Rationale: Lean body mass, including muscle, is known to decrease with age, which may contribute to loss of physical function, an indicator of frailty. Moreover, low muscle thickness is considered an indicator of frailty in critically ill patients. However, little is known about the relationship between muscle thickness and frailty in community dwelling adults. Therefore, we studied the association between frailty and whole body lean body mass index (LBMi) and muscle thickness of the rectus femoris (RF) in community dwelling older adults. Methods: In older adults aged ≥55y, who participated in the Hanze Health and Ageing Study, frailty status was assessed with a multidimensional instrument, measuring frailty on a cognitive, psychosocial en physical level, i.e., the Groningen Frailty Indicator (GFI), using ≥4 as cut-off score for frailty. LBMi (kg/m2) was estimated with BIA (Quadscan 4000©, Bodystat), using the build-in equation. Muscle thickness (mm) of the RF was measured with ultrasound, using the Bodymetrix© (Intelametrix). Univariate and multivariate binary logistic regression analyses were performed for LBMi and for RF thickness. Multivariate analysis corrected for age, sex, body mass index (kg/m2), and handgrip strength (handgrip dynamometer; kg). A p-level of <0.05 was considered significant and Odds Ratios (OR; [95% CI]) were presented. Results: 93 participants (age 65.2±7.7 years; male 46 %; LBMi 17.2±2.6 kg/m2; RF 14.6±4.4 mm; median GFI =1 (interquartile range=0-3; frail: n=18) were included in the analysis. In both the univariate and multivariate analysis, LBMi (p=0.082, OR=0.82 [0.66-1.03]; p=0.077, OR=0.55 [0.28-1.07] respectively) and muscle thickness of RF (p=0.436, OR=0.95 [0.84-1.08]; p=0.796, OR= 1.02 [0.88-1.18] respectively) were not significantly associated with frailty. None of the co-variables were significantly associated with frailty either. Conclusion: In this sample of older adults aged ≥55 years, LBMi and RF thickness are not associated with frailty. However, frail participants scored at cut-off or just above, and measurements in a population with higher scores for frailty may provide further insight in the association between lean body mass and muscle thickness and frailty.
Rationale: Currently use of muscle thickness measured with ultrasound is suggested as an indicator for overall muscle mass in nutritional assessment. However, not much is known about how the muscle thickness measured in patients with chronic obstructive pulmonary disease (COPD) compares to the muscle thickness in healthy persons. This study explores body mass index (BMI) and rectus femoris (RF) muscle thickness in patients with advanced COPD matched with healthy controls. Methods: Patients with advanced COPD at the start of a pulmonary rehabilitation program were matched for age (5 years difference tolerance), sex (exact match), and stature (0.1 m difference tolerance) with healthy controls in a 1:4 case control ratio. BMI (kg/m2) was calculated and muscle thickness (mm) of the RF was measured with a Bodymetrix device. Paired sample t-tests were performed. BMI and RF muscle thickness of the cases were paired with the average BMI and RF of their controls. A p-level of <0.05 was considered significant and 95% CI were presented for the mean difference. Results: In total, 21 cases (median GOLD score 3 [interquartile range 3-4]; age 64.5±6.4y; female 62%; height 1.68±0.07m; BMI 26.9±6.1 kg/m2; RF 12.4±3.4mm) and 84 controls (age 64.5±6.4y; female 62%; height 1.71±0.09 m; BMI 25.8±4.5; RF 14.6±4.5mm) were included in the analyses. In the paired test, BMI was not significantly different between cases and controls (p=0.645, mean difference 0.95 kg/m2 [CI:-2.12 – 4.01]), whereas RF muscle thickness of cases was significantly lower (p=0.003, mean difference -2.33 mm [CI:-3.73 - -0.92]). Conclusion: In this limited sample of patients with COPD, RF muscle thickness in cases was significantly lower than RF muscle thickness in matched controls. Research in bigger samples is needed to confirm whether RF muscle thickness measured with US provides more useful information about body composition for clinicians than BMI in patients with COPD.
Rationale: Sarcopenia is a major problem and is common in community-dwelling elderly. In daily practice, there is need for low cost and easily assessable measurement tools to assess depletion of skeletal muscle (SM) mass, for example as one of the indicators of sarcopenia. Bio-electrical impedance analysis (BIA) is often used to estimate body composition, whereas ultrasound measurement is an upcoming and promising tool, as it is quick, easy to use and inexpensive in comparison with other tools that assess SM mass. Ultrasound could assess site-specific loss of SM mass and determine myoesteatosis. Therefore, in this pilot study we aimed to assess agreement between muscle thickness of rectus femoris (RF) by ultrasound and SM mass by BIA in an older population. Methods: Twenty-six older adults (mean± standard deviation (SD) age 64 ±5.0 y, 62% women) from the Hanze Health and Ageing Study were included. SM mass by BIA was estimated using the Janssen equation. Muscle thickness of RF was assessed by analyzing ultrasound images from the right leg. Two non-parametric tests were used for analysis. Correlation between ultrasound and BIA was assessed with Spearman Rho. Agreement was determined with Kendall’s coefficient of concordance (Kendall’s W). In both tests a score ≥ 0.7 was considered a strong correlation.Results: Mean (±SD) RF thickness was 18.9 (±3.8) mm. Median SM mass (Interquartile range) was 23.5 (20.8-34.7) kg. Correlation between RF thickness and SM mass was moderately positive (Spearman r=0.611; P = 0.001), whereas Kendall’s W showed a strong agreement (W= 0.835; P=0.002).Conclusion: Ultrasound measurement of RF showed an acceptable agreement with skeletal muscle mass assessed by BIA in our sample of older adults. Therefore, ultrasound could be a promising portable tool to estimate muscle size.
