Table 1.
Studies reporting low skeletal muscle mass and/or muscle weakness in adults with obesity and knee or hip osteoarthritis
| Author, Year | Study purpose | Study design | Population | Definition of obesity | Body composition methodology | Definition of low muscle massa,b or muscle weakness | Study limitations | Relevant findings |
|---|---|---|---|---|---|---|---|---|
| Batsis et al. [59], 2015 | To describe the impact of dynapenic obesity on physical function in knee OA | Longi-tudinal, | North American population from OsteoArthritis Initiative (OAI), age ≥ 60 years, n = 526 in subgroup with knee OA (rKOA), | BMI ≥30 kg/m2 | NI | Lowest sex-specific tertile of knee extensor strength (dynapenia) | Secondary analysis of prospective data from longitudinal cohort. Excluded severe knee OA. No assessment of muscle mass or body composition | Prevalence of dynapenic obesity was 16%. |
| Clemence et al. [69], 2017 | To analyze the association between low lean mass and clinical symptoms in knee and hip OA | Cross-sectional | French adults with hip and knee OA (KL grade ≥ 2) from KHOALA study, n = 358, age 63.4 ± 8.4 years | BMI ≥30 kg/m2, or sex specific FM or WC cut-offs | DXA | ASM/BMI < 0.789 for men and < 0.512 for women (FNIH cutoffs) | Secondary analysis of prospective data from longitudinal cohort. No information on exclusion criteria. No assessment of muscle strength or function | SO prevalence was 16.2%. Low lean mass was associated with pain and impaired function in subjects with normal BMI, but not with obesity (no significant differences between NSO and SO groups). |
| Ji et al. [60], 2016 | To identify the prevalence of SO in knee and hip orthopedic surgery (OS) patients | Cross-sectional | Korean orthopedic surgery patients (hip or knee TJA or femoral fracture repair) (OS, n = 222) compared to control non-surgical outpatients (non-OS, n = 364) | BMI > 25 kg/m2 | DXA | ASM/height2, ASM/weight, and ASM/height and fat mass (residuals) | Retrospective analysis of data. No assessment of muscle strength or function | SO prevalence ranged from 1.3–35.4% in TKA and 0–18.4% in THA patients depending on definition used. SO rates were higher in OS patients compared to non-OS patients. |
| Jin et al. [61], 2017 | To examine the associations between obesity, sarcopenia and OA in elderly | Cross-sectional | Korean population (KNHANES) age ≥ 65 years group with knee OA (K/L grade ≥ 2) (n = 1865) compared to lumbar spondylosis group (n = 1709) | BMI ≥25 kg/m2 | DXA | ASM/weight, 2SDs below average of sex-matched young reference group | Secondary analysis of population survey data. No assessment of muscle strength or function | Results indicate correlation between SO and NSO with knee OA, but no relationship with lumbar spondylosis. Females with SO had increased OR for knee OA when adjusted for age and waist circumference (OR 1.80, CI 1.03–3.12). |
| Knoop et al. [62], 2011 | To identify distinct clinical phenotypes and their impact in knee OA | Cross-sectional | North American population with knee OA (K/L grade 0–4) from OsteoArthritis Initiative (n = 842, age 63.2 ± 9.1) | BMI ≥30 kg/m2 | NI | Low mean score of quadriceps and hamstring isometric strength | Secondary analysis of prospective data from longitudinal cohort. No assessment of muscle mass or body composition. No clear cut-off for defining weakness | Dynapenic obesity group (“obese and weak” phenotype) had higher pain and poorer physical function compared to “minimal joint disease”, “strong muscle”, and “non-obese and weak” phenotypes. |
| Lee et al. [63], 2016 | To investigate association between lower limb muscle mass and knee OA | Cross-sectional | Korean population (KNHANES) age ≥ 50 years, n = 821 with knee OA (K/L grade ≥ 2), (n = 821), and control group without knee OA (n = 4103) | BMI ≥27.5 kg/m2 | DXA | ASM/weight, 2SD below the mean in sex-matched young reference group (< 29.5% in men, < 23.2% in women) | Secondary analysis of population survey data. No assessment of muscle strength or function | SO prevalence was 5.2% in knee OA group compared to 1.8% in control group. |
| Lee et al. [64], 2012 | To analyze the association between knee OA, sarcopenia and obesity | Cross-sectional | Korean population (KNHANES) with bilateral knee OA (K/L grade ≥ 2) age ≥ 50 years, n = 2893 | BMI ≥27.5 kg/m2 | DXA | ASM/weight, 2SD below the mean in sex-matched young reference group (< 26.8% in men, < 21% in women) | Secondary analysis of population survey data. No assessment of muscle strength or function | SO prevalence was 3% overall. When adjusted for age and sex, SO had stronger association with knee OA (OR 3.51, CI 2.15–5.75) compared to NSO (OR 2.38, CI 1.80–3.15). |
| Manoy et al. [65], 2017 | To assess association between leptin, vitamin D, muscle strength and physical performance in knee OA | Cross-sectional | Thailand knee OA patients (K/L grade < 3) (n = 208), age 65 ± 7 years | BMI > 25 kg/m2 | BIA | ASM/weight < 30.4% in men and < 25.8% in women, and EWGSOP gait speed and grip strength cutoffs | Unclear if data collected retrospectively or prospectively. No description of sampling methods. Excluded severe knee OA | SO prevalence was 13.9%. Patients with SO had poorer performance on the timed up and go (TUG), sit to stand (STS) and 6 min walk tests (6MWT) compared to those with NSO or NO. |
| Oosting et al. [66], 2016 | To determine the association of obesity and recovery after THA when stratified by muscle strength | Cross-sectional | Netherlands THA patients (n = 297), age 69 ± 11 years | BMI > 30 kg/m2 | NI | Maximal handgrip strength (< 20 kg for woman and < 30 kg for men) | Secondary analysis of prospective cohort. No assessment of muscle mass or body composition | Obesity and muscle weakness (dynapenic obesity) was associated with prolonged length of stay > 4 days (OR 3.59, CI 1.09–11.89) and delayed inpatient recovery (> 2 days to walk with gait aid) (OR 6.21, CI 1.64–23.65), but not in those with obesity alone. |
| Segal et al. [67], 2005 | To analyze the impact of low limb lean mass in knee OA distinct from body weight | Cross-sectional | Japanese female orthopedic knee OA (K/L grade ≥ 2) patients age ≥ 45 years (n = 341), compared to control group with fracture, sprains or back pain (n = 604) | BMI > 24.9 kg/m2 | BIA | Lower limb LST | Unclear if data collected retrospectively or prospectively. No clear cut-off for defining low LST. No assessment of muscle strength or function | Females with knee OA had 5–15% less lower limb LST compared to control groups across BMI categories, with significant 1.8 kg and 1.5 kg differences in overweight and obesity groups, respectively. |
| Suh et al. [68], 2016 | To analyze the association between obesity, sex, and lower extremity lean mass in knee OA | Cross-sectional | Korean population (KNHANES) age ≥ 50 years with unilateral knee OA (K/L grade ≥ 2) (n = 4246; 1829 men and 2417 women) | BMI ≥27.5 kg/m2 | DXA | Lower extremity LST/weight, in lowest quartile | Secondary analysis of population survey data. No assessment of muscle strength or function | In females, obesity and low muscle mass was strongly association with knee OA (OR 2.31, CI 1.35–3.93) compared to obesity and normal muscle mass (OR 1.03, CI 0.26–4.02). |
ASM appendicular skeletal mass, ASMI ASM/height2, BIA bioelectrical impedance analysis, BMI body mass index, CI confidence interval, DXA dual-energy x-ray absorptiometry, EWGSOP European Working Group on Sarcopenia in Older People, FM fat mass, FFM fat free mass, FNIH Foundation for the National Institute of Health, KNHANES Korean National Health and Nutrition Examination Survey, K/L Kellgren/Lawrence radiographic osteoarthritis score, LST lean soft tissue, LSTI LST/height2, NI not included in study design, NO normal body composition, NSO non-sarcopenic obesity, OA osteoarthritis, OR odds ratio, rKOA radiographic evidence of knee osteoarthritis, SD standard deviation, SO sarcopenic obesity, THA total hip arthroplasty, TJA total joint arthroplasty, TKA total knee arthroplasty, VAS visual analog scale, WC waist circumference, WOMAC Western Ontario and McMaster Universities Osteoarthritis Index
aVaried indices for identifying low muscle mass: LSTI, LST/weight, ASM, ASMI, ASM/weight, ASM/BMI, ASM relative to height and FM (residuals), and FM:FFM ratio [26]. Indices that consider LST or ASM relative to weight, BMI or FM may be most appropriate in adults with obesity [26], and relevant to identify clinically relevant weakness [76]
bTerms from included studies were adjusted for consistency and accurate representation of body composition compartment, and may differ from original reports