Is the COPD assessment test (CAT) effective in demonstrating the systemic inflammation and other components in COPD?

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is currently a complex, multicomponent disorder. The COPD Assessment Test (CAT) has been increasingly used to assess COPD patients. This study aims to investigate the relationship between CAT and inflammation markers and other COPD components. METHODS: We enrolled 110 stable COPD patients and 65 control subjects in this study. All patients completed the CAT questionnaire and the modified Medical Research Council (mMRC) dispnea scale. The quality of life of these patients was measured with St. George's Respiratory Questionnaire (SGRQ). Levels of TNFα, IL-6, CRP were determined in blood samples. RESULTS: In COPD patients, serum levels of TNFα (109.5 ± 58 pg/ml), IL-6 (10.3 ± 18 pg/ml), and C-reactive protein (CRP) (1.6 ± 1.7 mg/L) were found to be significantly higher compared to controls (TNF-α: 14.6 ± 18 pg/ml, IL-6: 2.14 ± 1.9 pg/ml, CRP: 0.4 ± 0.3mg/L, p<0.001). These markers were correlated with smoking (r from 0.27 to 0.35, p<0.001), FEV1 (r from -0.39 to -0.57, p<0.001), FVC (r from -0.32 to -0.37, p<0.001) and FEV1/FVC (r from -0.31 to -0.66, p<0.001). The CAT score correlated with GOLD spirometric stages, mMRC dyspnea score, number of exacerbations in the previous year and FEV1 (p<0.001). There was a significant correlation between levels of CRP and the CAT score (r=0.43, p<0.001) but no similar relationship between levels of TNFα and IL-6 and the CAT was observed. CONCLUSION: Systemic inflammation persists in the stable period of COPD. CRP, one of the inflammation markers, was correlated with the CAT. Further studies are required to confirm the relationship between CAT and biomarkers.

Histopathological changes in rat pancreas and skeletal muscle associated with high fat diet induced insulin resistance.

The effects of a high fat diet on the development of diabetes mellitus, insulin resistance and secretion have been widely investigated. We investigated the effects of a high fat diet on the pancreas and skeletal muscle of normal rats to explore diet-induced insulin resistance mechanisms. Forty-four male Wistar rats were divided into six groups: a control group fed standard chow, a group fed a 45% fat diet and a group fed a 60% fat diet for 3 weeks to measure acute effects; an additional three groups were fed the same diet regimens for 8 weeks to measure chronic effects. The morphological effects of the two high fat diets were examined by light microscopy. Insulin in pancreatic islets was detected using immunohistochemistry. The homeostasis model assessment of insulin resistance index and insulin staining intensity in islets increased significantly with acute administration of high fat diets, whereas staining intensity decreased with chronic administration of the 45% fat diet. Islet areas increased significantly with chronic administration. High fat diet administration led to islet degeneration, interlobular adipocyte accumulation and vacuolization in the pancreatic tissue, as well as degeneration and lipid droplet accumulation in the skeletal muscle tissue. Vacuolization in the pancreas and lipid droplets in skeletal muscle tissue increased significantly with chronic high fat diet administration. We suggest that the glucolipotoxic effects of high fat diet administration depend on the ratio of saturated to unsaturated fatty acid content in the diet and to the total fat content of the diet.