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ABSTRACT: BACKGROUND: The risk of experiencing an osteoporotic fracture is greater for adults with type 2 diabetes despite higher than normal bone mineral density (BMD). In addition to BMD, trabecular bone microarchitecture contributes to bone strength, but is not assessed using conventional BMD measurement by dual x-ray absorptiometry (DXA). The aim of this study was to compare two year changes in trabecular bone microarchitecture in women with and without type 2 diabetes. METHODS: We used a 1 Tesla magnetic resonance imaging (MRI) scanner to acquire axial images (resolution 195mum x 195mum x 1000mum) of the distal radius. We report the change in the number and size of trabecular bone holes, bone volume fraction (BVTV), trabecular thickness (Tb.Th), number (Tb.N) and separation (Tb.Sp), endosteal area, nodal and branch density for each group. Lumbar spine and proximal femur BMD were measured with DXA (Hologic, Discovery QDR4500A) at baseline and follow-up. Using a multivariable linear regression model, we evaluated whether the percent change in the trabecular bone microarchitecture variables differed between women with and without type 2 diabetes. RESULTS: Of the 54 participants at baseline with valid MRI image sets, 37 participants (baseline mean [SD] age, 70.8 [4.4] years) returned for follow-up assessment after 25.4 [1.9] months. Lumbar spine BMD was greater for women with diabetes compared to without diabetes at both baseline and follow-up. After adjustment for ethnicity, women with diabetes had a higher percent increase in number of trabecular bone holes compared to controls (10[1] % versus -7 [2]%, p=0.010), however results were no longer significant after adjustment for multiple comparisons (p=0.090). There were no differences in the change in other trabecular bone microarchitecture variables between groups. CONCLUSION: There were no differences in percent change in trabecular bone microarchitecture variables over two years in women with type 2 diabetes compared to women without diabetes. This study provides feasibility data, which will inform future trials assessing change in trabecular bone microarchitecture in women with type 2 diabetes. Larger studies using higher resolution imaging modalities that can assess change in trabecular and cortical bone compartments in women with type 2 diabetes are needed.
BMC Musculoskeletal Disorders 03/2013; 14(1):114. · 1.58 Impact Factor
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ABSTRACT: OBJECTIVES: To determine the extent to which thigh intermuscular fat (IMF) and quadriceps muscle (QM) volumes explained variance in knee extensor strength and physical performance in women with (ROA) and without (NROA) radiographic knee osteoarthritis. METHODS: Baseline data from 125 women in the Osteoarthritis Initiative, ò50 years, with or at risk for ROA were included. Knee extensor strength was measured using a fixed force transducer, normalized to body mass (N/kg). Physical performance was the time required for five repeated chair stands (s). The IMF and QM volumes, normalized to height (cm(3) /m), were yielded from analyses of T1-weighted axial magnetic resonance images of the mid-thigh. Mean IMF and QM volumes, extensor strength and physical performance were compared between ROA and NROA, controlling for age. Hierarchical multiple regressions determined whether IMF and QM volumes were related to strength and performance after controlling for age, radiographic OA status (yes/no), alignment and pain. RESULTS: Compared to ROA, the NROA were stronger and performed chair stands faster (p<0.05). After adjusting for age, NROA had less IMF (61.1 ± 20.3 cm(3) /m) compared to ROA (72.0 ± 25.0 cm(3) /m, p<0.05). In the entire sample, 21.1% of variance in knee extensor strength was explained by alignment, pain and IMF. A model explaining 13.4% of variance in physical performance included OA status and IMF. QM volume was unrelated to strength and physical performance. Conclusions: Intermuscular fat volume explained a small amount of variance in knee extensor strength and physical performance among women with, or at risk for ROA. © 2012 by the American College of Rheumatology.
Arthritis care & research. 10/2012;
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Archives of physical medicine and rehabilitation 10/2012; 93(10):1882. · 2.18 Impact Factor
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ABSTRACT: Strontium ranelate is an approved pharmacotherapy for osteoporosis in Europe and Australia, but not in Canada or the United States. Strontium citrate, an alternative strontium salt, however, is available for purchase over-the-counter as a nutritional supplement. The effects of strontium citrate on bone are largely unknown. The study's objectives were 1) to quantify bone strontium accumulation in female Sprague Dawley rats administered strontium citrate (N=7) and compare these levels to rats administered strontium ranelate (N=6) and vehicle (N=6) over 8weeks, and 2) to verify an in vivo X-ray fluorescence spectroscopy (XRF) system for measurement of bone strontium in the rat. Daily doses of strontium citrate and strontium ranelate were determined with the intention to achieve equivalent amounts of elemental strontium. However, post-hoc analyses of each strontium compound conducted using energy dispersive spectrometry microanalysis revealed a higher elemental strontium concentration in strontium citrate than strontium ranelate. Bone strontium levels were measured at baseline and 8weeks follow-up using a unique in vivo XRF technique previously used in humans. XRF measurements were validated against ex vivo measurements of bone strontium using inductively coupled plasma mass spectrometry. Weight gain in rats in all three groups was equivalent over the study duration. A two-way ANOVA was conducted to compare bone strontium levels amongst the three groups. Bone strontium levels in rats administered strontium citrate were significantly greater (p<0.05) than rats administered strontium ranelate and vehicle. ANCOVA analyses were performed with Sr dose as a covariate to account for differences in strontium dosing. The ANCOVA revealed differences in bone strontium levels between the strontium groups were not significant, but that bone strontium levels were still very significantly greater than vehicle.
Bone 09/2012; 52(1):63-69. · 4.02 Impact Factor
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ABSTRACT: OBJECTIVE: To evaluate the sensitivity and specificity of the GALS exam to screen for signs and symptoms of rheumatoid arthritis when used by family physicians and nurse practitioners. METHODS: Participating healthcare professionals, including two rheumatologists, three family physicians and three nurse practitioners, were trained to perform the GALS exam by viewing an instructional DVD and attending a training workshop. One week after training, healthcare professionals performed the GALS exam on 20 individuals with rheumatoid arthritis and 21 individuals without rheumatoid arthritis. All participants were recruited through two rheumatology practices. Each participant was assessed by four healthcare professionals. Healthcare professionals were asked to record whether observed signs and symptoms were potentially consistent with a diagnosis of rheumatoid arthritis. Healthcare professionals understood the study's objective to be their agreement on GALS findings amongst one another and were unaware that half the participants had rheumatoid arthritis. Sensitivity and specificity were calculated to determine the ability of the GALS examination to screen for rheumatoid arthritis using the rheumatologist as the standard for comparison. RESULTS: For the 3 family physicians, sensitivity values varied from 60-100% and specificity values varied from 70-82%. For the 3 nurse practitioners, sensitivity values varied from 60-90% and specificity values varied from 73-100%. CONCLUSION: Following a very short training period, family physicians and nurse practitioners appear to be able to employ the GALS exam as a screening tool for RA signs and symptoms - particularly for identifying an individual with positive results who will benefit from further investigation or rheumatology referral. © 2012 by the American College of Rheumatology.
Arthritis care & research. 05/2012;
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ABSTRACT: Adults with type 2 diabetes mellitus (DM) have an elevated fracture risk despite normal areal bone mineral density (aBMD). The study objective was to compare trabecular bone microarchitecture of postmenopausal women with type 2 DM and women without type 2 DM.
An extremity 1T magnetic resonance imaging system was used to acquire axial images (195 × 195 × 1,000 μm(3) voxel size) of the distal radius of women recruited from outpatient clinics or by community advertisement. Image segmentation yielded geometric, topologic, and stereologic outcomes, i.e., number and size of trabecular bone network holes (marrow spaces), endosteal area, trabecular bone volume fraction, nodal and branch density, and apparent trabecular thickness, separation, and number. Lumbar spine (LS) and proximal femur BMD were measured with dual x-ray absorptiometry. Microarchitectural differences were assessed using linear regression and adjusted for percent body fat, ethnicity, timed up-and-go test, Charlson Index, and calcium and vitamin D intake; aBMD differences were adjusted for body mass index (BMI).
Women with type 2 DM (n = 30, mean ± SD age 71.0 ± 4.8 years) had larger holes (+13.3%; P = 0.001) within the trabecular bone network than women without type 2 DM (n = 30, mean ± SD age 70.7 ± 4.9 years). LS aBMD was greater in women with type 2 DM; however, after adjustment for BMI, LS aBMD did not differ between groups.
In women with type 2 DM, the average hole size within the trabecular bone network at the distal radius is greater compared to controls. This may explain the elevated fracture risk in this population.
Arthritis care & research. 01/2012; 64(1):83-91.
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ABSTRACT: To determine the feasibility of conducting a randomized controlled trial assessing the effect of low-intensity pulsed ultrasound (US) therapy on cartilage repair in patients with mild to moderate knee osteoarthritis (OA).
Pilot, double-blinded, randomized placebo-controlled trial with 2-months follow-up.
Rehabilitation research facility.
Adults (N=27; ≥45y) with grades 1 or 2 of medial joint space narrowing (Osteoarthritis Research Society International atlas) due to knee OA were randomly allocated to receive active (n=14) or sham (n=13) US therapy. Four participants withdrew for personal reasons.
Twenty-four sessions of active (20% duty cycle, 1MHz, average temporal intensity: 0.2W/cm(2), therapeutic dose: 112.5J/cm(2)) or sham (no sound-head crystal) US therapy.
Success of recruitment and adherence rates were established by a priori criteria. Effect on cartilage repair was assessed by measuring cartilage volume and thickness and scoring cartilage injury, subchondral cyst formation, and bone marrow lesions on magnetic resonance images.
Patient recruitment and adherence rates were successful. No significant age-adjusted differences were seen between groups in the cartilage repair outcomes. Age-adjusted analyses, including only subjects who attended 20 sessions or more, showed an increase in medial tibia cartilage thickness in the active US therapy group (90μm; 95% confidence interval, 1-200; P=.05).
Conducting a randomized controlled trial to assess the effects of US therapy on the cartilage repair in people with mild to moderate knee OA is feasible. However, further pilot studies are needed to determine the optimal US dose and application parameters before designing a full trial.
Archives of physical medicine and rehabilitation 01/2012; 93(1):35-42. · 2.18 Impact Factor
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The Journal of Rheumatology 12/2011; 38(12):2686-7. · 3.69 Impact Factor
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ABSTRACT: To quantify rates of change in quadriceps muscle (QM) and intermuscular fat (IMF) volumes over 2 years in women in the Osteoarthritis Initiative (OAI) study and examine group differences between those with radiographic osteoarthritis (ROA) and those without ROA.
The OAI database was queried for women ≥50 years of age in the incident and progression cohorts with and without ROA at baseline. Midthigh magnetic resonance imaging scans (15 contiguous slices, 5 mm slice thickness) of eligible women were randomly selected and anonymized. Image pairs were registered. QM and IMF were segmented in the 12 most proximal matching slices with the segmenter blinded to image time point. Age-adjusted differences in QM and IMF volume changes between groups were tested using analysis of covariance.
Forty-one women without ROA (mean ± SD age 60.7 ± 7.6 years) and 45 women with ROA (mean ± SD age 64.5 ± 6.7 years) were included. Mean ± SD QM and IMF volume changes in the non-ROA group were -4.1 ± 11.1 cm(3) and 3.4 ± 7.1 cm(3), respectively, and -5.4 ± 13.5 cm(3) and 3.1 ± 7.4 cm(3) in the ROA group, respectively. Age-adjusted between-group differences in QM and IMF changes were not significant (P > 0.05).
Two-year changes in QM and IMF volumes appear consistent with aging and do not seem to be related to OA status. Direct comparison with a control cohort without OA risk factors could confirm this. Since group assignment was based on baseline data, there may have been women in the non-ROA group who developed ROA over followup, resulting in some overlap between groups.
Arthritis care & research. 09/2011; 64(1):22-9.
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ABSTRACT: To evaluate the sensitivity, specificity and reliability of the gait, arms, legs and spine (GALS) examination to detect signs and symptoms of rheumatoid arthritis when used by physiotherapy students and physiotherapists.
Two physiotherapy students and two physiotherapists were trained to perform the GALS examination by viewing an instructional DVD and attending a workshop. Two rheumatologists familiar with the GALS examination also participated in the workshop. All healthcare professionals performed the GALS examination on 25 participants with rheumatoid arthritis recruited through a rheumatology practice and 23 participants without any arthritides recruited from a primary care centre. Each participant was assessed by one rheumatologist, one physiotherapist and one physiotherapy student. Abnormalities of gait, arms, legs and spine, including their location and description, were recorded, along with whether or not a diagnosis of rheumatoid arthritis was suspected. Healthcare professionals understood the study's objective to be their agreement on GALS findings and were unaware that half of the participants had rheumatoid arthritis. Sensitivity, specificity and likelihood ratios were calculated to determine the ability of the GALS examination to screen for rheumatoid arthritis.
Using rheumatologists' findings on the study day as the standard for comparison, sensitivity and specificity were 71 to 86% and 69 to 93%, respectively. Positive likelihood ratios ranged from 2.74 to 10.18, while negative likelihood ratios ranged from 0.21 to 0.38.
The GALS examination may be a useful tool for physiotherapists to rule out rheumatoid arthritis in a direct access setting. Differences in duration and type of experience of each healthcare professional may contribute to the variation in results. The merits of introducing the GALS examination into physiotherapy curricula and practice should be explored.
Physiotherapy 09/2011; 97(3):196-202. · 1.56 Impact Factor
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ABSTRACT: The study's purpose was to assess the effect of multiplanar reconstruction on precision of weight-bearing medial and lateral femoral cartilage (cMF, cLF) morphometry in maloriented coronal MR images. Twenty knees were scanned four times with a 1.0 Tesla extremity imager using a fat-suppressed T1-weighted three-dimensional spoiled gradient recalled echo sequence; twice with "best as" double bull's-eye orientation of the femoral condyles, and once each with 5° internal and external rotation. Multiplanar reconstruction was applied to maloriented scans to recover double bull's-eye orientation. Medial and lateral femoral cartilages were segmented and precision of bone area, cartilage volume and thickness (ThCtAB) evaluated for all scans. Test-retest precision (RMSCV%) of the double bull's-eye scans was 1.1% for total bone area and 4.1% for cartilage volume. Differences in precision between double bull's-eye and maloriented images were assessed. Higher precision errors were observed in malorientated images for all outcomes (1.7-4.8% for internally rotation scans; 1.7-4.8% for external rotation scans). Precision generally improved with multiplanar reconstruction correction (1.7-5.6% for internally rotated scans; 1.2-3.5% for external rotation scans). Precision of femoral cartilage morphometry is generally reduced when maloriented images are acquired. Multiplanar reconstruction can correct malorientated scans and recover precision losses. Measurements are affected in a rotationally and compartmentally dependent manner.
Magnetic Resonance in Medicine 10/2010; 65(3):790-5. · 2.96 Impact Factor
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ABSTRACT: To determine (a) adherence rates at 6, 9 and 18 months amongst patients receiving teriparatide treatment for severe osteoporosis and (b) causes of therapy discontinuation and the effect of teriparatide on bone mineral density (BMD) in adherent and nonadherent patients at different time intervals.
A retrospective chart review of 111 patients receiving teriparatide from September 2004 to June 2007 was performed. Patients self-reports were used to record adherence and causes of nonadherence at 6, 9 and 18 months. BMDs for all patients were measured using the same DXA scanner at baseline and follow up.
Of 111 participants, 17 were male (mean age 60 years) and 94 were female (mean age 69 years). Of these, 12 did not initiate therapy and 4 were lost to follow up. Reported adherence was 89.6% at 6 months, 87.6% at 9 months and 74.7% at 18 months. Causes of nonadherence included cost (n = 4), no benefit (n = 1) and adverse events (n = 8). Common adverse events were leg cramps (n = 9), headache (n = 5) and myalgia (n = 4). Mean spine and femur BMD changes were 3.30% and 0.67% at 4-9 months respectively, and 5.39% and 0.77% at 10-18 months respectively.
Adherence to teriparatide was almost 90% at 9 months and decreased to 75% at 18 months. Adverse events led to nonadherence in 20% of patients. Those who were nonadherent had lower baseline BMD values than those who were adherent. Changes in BMD at the lumbar spine were greater than changes observed at the femoral neck.
Therapeutic advances in musculoskeletal disease 02/2009; 1(1):5-11.
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