Rationale: Malnutrition is a common problem in patients with Chronic Obstructive Pulmonary Disease (COPD). Whereas estimation of fat-free muscle mass index (FFMi) with bio-electrical impedance is often used, less is known about muscle thickness measured with ultrasound (US) as a parameter for malnutrition. Moreover, it has been suggested that in this population, loss of muscle mass is characterized by loss of the lower body muscles rather than of the upper body muscles.1 Therefore, we explored the association between FFMi, muscle thickness of the biceps brachii (BB) and the rectus femoris (RF), and malnutrition in patients with COPD. Methods: Patients were assessed at the start of a pulmonary rehabilitation program. Malnutrition was assessed with the Scored Patient-Generated Subjective Global Assessment (PG-SGA). Malnutrition was defined as PG-SGA Stage B or C. FFMi (kg/m²) was estimated with bio-electrical impedance analysis BIA 101® (Akern), using the Rutten equation. Muscle thickness (mm) of the BB and the RF was measured with the handheld BodyMetrix® device (Intelametrix). Univariate and multivariate logistic regression analyses were performed to analyse associations between FFMi and muscle thickness for BB and RF, and malnutrition. Multivariate analysis corrected for sex, age, and GOLD-stage. Odds ratios (OR) and 95% confidence intervals (CI) were presented. A p-level of <0.05 was considered significant. Results: In total, 27 COPD patients (age 64±8.1 years; female 60%, GOLD-stage 3, interquartile range=3-4, BMI 27±6.6 kg/m2) were included in the analyses. In the univariate analysis, FFMi (p=0.014; OR=0.70, 95%CI: -0.12—0.15), RF thickness (p=0.021; OR=0.79, 95%CI: -0.09—0.01), and BB thickness (p=0.006; OR=0.83, 95%CI: -0.06—0.01) were all significantly associated with malnutrition. In the multivariate analysis, FFMi (p=0.031; OR=0.59, 95%CI: -0.18—0.01) and BB thickness (p=0.017; OR=0.73, 95%CI:-0.09—0.01) were significantly associated with malnutrition. None of the co-variables were significantly associated with malnutrition. Conclusion: In this relatively small sample of patients with severe COPD, low FFMi and low BB muscle thickness were both robustly associated with increased odds of being malnourished. BB muscle thickness measured with US may provide added value to the toolbox for nutritional assessment. The results of this exploratory study suggest that upper body muscles may reflect nutritional status more closely than lower body muscles. Reference: 1 Shrikrishna D, Patel M, Tanner RJ, Seymour JM, Connolly BA, Puthucheary ZA, et al. Quadriceps wasting and physical inactivity in patients with COPD. Eur Respir J. 2012;40(5):1115–22.)
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STUDY DESIGN: Cross-sectional study.OBJECTIVES: This study: (1) investigated the accuracy of bioelectrical impedance analysis (BIA) and skinfold thickness relative to dual-energy X-ray absorptiometry (DXA) in the assessment of body composition in people with spinal cord injury (SCI), and whether sex and lesion characteristics affect the accuracy, (2) developed new prediction equations to estimate fat free mass (FFM) and percentage fat mass (FM%) in a general SCI population using BIA and skinfolds outcomes.SETTING: University, the Netherlands.METHODS: Fifty participants with SCI (19 females; median time since injury: 15 years) were tested by DXA, single-frequency BIA (SF-BIA), segmental multi-frequency BIA (segmental MF-BIA), and anthropometry (height, body mass, calf circumference, and skinfold thickness) during a visit. Personal and lesion characteristics were registered.RESULTS: Compared to DXA, SF-BIA showed the smallest mean difference in estimating FM%, but with large limits of agreement (mean difference = -2.2%; limits of agreement: -12.8 to 8.3%). BIA and skinfold thickness tended to show a better estimation of FM% in females, participants with tetraplegia, or with motor incomplete injury. New equations for predicting FFM and FM% were developed with good explained variances (FFM: R2 = 0.94; FM%: R2 = 0.66).CONCLUSIONS: None of the measurement techniques accurately estimated FM% because of the wide individual variation and, therefore, should be used with caution. The accuracy of the techniques differed in different subgroups. The newly developed equations for predicting FFM and FM% should be cross-validated in future studies.
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Introduction: In clinical practice AP pelvis standard protocols are suitable for average size patients. However, as the average body size has increased over the past decades, radiographers have had to improve their practice in order to ensure that adequate image quality with minimal radiation dose to the patient is achieved. Gonad shielding has been found to be an effective way to reduce the radiation dose to the ovaries. However, the effect of increased body size, or fat thickness, in combination with gonad shielding is unclear. The goal of the study was to investigate the impact of gonad shielding in a phantom of adult female stature with increasing fat thicknesses on SNR (as a measure for image quality) and dose for AP pelvis examination. Methods: An adult Alderson female pelvis phantom was imaged with a variety of fat thickness categories as a representation of increasing BMI. 72 images were acquired using both AEC and manual exposure with and without gonad shielding. The radiation dose to the ovaries was measured using a MOSFET system. The relationship between fat thickness, SNR and dose when the AP pelvis was performed with and without shielding was investigated using the Wilcoxon signed rank test. P-values < 0.05 were considered to be statistically significant. Results: Ovary dose and SNR remained constant despite the use of gonad shielding while introducing fat layers. Conclusion: The ovary dose did not increase with an increase of fat thickness and the image quality was not altered. Implications for practice: Based on this phantom study it can be suggested that obese patients can expect the same image quality as average patients while respecting ALARA principle when using adequate protocols.
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