Obesity and body mass index: Past and future considerations in osteoarthritis research.

Obesity is an important topic for the osteoarthritis (OA) scientific community. However, the predominant use of body mass index (BMI) to define obesity in OA research is associated with uncertainties and limitations. These include an inability to discern fat and muscle mass, account for sex-differences in fat distribution, or identify adiposity-related health impairments. A focus on BMI in OA research may influence weight bias in clinical practice and impact disparities in access to effective OA treatments. To ensure that our understanding and approaches to improve health outcomes for individuals with or at risk for OA continues to advance in the next decade, future research will need to consider alternative measures beyond BMI for obesity identification and align with evolving obesity science. OA researchers must be aware of issues associated with weight stigma and work to minimize negative generalizations based on BMI.

Acceptability and preliminary effectiveness of a single-arm 12-week digital behavioral health intervention in patients with knee osteoarthritis.

BACKGROUND: Digital health interventions may improve osteoarthritis (OA) management. This study evaluated the acceptability and preliminary effectiveness of a multimodal digital nutrition, exercise, and mindfulness intervention in adults with knee OA. METHODS: Adults with advanced knee OA and an orthopaedic referral were invited to self-enroll in a pragmatic 12-week single-arm intervention. OA-focused nutrition and exercise resources were delivered weekly by email, and secondary components accessed on-demand (web-platform, webinars, and nutrition consultation). Acceptability was assessed by qualitative interview data and completion rates. Preliminary effectiveness on clinical outcomes was assessed by change in health-related quality of life, well-being, mindfulness, self-efficacy, and interest in total knee arthroplasty (TKA) between baseline and 12-weeks. RESULTS: N = 102 patients self-enrolled (73.5% female, age 64 ± 7 years, body mass index 32.9 ± 7.3 kg/m2); n = 53 completed the 12-week intervention (71.7% female, age 65 ± 7 years, body mass index 33.4 ± 6.3 kg/m2). Acceptability was demonstrated by positive perceptions of tailored intervention resources. In study completers, health-related quality of life components of pain and physical functioning domains improved at 12-weeks [change in SF36 4.4 (95%CI 0.2-8.6), p = 0.016, and 6.7 (95%CI 2.7-10.7), p < 0.001, respectively]. Self-efficacy for managing daily activities improved [change in PROMIS T-score 4.4 (95%CI 2.8-6.0), p < 0.001]. CONCLUSION: A 12-week digital multimodal intervention for knee OA was acceptable to patients and shows preliminary effectiveness in improving self-efficacy, aspects of quality of life, and decreasing interest in TKA. Digital behavioral interventions for knee OA may be an acceptable approach to improve patient outcomes and OA self-management while potentially reducing utilization of costly health system resources.

Predicting Enrollment in Multidisciplinary Clinical Care for Pediatric Weight Management.

OBJECTIVES: To characterize the children who were referred, determine the proportion of referred children who enrolled, and examine factors associated with enrollment in multidisciplinary clinical care for pediatric weight management. STUDY DESIGN: This cross-sectional study included the population of children (2-17 years of age; body mass index of ≥85th percentile) referred to 1 of 3 hospital-based multidisciplinary weight management clinics in Alberta, Canada, from April 2013 to April 2016. Referral and enrollment data were obtained from Alberta Health Services databases. Bivariate and multivariable logistic regression models were used to determine the independent and combined effects of predictors of enrollment. RESULTS: Of the 2014 children (51.8% male; mean body mass index z-score: 3.42 ± 0.03) referred to multidisciplinary clinical care, 757 (37.6%) enrolled in care. Most referred children had severe obesity and were referred by physicians. Several factors independently predicted enrollment; however, in our most parsimonious multivariable model, only the time gap (OR, 0.94; 95% CI, 0.88-0.99; P = .03) between the attendance date of the orientation session and the booking date of initial appointment predicted enrollment for all children. Body mass index z-score (OR, 0.81; 95% CI, 0.67-0.98; P = .03) and time gap (OR, 0.92; 95% CI, 0.85-0.99; P = .02) predicted enrollment in children with severe obesity exclusively. CONCLUSIONS: Fewer than 40% of referred children enrolled in multidisciplinary clinical care. Reducing the duration of enrollment and providing additional support for treatment initiation to children with severe obesity may enhance treatment uptake for pediatric weight management.

The impact of sarcopenic obesity on knee and hip osteoarthritis: a scoping review.

BACKGROUND: The progressive, debilitating nature of knee and hip osteoarthritis can result in severe, persistent pain and disability, potentially leading to a need for total joint arthroplasty (TJA) in end-stage osteoarthritis. TJA in adults with obesity is associated with increased surgical risk and prolonged recovery, yet classifying obesity only using body mass index (BMI) precludes distinction of obesity phenotypes and their impact on surgical risk and recovery. The sarcopenic obesity phenotype, characterized by high adiposity and low skeletal muscle mass, is associated with higher infection rates, poorer function, and slower recovery after surgery in other clinical populations, but not thoroughly investigated in osteoarthritis. The rising prevalence and impact of this phenotype demands further attention in osteoarthritis treatment models of care, particularly as osteoarthritis-related pain, disability, and current treatment practices may inadvertently be influencing its development. METHODS: A scoping review was used to examine the extent of evidence of sarcopenic obesity in adults with hip or knee osteoarthritis. Medline, CINAHL, Web of Science and EMBASE were systematically searched from inception to December 2017 with keywords and subject headings related to obesity, sarcopenia and osteoarthritis. RESULTS: Eleven studies met inclusion criteria, with indications that muscle weakness, low skeletal muscle mass or sarcopenia are present alongside obesity in this population, potentially impacting therapeutic outcomes, and TJA surgical risk and recovery. CONCLUSIONS: Consideration of sarcopenic obesity should be included in osteoarthritis patient assessments.

Vitamin D Status, Cardiometabolic, Liver, and Mental Health Status in Obese Youth Attending a Pediatric Weight Management Center.

BACKGROUND: Vitamin D (VitD) deficiency and obesity are reaching epidemic proportions in North America, particularly in those with comorbid conditions such as diabetes or liver disease. The study objective was to determine the prevalence of suboptimal vitD status and interrelationships with anthropometric, cardiometabolic, liver, mental health, and lifestyle (sleep/screen time) parameters in an ambulatory population of children with obesity. METHODS: Children (2-18 years) attending a pediatric weight management clinic (n = 217) were retrospectively reviewed. Variables studied included anthropometric (weight, height, body mass index, waist circumference), vitD (serum 25-hydroxyvitamin D), cardiometabolic (systolic blood pressure, diastolic blood pressure, glucose, insulin, homeostasis model assessment for insulin resistance, triglyceride, high-density lipoprotein, low-density lipoprotein, total cholesterol), liver enzymes (alanine aminotransferase, gamma-glutamyl transferase), and mental health (number, diagnosis) parameters. RESULTS: Suboptimal vitD status (25-hydroxyvitamin D <75 nmol/L was present in 76% of children with obesity (12.0 ±â€Š2.9 years). Blood pressure categorized as prehypertension, stage I hypertension, and stage II hypertension was present in 14%, 25%, and 7% of children, respectively. Mental health diagnoses including anxiety, attention-deficit hyperactivity disorder, mood disorders, and learning disabilities/developmental delays occurred in 18%, 17%, 10%, and 15%, of children, respectively. Waist circumferences >100 cm were associated with lower vitD levels (58 ±â€Š18 vs 65 ±â€Š17 nmol/L; P = 0.01). VitD status ≥50 nmol/L was associated with lower insulin (15.8 [11.7-23.1] mU/L vs 21.1 [14.3-34.2] mU/L; P < 0.01) and homeostasis model assessment for insulin resistance (3.5 [2.5-4.9] vs 4.8 [3.1-6.9]; P < 0.01) values and systolic blood pressure percentiles (73.0 ±â€Š25.8 vs 80.6 ±â€Š17.0; P = 0.04). CONCLUSIONS: Children with obesity had a high prevalence of vitD deficiency, particularly those at risk for hypertension, reduced insulin sensitivity, and central obesity.

Reducing weight bias and stigma in qualitative research interviews: Considerations for researchers.

Perceptions and biases influence how we interact with and experience the world, including in professional roles as researchers. Weight bias, defined as negative attitudes or perceptions towards people that have large bodies, can contribute to weight stigma and discrimination leading to negative health and social consequences. Weight bias is experienced by people living with obesity in media, health care, education, employment and social settings. In research settings, there is potential for weight bias to impact various aspects of qualitative research including the participant-researcher dynamic in interviews. However, evidence-based strategies to reduce weight bias in qualitative research interviews have yet to be identified. We discuss how weight bias may influence research interviews and identify several considerations and strategies for researchers to minimize the impact of weight bias. Strategies include practicing reflexivity, planning and conducting interviews in ways that support rapport building, using inclusive language, and considering participatory methods.

Consistent Factors Influence Body Mass Index Thresholds for Total Joint Arthroplasty Across Health-Care Systems: A Qualitative Study.

BACKGROUND: Body mass index (BMI) thresholds are used as eligibility criteria to reduce complication risk in total joint arthroplasty (TJA). This approach oversimplifies preoperative risk assessment and inadvertently restricts access to effective surgical treatment for osteoarthritis. A prior survey of orthopaedic surgeons in the United States identified complex underlying factors that influence BMI considerations. To understand whether similar factors exist and influence surgeons in a different health-care system setting, we investigated Canadian surgeons' views and use of BMI criterion thresholds for TJA access. METHODS: A cross-sectional online qualitative survey was conducted with orthopaedic surgeons performing TJA in the Canadian health-care system. Responses were anonymous and questions were open-ended to allow for candid perspectives. Survey data were coded and a systematic process was followed to identify major themes. Findings were compared with U.S. surgeon perspectives. RESULTS: Sixty-nine respondents had a mean age of 49.0 ± 11.4 years (range, 33 to 79 years), with a mean surgical experience duration of 15.7 ± 11.4 years (range, 2 to 50 years). Surgeons reported variable use of BMI thresholds in practice. Twelve interconnected factors that influence BMI considerations were identified: (1) variable evidence interpretation, (2) surgical challenge, (3) surgeon beliefs and biases, (4) hospital differences, (5) access to resources, (6) health system bias, (7) patient health status, (8) patient body fat distribution, (9) patient decisional burden (to lose weight or accept risk), (10) evidence gaps and uncertainties, (11) need for innovation, and (12) societal views. Nine themes matched with findings from U.S. surgeons. CONCLUSIONS: Parallel to the United States, complex, interconnected factors influence Canadian orthopaedic surgeons' variable use of BMI restrictions for TJA eligibility. Despite different health-care systems and reimbursement models, similar technical and personal factors were identified. With TJA practice guidelines advising against hard BMI criteria, attention regarding access to resources, surgical training, and innovations to address TJA complexity in patients with large bodies are critically needed. Future advancements in this sphere must balance barrier removal with risk reduction to ensure safe and equitable surgical care. CLINICAL RELEVANCE: This study may influence surgeon behaviors with regard to hard BMI cutoffs for TJA and encourage critical thought about factors that influence decisions about surgical eligibility for patients with high BMI.

"I Often Feel Conflicted in Denying Surgery": Perspectives of Orthopaedic Surgeons on Body Mass Index Thresholds for Total Joint Arthroplasty: A Qualitative Study.

BACKGROUND: Use of a patient body mass index (BMI) eligibility threshold for total joint arthroplasty (TJA) is controversial. A strict BMI criterion may reduce surgical complication rates, but over-restrict access to effective osteoarthritis (OA) treatment. Factors that influence orthopaedic surgeons' use of BMI thresholds are unknown. We aimed to identify and explore orthopaedic surgeons' perspectives regarding patient BMI eligibility thresholds for TJA. METHODS: A cross-sectional, online qualitative survey was distributed to orthopaedic surgeons who conduct hip and/or knee TJA in the United States. Survey questions were open-ended, and responses were collected anonymously. Survey data were coded and analyzed in an iterative, systematic process to identify predominant themes. RESULTS: Forty-five surveys were completed. Respondents were 54.3 ± 12.4 years old (range, 34 to 75 years), practiced in 22 states, and had 21.2 ± 13.3 years (range, 2 to 44 years) of surgical experience. Twelve factors influencing BMI threshold use by orthopaedic surgeons were identified: (1) evidence interpretation, (2) personal experiences, (3) difficulty of surgery, (4) professional ramifications, (5) ethics and biases, (6) health-system policies and performance metrics, (7) surgical capacity and resources, (8) patient body fat distribution, (9) patient self-advocacy, (10) control of decision-making in the clinical encounter, (11) expectations for demonstrated weight loss, and (12) research and innovation gaps. CONCLUSIONS: Multilevel, complex factors underlie BMI threshold use for TJA eligibility. Addressing identified factors at the patient, surgeon, and health-system levels should be considered to optimally balance complication avoidance with improving access to life-enhancing surgery. CLINICAL RELEVANCE: This study may influence how orthopaedic surgeons think about their own practices and how they approach patients and consider surgical eligibility.

Patient engagement in the design of an intervention to prevent muscle loss in individuals with knee osteoarthritis and a body mass index (BMI) ≥ 35.

OBJECTIVE: Interventions for knee osteoarthritis (OA) in adults with a large body size (defined as a body mass index [BMI] ≥ 35 kg/m2 ) often prioritise weight-loss, which may overshadow specific benefits for physical function, metabolic health, and body composition. As part of the development of a future clinical study, we gathered perspectives from individuals living with knee OA and a large body size to inform the proposed intervention design and delivery. METHODS: Purposive and voluntary sampling was used to engage individuals ≥40 years of age with self-reported knee OA and a BMI ≥ 35 kg/m2 . An anonymous electronic survey was distributed on social media between April 2020 and June 2020. Open-ended questions addressed a proposed 12-week multimodal intervention (involving targeted nutrition, resistance exercises, and self-management support). An optional semi-structured interview was offered upon completion, with interviews recorded and transcribed verbatim. Reflexive thematic analysis and interpretation guided by an acceptability framework was used to identify recommendations for the intervention design and delivery. RESULTS: Twenty individuals living across Canada completed the survey (100% female; 18 aged <65 years and 2 ≥ 65 years). Ten individuals completed the interview. From aggregate survey and interview data, three recommendations were generated: (1) the effectiveness of the intervention for health improvement (specifically mobility and pain) must be emphasised to avoid perceived weight-loss expectations; (2) extend support beyond 12-weeks and consider terminology free from weight-bias to enhance acceptance; (3) include optional customisation of intervention delivery to reduce acceptability-related burden. CONCLUSION: These female patient-derived recommendations may improve perceived intervention acceptability, and thereby may enhance participant enrolment and retention in clinical trials.

Protocol for the POMELO (Prevention Of MusclE Loss in Osteoarthritis) randomized pilot feasibility trial.

Objective: Individuals with advanced knee osteoarthritis (OA) and a large body size [a body mass index (BMI) ≥35 â€‹kg/m2] have a higher risk of complications with total knee arthroplasty (TKA), and hence may be ineligible for surgery unless they reduce their BMI. However, pre-TKA weight-loss has not been shown to reduce surgical infection risk and may inadvertently increase risk for muscle loss and development of sarcopenic obesity (low muscle and low strength with higher fat mass). This suggests that a knee OA management approach that doesn't focus on weight change (weight-neutral) may be beneficial. This study examines if a weight-neutral behavioural intervention is feasible and acceptable to participants, and improves muscle mass and physical function in comparison to usual care. Design: This pilot randomized clinical trial compares a 12-week multimodal intervention [including targeted nutrition, progressive resistance exercise, and arthritis self-management support] to usual care. Co-primary outcomes are feasibility and acceptability, with secondary outcomes of change in lean soft tissue and physical function within and between groups at 3-months and 9-months from baseline. Change in waist circumference, fat mass, blood biomarkers, energy metabolism, OA-related pain and function, health-related quality of life, self-efficacy for arthritis management, and interest in pursuing a TKA within and between groups will be explored. Conclusion: This study will inform future development of more personalized knee OA treatment approaches for adults with larger bodies. Further, this will contribute to effective alternative treatment pathways that reduce inequities in access to OA care for this understudied patient population.

Sarcopenic obesity diagnosis by different criteria mid-to long-term post-bariatric surgery.

BACKGROUND/AIMS: The aim of this study was to apply the European Society for Clinical Nutrition and Metabolism/European Association for the Study of Obesity (ESPEN/EASO) consensus to identify sarcopenic obesity (SO) in adults mid to long-term post-Roux-en-Y gastric bypass (RYGB) using both dual-energy x-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). Further, this approach was compared to accepted sarcopenia diagnostic criteria (Revised European Working Group on Sarcopenia in Older People [EWGSOP2] and Sarcopenia Definition and Outcomes Consortium [SDOC]). METHODS: This cross-sectional study included adults ≥2 years post-RYGB surgery. Obesity was diagnosed by excess fat mass (FM) for all diagnostic criteria. Agreement was evaluated using Cohen's Kappa. RESULTS: We evaluated 186 participants (90.9% female, median age 43.9 years, 6.8 years post-surgery), of which 60.2% (BIA), and 83.3% (DXA) had excess FM. Low muscle strength was not identified using absolute handgrip strength. The prevalence of SO by BIA or DXA, respectively, was 7.9% (95%CI 3.9-12.5), and 23.0% (95%CI 17.1-30.3) [ESPEN/EASO SO consensus]; 0.7% (95%CI 0-2.0), and 3.3% (95%CI 0.7-5.9) [EWGSOP2]; and 27.0% (95%CI 19.7-34.2), and 30.3% (95%CI 23.0-37.5) [SDOC]. Agreement between the ESPEN/EASO SO consensus and other diagnostic criteria was none to slight using DXA: EWGSOP2 k = 0.19; 95% CI 0.04-0.34, or SDOC k = 0.16; 95% CI -0.01-0.32. Moderate agreement was observed within the ESPEN/EASO SO consensus for BIA and DXA (k = 0.43; 95% CI 0.26-0.60). CONCLUSIONS: This is the first study to explore the prevalence of SO using the ESPEN/EASO criteria. We identified a high but variable prevalence of SO in post-bariatric surgery patients (7.9-23.0%), depending on the body composition technique used; prevalence was higher using DXA. Little agreement was observed for the diagnosis of SO using the three diagnostic criteria. Future studies are needed to explore the relationship between SO identified by the ESPEN/EASO consensus and health status/outcomes.

Associations Between Self-Reported Weight History and Sarcopenic Obesity in Adults with Knee Osteoarthritis.

OBJECTIVE: The purpose of this study was to examine associations between self-reported weight history and sarcopenic obesity in adults with advanced knee osteoarthritis (OA). METHODS: Self-reported weight history was collected from n = 151 adults (58.9% female) with knee OA and BMI ≥30 kg/m2 in a cross-sectional study. Body composition was assessed using dual-energy x-ray absorptiometry. Sarcopenic obesity was defined as appendicular skeletal muscle mass, adjusted by BMI, <0.51 kg/m2 in females and <0.79 kg/m2 in males; prevalence was 27.2%. Weight gain in the preceding year, weight gain ≥5% of body weight in the past decade, and multiple weight cycling events in life-span (loss of ≥10 lb [4.5 kg] with regain ≥3 times) were examined using logistic regression (adjusted by age, sex, and %fat mass), with the dependent variable of sarcopenic obesity presence. RESULTS: Weight gain in the preceding year was associated with sarcopenic obesity (odds ratio [OR]: 2.45, 95% CI: 1.02-5.87). No associations were found with weight gain in the past decade (OR: 1.04, 95% CI: 0.43-2.5) or weight cycling (OR: 0.86, 95% CI: 0.37-2.01). CONCLUSIONS: In adults with obesity and advanced knee OA, self-reported weight gain in the preceding year was associated with sarcopenic obesity. This patient population may benefit from recommendations that prioritize prevention of weight gain.

A critical review of weight loss recommendations before total knee arthroplasty.

OBJECTIVE: Increased infection risk after total knee arthroplasty (TKA) in patients with a higher body mass index (BMI), particularly a BMI ≥40kg/m2, suggests that BMI reduction (through weight loss) prior to TKA may be important. However, the impact of weight loss on TKA risk reduction is unclear. Furthermore, weight loss could have detrimental consequences with respect to muscle loss and development of sarcopenic obesity, whereby a potential weight loss paradox in adults with advanced knee OA and obesity may be present. Using a critical review approach, we examined the current evidence supporting weight loss in adults with obesity and advanced knee osteoarthritis (OA). We focused on three key areas: (1) TKA complication risk with severe obesity compared to obesity (BMI ≥40kg/m2 versus 30.0-39.9kg/m2); (2) weight loss recommendations for individuals with advanced knee OA; and (3) TKA outcomes after pre-surgical weight loss. METHODS: Medline and CINAHL databases were examined from Jan 2010 to May 2020 to identify high-level and/or clinically-influential evidence (systematic reviews, meta-analyses and clinical practice guidelines). RESULTS: The literature does not show a clear relationship between weight loss and reduction in TKA complications, and no indication that a patients' individual risk is lowered by reducing their BMI from a threshold of ≥40kg/m2 to ≤39.9kg/m2. Studies that have found a benefit of weight loss for knee OA have not included patients with higher BMIs (≥40kg/m2) or more advanced knee OA. Furthermore, there is unclear evidence of a benefit of pre-surgical weight loss on TKA outcomes. These are important evidence gaps, suggesting that recommendations for BMI reduction prior to TKA should be tempered by the current uncertainty in the literature. CONCLUSION: Evidence to support a benefit of weight loss prior to TKA is lacking. Until knowledge gaps are clarified, it is recommended that practitioners consider individual patient needs and risk before recommending weight loss (and therefore BMI reduction).

Clinical screening and identification of sarcopenic obesity in adults with advanced knee osteoarthritis.

BACKGROUND AND AIMS: Sarcopenic obesity (defined as low muscle mass and strength with high adiposity) requires attention in adults with advanced knee osteoarthritis (OA) due to implications on treatment outcomes. This study aimed to identify muscle function measures and patient characteristics associated with the presence of low muscle mass that could be used to screen and detect sarcopenic obesity in patients with knee OA in the clinical setting. METHODS: Cross-sectional study of patients with knee OA and a body mass index (BMI) ≥30 kg/m2. Body composition was measured in n = 151 patients (59% female, mean age 65.1 ± 7.9 years) using dual-energy x-ray absorptiometry. Appendicular skeletal muscle mass (ASM) adjusted by BMI and below established sex-specific cut-points was used to differentiate low muscle mass. Muscle function was assessed by 4-m gait speed, 6 min walk test, and maximal grip strength (absolute, and relative, adjusted by BMI). Logistic regression was used to assess the relationship between muscle function measures, patient characteristics, and low muscle mass. Receiver operating characteristic curves and area under the curve (AUC) were used to examine the final model and identify potential clinical cut-points. RESULTS: Sex and relative grip strength were associated with low muscle mass (AUC 0.774, p < 0.001). Cut-points for low relative grip strength (<0.65 kg/m2 in females and <1.1 kg/m2 in males) were distinguished and used in combination with low muscle mass to screen and identify sarcopenic obesity. Patients with both low relative grip strength and low muscle mass (sarcopenic obesity) had impaired mobility and quality of life. CONCLUSION: Relative grip strength shows promise as a clinical screening measure for sarcopenic obesity in patients with knee OA.