Can pain flares in knee osteoarthritis be predicted?

Objectives: This study examined whether risk factors for knee osteoarthritis (KOA) pain such as age, gender, body mass index (BMI), baseline pain, and other putative risk factors for knee osteoarthritis pain flares (KOAF) (e.g. knee buckling, injury, mood/stress/social support scores, and footwear) could predict KOAF.Method: People with KOA and previous history of KOAF were selected from a 3 month web-based longitudinal study. KOAF was defined as an increase of ≥ 2 points on a numeric rating scale (compared with background pain) which resolved within 20 days. Predictors assessed at baseline were gender, age, duration of KOA, BMI, pain, knee injury (7 days before), knee buckling (2 days before), Lubben Social Support, Knee Injury and Osteoarthritis Outcome Score, Intermittent and Constant Osteoarthritis Pain score (ICOAP), Positive/Negative Affect Score, and footwear stability/heel height. Outcome was occurrence of any KOAF during the ensuing 30 days. The combined ability of the above variables to predict occurrence of any KOAF was evaluated by multiple logistic regression with a 10-fold cross-validation method to build and internally validate the model. Variables that assessed similar domains were eliminated using receiver operating characteristics curve assessment for best fit.Results: Complete data were available for 313 people (66.6% female, mean ± sd age 62.3 ± 8.2 years, BMI 29.7 ± 6.5 kg/m²). Increasing age, years of osteoarthritis, BMI, background/worst levels of pain, knee injury, knee buckling, ICOAP, and footwear category/heel height significantly predicted the occurrence of KOAF during the following 30 days, with an area under the curve of 0.73 (95% confidence interval 0.67-0.80).Conclusion: A combination of risk factors assessed at baseline, including exposures with potential to vary, successfully predicts the KOAF in the ensuing 30 days.

What Triggers an LBP Flare? A Content Analysis of Individuals' Perspectives

OBJECTIVE

For many, low back pain (LBP) is a lifelong condition with symptoms varying over time. Previous studies have investigated long-term risk factors and triggers for onset of LBP. No study has examined causes for less distinct fluctuations of symptoms, such as "flares," which individuals with LBP identify as a significant and worrisome part of LBP. As little is known about what triggers this type of fluctuation, we aimed to investigate individuals' perspectives on LBP flare triggers.

METHODS

We conducted an online survey of 130 people with LBP, asking what they think triggers their flares. Data were qualitatively examined using content analysis.

RESULTS

Most participants identified biomedical (84.8%) triggers, endorsing physical/biological factors to explain the flare occurrence. Themes included active movements (35% of participants), static postures (28.1%), overdoing a task (5.3%), biomechanical dysfunction (4.4%), comorbidities (4%), lack of exercise (3.3%), work (1.8%), and medications (1.5%). Nonbiomedical triggers were reported by 15.2% and included psychosocial and contextual factors, including psychological state (6%), weather (5%), sleep (2%), diet (1.2%), and fatigue (1%). These results indicate that individuals consider biomedical factors to be the main triggers of LBP flares, but some acknowledge nonbiomedical triggers.

CONCLUSIONS

Study findings contrast with current pain theories, which suggest that there is a need for a reduced emphasis on biomedical causes of LBP pain, especially when persistent. Recognition of patients' views on causes of LBP flares is crucial to better guide clinical practice and inform further research. The validity of triggers identified by LBP patients requires further investigation.

Sleep Quality and Fatigue Are Associated with Pain Exacerbations of Hip Osteoarthritis: An Internet-based Case-crossover Study

OBJECTIVE

To evaluate the association of sleep quality, sleep duration, and fatigue with hip pain exacerbations in persons with symptomatic hip osteoarthritis (OA).

METHODS

Participants (n = 252) were followed for 90 days and asked to complete online questionnaires at 10-day intervals (control periods). A hip pain exacerbation (case periods) was defined as an increase of 2 points in pain intensity compared with baseline on a numeric rating scale (0-10). Subjective sleep quality and sleep duration were assessed using the Pittsburgh Sleep Quality Index, and fatigue was measured by Multidimensional Assessment of Fatigue in both periods. Univariable and multivariable conditional logistic regressions were used to assess the association.

RESULTS

Of the 252 participants, 130 (52%) were included in the final analysis. Univariate association analysis showed that both poor sleep quality and greater fatigue were associated with increased odds of pain exacerbations (OR 1.72, 95% CI 1.04-2.86; OR 1.92, 95% CI 1.21-3.05, respectively). Short sleep duration was not associated with pain exacerbations. Poor sleep quality and greater fatigue remained associated with pain exacerbations after adjustment for physical activity and night pain levels in multivariable analysis. There was no significant interaction between sleep quality and fatigue (p = 0.21).

CONCLUSION

Poor sleep quality and greater fatigue were related to pain exacerbation in persons with symptomatic hip OA. Sleep disorders and fatigue should be considered when dealing with pain exacerbations.

A Definition of "Flare" in Low Back Pain: A Multiphase Process Involving Perspectives of Individuals With Low Back Pain and Expert Consensus

Low back pain (LBP) varies over time. Consumers, clinicians, and researchers use various terms to describe LBP fluctuations, such as episodes, recurrences and flares. Although "flare" is use commonly, there is no consensus on how it is defined. This study aimed to obtain consensus for a LBP flare definition using a mixed-method approach. Step 1 involved the derivation of a preliminary candidate flare definition based on thematic analysis of views of 130 consumers in consultation with an expert consumer writer. In step 2, a workshop was conducted to incorporate perspectives of 19 LBP experts into the preliminary flare definition, which resulted in 2 alternative LBP flare definitions. Step 3 refined the definition using a 2-round Delphi consensus with 50 experts in musculoskeletal conditions. The definition favored by experts was further tested with 16 individuals with LBP in step 4, using the definition in three scenarios. This multiphase study produced a definition of LBP flare that distinguishes it from other LBP fluctuations, represents consumers' views, involves expert consensus, and is understandable by consumers in clinical and research contexts: "A flare-up is a worsening of your condition that lasts from hours to weeks that is difficult to tolerate and generally impacts your usual activities and/or emotions." Perspective: A multiphase process, incorporating consumers' views and expert consensus, produced a definition of LBP flare that distinguishes it from other LBP fluctuations.

Individuals' explanations for their persistent or recurrent low back pain: a cross-sectional survey

BACKGROUND

Most people experience low back pain (LBP), and it is often ongoing or recurrent. Contemporary research knowledge indicates individual's pain beliefs have a strong effect on their pain experience and management. This study's primary aim was to determine the discourses (patterns of thinking) underlying people's beliefs about what causes their LBP to persist. The secondary aim was to investigate what they believed was the source of this thinking.

METHODS

We used a primarily qualitative survey design: 130 participants answered questions about what caused their LBP to persist, and where they learned about these causes. We analysed responses about what caused their LBP using discourse analysis (primary aim), and mixed methods involving content analysis and descriptive statistics to analyse responses indicating where participants learnt these beliefs (secondary aim).

RESULTS

We found that individuals discussed persistent LBP as 1) due to the body being like a 'broken machine', 2) permanent/immutable, 3) complex, and 4) very negative. Most participants indicated that they learnt these beliefs from health professionals (116, 89%).

CONCLUSIONS

We concluded that despite continuing attempts to shift pain beliefs to more complex biopsychosocial factors, most people with LBP adhere to the traditional biomedical perspective of anatomical/biomechanical causes. Relatedly, they often see their condition as very negative. Contrary to current "best practice" guidelines for LBP management, a potential consequence of such beliefs is an avoidance of physical activities, which is likely to result in increased morbidity. That health professionals may be the most pervasive source of this thinking is a cause for concern. A small number of people attributed non-physical, unknown or complex causes to their persistent LBP - indicating that other options are possible.

What constitutes back pain flare? A cross sectional survey of individuals with low back pain

BACKGROUND AND PURPOSE

Low back pain (LBP) is a lifelong problem for many. In acute episodes, or as a persistent condition, LBP is fluctuating in nature, with pain and other features of the condition varying in intensity and duration over time. Symptom flares (also known as flare ups) contribute to this variation and can have a great impact on the lives of those who have LBP. An important goal of treatments for, and research on, LBP is arguably to decrease symptom flare in both frequency and severity. However, this goal is problematic with little research, and no consensus, on how to define LBP flare. In particular, patients' understandings of LBP flare have received limited attention in the literature. To appropriately address this issue, we sought to understand how flares are conceptualized by individuals with LBP.

METHODS

We used an inductive, predominantly qualitative methodology, conducting an online survey with 130 individuals who self-reported experiencing LBP. The survey investigated participants' views on LBP flare including its meaning, features and symptoms, and whether 'flare' and 'pain increase' were synonymous. Qualitative analysis of responses involved thematic and content analysis with descriptive statistics used for the quantitative component.

RESULTS

Our data analysis found that participants identified many aspects of a flare to be important. Qualitative analyses highlighted a number of themes including that LBP flare was conceptualized as: (1) an increase in pain and other uncomfortable sensations such as paraesthesia or muscle tension, (2) an increase in the area, quality and/or duration of symptoms, (3) a reduction in physical, cognitive and/or social functioning, and (4) negative psychological and/or emotional factors. Flare was also discussed as a change that was difficult to settle. When participants considered whether 'flare' and 'pain increase' were synonymous, responses were evenly divided between 'no' (47%) and 'yes' (46%) with remaining participants 'unsure'.

CONCLUSIONS

The key finding was that many people with LBP do not consider their condition to be flared simply on the basis of a pain increase. In general, other features were required to also change. Results highlighted that a narrow focus on pain is unlikely to differentiate minor pain events from a flare. These findings are important as they contrast with most commonly used definitions of a flare that focus predominantly on pain increase.

IMPLICATIONS

Our findings have implications for understanding the trajectory of LBP over time. Understandings derived from perspectives of individuals with LBP highlight that defining flare in LBP is complex. In order to provide person-centred care, individual context and experiences should be taken into account. Therefore, understandings of LBP flare require consideration of factors beyond simply an increase in pain. A comprehensive, person-centred understanding of flare that includes a number of features beyond simply an increase in pain intensity is likely to be useful to better identify flares in research settings, assisting endeavours to understand and reduce LBP. Similarly, in clinical settings a nuanced conceptualisation of flare is likely to help health professionals communicate understandings of flare when working with individuals to manage their LBP.

Is There a Dose-Response Relationship Between Weight Loss and Symptom Improvement in Persons With Knee Osteoarthritis?

OBJECTIVE

We examined the dose-response relationship between weight reduction and pain/functional improvement in persons with symptomatic knee osteoarthritis (KOA) participating in a community-based weight loss program.

METHODS

Consecutive participants with KOA and enrolled in the 18-week Osteoarthritis Healthy Weight for Life weight-loss program were selected. In this completer-type analysis, participants were assessed at baseline, 6 weeks, and 18 weeks for body weight and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales. The dose-response relationship between weight-change categories (>10%, 7.6-10%, 5.1-7.5%, 2.6-5.0%, and <2.5% of body weight loss) and change in KOOS scores was assessed by repeated-measures analysis of variance, controlling for sex and age, body mass index (BMI), and KOOS. The Western Ontario McMaster Universities Osteoarthritis Index function score derived from the KOOS was used to assess a meaningful clinical functional improvement.

RESULTS

A total of 1,383 persons (71% females) were enrolled. Mean ± SD age, height, and weight were 64 ± 8.7 years, 1.66 ± 0.09 meters, and 95.1 ± 17.2 kg, respectively. Mean ± SD BMI was 34.4 ± 5.2 kg/m(2) with 82% of participants obese at baseline. A total of 1,304 persons (94%) achieved a >2.5% reduction in body weight. There was a significant dose-response relationship between all KOOS subscales and percentage of weight change across all weight-change categories. Participants required ≥7.7% (95% confidence interval 5.2, 13.3) body weight loss to achieve a minimal clinically important improvement in function.

CONCLUSION

There is a significant dose-response relationship between percentage of weight loss and symptomatic improvement. This study confirms the feasibility of weight loss as a therapeutic intervention in KOA in a community-based setting.

Is the effectiveness of patellofemoral bracing modified by patellofemoral alignment and trochlear morphology?

Background

This study was performed to determine if the effectiveness of patellofemoral bracing as a treatment for patellofemoral osteoarthritis is influenced by patellofemoral joint alignment and trochlear morphology. We hypothesized that those with more extreme patellar malalignment would benefit more from bracing.

Methods

Thirty-eight patients who had received bracing as part of a comprehensive treatment plan for patellofemoral osteoarthritis were selected for this study. Ten measures of patellar alignment were taken from X-rays. These alignment measures were divided into percentile groups (tertiles) for contingency table analysis. Treatment outcome was measured by Western Ontario and Macmasters Universities Osteoarthritis Index (WOMAC) scores and these were dichotomised into two groups according to “Improved” or “Not Improved” according to the minimum clinically important difference (MCID). Spearman’s rho test was performed for continuous variables and Fisher’s exact test was performed for correlation between tertile groups and MCID categories.

Results

Thirty-eight patients (9 male and 29 female) between the ages of 51 to 89 were included in this study. WOMAC scores ranged from −25 to 41.67, with a mean change of −3.97, 31.6, 44.7 and 31.6% of patients falling into the “Improved” group for Global, Pain and Function scores respectively. We found a non-significant trend shown (p = 0.058, correlation coefficient 0.31) between bisect offset and change in WOMAC global, indicating a trend for higher change in WOMAC scores with increasing bisect offset. Statistically significant correlations were found between mean MCID categories for the WOMAC global and function groups when analysed against percentile groups for bisect offset (p < 0.01) and patellar subluxation distance (p < 0.05), indicating those in higher percentile groups were more likely not to improve after six months.

Conclusion

Higher bisect offset and patellar subluxation distance measures were associated with poorer outcomes. However, due to the limited sample size, more studies are required to fully examine this relationship.

The influence of weather on the risk of pain exacerbation in patients with knee osteoarthritis - a case-crossover study

OBJECTIVE

To quantify the risk of knee pain exacerbation associated with temperature, relative humidity, air pressure and precipitation in persons with knee osteoarthritis.

METHOD

A web-based case-crossover study was conducted. Participants with a diagnosis of symptomatic, radiographic knee osteoarthritis were measured at baseline and followed for 3 months. Participants were instructed to log on to the study website if they perceived experiencing knee pain exacerbation (hazard period). Pain exacerbation was defined as an increase of ≥2 on a 0-10 numeric rating scale (NRS) from the participant's mildest pain reported at baseline. A time-stratified case-crossover study was conducted to anchor the corresponding hazard date to four control periods within a particular 35-day interval. Data on maximum and minimum temperature (°C), relative humidity (%), barometric pressure (hPa) and precipitation (mm) were obtained for the hazard and control periods from the publicly available meteorological database of the Australian Bureau of Meteorology. The associations were assessed using conditional logistic regression.

RESULTS

Of the 345 participants recruited, 171 participants (women: 64%, mean age: 62 years, mean BMI: 30.2 kg/m²) experienced at least one episode of pain exacerbation, yielding 1,425 observations included in the analyses. There was no apparent association between temperature, relative humidity, air pressure or precipitation and risk of knee pain exacerbation.

CONCLUSION

Despite anecdotal reports from patients, change in weather factors does not appear to influence the risk of pain exacerbation in persons with knee osteoarthritis. Additional studies should quantify the association of weather and risk of pain exacerbation in regions with more extreme weather conditions.

Can We Predict Those With Osteoarthritis Who Will Worsen Following a Chronic Disease Management Program?

OBJECTIVE

To identify predictors of worsening symptoms and overall health of the treated hip or knee joint following 26 weeks of a nonsurgical chronic disease management program for hip and knee osteoarthritis (OA) and to examine the consistency of these predictors across 3 definitions of worsening.

METHODS

This prospective cohort study followed 539 participants of the program for 26 weeks. The 3 definitions of worsening included symptomatic worsening based on change in the Western Ontario and McMaster Universities Osteoarthritis Index Global score (WOMAC-G) measuring pain, stiffness, and function; a transition scale that asked about overall health of the treated hip or knee joint; and a composite outcome including both. Multivariate logistic regression models were constructed for the 3 definitions of worsening.

RESULTS

Complete data were available for 386 participants: mean age was 66.3 years, 69% were female, 85% reported knee joint pain as primary symptom (signal joint), 46% were waitlisted for total joint arthroplasty (TJA). TJA waitlist status, signal joint, 6-Minute Walk Test (6MWT), depressive symptoms, pain, and age were independently associated with at least 1 definition of worsening. TJA waitlist status and 6MWT remained in the multivariate models for the transition and composite definitions of worsening.

CONCLUSION

Participants reporting worsening on the transition scale did not consistently meet the WOMAC-G definition of worsening symptoms. TJA waitlist status was predictive of the composite definition of worsening, a trend apparent for the transition definition. However, variables that predict worsening remain largely unknown. Further research is required to direct comprehensive and targeted management of patients with hip and knee OA.

Relationship of Buckling and Knee Injury to Pain Exacerbation in Knee Osteoarthritis: A Web-Based Case-Crossover Study

BACKGROUND

Knee osteoarthritis (OA) is one of the most frequent causes of limited mobility and diminished quality of life. Pain is the main symptom that drives individuals with knee OA to seek medical care and a recognized antecedent to disability and eventually joint replacement. Evidence shows that patients with symptomatic OA experience fluctuations in pain severity. Mechanical insults to the knee such as injury and buckling may contribute to pain exacerbation.

OBJECTIVE

Our objective was to examine whether knee injury and buckling (giving way) are triggers for exacerbation of pain in persons with symptomatic knee OA.

METHODS

We conducted a case-crossover study, a novel methodology in which participants with symptomatic radiographic knee OA who have had knee pain exacerbations were used as their own control (self-matched design), with all data collected via the Internet. Participants were asked to log-on to the study website and complete an online questionnaire at baseline and then at regular 10-day intervals for 3 months (control periods)-a total of 10 questionnaires. They were also instructed to go to the website and complete pain exacerbation questionnaires when they experienced an isolated incident of knee pain exacerbation (case periods). A pain exacerbation "case" period was defined as an increase of ≥2 compared to baseline. At each contact the pain exacerbation was designated a case period, and at all other regular 10-day contacts (control periods) participants were asked about knee injuries during the previous 7 days and knee buckling during the previous 2 days. The relationship of knee injury and buckling to the risk of pain exacerbation was examined using conditional logistic regression models.

RESULTS

The analysis included 157 participants (66% women, mean age: 62 years, mean BMI: 29.5 kg/m(2)). Sustaining a knee injury was associated with experiencing a pain exacerbation (odds ratio [OR] 10.2, 95% CI 5.4, 19.3) compared with no injury. Knee buckling was associated with experiencing a pain exacerbation (OR 4.0, 95% CI 2.6, 6.2) compared with no buckling and the association increased with a greater number of buckling events (for ≥ 6 buckling events, OR 20.1, 95% CI 3.7, 110).

CONCLUSIONS

Knee injury and buckling are associated with knee pain exacerbation. Reducing the likelihood of these mechanical events through avoidance of particular activities and/or appropriate rehabilitation programs may decrease the risk of pain exacerbation.

Web-Based Study of Risk Factors for Pain Exacerbation in Osteoarthritis of the Knee (SPARK-Web): Design and Rationale

Background

Knee osteoarthritis (OA) is the most frequent cause of limited mobility and diminished quality of life. Pain is the main symptom that drives individuals with knee OA to seek medical care and a recognized antecedent to disability and eventually joint replacement. Many persons with symptomatic knee OA experience recurrent pain exacerbations. Knowledge and clarification of risk factors for pain exacerbation may allow those affected to minimize reoccurrence of these episodes.

Objective

The aim of this study is to use a Web-based case-crossover design to identify risk factors for knee pain exacerbations in persons with symptomatic knee OA.

Methods

Web-based case-crossover design is used to study persons with symptomatic knee OA. Participants with knee pain and radiographic knee OA will be recruited and followed for 90 days. Participants will complete an online questionnaire at the baseline and every 10 days thereafter (totaling up to 10 control-period questionnaires); participants will also be asked to report online when they experience an episode of increased knee pain. Pain exacerbation will be defined as an increase in knee pain severity of two points from baseline on a numeric rating scale (NRS 0-10). Physical activity, footwear, knee injury, medication use, climate, psychological factors, and their possible interactions will be assessed as potential triggers for pain exacerbation using conditional logistic regression models.

Results

This project has been funded by the National Health and Medical Research Council (NHMRC). The enrollment for the study has started. So far, 343 participants have been enrolled. The study is expected to be finished in October 2015.

Conclusions

This study will identify risk factors for pain exacerbations in knee OA. The identification and possible modification/elimination of such risk factors will help to prevent the reoccurrence of pain exacerbation episodes and therefore improve knee OA management.

Weight and fat distribution in patients taking valproate: a valproate-discordant gender-matched twin and sibling pair study

OBJECTIVES

Chronic treatment with valproate (VPA) is commonly associated with weight gain, which potentially has important health implications, in particular increased central fat distribution. We utilized a VPA-discordant same-sex, twin and matched sibling pair study design to primarily examine for differences in fat distribution between patients with epilepsy treated with VPA compared to their matched twin or sibling control. Weight, blood pressure, and leptin levels were assessed.

METHODS

Height, weight, waist and hip measurements, exercise, blood pressure (BP), and serum leptin levels were measured. Body composition was measured using dual-energy x-ray absorptiometry (DXA). Abdominal fat was expressed as a percentage of the abdominal region (AFat%); and of whole body fat (WBF); (AFat%WBF). Mean within-pair differences were assessed (VPA-user and nonuser). Restricted maximum likelihood (REML) linear mixed model analysis was fitted to examine associations of anthropometrics, zygosity, gender, menopausal status, VPA dose and duration, with weight and AFat%.

RESULTS

We studied 19 pairs of VPA-discordant, gender-matched (five male, 14 female) twins and siblings. Mean (standard deviation, SD) duration of therapy for VPA users was 11.0 (7.4) years. There were no statistically significant within-pair differences in age, height, weight, body mass index (BMI), BP, leptin level, WBF, AFat%, or AFat%WBF. For pairs in which VPA-user was treated for >11 years there were statistically significant mean within-pair differences in AFat%, (+7.1%, p = 0.03, n = 10 pairs), mean BP (+11.0 mm Hg, p = 0.006, n = 8 pairs); but not in AFat%WBF. VPA duration was positively associated with weight (estimate +0.98 kg/per year of VPA, p = 0.03); VPA treatment duration and dose were not significantly associated with AFat%.

SIGNIFICANCE

This study demonstrated a relationship between long-term VPA use and abdominal adiposity (AFat%), which could have significant health implications. We recommend ongoing monitoring of weight, BMI, and blood pressure for patients taking VPA.

The effect of anterior cruciate ligament injury on bone curvature: exploratory analysis in the KANON trial

OBJECTIVE

Investigate the 5-year longitudinal changes in bone curvature after acute anterior cruciate ligament (ACL) injury, and identify predictors of such changes.

METHODS

In the KANON-trial (ISRCTN 84752559), 111/121 young active adults with an acute ACL tear to a previously un-injured knee had serial 1.5 T MR images from baseline (within 5 weeks from injury) to 5 years after injury. Of these, 86 had ACL reconstruction (ACLR) performed early or delayed, 25 were treated with rehabilitation alone. Measures of articulating bone curvature were obtained from computer-assisted segmentation of MR images. Curvature (mm(-1)) was determined for femur, tibia, medial/lateral femur, trochlea, medial/lateral tibia. Age, sex, treatment, BMI, meniscal injury, osteochondral fracture on baseline MR images were tested for association.

RESULTS

Over 5 years, curvature decreased in each region (P < 0.001) suggesting flattening of convex shapes and increased concavity of concave shapes. A higher BMI was associated with flattening of the femur (P = 0.03), trochlea (P = 0.007) and increasing concavity of the lateral tibia (LT) (P = 0.011). ACLR, compared to rehabilitation alone, was associated with flatter curvature in the femur (P < 0.001), medial femoral condyle (P = 0.006) and trochlea (P = 0.003). Any meniscal injury at baseline was associated with a more flattened curvature in the femur (P = 0.038), trochlea (P = 0.039), lateral femoral condyle (P = 0.034) and increasing concavity of the LT (P = 0.048).

CONCLUSION

ACL injury is associated with significant changes in articulating bone curvature over a 5 year period. Higher BMI, baseline meniscal injury and undergoing ACL reconstruction (as distinct from undergoing rehabilitation alone) are all associated with flattening of the articulating bone.

Comparative effectiveness of anti-tumor necrosis factor drugs on health-related quality of life among patients with inflammatory arthritis

OBJECTIVE

To compare the relative effectiveness of anti-tumor necrosis factor (anti-TNF) therapies on health-related quality of life (HRQOL) by inflammatory arthritis types.

METHODS

Patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA) who had anti-TNF therapy (etanercept, adalimumab, or infliximab) in the Australian Rheumatology Association Database during 2001-2011 were assessed using the Medical Outcomes Study Short Form 36 (SF-36), Assessment of Quality of Life (AQoL), and Health Assessment Questionnaire (HAQ) disability index (DI) on a biannual basis. Linear regression was used for the analysis; the lack of independence in outcomes for multiple assessments in the same patient was taken into account using generalized estimating equations.

RESULTS

There were 18,119 assessments (first-time drug use n = 12,274, subsequent use n = 3,098, and no use n = 2,747) provided by 3,033 patients (2,240 RA, 507 AS, and 286 PsA patients) with the anti-TNF therapies. The effects of subsequent use versus first-time use were reduced on the SF-36 physical component summary, AQoL, and HAQ DI scores among RA patients. After adjusting for therapy order, calendar year, sex, age, smoking status, and various medication uses, the 3 anti-TNF preparations had similar effects on the HRQOL measures for patients with RA, AS, or PsA. However, differences between anti-TNF therapies were observed in the AQoL score among PsA patients (infliximab versus etanercept: -0.06 [95% confidence interval (95% CI) -0.12, -0.004]) and in the SF-36 mental component summary score among RA patients (adalimumab versus etanercept: -1.17 [95% CI -1.88, -0.46]).

CONCLUSION

This study revealed similar effectiveness of etanercept, adalimumab, and infliximab on the HRQOL measures among Australians with RA, AS, and PsA.

Vitamin D, bone mineral density and body mass index in eating disorder patients

AIM

To investigate associations of vitamin D with BMD and BMI in ED patients.

METHODS

Vitamin D, BMD and BMI for 50 patients admitted to a specialised ED inpatient unit were measured. Patients were aged 15-54 years with BMI 8-25 kg/m(2).

RESULTS

Of the patients, 18% were vitamin D deficient. There was a significant linear relationship between vitamin D and BMD T-score at the lumbar spine (p=0.029), femoral neck (p<0.001) and total hip (p=0.001). There was no relationship between vitamin D and BMI. There was a significant linear relationship between BMI and BMD T-score at the lumbar spine (p<0.001), femoral neck (p=0.008) and total hip (p=0.001).

CONCLUSIONS

Low vitamin D and low BMI are associated with low BMD in ED patients. Despite widespread belief that it is not necessary, our findings suggest it is appropriate to measure vitamin D in ED patients. It should not be assumed ED patients take supplements.

High osteoporotic fracture risk and CVD risk co-exist in postmenopausal women

INTRODUCTION

Osteoporosis related risk factors such as BMD have been associated with cardiovascular endpoints in previous studies but there have been no studies of integrated risk using risk factor algorithms.

METHODS

A sample of 358 peri- and postmenopausal women, mean age 59.3 (range 45-74) years were studied. Each individual had bone mineral density (BMD) measurements by dual energy X-ray absorptiometry. Fracture risk was assessed using the WHO FRAX algorithm and cardiovascular disease (CVD) risk using the Framingham Risk Tool.

RESULTS

Women with higher 10 year risk of major osteoporotic had significantly higher cardiovascular risk (4.634% vs 8.36%, p=0.001). In multiple regression analysis, 5-year CVD risk was significantly associated with the 10-year risk of having major osteoporotic (β=0.095, p=0.001) and hip (β=0.055, p=0.001) fracture. Women with the highest CVD risk were 5.4 times more likely to have higher risk of major osteoporotic fracture.

CONCLUSIONS

Fracture risk, determined by using a multiple risk factor algorithm such as FRAX, was positively associated with higher cardiovascular risk determined by using the Framingham Risk Tool. Awareness regarding these concurrent risk factors needs to be raised so that appropriate risk reduction can be implemented.

Serum uric acid plays a protective role for bone loss in peri- and postmenopausal women: a longitudinal study

OBJECTIVE

Oxidative stress has been linked to osteoporosis. Serum uric acid (UA), a strong endogenous antioxidant, has been associated with higher bone mineral density (BMD), lower bone turnover and lower prevalence of fractures in a large cross-sectional study of men. Whether this relationship is present in women and how UA relates to changes in BMD longitudinally has not been examined.

METHODS

A sample of 356 peri- and postmenopausal women, mean age 60.5 years was studied. Each individual had baseline BMD and body composition measurements by dual energy x-ray absorptiometry (DXA) and at least one repeat measure, on average 9.7 years later. Annual rate of change in BMD (A%ΔBMD) was calculated. UA was measured at each DXA visit. Calciotropic hormones and bone turnover markers were measured at the final visit only.

RESULTS

Cross-sectional data analyses revealed that women with higher UA levels had significantly higher absolute BMD measures at all skeletal sites. These women also had higher measures of body weight and its components such as lean mass (LM) and fat mass (FM). Results of multiple regression analyses showed a positive association between UA and BMD that remained significant even after accounting for possible confounders including LM and FM. Regression analyses of the longitudinal BMD data demonstrated significant associations between serum UA levels and annual rates of change in BMD at all skeletal sites. After adjustment associations remained significant for lumbar spine, forearm and whole body BMD but not for hip BMD.

CONCLUSION

Higher serum UA levels appear to be protective for bone loss in peri- and postmenopausal women and this relationship is not affected by changes in body composition measures.

Genome-wide association study using extreme truncate selection identifies novel genes affecting bone mineral density and fracture risk

Osteoporotic fracture is a major cause of morbidity and mortality worldwide. Low bone mineral density (BMD) is a major predisposing factor to fracture and is known to be highly heritable. Site-, gender-, and age-specific genetic effects on BMD are thought to be significant, but have largely not been considered in the design of genome-wide association studies (GWAS) of BMD to date. We report here a GWAS using a novel study design focusing on women of a specific age (postmenopausal women, age 55-85 years), with either extreme high or low hip BMD (age- and gender-adjusted BMD z-scores of +1.5 to +4.0, n = 1055, or -4.0 to -1.5, n = 900), with replication in cohorts of women drawn from the general population (n = 20,898). The study replicates 21 of 26 known BMD-associated genes. Additionally, we report suggestive association of a further six new genetic associations in or around the genes CLCN7, GALNT3, IBSP, LTBP3, RSPO3, and SOX4, with replication in two independent datasets. A novel mouse model with a loss-of-function mutation in GALNT3 is also reported, which has high bone mass, supporting the involvement of this gene in BMD determination. In addition to identifying further genes associated with BMD, this study confirms the efficiency of extreme-truncate selection designs for quantitative trait association studies.

Association between serum cholesterol and bone mineral density

BACKGROUND

Hypercholesterolaemia has been associated with low bone mineral density (BMD) in some but not all studies.

OBJECTIVES

To examine the influence of age, menopausal status and hormone replacement therapy (HRT) on the relationship between serum cholesterol and BMD in women.

PATIENTS AND MEASUREMENTS

497 female participants (age range 20-81) comprising 224 premenopausal and 273 postmenopausal women (156 on HRT and 117 no HRT) underwent measurements of bone mineral density (BMD) and serum lipid profile.

RESULTS

Total serum cholesterol (TC) and low density lipoprotein (LDL) levels were higher and lumbar spine BMD was lower in postmenopausal women not taking HRT compared to those taking HRT. TC and LDL were negatively associated with BMD at all measured sites among postmenopausal women not taking HRT in univariate regression analysis (all p<0.05). High density lipoprotein (HDL) had inverse relationships with BMD at all sites in pre-menopausal women and those who were exposed to HRT (p<0.05). In fully adjusted regression models the relationships between TC and BMD remained significant at the lumbar spine and whole body (p<0.05) and between LDL and lumbar spine BMD only (p<0.05). For subjects in the other groups, no significant associations between TC or LDL and BMD were found. Significant interactions between total cholesterol and LDL levels with HRT were detected among post-menopausal women in the regression analyses (all p<0.05). No such interactions were found between HDL levels and HRT.

CONCLUSION

There is a modest inverse relationship between lumbar spine and whole body BMD and serum TC and LDL levels and in post-menopausal women and HDL in pre-menopausal women. HRT use appears to modify these relationships. The mechanisms of this relationship require further study.

Genetic effects on bone loss in peri- and postmenopausal women: a longitudinal twin study

This longitudinal twin study was designed to assess the heritability of bone loss in peri- and postmenopausal women. A sample of 724 female twins was studied. Baseline and repeat BMD measurements were performed. Results of genetic model-fitting analysis indicated genetic effects on bone loss account for approximately 40% of the between-individual variation in bone loss at the lumbar spine, forearm, and whole body.

INTRODUCTION

BMD and bone loss are important predictors of fracture risk. Although the heritability of peak BMD is well documented, it is not clear whether bone loss is also under genetic regulation. This study was designed to assess the heritability of bone loss in peri- and postmenopausal women.

MATERIALS AND METHODS

A sample of 724 female twins (177 monozygotic [MZ] and 185 dizygotic [DZ] pairs), 45-82 yr of age, was studied. Each individual had baseline BMD measurements at the lumbar spine, hip, forearm, and total body by DXA and at least one repeat measure, on average 4.9 yr later. Change in BMD (DeltaBMD) was expressed as percent of gain or loss per year. Intraclass correlation coefficients for DeltaBMD were calculated for MZ and DZ pairs. Genetic model-fitting analysis was conducted to partition the total variance of DeltaBMD into three components: genetic (G), common environment (C), and specific environment, including measurement error (E). The index of heritability was estimated as the ratio of genetic variance over total variance.

RESULTS

The mean annual DeltaBMD was -0.37 +/- 1.43% (SD) per year at the lumbar spine, -0.27 +/- 1.32% at the total hip, -0.77 +/- 1.66% at the total forearm, -0.36 +/- 1.56% at the femoral neck, and -0.16 +/- 0.81% at the whole body. Intraclass correlation coefficients were significantly higher in MZ than in DZ twins for all studied parameters, except at the hip sites. Results of genetic model-fitting analysis indicated that the indices of heritability for DeltaBMD were 0.38, 0.49, and 0.44 for the lumbar spine, total forearm, and whole body, respectively. However, the genetic effect on DeltaBMD at all hip sites was not significant.

CONCLUSIONS

These data suggest that, although genetic effects on bone loss with aging are less pronounced than on peak bone mass, they still account for approximately 40% of the between-individual variation in bone loss for the lumbar spine, total forearm, and whole body in peri- and postmenopausal women. These findings are relevant for studies aimed at identification of genes that are involved in the regulation of bone loss.

Gender differences in plasma ghrelin and its relations to body composition and bone - an opposite-sex twin study

BACKGROUND

Ghrelin, a peptide hormone that plays a role in the regulation of appetite and body adiposity, may also play a role in bone metabolism.

OBJECTIVES

We used the opposite-sex twin model to study associations of plasma ghrelin levels with measures of bone mass and body composition, and determine how such associations were influenced by gender and age.

PATIENTS AND MEASUREMENTS

We measured total plasma ghrelin by radioimmunoassay (RIA) and bone mass/body composition parameters by dual energy X-ray absorptiometry in 79 pairs of opposite sex twins (n = 158 subjects). To examine the effect of age, the study population was divided by median age into two groups: under 51.2 years (38 pairs) and over 51.2 years (41 pairs).

RESULTS

Women had higher plasma ghrelin levels than men (median 1063 vs. 869 ng/l, P < 0.01). Age was a significant predictor of plasma ghrelin levels after adjustment for gender, fat mass and body size. In the older age group, plasma ghrelin levels were inversely associated with fat mass measures in men and women, but there were gender differences in the nature of these associations. In women, plasma ghrelin correlated inversely with body mass index (BMI, r = -0.32), total fat mass (r = -0.30) and fat mass/lean mass ratio (r = -0.42), whereas in men associations with abdominal fat mass (r = -0.31) and fat distribution index (r = -0.33) were observed. Plasma ghrelin was associated with alcohol consumption in older men and women. In the obese subgroup (BMI > 30) no significant gender differences in plasma ghrelin were found. Plasma ghrelin levels were not significantly associated with bone mineral density (BMD) generally, except for hip BMD in younger women (r = -0.39).

CONCLUSION

Plasma ghrelin levels are associated with age, gender, alcohol intake and fat mass measures but only weakly to bone mass measures.

Effect of antiepileptic medication on bone mineral measures

OBJECTIVE

Long-term antiepileptic drug (AED) use has been associated with bone disease, but many previous studies have been limited by inadequate control subjects. We used a cotwin affected sib-pair model to investigate this issue.

METHODS

The authors studied 31 female twin (15 monozygous and 16 dizygous) and four sibling pairs (< 3 years age difference) aged 21 to 75 years, in which one member had > 12 months of AED treatment. Areal bone mineral density (ABMD, g/cm2) was measured at the lumbar spine (LS), total hip (TH), femoral neck (FN), and total forearm (FA). Three primary a priori defined subgroups were analyzed: a) use for > 2 years, b) use of enzyme-inducing AEDs, or c) age older than 40 years.

RESULTS

For all pairs (n = 35), there were no significant within-pair differences in any ABMD measure. However, in Subgroup a (n = 27), there was a within-pair difference at the FA (0.513 vs 0.534, -3.9%, p = 0.016). In Subgroup b (n = 29), there was also a within-pair difference at the FA for AED user vs nonuser (0.508 vs 0.529, -3.8%, p = 0.010). In Subgroup c (n = 15), there were within-pair differences at the FA (0.492 vs 0.524, -6.1%, p = 0.017) and the LS (0.884 vs 0.980, -9.8%, p = 0.036).

CONCLUSIONS

Patients using AEDs for > 2 years, in particular those taking enzyme-inducing AEDs and those older than 40 years, have significantly lower bone mineral density at clinically relevant fracture risk sites.

Gender differences in relationships between body composition components, their distribution and bone mineral density: a cross-sectional opposite sex twin study

Numerous studies indicate that bone mineral density (BMD) is closely related to body mass and its components. Most studies have examined these relationships in women with little attention given to how these relationships differ by gender. The aims of the present study were to use the opposite sex twin model to determine if there were gender differences in the relationship between body composition and its relation to BMD and how any such differences were influenced by age. We measured body composition and bone mass by dual energy X-ray absorptiometry in 93 pairs of opposite sex twins. To examine the effect of age, they were divided into two age groups: under 50 years old (45 pairs) and over 50 years old (48 pairs). Lean mass (LM) had stronger positive relationships with the most bone variables than fat mass in both genders at all ages. Fat mass (FM) had positive relationships with total body and hip BMD in women under age 50, but not over 50. There was no significant relationship between FM and total or regional BMD in men under age 50, but men over 50 showed positive relationships between FM measures and total and some regional BMD measures. Central adiposity showed a positive relationship with BMD in men over 50 and women under 50. Fat mass (FM) and lean mass (LM) and their distribution in the body have different relationships with regional BMD in men and women that differ by age.