for single-site US measurement-based DI were 84.7 and 82.0%, respectively. The ultrasound measurements showed a high negative predictive value 97.7 to 99.2% in every age decade examined (ages 50-59, 60-69, 70-79 years).

CONCLUSIONS

The study data demonstrate that a strategy of combining ultrasound measurement with added DXA measurements in cases with intermediate ultrasound results (about 30%) can be useful for identifying subjects at risk for a low bone mineral density in the osteoporotic range.

PLS3 sequencing in childhood-onset primary osteoporosis identifies two novel disease-causing variants

Altogether 95 children with primary bone fragility were screened for variants in PLS3, the gene underlying X-linked osteoporosis. Two children with multiple peripheral and spinal fractures and low BMD had novel disease-causing PLS3 variants. Children with milder phenotypes had no pathogenic variants. PLS3 screening is indicated in childhood-onset primary osteoporosis.

INTRODUCTION

The study aimed to determine the role of pathogenic PLS3 variants in children's bone fragility and to elucidate the associated phenotypic features.

METHODS

Two cohorts of children with bone fragility were screened for variants in PLS3, the gene underlying X-linked osteoporosis. Cohort I comprised 31 patients with childhood-onset primary osteoporosis of unknown etiology. Cohort II comprised 64 children who had sustained multiple fractures but were otherwise healthy. Clinical and radiological data were reviewed. Peripheral blood DNA was Sanger sequenced for coding exons and flanking intronic regions of PLS3.

RESULTS

In two patients of cohort I, where other common genetic causes had been excluded, we identified two novel disease-causing PLS3 variants. Patient 1 was a male with bilateral femoral fractures at 10 years, low BMD (Z-score -4.1; 18 years), and multiple vertebral compression fractures. He had a novel nonsense variant in PLS3. Patient 2 was a girl with multiple long bone and vertebral fractures and low BMD (Z-score -6.6 at 6 years). She had a de novo missense variant in PLS3; whole exome sequencing and array-CGH identified no other genetic causes. Iliac crest bone biopsies confirmed low-turnover osteoporosis in both patients. In cohort II, no pathogenic PLS3 variants were identified in any of the subjects.

CONCLUSIONS

Two novel disease-causing variants in PLS3 were identified in a boy and a girl with multiple peripheral and spinal fractures and very low BMD while no pathogenic variants were identified in children with less severe skeletal fragility. PLS3 screening is warranted in male and female patients with childhood-onset primary osteoporosis.

Relationship of body anthropometric measures with skeletal muscle mass and strength in a reference cohort of young Finnish women

OBJECTIVES

1) To study if limb length explains variability in appendicular and total muscle mass better than height and 2) if muscle mass adjusted for limb length rather than height correlates better with grip and knee extension strength.

METHODS

400 healthy women aged 20-40 were recruited as a reference population. Body composition, limb length, grip strength and knee extension strength were measured. New relative muscle mass indexes were computed by adjusting upper limb muscle mass for upper limb length (ULRSMI) and lower limb muscle mass for lower limb length (LLRSMI).

RESULTS

Height correlated strongest with all muscle mass measures. Height had the highest R² values for predicting variability in appendicular skeletal muscle mass (0.33), upper limb skeletal muscle mass (0.20), lower limb skeletal muscle mass (0.34) and total skeletal muscle mass (0.36). Correlation of relative skeletal muscle mass index (RSMI) with grip and knee extension strength (r=0.47 and 0.43) was higher when compared with correlation of ULRSMI and LLRSMI with these measures.

CONCLUSION

Compared to limb length, height correlates better with regional and total muscle mass. Muscle mass adjusted for height correlates better with grip strength and knee strength when compared with muscle mass adjusted for limb length.

Inclusion of Regional Body Composition Parameters Improves Bone Mineral Density Cross-Calibration Between GE Lunar Prodigy and iDXA Densitometers

Since 1989, the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE, n = 14220) Study has followed long-term changes of bone mineral density (BMD) and body composition in women with GE Lunar devices. During the course of OSTPRE, the dual-energy X-ray absorptiometry device had to be replaced by a newer model. Then, it was essential to determine whether systematic measurement differences in BMD and body composition will occur. As a part of the OSTPRE study, BMD was measured in 54 women, whereas body composition was determined in 55 women, aged 27-71, by using both the GE Healthcare Lunar Prodigy and iDXA narrow-angle fan beam densitometers during the same visit. The total body fat mass (FM) and lean body mass (LBM) results of these scanners showed a high linear correlation (r = 0.981-0.994, p < 0.0001). However, the mean total body FM and LBM values measured by iDXA were on average 2.3% (0.5 kg, 95% confidence interval: 0.3-0.7 kg) higher and 0.8% (0.3 kg, 95% confidence interval: 0.1-0.6 kg) lower, respectively, than those measured by Prodigy. Inclusion of local soft tissue measurements (total body LBM, legs/android FM) improved the agreement of total body, total hip, and lumbar spine BMD values between the devices but not femoral neck BMD agreement. Equations, based on linear regression analyses, were derived to minimize differences between the instruments. Then, the differences in BMD and body composition measurements were negligible between Prodigy and iDXA. Using correction equations enables an objective comparison of longitudinal BMD and body composition measurements.

Association of Protein Intake with Bone Mineral Density and Bone Mineral Content among Elderly Women: The OSTPRE Fracture Prevention Study

It has been hypothesized that high protein intakes are associated with lower bone mineral content (BMC). Previous studies yield conflicting results and thus far no studies have undertaken the interaction of body mass index (BMI) and physical activity with protein intakes in relation to BMC and bone mineral density (BMD).

OBJECTIVE

To evaluate the associations of dietary total protein (TP), animal protein (AP) and plant protein (PP) intakes with BMC and BMD and their changes. We tested also the interactions of protein intake with, obesity (BMI ≤30 vs. >30 kg/m2) and physical activity level (passive vs. active). Design/ Setting: Prospective cohort study (Osteoporosis Risk-Factor and Fracture-Prevention Study). Participants/measures: At the baseline, 554 women aged 65-72 years filled out a 3-day food record and a questionnaire covering data on lifestyle, physical activity, diseases, and medications. Intervention group received calcium 1000 mg/d and cholecalciferol 800 IU for 3 years. Control group received neither supplementation nor placebo. Bone density was measured at baseline and year 3, using dual energy x-ray absorptiometry. Multivariable regression analyses were conducted to examine the associations between protein intake and BMD and BMC.

RESULTS

In cross-sectional analyses energy-adjusted TP (P≤0·029) and AP (P≤0·045) but not PP (g/d) were negatively associated with femoral neck (FN) BMD and BMC. Women with TP≥1·2 g/kg/body weight (BW) (Ptrend≤0·009) had lower FN, lumbar spine (LS) and total BMD and BMC. In follow-up analysis, TP (g/kg/BW) was inversely associated with LS BMD and LS BMC. The detrimental associations were stronger in women with BMI<30 kg/m2. In active women, TP (g/kg/BW) was positively associated with LS BMD and FN BMC changes.

CONCLUSIONS

This study suggests detrimental associations between protein intake and bone health. However, these negative associations maybe counteracted by BMI>30 kg/m2 and physical activity.

Targeted re-sequencing of linkage region on 2q21 identifies a novel functional variant for hip and knee osteoarthritis

OBJECTIVE

The aim of the study was to identify genetic variants predisposing to primary hip and knee osteoarthritis (OA) in a sample of Finnish families.

METHODS

Genome wide analysis was performed using 15 independent families (279 individuals) originating from Central Finland identified as having multiple individuals with primary hip and/or knee OA. Targeted re-sequencing was performed for three samples from one 33-member, four-generation family contributing most significantly to the LOD score. In addition, exome sequencing was performed in three family members from the same family.

RESULTS

Genome wide linkage analysis identified a susceptibility locus on chromosome 2q21 with a multipoint LOD score of 3.91. Targeted re-sequencing and subsequent linkage analysis revealed a susceptibility insertion variant rs11446594. It locates in a predicted strong enhancer element region with maximum LOD score 3.42 under dominant model of inheritance. Insertion creates a recognition sequence for ELF3 and HMGA1 transcription factors. Their DNA-binding affinity is highly increased in the presence of A-allele compared to wild type null allele.

CONCLUSION

A potentially novel functional OA susceptibility variant was identified by targeted re-sequencing. This variant locates in a predicted regulatory site and creates a recognition sequence for ELF3 and HMGA1 transcription factors that are predicted to play a significant role in articular cartilage homeostasis.

New method for point-of-care osteoporosis screening and diagnostics

SUMMARY

Due to the lack of diagnostics in primary health care, over 75% of osteoporotic patients are not diagnosed. A new ultrasound method for primary health care is proposed. Results suggest applicability of ultrasound method for osteoporosis diagnostics at primary health care.

INTRODUCTION

We lack effective screening and diagnostics of osteoporosis at primary health care. In this study, a new ultrasound (US) method is proposed for osteoporosis diagnostics.

METHODS

A total of 572 Caucasian women (age 20 to 91 years) were examined using pulse-echo US measurements in the tibia and radius. This method provides an estimate of bone mineral density (BMD), i.e. density index (DI). Areal BMD measurements at the femoral neck (BMD(neck)) and total hip (BMD(total)) were determined by using axial dual-energy X-ray absorptiometry (DXA) for women older than 50 years of age (n = 445, age = 68.8 ± 8.5 years). The osteoporosis thresholds for the DI were determined according to the International Society for Clinical Densitometry (ISCD). Finally, the FRAX questionnaire was completed by 425 participants.

RESULTS

Osteoporosis was diagnosed in individuals with a T-score -2.5 or less in the total hip or femoral neck (n = 75). By using the ISCD approach for the DI, only 28.7% of the subjects were found to require an additional DXA measurement. Our results suggest that combination of US measurement and FRAX in osteoporosis management pathways would decrease the number of DXA measurements to 16% and the same treatment decisions would be reached at 85.4% sensitivity and 78.5% specificity levels.

CONCLUSIONS

The present results demonstrate a significant correlation between the ultrasound and DXA measurements at the proximal femur. The thresholds presented here with the application to current osteoporosis management pathways show promise for the technique to significantly decrease the amount of DXA referrals and increase diagnostic coverage; however, these results need to be confirmed in future studies.

Association of adipokines and estradiol with bone and carotid calcifications in postmenopausal women

OBJECTIVES

Carotid artery calcifications (CAC) and high carotid artery intima-media thickness (cIMT) are associated with low bone mineral density (BMD) by unknown mechanisms in postmenopausal women. Leptin, adiponectin and estradiol may mediate these associations. Our aim was to study the relationships of the aforementioned factors to bone health (BMD) and carotid atherosclerosis (CAC and cIMT).

METHOD

Participants (n = 290, mean age 73.6 years) for this cross-sectional OSTPRE-BBA study (Kuopio Osteoporosis Risk Factor and Prevention - Bone, Brain and Atherosclerosis) were randomly selected from the OSTPRE cohort in 2009. Femoral neck and total body BMDs, trunk and total body fat mass were measured with dual-energy X-ray absorptiometry, and cIMT (mm) and CAC (no/yes) were measured with B-type ultrasound. Free estradiol, adiponectin and leptin were measured from serum samples.

RESULTS

Circulating estradiol levels were associated with leptin (β = 0.131, p < 0.001), but not with adiponectin (p > 0.05), when adjusted for total body fat mass. There were no associations between estradiol tertiles and BMDs, or with cIMT or CAC. Adiponectin levels were inversely associated with femoral neck BMD (p = 0.019, β = -0.138) and total body BMD (p = 0.009, β = -0.142), adjusted for total body fat mass, age, current smoking and estradiol, but showed no relationship with CAC or cIMT. Leptin levels were not associated with BMDs or cIMT; but the odds ratio was 1.5 between the CAC and leptin quartiles (p = 0.014), adjusted for total body fat mass, age, statin use and calcium intake.

CONCLUSION

The adipokines are associated with vascular calcification and low BMD. Moreover, estradiol was not independently associated with BMD or CAC.

The contribution of health selection to occupational status inequality in Germany - differences by gender and between the public and private sectors

OBJECTIVES

Estimating the size of health inequalities between hierarchical levels of job status and the contribution of direct health selection to these inequalities for men and women in the private and public sector in Germany.

STUDY DESIGN

The study uses prospective data from the Socio-Economic Panel study on 11,788 women and 11,494 men working in the public and private sector in Germany.

METHODS

Direct selection effects of self-rated health on job status are estimated using fixed-effects linear probability models. The contribution of health selection to overall health-related inequalities between high and low status jobs is calculated.

RESULTS

Women in the private sector who report very good health have a 1.9 [95% CI: 0.275; 3.507] percentage point higher probability of securing a high status job than women in poor self-rated health. This direct selection effect constitutes 20.12% of total health inequalities between women in high and low status jobs. For men in the private and men and women in the public sector no relevant health selection effects were identified.

CONCLUSIONS

The contribution of health selection to total health inequalities between high and low status jobs varies with gender and public versus private sector. Women in the private sector in Germany experience the strongest health selection. Possible explanations are general occupational disadvantages that women have to overcome to secure high status jobs.

Effect of one-year post-operative alendronate treatment on periprosthetic bone after total knee arthroplasty

Total knee arthroplasty (TKA) is known to lead to a reduction in periprosthetic bone mineral density (BMD). In theory, this may lead to migration, instability and aseptic loosening of the prosthetic components. Bisphosphonates inhibit bone resorption and may reduce this loss in BMD. We hypothesised that treatment with bisphosphonates and calcium would lead to improved BMD and clinical outcomes compared with treatment with calcium supplementation alone following TKA. A total of 26 patients, (nine male and 17 female, mean age 67 years) were prospectively randomised into two study groups: alendronate and calcium (bisphosphonate group, n = 14) or calcium only (control group, n = 12). Dual energy X-ray absorptiometry (DEXA) measurements were performed post-operatively, and at three months, six months, one, two, four, and seven years post-operatively.

Mean femoral metaphyseal BMD was significantly higher in the bisphosphonate group compared with controls, up to four years following surgery in some areas of the femur (p = 0.045). BMD was observed to increase in the lateral tibial metaphysis in the bisphosphonate group until seven years (p = 0.002), and was significantly higher than that observed in the control group throughout (p = 0.024). There were no significant differences between the groups in the central femoral metaphyseal, tibial medial metaphyseal or diaphyseal regions of interest (ROI) of either the femur or tibia.

Bisphosphonate treatment after TKA may be of benefit for patients with poor bone quality. However, further studies with a larger number of patients are necessary to assess whether this is clinically beneficial.

Cite this article: Bone Joint J 2015;97-B:337–45.

Perioperative complications after cemented or uncemented hemiarthroplasty in hip fracture patients

BACKGROUND AND AIMS

Both cemented and uncemented hemiarthroplasties are acceptable methods for treating displaced femoral neck fractures. Cemented hemiarthroplasty has traditionally been recommended as being more safe and reliable. However, the cementing process carries a risk of fat embolism and cardiovascular problems. This study attempted to determine whether these complications can be avoided when using a modern uncemented stem.

MATERIAL AND METHODS

We retrospectively compared 222 hip fracture patients treated with hemiarthroplasty in our hospital. A total of 100 of these patients were treated with a hydroxyapatite-coated uncemented hemiendoprosthesis (Bi-Metric BFx) and 122 patients with a cemented hemiendoprosthesis (Lubinus SPII). Information on mortality and complications during the first 18.7 months was retrieved from patient files.

RESULTS AND CONCLUSIONS

Nine perioperative fat-embolic events were found in the cemented group and none in the uncemented group. During the initial hospital treatment, there were five deaths (4.1%) in the cemented group and one death (1%) in the uncemented group. There were significantly more perioperative fractures in the uncemented versus cemented group (7% versus 0.8%). We conclude that uncemented hemiarthroplasty is associated with more perioperative fractures than cemented hemiarthroplasty. However, perioperative cardiovascular disturbances may be less frequent with uncemented hemiarthroplasty, and early mortality may be lower with uncemented hemiarthroplasty.

Dependence of light attenuation and backscattering on collagen concentration and chondrocyte density in agarose scaffolds

Optical coherence tomography (OCT) has been applied for high resolution imaging of articular cartilage. However, the contribution of individual structural elements of cartilage on OCT signal has not been thoroughly studied. We hypothesize that both collagen and chondrocytes, essential structural components of cartilage, act as important light scatterers and that variation in their concentrations can be detected by OCT through changes in backscattering and attenuation. To evaluate this hypothesis, we established a controlled model system using agarose scaffolds embedded with variable collagen concentrations and chondrocyte densities. Using OCT, we measured the backscattering coefficient (µb) and total attenuation coefficient (µt) in these scaffolds. Along our hypothesis, light backscattering and attenuation in agarose were dependent on collagen concentration and chondrocyte density. Significant correlations were found between µt and chondrocyte density (ρ = 0.853, p < 0.001) and between µt and collagen concentration (ρ = 0.694, p < 0.001). µb correlated significantly with chondrocyte density (ρ = 0.504, p < 0.001) but not with collagen concentration (ρ = 0.103, p = 0.422) of the scaffold. Thus, quantitation of light backscattering and, especially, attenuation could be valuable when evaluating the integrity of soft tissues, such as articular cartilage with OCT.

5-Methylcytosin-Gehalt in Rattenerythroleukämie-Zellen nach Induktion mit Dimethylsulfoxid / 5-Methylcytosine Content in Erythroleucemic Cells of Rats after Induction with Dimethylsulfoxid

Erythroleucemic cells of rats were induced by DMSO for the terminal erythroid differentia­tion. The base composition and the 5MC content of the DNA were analyzed by HPLC and a significant difference between non-induced and induced cells was not found. The analysis of labelled DNA by the restriction enzymes Hha I, Hpa II, and Msp I did not result in a different pattern before and after the induction. These results suggest that the 5 MC content of the DNA does not change during the induced terminal erythroid differentiation.

Zur Rolle des Substrats bei der Cortison-Induktion von Enzymen in der Leber

Studiert wurde das Zusammenspiel zwischen Cortisonacetat und Substrat bei der Induktion der Tyrosin-α-Ketoglutarat-Transaminase und der Tryptophan-Pyrrolase.

1. Nach intraperitonealer Injektion von 600 mg/kg ʟ-Tyrosin kann die Tyrosin-α-Ketoglutarat Transaminase noch 13 Stdn. später durch 2,5 mg/kg Cortisonacetat induziert werden. Dieses tritt nicht ein bei Applikation von 300 mg/kg L-Tyrosin.

2. Die Tryptophan-Pyrrolase läßt sich nach Gabe von ʟ-Tryptophan im Falle von 500 mg/kg über einen Zeitraum von 3 Stdn., im Falle von 250 mg/kg etwa 1 Stde. induzieren.

3. Es besteht eine deutliche Parallelität zwischen Induzierbarkeit der Enzyme und Gehalt an freiem Tyrosin bzw. Tryptophan in der Leber.

Einfluß von monochromatischem UV-Licht verschiedener Wellenlänge auf die Matrizenfunktion der DNS im RNS-Polymerase-System

Die Matrizenfunktion von DNS im RNS-Polymerase-System wird bei monochromatischer UV-Bestrahlung stärker bei höheren Wellenlängen eingeschränkt. Die Synthese von Poly A ist durch die UV-Bestrahlung wesentlich weniger beeinträchtigt als die RNS-Synthese.

Arthroscopic ultrasound technique for simultaneous quantitative assessment of articular cartilage and subchondral bone: an in vitro and in vivo feasibility study

Traditional arthroscopic examination is subjective and poorly reproducible. Recently, we introduced an arthroscopic ultrasound method for quantitative diagnostics of cartilage lesions. Here we describe our investigation of the feasibility of ultrasound arthroscopy for simultaneous measurements of articular cartilage and subchondral bone. Human osteochondral samples (n = 13) were imaged using a clinical 9-MHz ultrasound system. Ultrasound reflection coefficients (R, IRC), the ultrasound roughness index (URI) and the apparent integrated backscattering coefficient (AIB) were determined for both tissues. Mechanical testing, histologic analyses and micro-scale computed tomography imaging were the reference methods. Ultrasound arthroscopies were conducted on two patients. The ultrasound reflection coefficient correlated with the Mankin score and Young's modulus of cartilage (|r| > 0.56, p < 0.05). Ultrasound parameters (R, IRC, AIB) for subchondral bone correlated with the bone surface/volume ratio (|r| > 0.70, p < 0.05) and trabecular thickness (|r| > 0.59, p < 0.05). Furthermore, R and subchondral bone mineral density were significantly correlated (|r| > 0.65, p < 0.05). Arthroscopic ultrasound examination provided diagnostically valuable information on cartilage and subchondral bone in vivo.

Longitudinal elastic properties and porosity of cortical bone tissue vary with age in human proximal femur

Tissue level structural and mechanical properties are important determinants of bone strength. As an individual ages, microstructural changes occur in bone, e.g., trabeculae and cortex become thinner and porosity increases. However, it is not known how the elastic properties of bone change during aging. Bone tissue may lose its elasticity and become more brittle and prone to fractures as it ages. In the present study the age-dependent variation in the spatial distributions of microstructural and microelastic properties of the human femoral neck and shaft were evaluated by using acoustic microscopy. Although these properties may not be directly measured in vivo, there is a major interest to investigate their relationships with the linear elastic measurements obtained by diagnostic ultrasound at the most severe fracture sites, e.g., the femoral neck. However, before the validity of novel in vivo techniques can be established, it is essential to understand the age-dependent variation in tissue elastic properties and porosity at different skeletal sites. A total of 42 transverse cross-sectional bone samples were obtained from the femoral neck (Fn) and proximal femoral shaft (Ps) of 21 men (mean±SD age 47.1±17.8, range 17-82years). Samples were quantitatively imaged using a scanning acoustic microscope (SAM) equipped with a 50MHz ultrasound transducer. Distributions of the elastic coefficient (c33) of cortical (Ct) and trabecular (Tr) tissues and microstructure of cortex (cortical thickness Ct.Th and porosity Ct.Po) were determined. Variations in c33 were observed with respect to tissue type (c33Tr<c33Ct), location (c33(Ct.Ps)=37.7GPa>c33(Ct.Fn)=35.3GPa>c33(Tr.Ps)=33.8GPa>c33(Tr.Fn)=31.9GPa), and cadaver age (R(2)=0.28-0.46, p<0.05). Regional variations in porosity were found in the neck (superior 13.1%; inferior 6.1%; anterior 10.1%; posterior 8.6%) and in the shaft (medial 9.5%; lateral 7.7%; anterior 8.6%; posterior 12.0%). In conclusion, significant variations in elastic coefficients were detected between femoral neck and shaft as well as between the quadrants of the cross-sections of neck and shaft. Moreover, an age-related increase in cortical porosity and a stiffening of the bone tissue were observed. These findings may explain in part the increase in susceptibility to suffer low energy fractures during aging and highlight the potential of ultrasound in clinical osteoporosis diagnostics.

Obesity has a negative impact on clinical outcome after total knee arthroplasty

BACKGROUND AND AIMS

Obesity has been linked to the development of osteoarthritis of the knee and since the incidence of obesity is increasing, the need for total knee arthroplasty (TKA) is likely to increase. Conflicting findings have been reported concerning the relationship between obesity and TKA. It has been shown in several studies, that obese patients have poorer clinical results after operation. On the other hand it has also been reported similar results for obese and non-obese patients. The purpose of this study was to analyze clinically and radiologically the results of total knee artrhoplasty in obese patients.

MATERIAL AND METHODS

The study consisted of 48 patients who had a TKA. The patients were divided in two groups according their body mass index. Patients of BMI over 30 were regarded as obese.

RESULTS

The obese patients had poorer clinical success at the final follow-up, their WOMAC scores were significantly higher compared to non-obese (pain 20.7 vs. 11.6; p = 0.021, stiffness 26.9 vs. 13.4; p = 0.006, physical function 26.5 vs. 14.4; p = 0.003). Differences were also found in the Knee (KS) and Function (FS) scores and a long-term postoperative ROM and (KS: 83.6 vs. 88.9; p = 0.01, FS: 63.6/76.3; p = 0.051, ROM: 104.6 vs. 109.6; p = 0.016). Non-obese patients reached better percentage improvement in the KSS compared to obese patients (KS change + 194.5% vs. + 59.5%, p = 0.03; FS change + 51.5% vs. + 14.9%, p = 0.19).

CONCLUSIONS

Obesity has a negative impact on the outcome of TKA, assessed by patients' clinical function and satisfaction level.

Once-monthly oral ibandronate provides significant improvement in bone mineral density in postmenopausal women treated with glucocorticoids for inflammatory rheumatic diseases: a 12-month, randomized, double-blind, placebo-controlled trial

OBJECTIVES

To study the efficacy and safety of once-monthly oral ibandronate in the prevention of glucocorticoid (GC)-induced osteoporosis (GIOP) in postmenopausal women with inflammatory rheumatic diseases.

METHOD

A randomized, double-blind, placebo-controlled, parallel-group study of 140 postmenopausal women was conducted. At baseline, the mean lumbar spine (LS) (L1-L4) bone mineral density (BMD) was normal or osteopaenic (T-score ≥ -2.0) and the patients were receiving treatment with 5-15 mg/day of prednisone equivalent. Patients were randomized 1:1 to receive either monthly oral ibandronate 150 mg or placebo for 12 months. All patients received vitamin D and calcium supplements. The primary endpoint was the relative change in mean LS BMD from baseline to 12 months.

RESULTS

Mean LS BMD increased significantly by 2.6% and 3.2% from baseline to 6 and 12 months with ibandronate compared to 0.3% and -0.1% with placebo, respectively (p < 0.001). Comparable significant mean increases were also found in trochanter, femoral neck and total hip BMDs at 12 months. Reductions in the serum levels of bone turnover markers C-terminal telopeptide of type I collagen (sCTX), N-terminal propeptide of type I procollagen (P1NP), and tartrate-resistant acid phosphatase (TRACP) were significantly more marked in the ibandronate group than in the placebo group at 1, 6, and 12 months. Adverse events (AEs) were reported at a similar frequency in both groups. A higher proportion of serious AEs (SAEs) were reported in the ibandronate group without emergence of any single SAE.

CONCLUSIONS

Once-monthly oral ibandronate provides a significant increase in LS and total hip BMD with an acceptable safety profile in postmenopausal women treated with low-dose GCs for inflammatory rheumatic diseases.

Preoperative Predictors for Good Postoperative Satisfaction and Functional Outcome in Lumbar Spinal Stenosis Surgery — A Prospective Observational Study with a Two-Year Follow-up

Background and Aims:

Lumbar spinal stenosis (LSS) is the most frequent indication for back surgery in adults aged over 65 years, but about one-third of operated patients have less than good/excellent results from the operation. Awareness of outcome predictors and their predictive values may help clinicians in their assessment of the prognosis of patients when considering surgical treatment. Our aim was to study the preoperative predictors in LSS for a good postoperative outcome (satisfaction with surgery and functional improvement) with a two-year follow-up.

Material and Methods:

LSS patients (n = 102) completed a questionnaire preoperatively and on two-year follow-up. Preoperative patient-related predictors, self-rated health, comorbidities and preoperative treatment were assessed. Satisfaction with the surgical outcome was assessed with a seven-category scale; satisfaction was determined to be good if the patient response was “condition has considerably improved” or “totally cured”. Other responses (“condition has slightly improved” or worse) represented poorer satisfaction. A good functional outcome was determined as > 30% relative improvement compared to the presurgery score in the Oswestry Disability Index (ODI).

Results:

The predictors for good satisfaction were age < 75 years at operation (OR 4.03; 95% CI 1.35–12.02; p = 0.012) and no previous lumbar operation (OR 3.65; 95% CI 1.13–11.79; p = 0.031). Predictors for a good improvement in the ODI score were regular preoperative analgesic use < 12 months (OR 3.40; 95% CI 1.21–9.53; p = 0.020), non-smoking (OR 3.47; 95% CI 1.09–11.03; p = 0.035) and good (above average) self-rated health (OR 3.27; 95% CI 1.06–10.12; p = 0.039).

Conclusions:

In LSS, regular analgesic treatment preoperatively for 12 months or less, self-rated health above average and non-smoking predicted a good postoperative functional improvement. An age under 75 years and no previous lumbar operation predicted good postoperative satisfaction with the surgery.

Femoral Neck Bone Mineral Density after Resurfacing Hip Arthroplasty

Introduction:

Resurfacing hip arthroplasty (RHA) has been suggested to provide an alternative to conventional total hip arthroplasty in younger, active patients. It seems to have an ability to conserve the bone mass on the femoral side. Some controversy exists regarding to the possible disadvantages of RHA and some of them are connected to poor femoral bone quality after surgery. Hence we wanted to study the bone mineral density changes 3 and 12 months after RHA.

Materials and Methods:

A total of 26 patients (22 men and 4 women, 28 hips) underwent a hip resurfacing arthroplasty. The mean age of the patients was 55,2 (range 38–69) years. Bone mineral density (BMD) of the proximal femur was measured by using the dual-energy X-ray absorptiometry (DXA) postoperatively and within 3 and 12 months from surgery. For analysis, we divided the femoral neck area into four equal-sized regions of interest ranging from the prosthesis to the trochanter level.

Results:

At three months follow-up the BMD changes varied between −5.1% (ROIC) and + 1.9% (ROIA), as compared with the immediate postoperative values. After one year follow-up the BMD changes were + 1.1% in the ROIA, + 5.4% in the ROIB, −3.9% in the ROIC and + 1.3% in the ROID. The changes in BMD were not statistically significant.

Discussion:

While there is still much debate and room for additional research in this topic, the results suggest that BMD is conserved in the femoral neck one year after hip resurfacing arthroplasty.

Multi-site bone ultrasound measurements in elderly women with and without previous hip fractures

About 75% of patients suffering from osteoporosis are not diagnosed. This study describes a multi-site bone ultrasound method for osteoporosis diagnostics. In comparison with axial dual energy X-ray absorptiometry (DXA), the ultrasound method showed good diagnostic performance and could discriminate fracture subjects among elderly females.

INTRODUCTION

Axial DXA, the gold standard diagnostic method for osteoporosis, predicts fractures only moderately. At present, no reliable diagnostic methods are available at the primary health care level. Here, a multi-site ultrasound method is proposed for osteoporosis diagnostics.

METHODS

Thirty elderly women were examined using the ultrasound backscatter measurements in proximal femur, proximal radius, proximal and distal tibia in vivo. First, we predicted the areal bone mineral density (BMD) at femoral neck by ultrasound measurements in tibia combined with specific subject characteristics (density index, DI) and, second, we tested the ability of ultrasound backscatter measurements at proximal femur to discriminate between individuals with previously fractured hips from those without fractures. Areal BMD was determined by axial DXA.

RESULTS

Combined ultrasound parameters, cortical thickness at distal and proximal tibia, with age and weight of the subject, provided a significant estimate of BMD(neck) (r = 0.86, p < 0.001, n = 30). When inserted into FRAX (World Health Organization fracture risk assessment tool), the DI indicated the same treatment proposal as the BMD(neck) with 86% sensitivity and 100% specificity. The receiver operating characteristic analyses, with a combination of ultrasound parameters and patient characteristics, discriminated fracture subjects from the controls similarly as the model combining BMD(neck) and patient characteristics.

CONCLUSIONS

For the first time, ultrasound backscatter measurements of proximal femur were conducted in vivo. The results indicate that ultrasound parameters, combined with patient characteristics, may provide a means for osteoporosis diagnostics.

Associations of dietary polyunsaturated fatty acids with bone mineral density in elderly women

BACKGROUND/OBJECTIVES

Significance of dietary fatty acids on bone health is not clear, and the evidence is controversial. This study aimed to investigate the relationship between dietary polyunsaturated fatty acids (PUFAs) and bone mineral density (BMD) among elderly women.

SUBJECTS/METHODS

Subjects (n=554) were drawn from the Kuopio OSTPRE Fracture Prevention Study. At baseline they filled a 3-day food record and a questionnaire on lifestyle factors, diseases and medications. BMD was measured at lumbar spine (L2-L4), femoral neck and total body by dual energy X-ray absorptiometry at baseline and after 3 years. The associations between dietary fatty acids and BMD were analyzed by a linear mixed model adjusting for potential dietary and non-dietary confounders.

RESULTS

Our findings suggested a positive relationship between the dietary PUFAs and BMD at lumbar spine and in total body but not at femoral neck. Further analyses revealed that these results were due to associations among the women without hormone therapy (HT) at baseline. Among them, the intake of total PUFAs as well the intakes of linoleic and linolenic acids and total n-3 and n-6 fatty acids were significantly associated with BMD at lumbar spine; P for trend over the quartiles ranged between 0.013 and 0.001. Similarly, significant associations were demonstrated for total body BMD and fatty acids with an exception of total PUFA. No significant associations were found among women with HT at baseline.

CONCLUSIONS

Our findings among elderly women without HT support the suggested beneficial effect of dietary PUFAs on bone health.

Analysis of plastic deformation in cortical bone after insertion of coated and non-coated self-tapping orthopaedic screws

Insertion of internal fracture fixation devices, such as screws, mechanically weakens the bone. Diamond-like carbon has outstanding tribology properties which may decrease the amount of damage in tissue. The purpose of this study was to investigate methods for quantification of cortical bone damage after orthopaedic bone screw insertion and to evaluate the effect of surface modification on tissue damage. In total, 48 stainless steel screws were inserted into cadaver bones. Half of the screws were coated with a smooth amorphous diamond coating. Geometrical data of the bones was determined by peripheral quantitative computed tomography. Thin sections of the bone samples were prepared after screw insertion, and histomorphometric evaluation of damage was performed on images obtained using light microscopy. Micro-computed tomography and scanning electron microscopy were also used to examine tissue damage. A positive correlation was found between tissue damage and the geometric properties of the bone. The age of the cadaver significantly affected the bone mineral density, as well as the damage perimeter and diameter of the screw hole. However, the expected positive effect of surface modification was probably obscured by large variations in the results and, thus, statistically significant differences were not found in this study. This can be explained by natural variability in bone tissue, which also made automated image analysis difficult.

Body fat distribution is associated with lumbar spine bone density independently of body weight in postmenopausal women

OBJECTIVE

To assess the association between the body fat distribution and axial bone mineral density (BMD) in postmenopausal women with or without hormone replacement therapy (HRT).

DESIGN

Cross-sectional population-based study.

SETTING

University of Eastern Finland, Bone and Cartilage Research Unit, Kuopio, Finland.

POPULATION

198 postmenopausal women, mean age 67.5 (1.9 SD), mean BMI 27.1 (3.9 SD).

METHODS

Regional body composition and BMD assessed by dual X-ray absorptiometry (DXA, Prodigy).

MAIN OUTCOME MEASURES

Spinal and Femoral BMD.

RESULTS

Out of the body composition parameters, FM was the main determinant of postmenopausal bone mass. Only the lumbar spine (L2-L4) BMD, not the femoral neck BMD, was positively associated with the trunk FM. Positive trends for association were revealed between the spinal BMD and the trunk FM regardless of the use of HRT. Adjustments did not change the results.

CONCLUSIONS

Higher trunk fat mass was associated with the spinal BMD, but not with the hip BMD in postmenopausal women, irrespective of the HRT use. In addition to biological factors, uncertainties related to DXA measurements in patients with varying body mass may contribute to this phenomenon.

Bone health-related factors and the use of bisphosphonates in community setting--15-year follow-up study

The present study investigated the bone health related factors that were associated with the use of bisphosphonates (BP) among 2,050 postmenopausal Finnish women. Low BMD + low trauma energy fracture was the strongest determinant of BP use, while other secondary causes of osteoporosis were less strongly related with BP use. BP use was associated with reduced femoral neck (FN) and lumbar spine (LS) bone loss rate.

INTRODUCTION

The aim was to identify bone health related factors associated with the use of BP in a community setting.

METHODS

A population-based sample of 2,050 Finnish postmenopausal women was measured with dual X-ray absorptiometry at the FN and LS in 1989, 1994, 1999 and 2004, and information on osteoporosis risk factors, including low-trauma energy fractures, were collected with postal inquiries. Self-reported use of BP in 2004 was considered as the end point variable.

RESULTS

Among BP users, 12% had T-score > -2.0 SD and no fracture during follow-up (FU). In women without any bone medication, 26% had T-score < -2.0 SD or low-trauma energy fracture or both during the FU. In BP users, a significant reduction in FN and LS bone loss rate, cumulative with duration of use, was observed in ANCOVA (p < 0.001). Among BP users, there was a significantly higher proportion of women with several independent risk factors for osteoporosis and more spine and humerus fractures but less ankle fractures. T-score < -2 SD combined with low-trauma energy fracture was significantly related to the use of BPs (p < 0.001, OR = 15.96) and T-score < -2 SD was a stronger predictor of BP use (p < 0.001, OR = 13.29) than fracture (p > 0.05, OR = 1.35) in multivariate logistic regression. Other factors related with BP use were vitamin D use (p = 0.001, OR = 2.27), high number of medications (p < 0.001, OR = 1.26) and rheumatoid arthritis (p < 0.05, OR 2.55).

CONCLUSIONS

These findings reveal the recent bone health-related indications for BP prescription.

Structural parameters of normal and osteoporotic human trabecular bone are affected differently by microCT image resolution

This study employed microCT to investigate whether image resolution affects bone structural parameters differently in healthy normal and osteoporotic trabecular bone. With increasing image voxel size, the originally detected differences between sample groups diminished. The results suggest that structural differences may not be reliably detected with clinical scanners.

INTRODUCTION

Structural parameters of bone reflect its health status, but are highly dependent on the image resolution. We hypothesized that image resolution affects bone structural parameters differently in normal and osteoporotic trabecular bone.

METHODS

Human trabecular bone samples from the iliac crest and the knee were analyzed (normal n = 11, osteoporotic n = 15) using a high-resolution microCT (14 or 18 µm voxel sizes). Images were re-sampled to voxel sizes 1-16 times larger than the original image and thresholded with global or local adaptive algorithms. Absolute and normalized values of each structural parameter were calculated, and the effect of decreasing image resolution was compared between the normal and osteoporotic samples.

RESULTS

Normal and osteoporotic samples had different (p < 0.05) absolute bone volume fractions. However, the normalized values showed that the osteoporotic samples were more prone to errors (p < 0.05) with increased voxel size. The absolute values of trabecular number, trabecular separation, degree of anisotropy, and structure model index were different between the groups at the original voxel size (p < 0.05), but at voxel sizes between 60 and 110 µm, those differences were no longer significant.

CONCLUSIONS

The results suggest that structural differences between osteoporotic and normal trabecular bone may not be reliably detected with clinical CT scanners providing image voxel sizes above 100 µm.

Severity of vertebral fracture and risk of hip fracture: a nested case-control study

Severe vertebral fractures strongly predicted subsequent hip fracture in this population-based study. Such high-risk patients should be provided with clinical evaluation and care for osteoporosis.

INTRODUCTION

Vertebral fractures are commonly osteoporotic and known to predict hip fracture. The aim of this study was to evaluate associations between the severity of vertebral fractures and the risk of subsequent hip fracture.

METHODS

Chest radiographs were obtained of 7,095 Finnish men and women aged 30 years or over in the Mini-Finland Health Survey in 1978-1980. Record linkage to the National Hospital Discharge Register identified 182 subjects from the survey who had subsequently been hospitalized for primary treatment of hip fracture by the end of 1994. A nested case-control setting was adopted, where three controls individually matched for age, gender, and place of residence were drawn for 169 subjects with hip fracture from the same cohort. Baseline vertebral fractures were identified at levels T3 to T12, and their morphology was categorized to mild, moderate, or severe according to Genant's classification.

RESULTS

Severe vertebral fracture (>40% reduction in vertebral body height) strongly predicted hip fracture. After controlling for education, physical activity, smoking, alcohol consumption, and self-rated general health, the adjusted relative odds was 12.06 (95% confidence interval, 3.80-38.26). Mild to moderate fracture grades and the number of compressed vertebral bodies showed no prediction for hip fracture.

CONCLUSIONS

The presence of a severe vertebral fracture in the thoracic spine strongly predicts subsequent hip fracture. Such high-risk patients should be clinically evaluated and provided with care for osteoporosis and measures to reduce the risk of falling as required.

Effect of calcium and vitamin D supplementation on bone mineral density in women aged 65-71 years: a 3-year randomized population-based trial (OSTPRE-FPS)

SUMMARY

The Osteoporosis Risk Factor and Prevention-Fracture Prevention Study (OSTPRE-FPS) was a randomized population-based open trial (n = 593). The supplementation group (n = 287) received daily cholecalciferol 800 IU + calcium 1,000 mg for 3 years while the control group (n = 306) received neither supplementation nor placebo. Daily vitamin D and calcium supplementation have a positive effect on the skeleton in ambulatory postmenopausal women.

INTRODUCTION

vitamin D deficiency is common in the elderly, and vitamin D levels are associated with low bone mineral density (BMD). The working hypothesis was that vitamin D and calcium supplementation could prevent bone loss in ambulatory postmenopausal women.

METHODS

the OSTPRE-FPS was a randomized population-based open trial with a 3-year follow-up in 3,432 women (aged 66 to 71 years). A randomly selected subsample of 593 subjects underwent BMD measurements. The supplementation group (n = 287) received daily cholecalciferol 800 IU + calcium 1,000 mg for 3 years while the control group (n = 306) received neither supplementation nor placebo.

RESULTS

in the intention-to-treat analysis, total body BMD (n = 362) increased significantly more in the intervention group than in the control group (0.84% vs. 0.19%, p = 0.011). The BMD change differences at the lumbar spine (p = 0.372), femoral neck (p = 0.188), trochanter (p = 0.085), and total proximal femur (p = 0.070) were statistically nonsignificant. Analyses in compliant women (≥ 80% of use) resulted in stronger and statistically significant effects at the total body and femoral regions.

CONCLUSION

daily vitamin D and calcium supplementation have a positive effect on the skeleton in ambulatory postmenopausal women with adequate nutritional calcium intake.