Larger proportions of chronic obstructive pulmonary disease (COPD) patients are currently overweight or with obesity than underweight, and the combination of COPD and obesity is increasing. The purpose of this study was to investigate differences in the body composition, pulmonary function tests, exercise capacity, and health-related quality of life among normal weight, overweight, and obese patients with COPD. A total of 514 patients with COPD were included in the study. According to the World Health Organization criteria for body mass index, the patients were classified as normal weight, overweight, and obese. Evaluations included fat-free mass, fat-free mass index, phase angle, pulmonary function tests, and 6-minute walk test. Dyspnea was assessed using the modified Medical Research Council dyspnea scale, and the health-related quality of life was evaluated using COPD Assessment Test and St. George’s Respiratory Questionnaire. Values were compared among the three groups. There were 315 male and 199 female patients, with a mean age of 66.7 ± 8.4 years. Fat-free mass, fat-free mass index, and phase angle values were significantly higher in COPD patients with obesity than in other patients (P < .001, P < .001, P < .001). Forced expiratory volume in 1 s, forced expiratory volume in 1 s/forced vital capacity, and diffusing capacity of lung for carbon monoxide value in pulmonary function tests were significantly higher in COPD patients with obesity than in other patients (P = .046, P < .001, P < .001), while the forced vital capacity values were similar in all groups. Exercise capacity (6-min walk test distance), dyspnea symptoms (modified Medical Research Council scale), and health-related quality of life (COPD Assessment Test and St. George’s Respiratory Questionnaire) did not differ significantly between groups. According to our study, obesity has no negative effect on pulmonary function tests, dyspnea perception, exercise capacity, and health-related quality of life. What is already known on this topic: The combination of chronic obstructive pulmonary disease (COPD) and obesity is increasing. Previous studies on obesity’s impact on exercise capacity, pulmonary function, and quality of life in COPD patients present contradictory findings. Abnormal body composition is an independent determinant of COPD outcomes. What this study adds: In this study, we observed statistically significant higher values of fat-free mass, fat-free mass index, and phase angle in COPD patients with obesity. According to our study, obesity has no negative effect on pulmonary function tests, dyspnea perception, exercise capacity, and health-related quality of life. Our understanding of the complex interaction between obesity and COPD is still limited. How this study might affect research, practice, or policy: This study emphasizes the importance of paying attention to obese COPD patients in clinical practice. Measuring body composition in all COPD patients is mandatory in the further care and treatment of COPD patients. It is of great clinical interest to further explore obese COPD patients in dedicated randomized trials.

Background: Mild asthma is often characterized by normal spirometric values and a negative bronchodilation test (BDT), which makes accurate diagnosis challenging. The aim of our study was to evaluate the diagnostic accuracy of fractional exhaled nitric oxide (FeNO) in mild asthma. Methods: In adults with symptoms suggestive of asthma and normal spirometry values, BDT, FeNO, BPT and skin prick testing were performed. Patients with positive BPT started inhaled corticosteroid (ICS) therapy. Those with positive response to ICS were considered asthmatics. Results: There were 142 asthmatics and 140 non-asthmatics. No significant difference was found in BDT between the groups, p = 0.233. Median FeNO levels were significantly higher in the asthma group (49.5 ppb) than in the non-asthma group (23 ppb), p < 0.001. BPT was positive in 145 (51.42%) and negative in 137 (48.58%) patients. Positive response to ICS treatment was recorded in 142/145 (97.9%) patients. In diagnosing asthma, FeNO ≥ 25 ppb had a sensitivity of 75.4% and specificity of 47.9%. Conclusions: FeNO has insufficient sensitivity and specificity in mild asthma and the application of BPT is often necessary to establish an accurate diagnosis.

The nutritional status of patients with chronic obstructive pulmonary disease (COPD) is a significant factor that influences the prognosis of the disease. This observational study aimed to analyse the nutritional status of COPD patients and assess the associations between nutritional status, disease severity, and exercise capacity in four different regions of Croatia. In this multicentre study, 534 COPD patients were recruited and evaluated concerning fat-free mass (FFM), fat-free mass index (FFMI), skeletal muscle mass index (SMMI), phase angle (PhA), pulmonary function tests, and the 6-minute walk test (6MWT). There were 325 (60.9%) male and 209 (39.1%) female patients with a mean age of 66.7±8.4 years. Most patients (73.2%) exhibited a moderate to severely abnormal obstructive pattern and had a reduced 6MWT distance (396.5±110.8 m). Among the participants, 32.8% were overweight and 22.3% were obese, and they had satisfactory values for nutritional status variables (FFM, FFMI, SMMI, PhA). There were no statistical differences between the centres in terms of nutritional status variables. There was a significantly positive correlation of FEV1 with BMI (r=0.148, p=0.001), PhA (r=0.256, p=0.00), FFM (r=0.365, p=0.00), and SMMI (r=0.238, p=0.00). However, there was no significant correlation of the 6MWT with BMI (r=-0.049, p=0.254), FFM (r=0.065, p=0.133), and SMMI (r=-0.007, p=0.867). The data analysis demonstrated that our patients were not underweight and that there was no significant difference between the centres in terms of BMI, FFM, FFMI, SMMI, and PhA. This lack of significant difference was observed even though one of the regions studied was Mediterranean.

Background: The cough variant asthma (CVA) is characterized by non-specific symptoms and normal spirometric values, which makes diagnosis challenging. To diagnose CVA it is necessary to document airway hyperreactivity (AHR). The aim of our study was to evaluate the diagnostic value of body plethysmography in the assessment of AHR by methacholine challenge test (MCT). Methods: In CVA-suspected patients, a bronchodilation test (BDT), MCT with spirometry, and body plethysmography were performed. MCT was considered positive if there was a 20% decrease in forced expiratory volume in 1 second from the baseline value (PC20FEV1) or a 40% reduction in specific conductance (PC40sGaw) after inhaling methacholine concentration < 8 mg/mL. Sensitivity and specificity were generated for different cut off points of sGaw (PC40sGaw, PC45sGaw, PC50sGaw). Anti-asthma treatment was started for those with proven AHR. The diagnosis of asthma was made after one year of follow-up based on response to treatment. Results: AHR was diagnosed in 83.5% (91/109) of patients by either BDT, PC20FEV1, or PC40sGaw. After one year of follow-up asthma was confirmed in 76 patients. The sensitivity of BDT, PC20FEV1, and PC40sGaw was 25%, 64%, and 97%, respectively. The specificity of BDT, PC20FEV1 and PC40sGaw was 94%, 88%, and 67%, respectively. The sensitivity for PC45sGaw and PC50sGaw was 88% and 63%, and the specificity was 82% and 91%, respectively. Conclusions: Body plethysmography is a valuable tool in the assessment of AHR in CVA, with the best sensitivity-to-specificity ratio for PC45sGaw.

Background/Objectives: Cough variant asthma (CVA) is characterized by nonspecific symptoms and normal spirometric values, which makes diagnosis challenging. To diagnose CVA it is necessary to document airway hyperreactivity (AHR). The aim of our study was to evaluate the diagnostic value of body plethysmography in the assessment of AHR using the methacholine challenge test (MCT). Methods: In CVA-suspected patients, a bronchodilation test (BDT), an MCT with spirometry, and body plethysmography were performed. The MCT was considered positive if there was a 20% decrease in forced expiratory volume in 1 s from the baseline value (PC₂₀FEV₁) or a 40% reduction in specific conductance (PC₄₀sGaw) after inhaling methacholine of concentration < 8 mg/mL. Sensitivity and specificity were generated for different cut off points of sGaw (PC₄₀sGaw, PC₄₅sGaw, PC₅₀sGaw). Anti-asthma treatment was started for those with proven AHR. The diagnosis of asthma was made after one year of follow-up based on the response to treatment. Results: AHR was diagnosed in 83.5% (91/109) of patients by either a BDT, PC₂₀FEV₁, or PC₄₀sGaw. After one year of follow-up, asthma was confirmed in 76 patients. The sensitivities of the BDT, PC₂₀FEV₁, and PC₄₀sGaw were 25%, 64%, and 97%, respectively. The specificities of the BDT, PC₂₀FEV₁ and PC₄₀sGaw were 94%, 88%, and 67%, respectively. The sensitivities for a PC₄₅sGaw and PC₅₀sGaw were 88% and 63%, and the specificities were 82% and 91%, respectively. Conclusions: Body plethysmography is a valuable tool in the assessment of AHR in CVA, with the best sensitivity-to-specificity ratio found at a PC₄₅sGaw.