Potential Effects of an Exoskeleton-Assisted Overground Walking Program for Individuals With Spinal Cord Injury Who Uses a Wheelchair on Imaging and Serum Markers of Bone Strength: Pre-Post Study.

BACKGROUND: As many as 60% of individuals use a wheelchair long term after a spinal cord injury (SCI). This mode of locomotion leads to chronic decline in lower-extremity weight-bearing activities and contributes to the development of severe sublesional osteoporosis and high rates of fragility fracture. Overground exoskeleton-assisted walking programs provide a novel opportunity to increase lower-extremity weight bearing, with the potential to improve bone health. OBJECTIVE: The aim of the study is to measure the potential effects of an exoskeleton-assisted walking program on lower-extremity bone strength and bone remodeling biomarkers in individuals with chronic (≥18 months) SCI who use a wheelchair. METHODS: In total, 10 participants completed a 16-week exoskeleton-assisted walking program (34 individualized 1-hour sessions, progressing from 1 to 3 per week). Bone mineral density and bone strength markers (dual-energy x-ray absorptiometry: total body, left arm, leg, total hip, and femoral neck and peripheral quantitative computed tomography: 25% of left femur and 66% of left tibia) as well as bone remodeling biomarkers (formation=osteocalcin and resorption=C-telopeptide) were measured before and after intervention and compared using nonparametric tests. Changes were considered significant and meaningful if the following criteria were met: P<0.1, effect size ≥0.5, and relative variation >5%. RESULTS: Significant and meaningful increases were observed at the femur (femoral neck bone mineral content, bone strength index, and stress-strain index) and tibia (cortical cross-sectional area and polar moment of inertia) after the intervention (all P<.10). We also noted a decrease in estimated femoral cortical thickness. However, no changes in bone remodeling biomarkers were found. CONCLUSIONS: These initial results suggest promising improvements in bone strength markers after a 16-week exoskeleton-assisted walking program in individuals with chronic SCI. Additional research with larger sample sizes, longer interventions (possibly of greater loading intensity), and combined modalities (eg, pharmacotherapy or functional electrical stimulation) are warranted to strengthen current evidence. TRIAL REGISTRATION: ClinicalTrials.gov NCT03989752; https://clinicaltrials.gov/ct2/show/NCT03989752. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/19251.

FRAX predicts cardiovascular risk in women undergoing osteoporosis screening: the Manitoba bone mineral density registry.

Osteoporosis and cardiovascular disease (CVD) are highly prevalent in older women, with increasing evidence for shared risk factors and pathogenesis. Although FRAX was developed for the assessment of fracture risk, we hypothesized that it might also provide information on CVD risk. To test the ability of the FRAX tool and FRAX-defined risk factors to predict incident CVD in women undergoing osteoporosis screening with DXA, we performed a retrospective prognostic cohort study which included women aged 50 yr or older with a baseline DXA scan in the Manitoba Bone Mineral Density Registry between March 31, 1999 and March 31, 2018. FRAX scores for major osteoporotic fracture (MOF) were calculated on all participants. Incident MOF and major adverse CV events (MACE; hospitalized acute myocardial infarction [AMI], hospitalized non-hemorrhagic cerebrovascular disease [CVA], or all-cause death) were ascertained from linkage to population-based healthcare data. The study population comprised 59 696 women (mean age 65.7 ± 9.4 yr). Over mean 8.7 yr of observation, 6021 (10.1%) had MOF, 12 277 women (20.6%) had MACE, 2274 (3.8%) had AMI, 2061 (3.5%) had CVA, and 10 253 (17.2%) died. MACE rates per 1000 person-years by FRAX risk categories low (10-yr predicted MOF <10%), moderate (10%-19.9%) and high (≥20%) were 13.5, 34.0, and 64.6, respectively. Although weaker than the association with incident MOF, increasing FRAX quintile was associated with increasing risk for MACE (all P-trend <.001), even after excluding prior CVD and adjusting for age. HR for MACE per SD increase in FRAX was 1.99 (95%CI, 1.96-2.02). All FRAX-defined risk factors (except parental hip fracture and lower BMI) were independently associated with higher non-death CV events. Although FRAX is intended for fracture risk prediction, it has predictive value for cardiovascular risk.

Advanced glycation end products are not associated with bone mineral density, trabecular bone score, and bone turnover markers in adults with and without type 1 diabetes: a cross-sectional study.

It is unclear if AGEs are involved in the bone fragility of type 1 diabetes (T1D). We evaluated whether skin AGEs by skin autofluorescence and serum AGEs (pentosidine, carboxymethyl-lysine [CML]) are independently associated with BMD by DXA (lumbar spine, hip, distal radius), trabecular bone score (TBS), serum bone turnover markers (BTMs: CTX; P1NP; osteocalcin), and sclerostin in participants with and without T1D. Linear regression models were used, with interaction terms to test effect modification by T1D status. In participants with T1D, correlations between skin and serum AGEs as well as between AGEs and 3-year HbA1C were evaluated using Spearman's correlations. Data are mean ± SD or median (interquartile range). We included individuals who participated in a cross-sectional study and had BMD and TBS assessment (106 T1D/65 controls, 53.2% women, age 43 ± 15 yr, BMI 26.6 ± 5.5 kg/m2). Participants with T1D had diabetes for 27.6 ± 12.3 yr, a mean 3-yr HbA1C of 7.5 ± 0.9% and skin AGEs of 2.15 ± 0.54 arbitrary units. A subgroup of 65 T1D/57 controls had BTMs and sclerostin measurements, and those with T1D also had serum pentosidine (16.8[8.2-32.0] ng/mL) and CML [48.0 ± 16.8] ng/mL) measured. Femoral neck BMD, TBS, and BTMs were lower, while sclerostin levels were similar in participants with T1D vs controls. T1D status did not modify the associations between AGEs and bone outcomes. Skin AGEs were significantly associated with total hip and femoral neck BMD, TBS, BTMs, and sclerostin before, but not after, adjustment for confounders. Serum AGEs were not associated with any bone outcome. There were no significant correlations between skin and serum AGEs or between AGEs and 3-yr HbA1C. In conclusion, skin and serum AGEs are not independently associated with BMD, TBS, BTMs, and sclerostin in participants with relatively well-controlled T1D and participants without diabetes.

Sedentary behavior does not predict low BMD nor fracture-population-based Canadian Multicentre Osteoporosis Study.

Sedentary behavior (SB) or sitting is associated with multiple unfavorable health outcomes. Bone tissue responds to imposed gravitational and muscular strain with there being some evidence suggesting a causal link between SB and poor bone health. However, there are no population-based data on the longitudinal relationship between SB, bone change, and incidence of fragility fractures. This study aimed to examine the associations of sitting/SB (defined as daily sitting time), areal BMD (by DXA), and incident low trauma (fragility) osteoporotic fractures (excluding hands, feet, face, and head). We measured baseline (1995-7) and 10-yr self-reported SB, femoral neck (FN), total hip (TH), and lumbar spine (L1-L4) BMD in 5708 women and 2564 men aged 25 to 80+ yr from the population-based, nationwide, 9-center Canadian Multicentre Osteoporosis Study. Incident 10-yr fragility fracture data were obtained from 4624 participants; >80% of fractures were objectively confirmed by medical records or radiology reports. Vertebral fractures were confirmed by qualitative morphological methods. All analyses were stratified by sex. Multivariable regression models assessed SB-BMD relationships; Cox proportional models were fit for fracture risk. Models were adjusted for age, height, BMI, physical activity, and sex-specific covariates. Women in third/fourth quartiles had lower adjusted FN BMD versus women with the least SB (first quartile); women in the SB third quartile had lower adjusted TH BMD. Men in the SB third quartile had lower adjusted FN BMD than those in SB first quartile. Neither baseline nor stable 10-yr SB was related to BMD change nor to incident fragility fractures. Increased sitting (SB) in this large, population-based cohort was associated with lower baseline FN BMD. Stable SB was not associated with 10-yr BMD loss nor increased fragility fracture. In conclusion, habitual adult SB was not associated with subsequent loss of BMD nor increased risk of fracture.

The number of hours of sitting in a day (often called "sedentary behavior") is currently understood to be "bad for bone health" both because of increased bone loss and a higher risk for fractures. Very few studies in randomly sampled men and women from a whole population have consistently asked about hours of sitting and examined baseline bone density. Fewer still have compared hours of sitting and its changes over 10 yr with changes in bone density and the number of new fractures that occurred. The Canadian Multicentre Osteoporosis Study obtained sitting hours from 5708 women and 2564 men aged 25 to 80+ yr and compared it with the spine, total hip (TH), and femoral neck (FN) bone density values. The average sitting at 7.4 h in men was associated with slightly lower adjusted femoral neck bone density; in women, sitting 6.7 h/d was associated with slightly lower adjusted FN and TH bone density. Ten-year follow-up data (now in about 5000 people) showed no relationship between the slightly longer sitting (an increase of 18% in men and 22% in women) and bone loss or new bone fractures. In this large country-wide population-based study, hours of sitting each day were not associated with 10-yr BMD loss in women or men nor did sitting more associate with new bone fractures. These data are reassuring; women and men who walk regularly and have some moderate-vigorous physical activity each day, despite more sitting, do not seem to be at greater risk for osteoporosis.

Perspectives of wheelchair users with chronic spinal cord injury following a walking program using a wearable robotic exoskeleton.

PURPOSE: To examine the perspectives of wheelchair users with spinal cord injury (WUSCI) regarding their participation in a 16-week walking program using a wearable robotic exoskeleton (WRE); and explore concerns and expectations regarding potential use of this device and intervention in the context of a home or community-based adapted physical activity program. METHOD: Semi-structured interviews were conducted using a narrative research, 3 weeks post-intervention. Thematic analysis resulted in 6 themes and 21 subthemes. RESULTS: Seven men and 4 women aged between 32 and 72 years were interviewed; 8 of them had a complete SCI. After the walking program, WUSCI reported positive psychological aspects (having fun and motivation) and experiencing improvements in physical aspects (strength, endurance, balance and flexibility, blood circulation and intestinal transit). The structural aspects of the WRE device were acceptable in a lab with research personnel (appearance, size, weight, and comfort). Participants had concerns about safety on uneven surfaces, and possibility of falling. They expressed the desire to use the WRE for more life habits than just walking. CONCLUSION: This is the first study in which WUSCI report that the WRE should be implemented in initial rehabilitation. Lack of availability for community use after rehabilitation remains a concern.

Participation in a walking training program using a wearable robotic exoskeleton, 1-3 times weekly over several weeks, may be well tolerated and provide physical and psychological benefits for wheelchair users with spinal cord injuries.Using a robotic exoskeleton during initial rehabilitation may be well received and help with regaining strength, endurance, balance, and flexibility as well as promoting blood circulation and intestinal transit.The use of the wearable robotic exoskeleton always needs supervision of a clinician for walking and can't be used independently by wheelchair users; there is no possibility for hands free for household tasks (e.g., washing floors, accessing cupboards or reaching shelves, using stairs), and for recreation (e.g., exercising, taking walks, cultural activities, concerts).