Comorbidities are frequent in COPD and 12 of them negatively influence survival. A simple disease-specific comorbidities index (COTE) helps assess mortality risk in patients with COPD.

Multimorbidity frequently affects the ageing population and their co-existence may not occur at random. Understanding their interactions and that with clinical variables could be important for disease screening and management.In a cohort of 1969 chronic obstructive pulmonary disease (COPD) patients and 316 non-COPD controls, we applied a network-based analysis to explore the associations between multiple comorbidities. Clinical characteristics (age, degree of obstruction, walking, dyspnoea, body mass index) and 79 comorbidities were identified and their interrelationships quantified. Using network visualisation software, we represented each clinical variable and comorbidity as a node with linkages representing statistically significant associations.The resulting COPD comorbidity network had 428, 357 or 265 linkages depending on the statistical threshold used ( p⩽0.01, p⩽0.001 or p⩽0.0001). There were more nodes and links in COPD compared with controls after adjusting for age, sex and number of subjects. In COPD, a subset of nodes had a larger number of linkages representing hubs. Four sub-networks or modules were identified using an interlinkage affinity algorithm and their display provided meaningful interactions not discernible by univariate analysis.COPD patients are affected by larger number of multiple interlinked morbidities which clustering pattern may suggest common pathobiological processes or be utilised for screening and/or therapeutic interventions. @ERSpublications COPD patients are affected by interlinked comorbidities forming structured networks

BackgroundThe Global Obstructive Lung Disease (GOLD) 2011 revision recommends the multidimensional assessment of COPD including comorbidities and has developed a disease categories system (ABCD) attempting to implement this strategy. The added value provided by quantifying comorbidities and integrating them to multidimensional indices has not been explored. Objective Compare the prognostic value of the GOLD ABCD categories versus the BMI, Obstruction, Dyspnea, Exercise (BODE) index, and explore the added prognostic value of comorbidities evaluation to this multidimensional assessment. Methods From the patients who have been enrolled in the BODE study, we selected the most recent ones who had the available information needed to classify them by the ABCD GOLD categories. Cox proportional hazards ratios for all-cause mortality were performed for GOLD categories and BODE index. The added value of the comorbidity Copd cO-morbidity TEst (COTE) index was also explored using receiver operating curves (ROC) values. Results 707 patients were followed for 50±30 months including all degrees of airway limitation and BODE index severity. ABCD GOLD predicted global mortality (HR: 1.47; 95% CI 1.28 to 1.70) as did the BODE index (HR: 2.02; 95% CI 1.76 to 2.31). Area under the curve (AUC) of ROC for ABCD GOLD was 0.68; (95% CI 0.64 to 0.73) while for the BODE index was 0.71 (95% CI 0.67 to 0.76). The C statistics value was significantly higher for the observed difference. Adding the COTE index to the BODE index improved its AUC to 0.81 (95% CI 0.77 to 0.85), (χ 2 =40.28, p<0.001).Conclusions In this population of COPD patients, the BODE index had a better survival prediction than the ABCD GOLD categories. Adding the COTE to the BODE index was complimentary and significantly improved outcome prediction.

Chronic obstructive pulmonary disease (COPD), although frequent in older individuals, can also occur at younger age; this latter population has not been well described.We reviewed the functional progression of 1708 patients with COPD attending pulmonary clinics. Those with three or more annual spirometries were divided into those who, at enrolment, were f55 (n5103) or o65 (n5463) years of age (younger and older COPD, respectively). Baseline and annual changes in lung function (forced expiratory volume in 1 s (FEV1)) and BODE (body mass index, airflow obstruction, dyspnoea, exercise capacity) score were recorded and compared between both groups. Severity distribution by Global Initiative for Chronic Obstructive Lung Disease and BODE scores were similar in both groups, except for mild obstruction, which was higher in the younger group. Mean FEV1 decline was 38.8 and 40.6 mL?year -1 , while BODE scores increased 0.19 and 0.23 units per year, for younger and older COPD, respectively. Both groups had similar proportion of FEV1 rapid decliners (42% and 46%, respectively).The severity distribution and progression of disease in younger patients with COPD is similar to that of patients of older age. This observation suggests that younger individuals presenting with COPD develop the disease from an already compromised pulmonary and systemic status, complementing the model of steeper decline of lung function proposed by Fletcher and Peto. @ERSpublications Baseline distribution of COPD severity and disease progression is similar in younger and older patients

Contrary to the general population, in patients with chronic obstructive pulmonary disease (COPD) a low body mass index (BMI) is associated with excess mortality, while obesity appears protective (obesity paradox). We hypothesized that BMI is associated with a distinct number and expression of comorbidities in patients with COPD. The type of comorbidity may relate to mortality variability. We followed 1659 COPD patients for a median of 51 months [IQR 27-77] with detailed comorbidity records and tracking pulmonary function, exercise capacity, dyspnea, health status, and cause of death. The cohort was categorized into the 5 National Heart Lung and Blood Institute (NHLBI) BMI groups with determination made about each group's relationship to specific comorbidities, clinical parameters and risk for death. Whereas osteoporosis, substance abuse, abdominal aortic aneurism and peripheral arterial disease were more prevalent in patients with low BMI, metabolic and cardiac problems were more frequent in those with high BMI. The BMI was inversely related to the ratio of forced expiratory volume in 1 second (FEV) to forced vital capacity (FVC)(FEV %), BODE (Body mass index, airway Obstruction, Dyspnea, Exercise capacity) index and hyperinflation, had a "U" shape with dyspnea and the St. George's Respiratory Questionaire (SGRQ) score and an inverse "U" with exercise capacity. The crude mortality rate was 60%, 43%, 37%, 36% and 28% from the lowest to highest BMI groups (p<.0001). More respiratory deaths were observed in the lowest BMI group even though they had a lower number of comorbidities. Different BMI categories are associated with distinct clinical expressions of COPD and comorbidity patterns. The relationship between BMI and mortality in patients with COPD remains an unresolved paradox.