Brown adipose tissue activation is not related to hypermetabolism in emphysematous chronic obstructive pulmonary disease patients.

BACKGROUND: Brown adipose tissue (BAT) has been primarily researched as a potential target for mitigating obesity. However, the physiological significance of BAT in relation to cachexia remains poorly understood. The objective of this study was to investigate the putative contribution of BAT on different components of energy metabolism in emphysematous chronic obstructive pulmonary disease (COPD) patients. METHODS: Twenty COPD patients (mean ± SD age 62 ± 6, 50% female, median [range] BMI 22.4 [15.1-32.5] kg/m2 and 85% low FFMI) were studied. Basal metabolic rate (BMR) was assessed by ventilated hood, total daily energy expenditure (TDEE) by doubly labelled water and physical activity by triaxial accelerometry. BMR was adjusted for fat-free mass (FFM) as assessed by deuterium dilution. Analysis of BAT and WAT was conducted in a subset of ten patients and six age-matched, gender-matched and BMI-matched healthy controls. BAT glucose uptake was assessed by means of cold-stimulated integrated [18F]FDG positron-emission tomography and magnetic resonance imaging. WAT was collected from subcutaneous abdominal biopsies to analyse metabolic and inflammatory gene expression levels. Lung function was assessed by spirometry and body plethysmography and systemic inflammation by high sensitivity C-reactive protein. RESULTS: Mean TDEE was 2209 ± 394 kcal/day, and mean BMR was 1449 ± 214 kcal/day corresponding to 120% of predicted. FFM-adjusted BMR did not correlate with lung function or C-reactive protein. Upon cooling, energy expenditure increased, resulting in a non-shivering thermogenesis of (median [range]) 20.1% [3.3-41.3] in patients and controls. Mean BAT glucose uptake was comparable between COPD and controls (1.5 [0.1-6.2] vs. 1.1 [0.7-3.9]). In addition, no correlation was found between BMR adjusted for FFM and BAT activity or between cold-induced non-shivering energy expenditure and BAT activity. Gene expression levels of the brown adipocyte or beige markers were also comparable between the groups. No (serious) adverse events were reported. CONCLUSIONS: Although COPD patients were hypermetabolic at rest, no correlation was found between BMR or TDEE and BAT activity. Furthermore, both BAT activity and gene expression levels of the brown adipocyte or beige markers were comparable between COPD patients and controls.

Handgrip weakness, low fat-free mass, and overall survival in non-small cell lung cancer treated with curative-intent radiotherapy.

BACKGROUND: Assessment of handgrip strength and fat-free mass provides quick and objective information on muscle performance and mass that might complement subjective World Health Organization Performance Status (WHO PS). We investigated to what extent the presence of pre-treatment handgrip weakness and low fat-free mass index (FFMI) provides additional prognostic information on top of well-established prognostic factors (including WHO PS) in non-small cell lung cancer (NSCLC) patients selected for curative-intent (chemo)radiation. METHODS: Prospectively, patients with early and locally advanced NSCLC (stages I-III) treated with (chemo)radiation were enrolled. Handgrip weakness and low FFMI, derived from bioelectrical impedance analysis, were defined using normative values and were correlated with overall survival (OS). RESULTS: We included 936 patients (age 68 ± 10 years; 64% male; 19% stage I, 9% stage II, and 72% stage III disease; 26% handgrip weakness; 27% low FFMI). In patients with good performance status (WHO PS 0 or 1), handgrip weakness and low FFMI were significant prognostic factors for OS, after adjustment for age, gender, disease stage, and co-morbidities. The combined presence of handgrip weakness and low FFMI was a strong prognostic factor for OS when compared with patients with normal handgrip strength and FFMI (hazard ratio: 1.79, 95% confidence interval: 1.34-2.40, P < 0.0001). In patients with impaired performance status (WHO PS ≥ 2, 19% of sample), handgrip weakness and low FFMI were not related to OS. CONCLUSIONS: In early and locally advanced NSCLC patients treated with curative-intent (chemo)radiation who have good WHO PS, patients with combined handgrip weakness and low FFMI have the worst prognosis.

Cross-sectional and longitudinal assessment of muscle from regular chest computed tomography scans: L1 and pectoralis muscle compared to L3 as reference in non-small cell lung cancer.

Background: Computed tomography (CT) is increasingly used in clinical research for single-slice assessment of muscle mass to correlate with clinical outcome and evaluate treatment efficacy. The third lumbar level (L3) is considered as reference for muscle, but chest scans generally do not reach beyond the first lumbar level (L1). This study investigates if pectoralis muscle and L1 are appropriate alternatives for L3. Methods: CT scans of 115 stage IV non-small cell lung cancer patients were analyzed before and during tumor therapy. Skeletal muscle assessed at pectoralis and L1 muscle was compared to L3 at baseline. Furthermore, the prognostic significance of changes in muscle mass determined at different locations was investigated. Results: Pearson's correlation coefficient between skeletal muscle at L3 and L1 was stronger (r=0.90, P<0.001) than between L3 and pectoralis muscle (r=0.71, P<0.001). Cox regression analysis revealed that L3 (HR 0.943, 95% CI: 0.92-0.97, P<0.001) and L1 muscle loss (HR 0.954, 95% CI: 0.93-0.98, P<0.001) predicted overall survival, whereas pectoralis muscle loss did not. Conclusion: L1 is a better alternative than pectoralis muscle to substitute L3 for analysis of muscle mass from regular chest CT scans.

TSH suppression aggravates arterial inflammation - an 18F-FDG PET study in thyroid carcinoma patients.

PURPOSE: We aimed to investigate the influence of both hypothyroidism and thyroid-stimulating hormone (TSH) suppression on vascular inflammation, as assessed with 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT). METHODS: Ten thyroid carcinoma patients underwent an 18F-FDG PET/CT during post-thyroidectomy hypothyroidism and during thyrotropin (TSH) suppression after 131I (radioiodine) ablation therapy. We analysed the 18F-FDG uptake in the carotids, aortic arch, ascending, descending, and abdominal aorta to investigate the effects of thyroid hormone status on arterial inflammation. Target-to-background ratios (TBRs) corrected for blood pool activity were established for all arterial territories. Results were further compared to euthyroid historic control subjects. RESULTS: In general, there was a trend towards higher vascular TBRs during TSH suppression than during hypothyroidism (TBRmax all vessels = 1.6 and 1.8, respectively, p = 0.058), suggesting a higher degree of arterial inflammation. In concurrence with this, we found increased C-reactive protein (CRP) levels after levothyroxine treatment (CRP = 2.9 mg/l and 4.8 mg/l, p = 0.005). An exploratory comparison with euthyroid controls showed significant higher TBRs during TSH suppression for the carotids, aortic arch, thoracic descending aorta, and when all vascular territories were combined (TBRmaxp = 0.013, p = 0.016, p = 0.030 and p = 0.018 respectively). CONCLUSIONS: Arterial inflammation is increased during TSH suppression. This finding sheds new light on the underlying mechanism of the suspected increased risk of cardiovascular disease in patients with TSH suppression.

CT-derived muscle remodelling after bronchoscopic lung volume reduction in advanced emphysema.

Muscle wasting frequently occurs in severe emphysema. Improving respiratory mechanics by bronchoscopic lung volume reduction using endobronchial valves (EBV) might prevent further loss or even increase in muscle mass. CT-derived skeletal muscle mass gain was observed in 39/49 patients 6 months after EBV. Multiple linear regression showed that gain in muscle (ß=2.4; 95% CI 0.2 to 4.6; p=0.036) and intramuscular fat (ß=3.1; 95% CI 0.2 to 5.9; p=0.035) is associated with improved 6 min walk distance independent of the change in residual volume. Skeletal muscle remodelling associates with improved exercise capacity after EBV, independent of hyperinflation reduction. TRIAL REGISTRATION NUMBER: Clinical trial registered with the Dutch trial register www.trialregister.nl (NTR2876), Results.

Imaging approaches to understand disease complexity: chronic obstructive pulmonary disease as a clinical model.

The clinical manifestations of chronic obstructive pulmonary disease (COPD) reflect an aggregate of multiple pulmonary and extrapulmonary processes. It is increasingly clear that full assessment of these processes is essential to characterize disease burden and to tailor therapy. Medical imaging has advanced such that it is now possible to obtain in vivo insight in the presence and severity of lung disease-associated features. In this review, we have assembled data from multiple disciplines of medical imaging research to review the role of imaging in characterization of COPD. Topics include imaging of the lungs, body composition, and extrapulmonary tissue metabolism. The primary focus is on imaging modalities that are widely available in clinical care settings and that potentially contribute to describing COPD heterogeneity and enhance our insight in underlying pathophysiological processes and their structural and functional effects.

Cachexia in chronic obstructive pulmonary disease: new insights and therapeutic perspective.

Cachexia and muscle wasting are well recognized as common and partly reversible features of chronic obstructive pulmonary disease (COPD), adversely affecting disease progression and prognosis. This argues for integration of weight and muscle maintenance in patient care. In this review, recent insights are presented in the diagnosis of muscle wasting in COPD, the pathophysiology of muscle wasting, and putative mechanisms involved in a disturbed energy balance as cachexia driver. We discuss the therapeutic implications of these new insights for optimizing and personalizing management of COPD-induced cachexia.

Early Weight Loss during Chemoradiotherapy Has a Detrimental Impact on Outcome in NSCLC.

OBJECTIVES: The aim of this study was to assess the effect of early weight loss before the onset of radiation esophagitis on overall survival (OS) in patients with non-small cell lung cancer treated with concurrent chemoradiotherapy. METHODS: Characteristics (e.g., patient weight, radiation esophagitis score, sex, World Health Organization performance status, chemotherapy dose, nodal status, and gross tumor volume) of 151 patients who received concurrent chemoradiotherapy (in 2006-2013) were retrospectively correlated with OS. Early weight loss was defined as weight loss of more than 5% between the start and third week of radiotherapy in patients whose weight was stable before treatment initiation. RESULTS: In 17% of the patients early weight loss was observed. Median OS (95% confidence interval [CI]) was significantly shorter in the early weight loss group (OS = 13.0 months, 95% CI: 2.0-24.0) versus in the non-early weight loss group (OS = 23.0 months, 95% CI: 14.7-31.3) (hazard ratio [HR] = 1.8, 95% CI: 1.12-2.96, p = 0.017). On multivariate analysis sex (HR = 2.1, 95% CI: 1.33-3.29, p = 0.001), World Health Organization performance status (HR = 1.9, 95% CI: 1.20-2.97, p = 0.006), nodal status (HR = 2.9, 95% CI: 1.38-6.01, p = 0.005), and early weight loss (HR = 1.9, 95% CI: 1.10-3.19, p = 0.022) were associated with OS. CONCLUSIONS: Early weight loss in patients with non-small cell lung cancer was found to be associated with worse prognosis. These data warrant further investigation into the efficacy of tailored intervention to prevent early weight loss.