Prognostic value of the serum creatinine/cystatin C ratio in patients with chronic obstructive pulmonary disease

BACKGROUND

Sarcopenia, characterized by skeletal muscle atrophy and physical inactivity, is a manifestation of chronic obstructive pulmonary disease (COPD) and is associated with a poor prognosis. The serum creatinine (Cr)/cystatin C (CysC) ratio has been proposed as a marker of sarcopenia, given its correlation with total skeletal muscle mass, and as a prognostic indicator in COPD. This study aimed to evaluate the usefulness of the serum Cr/CysC ratio as a prognostic determinant in these patients.

METHODS

A total of 124 outpatients with COPD were enrolled in this study. Their serum Cr and CysC levels were measured. Survival time analyses were conducted to compare mortality rates between the low and high serum Cr/CysC ratio groups. Multivariate analysis was performed to investigate the association between various factors.

RESULTS

Using a serum Cr/CysC cut-off value of 0.885, the mortality rate (per 1000 person-years) for overall mortality was significantly higher in the low serum Cr/CysC ratio group (69.2 versus 28.6; hazard ratio, 2.47; 95% confidence interval, 1.06-5.79; p < 0.05). Similarly, the mortality rate due to respiratory disease was also higher (37.8 versus 8.2; hazard ratio, 4.68; 95% confidence interval, 1.05-20.9; p < 0.05). Multivariate Cox proportional hazards analysis revealed that serum Cr/CysC was an independent risk factor for respiratory disease mortality, regardless of age and airflow limitations.

CONCLUSIONS

The serum Cr/CysC ratio could be a valuable clinical parameter for identifying sarcopenia and severe airflow obstruction. The study findings highlight the utility of this ratio as a prognostic predictor in patients with COPD.

Associations between spirometric impairments and microvascular complications in type 2 diabetes: a cross-sectional study

OBJECTIVE

Evidence shows that the conventional cardiometabolic risk factors do not fully explain the burden of microvascular complications in type 2 diabetes (T2D). One potential factor is the impact of pulmonary dysfunction on systemic microvascular injury. We assessed the associations between spirometric impairments and systemic microvascular complications in T2D.

DESIGN

Cross-sectional study.

SETTING

National Diabetes Management and Research Centre in Ghana.

PARTICIPANTS

The study included 464 Ghanaians aged ≥35 years with established diagnosis of T2D without primary myocardial disease or previous/current heart failure. Participants were excluded if they had primary lung disease including asthma or chronic obstructive pulmonary disease.

PRIMARY AND SECONDARY OUTCOME MEASURES

The associations of spirometric measures (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio) with microvascular complications (nephropathy (albumin-creatinine ratio ≥3 mg/g), neuropathy (vibration perception threshold ≥25 V and/or Diabetic Neuropathy Symptom score >1) and retinopathy (based on retinal photography)) were assessed using multivariable logistic regression models with adjustments for age, sex, diabetes duration, glycated haemoglobin concentration, suboptimal blood pressure control, smoking pack years and body mass index.

RESULTS

In age and sex-adjusted models, lower Z-score FEV1 was associated with higher odds of nephropathy (OR 1.55, 95% CI 1.19-2.02, p=0.001) and neuropathy (1.27 (1.01-1.65), 0.038) but not retinopathy (1.22 (0.87-1.70), 0.246). Similar observations were made for the associations of lower Z-score FVC with nephropathy (1.54 (1.19-2.01), 0.001), neuropathy (1.25 (1.01-1.54), 0.037) and retinopathy (1.19 (0.85-1.68), 0.318). In the fully adjusted model, the associations remained significant for only lower Z-score FEV1 with nephropathy (1.43 (1.09-1.87), 0.011) and neuropathy (1.34 (1.04-1.73), 0.024) and for lower Z-score FVC with nephropathy (1.45 (1.11-1.91), 0.007) and neuropathy (1.32 (1.03-1.69), 0.029). Lower Z-score FEV1/FVC ratio was not significantly associated with microvascular complications in age and sex and fully adjusted models.

CONCLUSION

Our study shows positive but varying strengths of associations between pulmonary dysfunction and microvascular complications in different circulations. Future studies could explore the mechanisms linking pulmonary dysfunction to microvascular complications in T2D.

Emergency Department Presentation of Life-threatening Symptomatic Hyperkalemia From an Angiotensin Receptor Blocker in a Low-risk Individual

Hyperkalemia is a common electrolyte abnormality with characteristic electrocardiogram changes. Both angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) increase the risk of developing hyperkalemia. This case highlights a rare life-threatening episode of hyperkalemia in an individual whose only risk factor was an ARB. A 58-year-old female presented with sudden-onset chest pressure, light-headedness, and diaphoresis. Her initial electrocardiogram showed a nearly sinusoidal rhythm with a widened ventricular depolarization (QRS) and prolonged QT-interval (QTc). Life-threatening hyperkalemia of 9.1 mmol/L was confirmed with a rapid point-of-care electrolyte panel. She was rapidly treated with calcium, potassium-shifting and eliminating medications, and emergent hemodialysis. After stabilization, a thorough workup found that the patient's only risk factor for hyperkalemia was her use of an ARB. While both ARBs and ACEIs are commonly associated with mild hyperkalemia, life-threatening hyperkalemia is rare, particularly in patients without concomitant renal failure, diabetes mellitus, adrenal disease, or potassium-sparing diuretic use. However, this case illustrates that life-threatening hyperkalemia is possible in patients solely taking an ARB without prior significant risk factors. Despite normal renal function in an individual without heart failure or diabetes, this patient developed life-threatening hyperkalemia.

Serum levels of erythropoietin in patients with chronic obstructive pulmonary disease and anemia

The important association of erythropoietin (EPO) serum levels and chronic obstructive pulmonary disease (COPD) with anemia has been inadequately studied and remains a controversial issue. We aimed to shed light on this matter by comparing EPO levels in anemic and non-anemic COPD patients, along with a review of published literature. This cross-sectional study was conducted on COPD patients referred to the pulmonary clinic of Shahid Faghihi Hospital and Motahari clinic, Shiraz, Iran, for one year. We measured complete blood count, red blood cell indices, serum iron, TIBC and ferritin levels, serum EPO levels, and body mass index. Among 35 patients in this study, 28 males and 7 females were enrolled with a mean age of 54.57 ± 8.07 years. The average Forced expiratory volume in first second (FEV1) was 37.26 ± 7.33% and FEV1/FVC was 0.46 ± 0.12. Mean EPO levels were 30.29 ± 2.066 mU/mL. No statistically significant association was observed among erythropoietin levels and Hb, COPD severity, and age. There was no significant difference in EPO levels between anemic and non-anemic patients. EPO level, against the traditional expectation, didn't increase in COPD patients. EPO production also didn't compensate for the anemia of chronic disease which considers as a common comorbid disorder in these patients.

Chronic Obstructive Pulmonary Disease and Its Effect on Red Blood Cell Indices

Chronic obstructive pulmonary disease (COPD) constitutes a set of heterogeneous symptoms affecting millions of people worldwide. The associated comorbidities developing in COPD involve dysregulation in physiological pathways resulting from systemic inflammation in respiratory airways. In addition to mentioning the pathophysiology, stages, and consequences of COPD, this paper also defines red blood cell (RBC) indices such as hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, red blood cell distribution width, and RBC count. It explains the role of RBC indices and RBC structural abnormalities with disease severity and exacerbations in COPD patients. Although many factors have been studied as a marker of morbidity and mortality for COPD patients, RBC indices have emerged as revolutionary evidence. Therefore, the effectiveness of evaluating RBC indices in COPD patients and their importance as a negative predictor of survival, mortality, and clinical outcomes have been debated through rigorous literature reviews. Furthermore, the prevalence, mechanisms of development, and prognosis of underlying anemia and polycythemia in COPD have also been evaluated, with anemia most significantly associated with COPD. Therefore, more studies should be conducted to address underlying anemia in COPD patients to lessen the severity and disease burden. Correcting the RBC indices in COPD patients remarkably impacts the quality of life and reduces in-patient admissions, healthcare resource utilization, and costs. Hence, it is noteworthy to understand the significance of considering RBC indices while dealing with COPD patients.

Impact of Chronic Obstructive Pulmonary Disease on Outcomes After Total Joint Arthroplasty: A Meta-analysis and Systematic Review

Background

Comorbid chronic obstructive pulmonary disease (COPD) is increasingly common and may have an adverse impact on outcomes in patients undergoing total joint arthroplasty (TJA) of lower extremity. The purpose of this meta-analysis is to compare the postoperative complications between COPD and non-COPD patients undergoing primary TJA including total hip and knee arthroplasty.

Methods

PubMed, EMBASE, and Cochrane Library were systematically searched for relevant studies published before December 2021. Postoperative outcomes were compared between patients with COPD versus those without COPD as controls. The outcomes were mortality, re-admission, pulmonary, cardiac, renal, thromboembolic complications, surgical site infection (SSI), periprosthetic joint infection (PJI), and sepsis.

Results

A total of 1,002,779 patients from nine studies were finally included in this meta-analysis. Patients with COPD had an increased risk of mortality (OR [odds ratio] = 1.69, 95% confidence interval [CI] 1.42-2.02), re-admission (OR = 1.54, 95% CI 1.38-1.71), pulmonary complications (OR = 2.73, 95% CI 2.26-3.30), cardiac complications (OR = 1.40, 95% CI 1.15-1.69), thromboembolic complications (OR = 1.21, 95% CI 1.15-1.28), renal complications (OR = 1.50, 95% CI 1.14-1.26), SSI (OR = 1.23, 95% CI 1.18-1.30), PJI (OR = 1.26, 95% CI 1.15-1.38), and sepsis (OR = 1.36, 95% CI 1.22-1.52).

Conclusion

Patients with comorbid COPD showed an increased risk of mortality and postoperative complications following TJA compared with patients without COPD. Therefore, orthopedic surgeons can use the study to adequately educate these potential complications when obtaining informed consent. Furthermore, preoperative evaluation and medical optimization are crucial to minimizing postoperative complications from arising in this difficult-to-treat population.

Level of evidence

Level III.

Registration

None.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00794-2.

Features of Kidney Function in Patients With Comorbidity of Arterial Hypertension and Chronic Obstructive Pulmonary Disease

Background and objective Chronic kidney disease (CKD) and hypertension are closely linked in terms of cause and effect. Decreased renal function is usually associated with increased blood pressure, and a steady increase in blood pressure accelerates the decline in renal function. In this study, we aimed to investigate laboratory parameters of renal function - blood creatinine level, urine creatinine level, urea blood level, urine albumin level, and in particular, serum cystatin C level - as early predictors of kidney damage and assess the filtration function of the kidneys based on the glomerular filtration rate (GFR) in patients with isolated arterial hypertension, those with a comorbid pathology of hypertension and chronic obstructive pulmonary disease (COPD). and those with isolated COPD. Materials and methods The study included a total of 101 patients (the final sample consisted of 88 patients) with hypertension and COPD, who were divided into three groups: Group I consisted of 38 patients with hypertension, Group II comprised 27 patients with hypertension and COPD, and Group III was made up of 23 patients with COPD. The average age of patients in groups - presented as mean [standard deviation (SD)] - was as follows - Group I: 55.7 (11.2) years, Group II: 59.3 (9.2) years, and Group III: 57.8 (9.1) years. For statistical data processing, the program Statistics 10 was used. Results The level of blood creatinine - presented as median (Me) and interquartile range (IQR) - was statistically significantly different between the groups, and the values in the three groups were as follows - Group I (patients with hypertension): 88.3 (84.2; 102.7) μmol/l, Group II (patients with comorbid pathology of arterial hypertension and COPD): 99.0 (80.0; 115.0) μmol/l, and Group III (patients with COPD): 84.6 (75.0; 94.2) μmol/l (p=0.008). The highest level was determined in patients with hypertension and comorbid COPD, while the lowest was in the comparison group, in patients with COPD. Urinary creatinine levels were as follows - Group I: 1081.0 (578.0; 1749.0) mg/l, Group II: 1318.5 (1124.0; 1817.0) mg/l, and Group III: 822.0 (625.0; 1320.5) mg/l (p=0.08). Blood urea values were as follows - Group I: 5.7 (5.2; 6.0) mmol/l, Group II: 5.7 (4.9; 6.6) mmol/l, Group III: 5.9 (4.4; 7.7) mmol/l. The calculation of GFR revealed a statistically significant difference between the three groups - Group I: 70.5 (56.0; 83.0) ml/min, Group II: 66.5 (57.0; 77.0) ml/min, and Group III: 81.5 (70.0; 88.0) ml/min (p=0.02). The cystatin C level was 1.16 (1.03; 1.27) mg/l in Group I, 1.3 (1.22; 1.38) mg/l in Group II, and 1.05 (0.96; 1.05) mg/l in Group III. Conclusions In patients of all three groups, there was a decrease in renal filtration function based on the results of creatinine and cystatin C levels. Even in the group of patients with COPD without kidney disease, a decrease in GFR was observed. We noted a negative aggravating effect of COPD on renal function in patients with hypertension, which can be attributed to increased endothelial dysfunction and increased general inflammation in this group of patients.

Correlation Analysis of Early Renal Injury in Elderly Patients with Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Objective

To investigate the correlation between serum cystatin C (Cys-C) and beta-2 (β2) microglobulin (β2-MG) levels and renal injury in elderly patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) with a view to detecting renal injury in its early stages.

Methods

A total of 106 patients with AECOPD were enrolled and divided into three groups according to their oxygen partial pressure (PO₂) levels: severe hypoxia group, moderate hypoxia group, and mild hypoxia group. Another 60 healthy subjects were selected as the control group. General clinical data were collected from all the study subjects, along with measurements of arterial blood gas, Cys-C, β2-MG, serum creatinine (Scr), urea nitrogen (BUN), partial pressure of carbon dioxide (PCO₂), and high-sensitivity C-reactive protein (hs-CRP).

Results

The levels of hs-CRP, Cys-C, β2-MG, Scr, and BUN were highest in the severe hypoxia group, followed by the moderate hypoxia group, then the mild hypoxia group, and lowest in the control group. The differences between the groups were statistically significant for these indicators (P < 0.05). Apart from in the cases of Scr and BUN, there were no statistically significant differences between the mild group and the control group (P > 0.05). The levels of Cys-C and β2-MG were positively correlated with the levels of hs-CRP, PCO₂, Scr, and BUN and negatively correlated with PO₂ levels. hs-CRP and PO₂ were high-risk factors influencing Cys-C levels, and β2-MG was a risk factor influencing Cys-C levels. The level of PO₂ was a high-risk factor influencing β2-MG levels, and PCO₂ and Cys-C were risk factors influencing β2-MG levels.

Conclusion

Renal injury was found to be present in patients with AECOPD and worsened with increasing degrees of hypoxia. Hypoxia and inflammation might be risk factors for renal injury in patients with AECOPD, Cys-C and β2-MG could be sensitive indicators for the early detection of renal injury.

Nonadherence to health promotion depending on chronic obstructive pulmonary disease severity

BACKGROUND

Nonadherence to recommended health behaviors reportedly correlates with the prevalence and health outcomes of COPD, but the factors contributing to multiple health promotions are not well understood.

OBJECTIVE

To examine the factors associated with nonadherence to health behaviors, specifically focusing on COPD severity.

METHODS

We conducted a secondary data analysis with data from the 2016-2019 Korea National Health and Nutrition Examination Survey. The analyzed data were from 1,627 individuals aged over 40 years who had a FEV1/FVC ratio < 70% measured via spirometer. In this study, nonadherence to health behaviors is the sum of seven health-promoting behaviors in terms of smoking cessation, alcohol abstinence, regular exercise, weight control, recommended sleep time, influenza vaccination, and medical check-up.

RESULTS

COPD patients' nonadherence to health behaviors was significantly associated with comorbidity (p=0.017), stress (p=0.002), and COPD severity (moderate, severe; p=0.010, p=0.039, respectively). In addition, the moderate and severe COPD groups showed a higher nonadherence rate than the mild COPD group. Specifically, nonadherence to weight control was the most significantly different behavior according to COPD severity levels, based on the GOLD classification of airflow limitation.

CONCLUSION

Our study findings support that those with higher levels of stress, comorbidities, and severe disease conditions are less likely to adhere to health behaviors. Thus, healthcare providers and policymakers should provide tailored approaches according to COPD severity to educate and support appropriate health behaviors for individuals with COPD.

Expert consensus recommendations for the management of asthma in older adults

Asthma is a public health problem in patients of any age, although there is still a tendency to erroneously assume that it is almost always confined to children and young people. Epidemiological studies indicate that, from the sixth decade of life, the prevalence of this disease in countries such as Spain reaches 6-10%, with a higher prevalence among women aged 64 to 75 years. In addition, two-thirds of asthma deaths occur at this stage of life, resulting in a substantial number of hospital admissions, longer hospital stays and, from a finance point of view, significant direct economic costs. Asthma in older adults (65 years or older) is now a matter of great concern, the reality of which is underestimated and undertreated. It is therefore essential to establish appropriate recommendations for the diagnosis and treatment of asthma in the aging population. This consensus, which brings together the latest evidence available, was conceived with this objective. The proposed recommendations/conclusions are the result of a nominal consensus developed throughout 2019 and validated by panellists in successive rounds of voting.

Is There an Association Between Chronic Obstructive Pulmonary Disease and Chronic Renal Failure?

Chronic obstructive pulmonary disease (COPD) is one of the most common diseases worldwide with its prevalence increasing with age. It is commonly comorbid with other diseases and managing patients could be difficult and expensive. Chronic kidney disease (CKD) is often present in COPD patients and may be underdiagnosed, especially if it is mild. This study intended to summarize recent findings showing the correlation between the two diseases. Studies were gathered that were published in the last 11 years, from 2010 to 2021. PubMed was used as the main source of data, but papers from the references of the included other sources were added for thoroughness. Observational studies on examining the prevalence and prognosis of comorbid COPD and CKD published in the English language were included. A higher prevalence of CKD in COPD patients was found in most studies; it was found that a higher risk of mortality is present if these diseases coexist. Further research is required and more extensive prospective studies are needed with matched control groups to support the correlation.

Survival Impact of Chronic Obstructive Pulmonary Disease or Acute Exacerbation on Patients with Rectal Adenocarcinoma Undergoing Curative Resection: A Propensity Score-Matched, Nationwide, Population-Based Cohort Study

PURPOSE

The survival effect of current smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) is unclear for patients with rectal adenocarcinoma undergoing curative resection.

METHODS

We recruited patients with clinical stage I-IIIC rectal adenocarcinoma from the Taiwan Cancer Registry Database who had received surgery. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into two groups by using propensity score matching based on COPD status to compare overall survival outcomes: Group 1 (current smokers with COPD) and Group 2 (nonsmokers without COPD).

RESULTS

In the multivariate Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality for Group 1 compared with Group 2 was 1.25 (1.04-1.51). The aHRs (95% cis) of all-cause mortality for frequency of ≥1 hospitalizations for COPDAE or ≥2 hospitalizations within 1 year before diagnosis were 1.17 (1.05-1.51) and 1.48 (1.03-2.41) compared with no COPDAE in patients with rectal adenocarcinoma undergoing curative resection.

CONCLUSION

In patients with rectal adenocarcinoma undergoing curative resection, being a current smoker with COPD (Group 1) was associated with worse survival outcomes than being a nonsmoker without COPD (Group 2). Being hospitalized at least once for COPDAE within 1 year before the diagnosis of rectal adenocarcinoma is an independent risk factor for poor overall survival in these patients, and a higher number of hospitalizations for COPDAE within 1 year before diagnosis was associated with poorer survival.

Predictors of Renal Function Worsening in Patients with Chronic Obstructive Pulmonary Disease (COPD): A Multicenter Observational Study

Background. Chronic obstructive pulmonary disease (COPD) patients have multiple comorbidities which may affect renal function. Chronic kidney disease (CKD) is a risk factor for adverse outcomes in COPD patients. The predictors of CKD in COPD are not well investigated. Methods. A multicenter observational cohort study including patients affected by COPD (GOLD stages 1 and 2) was carried out. Principal endpoints were the incidence of CKD, as defined by an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m², and the rapid decline of eGFR >5 mL/min/1.73 m²/year. Results. We enrolled 707 outpatients. Overall, 157 (22.2%) patients had CKD at baseline. Patients with CKD were older, with higher serum uric acid (UA) levels, and lower FEV₁. During a mean follow-up of 52.3 ± 30.2 months, 100 patients developed CKD, and 200 patients showed a rapid reduction of eGFR. Multivariable Cox regression analysis displayed that UA (hazard ratio (HR) 1.148, p < 0.0001) and diabetes (HR 1.050, p < 0.0001) were predictors of incident CKD. The independent predictors of rapidly declining renal function were represented by an increase of 1 mg/dL in UA (odds ratio (OR) 2.158, p < 0.0001)), an increase of 10 mL/min/1.73 m² in baseline eGFR (OR 1.054, p < 0.0001) and the presence of diabetes (OR 1.100, p < 0.009). Conclusions. This study shows that COPD patients have a significant worsening of renal function over time and that UA and diabetes were the two strongest predictors. Optimal management of these risk factors may reduce the incidence of CKD in this population thus probably improving clinical outcome.

Kidney function and obstructive lung disease: a bidirectional Mendelian randomisation study

BACKGROUND

Additional study is warranted to investigate the causal effects between kidney function and obstructive lung disease.

METHODS

This study was a bidirectional two-sample Mendelian randomisation (MR) analysis. The CKDGen genome-wide association study (GWAS) meta-analysis for estimated glomerular filtration rate (eGFR) including individuals of European ancestry (N=567 460) provided the genetic instrument for kidney function and outcome summary statistics. A GWAS for FEV1/FVC including individuals of European ancestry from the UK Biobank (N=321 047) provided the genetic instrument for FEV1/FVC and outcome data. A polygenic score (PGS) analysis was performed to test the causal estimates from kidney function to binary obstructive lung disease outcomes, including chronic obstructive pulmonary disease (COPD), asthma, and FEV1/FVC<70%, and to perform non-linear MR with individual-level UK Biobank data.

RESULTS

The causal estimates by summary-level MR indicated that genetically predicted increased kidney function was significantly associated with increased FEV1/FVC Z scores [10% increase in eGFR, beta 0.055 (0.024, 0.086)]. The PGS for increased eGFR showed a significant association with a reduced risk of FEV1/FVC<70% [OR 0.93 (0.87, 0.99)], COPD [OR 0.93 (0.87, 0.99)] and late-onset (≥50 years old) asthma [OR 0.93 (0.88, 0.99)]. The non-linear MR demonstrated that the causal effect from eGFR to FEV1/FVC was apparent in eGFR ranges lower than 60 mL/min/1.73 m². On the other hand, genetically predicted FEV1/FVC showed nonsignificant causal estimates of eGFR change [beta 0.568% (-0.458, 1.605%)].

CONCLUSION

This study supports kidney function impairment would be a causative factor for obstructive lung disease.

Exercise intolerance in kidney diseases: physiological contributors and therapeutic strategies

Exertional fatigue, defined as the overwhelming and debilitating sense of sustained exhaustion that impacts the ability to perform activities of daily living, is highly prevalent in chronic kidney disease (CKD) and end-stage renal disease (ESRD). Subjective reports of exertional fatigue are paralleled by objective measurements of exercise intolerance throughout the spectrum of the disease. The prevalence of exercise intolerance is clinically noteworthy, as it leads to increased frailty, worsened quality of life, and an increased risk of mortality. The physiological underpinnings of exercise intolerance are multifaceted and still not fully understood. This review aims to provide a comprehensive outline of the potential physiological contributors, both central and peripheral, to kidney disease-related exercise intolerance and highlight current and prospective interventions to target this symptom. In this review, the CKD-related metabolic derangements, cardiac and pulmonary dysfunction, altered physiological responses to oxygen consumption, vascular derangements, and sarcopenia are discussed in the context of exercise intolerance. Lifestyle interventions to improve exertional fatigue, such as aerobic and resistance exercise training, are discussed, and the lack of dietary interventions to improve exercise tolerance is highlighted. Current and prospective pharmaceutical and nutraceutical strategies to improve exertional fatigue are also broached. An extensive understanding of the pathophysiological mechanisms of exercise intolerance will allow for the development of more targeted therapeutic approached to improve exertional fatigue and health-related quality of life in CKD and ESRD.

Impaired kidney function is associated with lower quality of life among community-dwelling older adults : The screening for CKD among older people across Europe (SCOPE) study

Background

Quality of life (QoL) refers to the physical, psychological, social and medical aspects of life that are influenced by health status and function. The purpose of this study was to measure the self-perceived health status among the elderly population across Europe in different stages of Chronic Kidney Disease (CKD).

Methods

Our series consisted of 2255 community-dwelling older adults enrolled in the Screening for Chronic Kidney Disease (CKD) among Older People across Europe (SCOPE) study. All patients underwent a comprehensive geriatric assessment (CGA), including included demographics, clinical and physical assessment, number of medications taken, family arrangement, Geriatric Depression Scale (GDS), Cumulative Illness Rating Scale, History of falls, Lower urinary tract symptoms, and Short Physical Performance Battery (SPPB). Estimated glomerular filtration rate (eGFR) was calculated by Berlin Initiative Study (BIS) equation. Quality of life was assessed by Euro Qol questionnaire (Euro-Qol 5D) and EQ-Visual Analogue Scale (EQ-VAS). The association between CKD (eGFR < 60, < 45 ml or < 30 ml/min/1.73m²) and low EQoL-VAS was investigated by multivariable logistic regression models.

Results

CKD was found to be significantly associated with low EQoL-VAS in crude analysis (OR = 1.47, 95%CI = 1.16–1.85 for eGFR< 60; OR = 1.38, 95%CI = 1.08–1.77 for eGFR< 45; OR = 1.57, 95%CI = 1.01–2.44). Such association was no longer significant only when adjusting for SPPB (OR = 1.20, 95%CI = 0.93–1.56 for eGFR< 60; OR = 0.87, 95%CI = 0.64–1.18 for eGFR< 45; OR = 0.84, 95%CI = 0.50–1.42), CIRS and polypharmacy (OR = 1.16, 95%CI = 0.90–1.50 for eGFR< 60; OR = 0.86, 95%CI = 0.64–1.16 for eGFR< 45; OR = 1.11, 95%CI = 0.69–1.80) or diabetes, hypertension and chronic obstructive pulmonary disease (OR = 1.28, 95%CI = 0.99–1.64 for eGFR< 60; OR = 1.16, 95%CI = 0.88–1.52 for eGFR< 45; OR = 1.47, 95%CI = 0.92–2.34). The association between CKD and low EQoL-VAS was confirmed in all remaining multivariable models.

Conclusions

CKD may significantly affect QoL in community-dwelling older adults. Physical performance, polypharmacy, diabetes, hypertension and COPD may affect such association, which suggests that the impact of CKD on QoL is likely multifactorial and partly mediated by co-occurrent conditions/risk factors.

Targeting Aging Pathways in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) has become a global epidemic and is the third leading cause of death worldwide. COPD is characterized by chronic airway inflammation, loss of alveolar-capillary units, and progressive decline in lung function. Major risk factors for COPD are cigarette smoking and aging. COPD-associated pathomechanisms include multiple aging pathways such as telomere attrition, epigenetic alterations, altered nutrient sensing, mitochondrial dysfunction, cell senescence, stem cell exhaustion and chronic inflammation. In this review, we will highlight the current literature that focuses on the role of age and aging-associated signaling pathways as well as their impact on current treatment strategies in the pathogenesis of COPD. Furthermore, we will discuss established and experimental COPD treatments including senolytic and anti-aging therapies and their potential use as novel treatment strategies in COPD.

Management of the COPD Patient with Comorbidities: An Experts Recommendation Document

Background

Chronic obstructive pulmonary disease (COPD) is associated with multiple comorbidities, which impact negatively on patients and are often underdiagnosed, thus lacking a proper management due to the absence of clear guidelines.

Purpose

To elaborate expert recommendations aimed to help healthcare professionals to provide the right care for treating COPD patients with comorbidities.

Methods

A modified RAND-UCLA appropriateness method consisting of nominal groups to draw up consensus recommendations (6 Spanish experts) and 2-Delphi rounds to validate them (23 Spanish experts) was performed.

Results

A panel of Spanish internal medicine experts reached consensus on 73 recommendations and 81 conclusions on the clinical consequences of the presence of comorbidities. In general, the experts reached consensus on the issues raised with regard to cardiovascular comorbidity and metabolic disorders. Consensus was reached on the use of selective serotonin reuptake inhibitors in cases of depression and the usefulness of referring patients with anxiety to respiratory rehabilitation programmes. The results also showed consensus on the usefulness of investigating the quality of sleep, the treatment of pain with opioids and the evaluation of osteoporosis by lateral chest radiography.

Conclusion

This study provides conclusions and recommendations that are intended to improve the management of the complexity of patients with COPD and important comorbidities, usually excluded from clinical trials.

Aspects extrapulmonaires des exacerbations de bronchopneumopathie chronique obstructive

La bronchopneumopathie chronique obstructive (BPCO) est une maladie systémique aux multiples atteintes, émaillée d’exacerbations. L’inflammation, l’hypoxémie, les troubles de la coagulation et les perturbations des interactions coeur–poumon expliquent en partie les atteintes non pulmonaires observées notamment lors d’exacerbations aiguës. Les événements cardiovasculaires sont la première cause de mortalité des patients BPCO, et leur recrudescence est observée pendant plusieurs semaines après une exacerbation. Aux urgences, la prise en charge des patients en exacerbation de BPCO repose donc en plus du support ventilatoire sur une bonne évaluation des potentielles pathologies associées telles que l’insuffisance cardiaque, l’ischémie myocardique, l’insuffisance rénale ou encore la maladie thromboembolique. Cette évaluation globale permet d’adapter les thérapeutiques parfois délétères sur la fonction cardiaque ou l’équilibre acide−base et de prendre en compte le risque extrapulmonaire dans le choix du parcours de soins du patient. Dans cette mise au point, nous abordons quelques explications physiologiques des multiples perturbations observées au cours de l’exacerbation de BPCO, et proposons une vision globale de l’évaluation de ces patients admis pour une dyspnée ou un autre motif pouvant être en rapport avec la BPCO.

Low lung function and the risk of incident chronic kidney disease in the Malmö Preventive Project cohort

BACKGROUND

Although the prevalence of kidney disease is higher in those with reduced lung function, the longitudinal relationship between low lung function and future risk of chronic kidney disease (CKD) has not been widely explored.

METHODS

Baseline lung function was assessed in 20,700 men and 7325 women from 1974 to 1992. Mean age was 43.4 (±6.6) and 47.5 (±7.9) for men and women respectively. Sex-specific quartiles of FEV1 and FVC (L) were created (Q4: highest, reference) and the cohort was also divided by the FEV1/FVC ratio (≥ or < 0.70). Cox proportional hazards regression was used to determine the risk of incident CKD events (inpatient or outpatient hospital diagnosis of CKD) in relation to baseline lung function after adjustment for various confounding factors.

RESULTS

Over 41 years of follow-up there were 710 and 165 incident CKD events (main diagnosis) in men and women respectively. Low FEV1 was strongly associated with future risk of CKD in men (Q1 vs Q4 adjusted HR: 1.46 (CI:1.14-1.89), p-trend 0.002). Similar findings were observed for FVC in men (1.51 (CI:1.16-1.95), p-trend 0.001). The adjusted risks were not found to be significant in women, for either FEV1 or FVC. FEV1/FVC < 0.70 was not associated with increased incidence of CKD in men or women.

CONCLUSION

Low FEV1 and FVC levels at baseline are a risk factor for the development of future incident CKD in men. Monitoring kidney function in those with reduced vital capacity in early life could help with identifying those at increased risk of future CKD.

Association among chronic kidney disease, airflow limitation, and mortality in a community-based population: The Yamagata (Takahata) study

Chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD) are known risk factors for mortality. In this study, we examined the overlap of CKD and airflow limitation (AFL) that characterises COPD and its effect on 10-year mortality in a community-based population. This study included 1,233 health check-up participants (mean age, 63.7 years; 46.7% men). We defined serum creatinine-based CKD (CKDcr) and serum cystatin C-based CKD (CKDcys) as glomerular filtration rate <60 mL/min/1.73 m², estimated using serum creatinine or cystatin C, and/or dipstick proteinuria ≥1+. AFL was defined as forced expiratory volume in 1 s to forced vital capacity ratio <70% on spirometry. Compared with subjects without AFL, those with AFL showed a significantly higher prevalence of CKDcys but not of CKDcr. Cox proportional hazard analysis adjusted for confounders showed that the hazard ratio (95% confidence interval) for all-cause mortality was 1.45 (0.77–2.63) in subjects with CKDcys alone, 1.29 (0.60–2.54) in those with AFL alone, and 2.94 (1.33–6.12) in those with both CKDcys and AFL, with subjects without both AFL and CKD as the reference. This study showed that AFL and CKDcys are strongly associated and that their overlap is a significant risk factor for mortality in community-based populations.

The burden of chronic obstructive pulmonary disease in open heart surgery-a retrospective cohort analysis of postoperative complications: STROBE compliant

Chronic obstructive pulmonary disease (COPD) has a major impact on mortality and morbidity in patients undergoing cardiac surgery. Mortality risk increases by 50% in patients who were re-intubated or required prolonged mechanical ventilation after the operation. The aim of this study was to assess the impact of COPD on the prediction of postoperative complications and outcome including intensive care unit (ICU) and hospital stay, postoperative morbidity and mortality in patients undergoing all types of cardiac surgery.We performed a retrospective cohort analysis of prospectively collected data from a tertiary cardiac surgery department of a university hospital between 2014 and 2016. We divided patients undergoing cardiac surgery into 2 sub-groups - the first - with a clinical diagnosis of COPD (n = 198) and the second comprised all other non-COPD patients (n = 2980).Among patients with COPD a longer intubation time (P = .039), longer ICU stay (P < .001) and longer hospitalization time (P = .006) was noted as compared with non-COPD patients. Patients with COPD required reintubation more often than non-COPD patients, reintubation occurring twice, 19 (9.60%) versus 144 (4.83%) P = .002, reintubation occurring 3 or more times, 7 (3.54%) versus 34 (1.14%) P = .006. Mortality within 30 days after surgery was higher in patients with pulmonary problems before surgery (P = .003). Multivariable logistic regression analysis corrected for interfering variables showed an increased risk of postoperative bronchoconstriction (odds ratio [OR] = 4.40, P = .002), respiratory failure (OR = 1.67, P = .018), atrial fibrillation (OR = 1.45, P = .023), and use of hemofiltration (OR = 1.60, P = .029) for patients with COPD.Patients with COPD undergoing all types of cardiac surgery are at increased risk of respiratory complications and mortality. The occurrence of COPD was associated with longer ICU and hospital stay. In COPD patients, undergoing cardiac surgery, treatment strategies aimed at preventing reintubation and early weaning mechanical ventilation must be employed to reduce postoperative complications.

Association of urine mitochondrial DNA with clinical measures of COPD in the SPIROMICS cohort

BACKGROUNDMitochondrial dysfunction, a proposed mechanism of chronic obstructive pulmonary disease (COPD) pathogenesis, is associated with the leakage of mitochondrial DNA (mtDNA), which may be detected extracellularly in various bodily fluids. Despite evidence for the increased prevalence of chronic kidney disease in COPD subjects and for mitochondrial dysfunction in the kidneys of murine COPD models, whether urine mtDNA (u-mtDNA) associates with measures of disease severity in COPD is unknown.METHODSCell-free u-mtDNA, defined as copy number of mitochondrially encoded NADH dehydrogenase-1 (MTND1) gene, was measured by quantitative PCR and normalized to urine creatinine in cell-free urine samples from participants in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort. Urine albumin/creatinine ratios (UACR) were measured in the same samples. Associations between u-mtDNA, UACR, and clinical disease parameters - including FEV1 % predicted, clinical measures of exercise tolerance, respiratory symptom burden, and chest CT measures of lung structure - were examined.RESULTSU-mtDNA and UACR levels were measured in never smokers (n = 64), smokers without airflow obstruction (n = 109), participants with mild/moderate COPD (n = 142), and participants with severe COPD (n = 168). U-mtDNA was associated with increased respiratory symptom burden, especially among smokers without COPD. Significant sex differences in u-mtDNA levels were observed, with females having higher u-mtDNA levels across all study subgroups. U-mtDNA associated with worse spirometry and CT emphysema in males only and with worse respiratory symptoms in females only. Similar associations were not found with UACR.CONCLUSIONU-mtDNA levels may help to identify distinct clinical phenotypes and underlying pathobiological differences in males versus females with COPD.TRIAL REGISTRATIONThis study has been registered at ClinicalTrials.gov ( NCT01969344).FUNDINGUS NIH, National Heart, Lung and Blood Institute, supplemented by contributions made through the Foundation for the NIH and the COPD Foundation from AstraZeneca/MedImmune, Bayer, Bellerophon Therapeutics, Boehringer-Ingelheim Pharmaceuticals Inc., Chiesi Farmaceutici S.p.A., Forest Research Institute Inc., GlaxoSmithKline, Grifols Therapeutics Inc., Ikaria Inc., Novartis Pharmaceuticals Corporation, Nycomed GmbH, ProterixBio, Regeneron Pharmaceuticals Inc., Sanofi, Sunovion, Takeda Pharmaceutical Company, and Theravance Biopharma and Mylan.

Anaemia and iron dysregulation: untapped therapeutic targets in chronic lung disease?

Hypoxia is common in many chronic lung diseases. Beyond pulmonary considerations, delivery of oxygen (O2) to the tissues and subsequent O2 utilisation is also determined by other factors including red blood cell mass and iron status; consequently, disruption to these mechanisms provides further physiological strains on an already stressed system. O2 availability influences ventilation, regulates pulmonary blood flow and impacts gene expression throughout the body. Deleterious effects of poor tissue oxygenation include decreased exercise tolerance, increased cardiac strain and pulmonary hypertension in addition to pathophysiological involvement of multiple other organs resulting in progressive frailty. Increasing inspired O2 is expensive, disliked by patients and does not normalise tissue oxygenation; thus, other strategies that improve O2 delivery and utilisation may provide novel therapeutic opportunities in patients with lung disease. In this review, we focus on the rationale and possibilities for doing this by increasing haemoglobin availability or improving iron regulation.

Consequences of chronic kidney disease in chronic obstructive pulmonary disease

Background

The combination of chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD) is associated with a higher prevalence of comorbidities and increased mortality. The impact of kidney function on patient-centered outcomes in COPD has not been evaluated.

Methods

Patients from the German COPD and Systemic Consequences - Comorbidities Network (COSYCONET) cohort COPD were analysed. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) measurements were < 60 mL/min/1.73m² at study inclusion and six month later. The effect of CKD, on comorbidities, symptoms [modified British Medical Research Council dyspnoea scale], physical capacity [six-minute walk test, and timed up and go] and St George’s Respiratory Questionnaire were analysed. Restricted cubic spline models were used to evaluate a nonlinear relationship between eGFR with patient-centered outcomes, cox survival analysis was applied to evaluate mortality.

Results

2274 patients were analysed, with CKD diagnosed in 161 (7.1%). Spline models adjusted for age, gender, BMI, FEV₁ and cardiovascular comorbidities revealed independent associations between eGFR with modified British Medical Research Council dyspnoea scale, St George’s Respiratory Questionnaire, (p < 0.001 and p = 0.011), six-minute walk test (p = 0.015) and timed up and go (p < 0.001). CKD was associated with increased mortality, independently from for other cardiovascular comorbidities (hazard ratio 2.3; p < 0.001).

Conclusion

These data show that CKD is a relevant comorbidity in COPD patients which impacts on patient-centered outcomes and mortality.

Trial registration

NCT01245933

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1107-x) contains supplementary material, which is available to authorized users.

Clinical characteristics of pulmonary hypertension patients living in plain and high-altitude regions

OBJECTIVE

The demographic characteristics, ratio of aetiologies and biochemical parameters of adult patients with pulmonary hypertension (PH) living in plain and high-altitude regions were investigated and analysed.

METHODS

In total, 2846 adult patients with PH hospitalized from 2010 to 2015 in the Second Xiangya Hospital of Central South University and Qinghai Red Cross Hospital were retrospectively investigated.

RESULTS

(1) In the present study, the numbers of patients with PH in both the plain and high-altitude regions increased annually (P < 0.05), and the in-hospital prevalence of PH significantly increased over time in the high-altitude region. PH was more common in women in the plain region. Furthermore, compared with PH patients living in the plain region, those living in the high-altitude region were older (P < 0.05) and had higher smoking rates (P < 0.05). In the plain region, the greatest proportion of patients with PH belonged to group 2 (PH because of left heart disease), while in the high-altitude region, group 3 (PH because of lung diseases and/or hypoxia) was the most common (P < 0.05). (2) Haemoglobin levels, red blood cell counts, mean platelet volumes and platelet volume distribution widths were lower in PH patients living in the plain region than in those living in the high-altitude region. Furthermore, platelet counts were higher in patients living in the plain region than in those living in the high-altitude region (P < 0.05). The BNP/NT-proBNP levels were higher in PH patients living in the plain region (45.5%), which were mostly in group 4, than in those living the high-altitude region (P < 0.05).

CONCLUSIONS

The data from the hospitals in both the plain and high-altitude regions show a tendency towards increased in-hospital prevalence of PH over the last 6 years. The most common aetiologies of PH in patients living in the plain region and high-altitude regions were left heart disease and lung disease, respectively. Compared with PH patients living in the plain region, those living in the high-altitude region had better cardiac function and less severe PH.

Revealing Methodological Challenges in Chronic Obstructive Pulmonary Disease Studies Assessing Comorbidities: A Narrative Review

Beyond respiratory impairment, patients with chronic obstructive pulmonary disease (COPD) often suffer from comorbidities which are associated with worse health status, higher health care costs and worse prognosis. Reported prevalences of comorbidities largely differ between studies which might be explained by different assessment methods (objective assessment, self-reported assessment, or assessment by medical records), heterogeneous study populations, inappropriate control groups, incomparable methodologies, etc. This narrative review demonstrates and further evaluates the variability in prevalence of several comorbidities in patients with COPD and control individuals and discusses several shortcomings and pitfalls which need to be considered when interpreting comorbidity data. Like in other chronic organ diseases, the accurate diagnosis and integrated management of comorbidities is a key for outcome in COPD. This review highlights that there is a need to move from the starting point of an established index disease towards the concept of the development of multimorbidity in the elderly including COPD as an important and highly prevalent pulmonary component.

Smooth Bayesian network model for the prediction of future high-cost patients with COPD

INTRODUCTION

The clinical course of chronic obstructive pulmonary disease (COPD) is marked by acute exacerbation events that increase hospitalization rates and healthcare spending. The early identification of future high-cost patients with COPD may decrease healthcare spending by informing individualized interventions that prevent exacerbation events and decelerate disease progression. Existing studies of cost prediction of other chronic diseases have applied regression and machine-learning methods that cannot capture the complex causal relationships between COPD factors. Thus, the exploration of these factors through nonlinear, high-dimensional but explainable modeling is greatly needed.

OBJECTIVES

We aimed to develop a machine-learning model to identify future high-cost patients with COPD. Such a model should incorporate expert knowledge about causal relationships, and the method for estimating the model could provide more accurate predictions than other machine learning methods.

METHODS

We used the 2011-2013 medical insurance data of patients with COPD in a large city. The data set included demographic information and admission records. Leveraging on developments in graphical modeling methods, we proposed a smooth Bayesian network (SBN) model for the prediction of high-cost individuals using medical insurance data. The modeling method incorporated some expert knowledge about causal relationships (i.e., about the Bayesian network structure). We employed a smoothing kernel based on the weighted nearest neighborhood method in the SBN model to address overfitting, case-mix effect, and data sparsity (i.e., using data about "similar patients").

RESULTS

The proposed SBN achieved the area under curve (AUC) of 0.80 and showed considerable improvement over the baseline machine-learning methods. Besides confirming the known factors from the literature, we found "region" (i.e., a suburban or urban area) to be a significant factor, and that in a 3-tier system with primary, secondary and tertiary hospitals, COPD patients who had been admitted to primary hospitals were more likely to develop into future high-cost patients than patients who had been admitted to tertiary hospitals.

CONCLUSION

The proposed SBN model not only obtained higher prediction accuracy and stronger generalizability than a number of benchmark machine-learning methods, but also used the Bayesian network to capture the complex causal relationships between different predictors by incorporating expert knowledge. Furthermore, a framework was developed to establish the relationships between exposure to historical trajectory and future outcome, which can also be applied to other temporal data to model different trajectory information and predict other outcomes.

Beyond chronic kidney disease: the diagnosis of Renal Disease in the Elderly as an unmet need. A position paper endorsed by Italian Society of Nephrology (SIN) and Italian Society of Geriatrics and Gerontology (SIGG)

The dramatic increase in prevalence of chronic kidney disease (CKD) with ageing makes the recognition and correct referral of these patients of paramount relevance in order to implement interventions preventing or delaying the development of CKD complications and end-stage renal disease. Nevertheless, several issues make the diagnosis of CKD in the elderly cumbersome. Among these are age related changes in structures and functions of the kidney, which may be difficult to distinguish from CKD, and multimorbidity. Thus, symptoms, clinical findings and laboratory abnormalities should be considered as potential clues to suspect CKD and to suggest screening. Comprehensive geriatric assessment is essential to define the clinical impact of CKD on functional status and to plan treatment. Correct patient referral is very important: patients with stage 4-5 CKD, as well as those with worsening proteinuria or progressive nephropathy (i.e. eGFR reduction > 5 ml/year) should be referred to nephrologist. Renal biopsy not unfrequently may be the key diagnostic exam and should not be denied simply on the basis of age. Indeed, identifying the cause(s) of CKD is highly desirable to perform a targeted therapy against the pathogenetic mechanisms of CKD, which complement and may outperform in efficacy the general measures for CKD.

The burden and impact of arrhythmia in chronic obstructive pulmonary disease: Insights from the National Inpatient Sample

BACKGROUND

We aimed to analyze the burden and predictors of arrhythmias and in-hospital mortality in chronic obstructive pulmonary disease (COPD)-related hospitalizations using the nationwide cohort.

METHODS

We queried the National Inpatient Sample (NIS) (2010-2014) databases to identify adult COPD hospitalizations with arrhythmia. Categorical and continuous variables were compared using Chi-square and Student's t-test/ANOVA. Predictors of any arrhythmia including AF and in-hospital mortality were evaluated by multivariable analyses.

RESULTS

Out of 21,596,342 COPD hospitalizations, 6,480,799 (30%) revealed co-existent arrhythmias including 4,767,401 AF-arrhythmias (22.1%) and 1,713,398 non AF-arrhythmias (7.9%). The AF or non-AF arrhythmia cohort consisted mostly of older (mean age~ 75.8 & 69.1 vs. 67.5 years) white male (53.3% & 51.9% vs. 46.9%) patients compared to those without arrhythmias (p < 0.001). The all-cause mortality (5.7% & 5.2 vs. 2.9%), mean length of stay (LOS) (6.4 & 6.5 vs. 5.3 days), and hospital charges ($52,699.49 & $58,102.39 vs. $41,208.02) were higher with AF and non AF-arrhythmia compared to the non-arrhythmia group (p < 0.001). Comorbidities such as cardiomyopathy (OR 2.11), cardiogenic shock (OR 1.88), valvular diseases (OR 1.60), congestive heart failure (OR 1.48) and pulmonary circulation disorders (OR 1.25) predicted in-hospital arrhythmias. Invasive mechanical ventilation (OR 6.41), cardiogenic shock (OR 5.95), cerebrovascular disease (OR 3.95), septicemia (OR 2.30) and acute myocardial infarction (OR 2.24) predicted higher mortality (p < 0.001) in the COPD-arrhythmia cohort.

CONCLUSIONS

About 30% of COPD hospitalizations revealed co-existent arrhythmias (AF 22.1%). All-cause mortality, LOS and hospital charges were significantly higher with arrhythmias. We observed racial and sex-based disparities for arrhythmias and related mortality.

Towards quantitative perfusion MRI of the lung in COPD: The problem of short-term repeatability

Purpose

4D perfusion magnetic resonance imaging (MRI) with intravenous injection of contrast agent allows for a radiation-free assessment of regional lung function. It is therefore a valuable method to monitor response to treatment in patients with chronic obstructive pulmonary disease (COPD). This study was designed to evaluate its potential for monitoring short-term response to hyperoxia in COPD patients.

Materials and methods

19 prospectively enrolled COPD patients (median age 66y) underwent paired dynamic contrast-enhanced 4D perfusion MRI within 35min, first breathing 100% oxygen (injection 1, O₂) and then room air (injection 2, RA), which was repeated on two consecutive days (day 1 and 2). Post-processing software was employed to calculate mean transit time (MTT), pulmonary blood volume (PBV) and pulmonary blood flow (PBF), based on the indicator dilution theory, for the automatically segmented whole lung and 12 regions of equal volume.

Results

Comparing O₂ with RA conditions, PBF and PBV were found to be significantly lower at O₂, consistently on both days (p<10–8). Comparing day 2 to day 1, MTT was shorter by 0.59±0.63 s (p<10–8), PBF was higher by 22±80 ml/min/100ml (p<3·10–4), and PBV tended to be lower by 0.2±7.2 ml/100ml (p = 0.159) at both, RA and O_2, conditions.

Conclusion

The second injection (RA) yielded higher PBF and PBV, which apparently contradicts the established hypothesis that hyperoxia increases lung perfusion. Quantification of 4D perfusion MRI by current software approaches may thus be limited by residual circulating contrast agent in the short-term and even the next day.

When kidneys and lungs suffer together

A significant interaction between kidneys and lungs has been shown in physiological and pathological conditions. The two organs can both be targets of the same systemic disease (eg., some vasculitides). Moreover, loss of normal function of either of them can induce direct and indirect dysregulation of the other one. Subjects suffering from COPD may have systemic inflammation, hypoxemia, endothelial dysfunction, increased sympathetic activation and increased aortic stiffness. As well as the exposure to nicotine, all the foresaid factors can induce a microvascular damage, albuminuria, and a worsening of renal function. Renal failure in COPD can be unrecognized since elderly and frail patients may have normal serum creatinine concentration. Lungs and kidneys participate in maintaining the acid-base balance. Compensatory role of the lungs rapidly expresses through an increase or reduction of ventilation. Renal compensation usually requires a few days as it is achieved through changes in bicarbonate reabsorption. Chronic kidney disease and end-stage renal diseases increase the risk of pneumonia. Vaccination against Streptococcus pneumonia and seasonal influenza is recommended for these patients. Vaccines against the last very virulent H1N1 influenza A strain are also available and effective. Acute lung injury and acute kidney injury are frequent complications in critical illnesses, associated with high morbidity and mortality. The concomitant failure of kidneys and lungs implies a multidisciplinary approach, both in terms of diagnostic processes and therapeutic management.

Comorbidities and length of stay in chronic obstructive pulmonary disease patients

Chronic Obstructive Pulmonary Disease (COPD) has a significant burden on patients and the healthcare system. There is a link between COPD and comorbidities such as congestive heart failure (CHF), fluid and electrolyte disorders, and renal failure. This adds to the complexity of healthcare in these patients. The objective of this study is to determine if certain comorbidities affect length of stay. A sample of 3,399 patients with COPD were assessed from the Premier^© healthcare database. The cohort had a mean (standard deviation (SD)) age of 68.41 (10.85) years. The average number of comorbidities was 24.83 (10.46) with a mean length of stay (SD) of 11.64 (9.40) days. A negative binomial regression model was used to evaluate the impact that comorbidities have on the length of hospital stay. The authors found that the number of comorbidities was associated with an increased length of stay (r = .4596, p < .0001). Having at least one comorbidity was associated with a 13% greater length of stay (IRR = 1.13, 95% CI 1.11-1.15, p < 0.0001). CHF was associated with a 28% greater length of stay (IRR = 1.28, 95% CI 1.24-1.31, p < 0.0001). Fluid and electrolyte disorders were associated with a 2-fold greater length of stay (IRR = 2.57, 95% CI 2.52-2.62, p < 0.0001). Renal failure was associated with a 50% greater length of stay (IRR = 1.50, 95% CI 1.45-1.55, p < 0.0001). However, uncomplicated diabetes was associated with 13% shorter length of stay than not having uncomplicated diabetes (IRR = .87, 95% CI .82-.91, p < .0001). This study demonstrated that specific comorbidities have an impact on length of stay.

Beclin-1 regulates cigarette smoke-induced kidney injury in a murine model of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), associated with cigarette smoke-induced (CS-induced) emphysema, contributes significantly to the global health care burden of disease. Although chronic kidney disease (CKD) may occur in patients with COPD, the relationship between COPD and CKD remains unclear. Using a murine model of experimental COPD, we show that chronic CS exposure resulted in marked kidney injury and fibrosis, as evidenced by histological and ultrastructural changes, altered macrophage subpopulations, and expression of tissue injury, fibrosis, and oxidative stress markers. CS induced mitochondrial dysfunction, and increased autophagic flux in kidney tissues and in kidney tubular epithelial (HK-2) cells, as determined by LC3B turnover assays. Mice heterozygous for Beclin-1 (Becn1+/-) were protected from the development of kidney tissue injury and renal fibrosis in response to CS exposure, and displayed impaired basal and inducible mitochondrial turnover by mitophagy. Interestingly, CS caused a reduction of Beclin-1 expression in mouse kidneys and kidney tubular epithelial cells, attributed to increased autophagy-dependent turnover of Beclin-1. These results suggest that Beclin-1 is required for CS-induced kidney injury and that reduced levels of Beclin-1 may confer renoprotection. These results identify the kidney as a target for CS-induced injury in COPD and the Beclin-1-dependent autophagy pathway as a potential therapeutic target in CKD.

Application of albumin/globulin ratio in elderly patients with acute exacerbation of chronic obstructive pulmonary disease

Background

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) has become an important disease of hospitalized elderly patients, which lack simple and inexpensive indicators for evaluating the condition and prognosis. This study was performed to investigate the clinical significance of the serum albumin/globulin ratio (AGR) in elderly patients with AECOPD.

Methods

The data of 252 hospitalized elderly patients with AECOPD, 89 stable COPD patients and 115 elderly healthy individuals were analyzed and compared. The differences in the AGR, logarithm of the serum C-reactive protein (LogCRP) level, prealbumin (PA) level, and immunoglobulin G (IgG) level were compared. AECOPD patients were grouped using the optimal cutoff values of each index to compare the difference in the combined infection rate. The correlation between hospital stays and AGR was analyzed.

Results

The AGR, LogCRP, PA level, and IgG level were different among the AECOPD group, stable COPD group and healthy control groups (P<0.05). The AGR, LogCRP, and PA level were different (P<0.05) among the Global Initiative for Chronic Obstructive Lung Disease (GOLD) I, II, II, and IV groups. Age, AGR, LogCRP, and PA level were different (P<0.05) between the infection and non-infection groups. After grouping according to the optimal cutoff values, the combined infection rate was different (P<0.05). The AGR was negatively correlated with the hospital stay (r=-0.583, P<0.001). The hospital stay was longer in patients with an AGR of <1.37 than ≥1.37 (P<0.001).

Conclusions

The AGR can be regarded as a reference index for evaluating the condition of elderly patients with AECOPD, determining the presence of combined infection, and predicting the prognosis.

The pharmacological treatment of chronic comorbidities in COPD: mind the gap!

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is commonly associated with other chronic diseases, which poses several diagnostic and therapeutic problems. Indeed, important comorbidities frequently remain unrecognized and, then, untreated, whereas respiratory drugs may have non respiratory side effects, and selected non respiratory drugs may variably affect the respiratory function.

OBJECTIVE

to describe: how COPD affects the presentation and contributes to the diagnostic challenges of its most common comorbidities; how coexisting COPD impacts the therapeutic approach to selected comorbidities and viceversa.

METHODS

we distinguish comorbidities of COPD depending upon whether they are complications of COPD or share risk factors, mainly smoke, with it or, finally, aggravate COPD. We describe atypical presentations of and diagnostic clues to comorbidities and suggest screening procedures. Finally, the main therapeutic problems, as resulting from the risk of untoward effects of therapies of COPD and its comorbidity, with special attention to drug-drug interactions and possible overdosages, are described.

RESULTS

selected complications of COPD, such as osteoporosis, sarcopenia and dysphagia, are rarely recognized and treated, likely due to the poor awareness of them. Important comorbidities, such as coronary artery disease, chronic heart failure, obstructive sleep apnoea syndrome and chronic renal failure, also should be systematically searched for because of their commonly variant presentation. Disease-related symptoms should be distinguished from drug effects or drug-drug interaction effects.

CONCLUSIONS

a truly comprehensive view of the complex COPD patient, hopefully capitalizing on multidimensional geriatric assessment, is needed to dissect the many components of health status impairment and to provide the optimal care. Selected screening procedures are highly desirable to identify frequently missed comorbidities. Pharmacosurveillance is an essential part of the approach to COPD and its comorbidities.

Are Systemic Manifestations Ascribable to COPD in Smokers? A Structural Equation Modeling Approach

Whether the systemic manifestations observed in Chronic Obstructive Pulmonary Disease (COPD) are ascribable to lung dysfunction or direct effects of smoking is in debate. Structural Equations Modeling (SEM), a causal-oriented statistical approach, could help unraveling the pathways involved, by enabling estimation of direct and indirect associations between variables. The objectives of the study was to investigate the relative impact of smoking and COPD on systemic manifestations, inflammation and telomere length. In 292 individuals (103 women; 97 smokers with COPD, 96 smokers without COPD, 99 non-smokers), we used SEM to explore the pathways between smoking (pack-years), lung disease (FEV₁, K_CO), and the following parameters: arterial stiffness (aortic pulse wave velocity, PWV), bone mineral density (BMD), appendicular skeletal muscle mass (ASMM), grip strength, insulin resistance (HOMA-IR), creatinine clearance (eGFR), blood leukocyte telomere length and inflammatory markers (Luminex assay). All models were adjusted on age and gender. Latent variables were created for systemic inflammation (inflammatory markers) and musculoskeletal parameters (ASMM, grip strength, BMD). SEM showed that most effects of smoking were indirectly mediated by lung dysfunction: e.g. via FEV₁ on musculoskeletal factor, eGFR, HOMA-IR, PWV, telomere length, CRP, white blood cells count (WBC) and inflammation factor, and via K_CO on musculoskeletal factor, eGFR and PWV. Direct effects of smoking were limited to CRP and WBC. Models had excellent fit. In conclusion, SEM highlighted the major role of COPD in the occurrence of systemic manifestations while smoking effects were mostly mediated by lung function.

The clinical implications of tests confirming COPD in subjects hospitalized with exacerbations

BACKGROUND

The diagnosis of COPD in patients hospitalized for AECOPD can be confirmed by spirometry showing obstruction or radiographs showing emphysema. The evidence for COPD is sometimes absent or contradicts this diagnosis. The inaccurate attribution of the exacerbation to COPD can lead to suboptimal care and worse outcome.

OBJECTIVES

We determined if the presence of tests that confirm the diagnosis of COPD has any implications on the course of the hospitalization and readmission rate.

METHODS

We selected subjects hospitalized between 2012 and 2014 for AECOPD. We divided them into four hierarchical, mutually exclusive groups based on the presence of tests that confirm the diagnosis of COPD: spirometry (COPD_SPIRO), radiology (COPD_RAD), clinical diagnosis (COPD_CLIN), and no COPD by spirometry (NotCOPD). We compared the presentation, hospital course, outcome, and readmission rate between the four groups.

RESULTS

We identified 974 subjects: COPD_SPIRO 22%, COPD_RAD 24%, COPD_CLIN 46% and 7% NotCOPD. The vital signs, use of respiratory support, admission to the MICU, and length of stay were similar between the groups. The age, gender, BMI, presence of comorbidities, and readmission rate were different between the groups. The NotCOPD group had the highest BMI (38 kg/m²), comorbidities, and 30-day all-cause readmission (17%). Logistic regression showed that serum creatinine and presence of any comorbidity were the independent predictors of 30-day all-cause readmission.

CONCLUSION

COPD was confirmed by spirometry or radiographs in half of the subjects hospitalized for AECOPD. The presence of confirmation did not influence the hospital course. The presence of confirmation was associated with different readmission rate, but was accounted for by the presence of comorbidities.

Severity of acidosis affects long-term survival in COPD patients with hypoxemia after intensive care unit discharge

Background

Patients admitted to the intensive care unit (ICU) with acute respiratory failure (ARF) due to COPD have high mortality and morbidity. Acidosis has several harmful effects on hemodynamics and metabolism, and the current knowledge regarding the relationship between respiratory acidosis severity on the short- and long-term survival of COPD patients is limited. We hypothesized that COPD patients with severe acidosis would have a poorer short- and long-term prognosis compared with COPD patients with mild-to-moderate acidosis.

Patients and methods

This retrospective observational cohort study was conducted in a level III respiratory ICU of a tertiary teaching hospital for chest diseases between December 1, 2013, and December 30, 2014. Subject characteristics, comorbidities, ICU parameters, duration of mechanical ventilation, length of ICU stay, ICU mortality, use of domiciliary noninvasive mechanical ventilation (NIMV) and long-term oxygen therapy (LTOT), and short- and long-term mortality were recorded. Patients were grouped according to their arterial blood gas (ABG) values during ICU admission: severe acidotic (pH≤7.20) and mild-to-moderate acidotic (pH 7.21–7.35). These groups were compared with the recorded data. The mortality predictors were analyzed by logistic regression test in the ICU and the Cox regression test for long-term mortality predictors.

Results

During the study period, a total of 312 COPD patients admitted to the ICU with ARF, 69 (72.5% male) in the severe acidosis group and 243 (79% male) in the mild-to-moderate acidosis group, were enrolled. Group demographics, comorbidities, duration of mechanical ventilation, and length of ICU stay were similar in the two groups. The severe acidosis group had a significantly higher rate of NIMV failure (60.7% vs 40%) in the ICU. Mild-to-moderate acidotic COPD patients using LTOT had longer survival after ICU discharge than those without LTOT. On the other hand, severely acidotic COPD patients without LTOT showed shorter survival than those with LTOT. Kaplan–Meier cumulative survival analysis showed that the 28-day and 1-, 2-, and 3-year mortality rates were 12.2%, 36.2%, 52.6%, 63.3%, respectively (p=0.09). The Cox regression analyses showed that older age, PaO₂/FiO₂ <300 mmHg, and body mass index ≤20 kg/m² was associated with mortality of all patients after 3 years.

Conclusion

Severely acidotic COPD patients had a poorer short- and long-term prognosis compared with mild-to-moderate acidotic COPD patients if acute and chronic hypoxemia was predominant.

Effects of aging and comorbidities on nutritional status and muscle dysfunction in patients with COPD

Chronic obstructive pulmonary disease (COPD) is a prevalent, complex and debilitating disease which imposes a formidable burden on patients and the healthcare system. The recognition that COPD is a multifaceted disease is not new, and increasing evidence have outlined the importance of its extra-pulmonary manifestations and its relation to other comorbid conditions in the clinical course of the disease and its societal cost. The relationship between aging, COPD and its comorbidities on skeletal muscle function and nutritional status is complex, multidirectional and incompletely understood. Despite this, the current body of knowledge allows the identification of various, seemingly partially independent factors related both to the normal aging process and to the independent deleterious effects of chronic diseases on muscle function and body composition. There is a dire need of studies evaluating the relative contribution of each of these factors, and their potential synergistic effects in patients with COPD and advanced age/comorbid conditions, in order to delineate the best course of therapeutic action in this increasingly prevalent population.

Restrictive lung disorder is common in patients with kidney failure and associates with protein-energy wasting, inflammation and cardiovascular disease

BACKGROUND

Cardiovascular disease (CVD), protein-energy wasting (PEW), and inflammation are common interrelated features of chronic kidney disease (CKD). Less is known about lung dysfunction in CKD and its possible role in this context. We evaluated lung function and its association with estimated glomerular filtration rate (GFR), CVD, PEW, and inflammation in individuals with normal to severely reduced GFR.

METHODS

In 404 individuals with GFR category G1 (n = 31; GFR >90mL/min/1.73 m2), G2 (n = 46), G3 (n = 33), G4 (n = 49) and G5 (n = 245; GFR<15mL/min/1.73 m2), pulmonary function was assessed by spirometry. Obstructive (OLD) and restrictive (RLD) lung dysfunction was defined based on forced vital capacity (FVC), forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF), expressed as percentages of predicted values (%FEV1, %FVC and %PEF, respectively). PEW was evaluated by subjective global assessment, handgrip strength (HGS) and lean body mass index (LBMI), and inflammation by interleukin-6 and high sensitivity C-reactive protein.

RESULTS

RLD (defined as FEV1/FVC ≥ 0.70 and %FVC<80) associated with GFR and was present in 36% of G5 and 14% of G1-4 individuals. OLD (FEV1/FVC<0.70) was less common with similar prevalence among G1-4 (9%) and G5 (11%) individuals. Notably, 64% of those with concomitant presence of PEW, inflammation and clinical signs of CVD had RLD while 79% of those lacking these complications had normal lung function. In multivariate logistic regression analysis, RLD associated with CVD, PEW and inflammation, after adjusting for Framingham's CVD risk score, serum albumin, and GFR category.

CONCLUSIONS

RLD is a common complication in patients with advanced CKD, especially in those with concomitant presence of CVD, inflammation and PEW. RLD appears to be an integral albeit scarcely explored consequence of pulmonary-renal interactions in CKD patients.

Is decreased lung function associated with chronic kidney disease? A retrospective cohort study in Korea

OBJECTIVE

There is some evidence that lung function and chronic kidney disease (CKD) may be related. We evaluated the impact of lung function on the development of CKD in a large-scale longitudinal study.

METHOD

Retrospective longitudinal analyses were conducted among subjects who participated in comprehensive health check-ups at least four times during 7 years (between 2006 and 2012). We investigated the development of CKD during the follow-up period according to lung function status.

RESULTS

Ten thousand one hundred and twenty-eight individuals (mean age =51.2 years) without CKD at baseline were enrolled. During the mean follow-up of 5 years (58.5±14.4 months), 167 of the 10 128 subjects (1.6%) developed CKD. Multivariable Cox proportional hazards analyses adjusting for age, sex, body mass index, systolic blood pressure, fasting glucose, estimated glomerular filtration rate, uric acid, triglycerides, serum albumin, and the presence of diabetes and hypertension revealed that a decrease of 10% in the forced expiratory volume in 1s (FEV₁)/forced vital capacity (FVC) ratio was associated with a 35% increase in the development of CKD during the follow-up. The incidence of CKD was higher in those with an FEV₁/FVC ratio <0.8 compared with those with FEV₁/FVC ratio ≥0.8 (HR=1.454; 95% CI 1.042 to 2.028, p=0.028).

CONCLUSIONS

Limited airflow as measured by the FEV₁/FVC ratio was associated with an increased risk of CKD.

Risk factors for osteoporosis in male patients with chronic obstructive pulmonary disease in Taiwan

Objective

To investigate the risk factors for osteoporosis in male Taiwanese patients with chronic obstructive pulmonary disease (COPD).

Methods

This cross-sectional study evaluated male COPD outpatients and age-matched male subjects at a regional teaching hospital. The following data were obtained and analyzed: bone mineral density of the lumbar spine and hip on dual-energy X-ray absorptiometry, demographic characteristics, questionnaire interview results, pulmonary function test results, chest posterior–anterior radiographic findings, and biochemical and high-sensitivity C-reactive protein (hs-CRP) levels.

Results

Fifty-nine male COPD patients and 36 age-matched male subjects were enrolled. COPD patients had lower body mass index (BMI) (23.6 ± 4.1 vs. 25.2 ± 3.0 kg/m²) and higher total prevalence for osteoporosis and osteopenia than controls. Among COPD patients, patients with osteoporosis had lower BMI, body weight, waist circumference, and triglyceride level but higher hs-CRP level, and tended to have lower creatinine level. Binary logistic regression analysis for factors including age, BMI, creatinine, hs-CRP, smoking, steroid use, and forced expiratory volume in one second (FEV1) revealed that an hs-CRP level ≥5 and decreased creatinine level were independent risk factors for osteoporosis in COPD patients. Lower BMI tended to be associated with osteoporosis development, although it did not reach statistical significance, and hs-CRP was associated with COPD severity and steroid use history.

Conclusion

The total prevalence of osteoporosis and osteopenia in male Taiwanese COPD patients is higher than that in age-matched male subjects and systemic inflammation is an independent risk factors for osteoporosis. Low creatinine level in COPD patients should raise the suspicion of sarcopenia and associated increased risk of osteoporosis.

COPD as an endothelial disorder: endothelial injury linking lesions in the lungs and other organs? (2017 Grover Conference Series)

Chronic obstructive pulmonary disease (COPD) is characterized by chronic expiratory airflow obstruction that is not fully reversible. COPD patients develop varying degrees of emphysema, small and large airway disease, and various co-morbidities. It has not been clear whether these co-morbidities share common underlying pathogenic processes with the pulmonary lesions. Early research into the pathogenesis of COPD focused on the contributions of injury to the extracellular matrix and pulmonary epithelial cells. More recently, cigarette smoke-induced endothelial dysfunction/injury have been linked to the pulmonary lesions in COPD (especially emphysema) and systemic co-morbidities including atherosclerosis, pulmonary hypertension, and chronic renal injury. Herein, we review the evidence linking endothelial injury to COPD, and the pathways underlying endothelial injury and the "vascular COPD phenotype" including: (1) direct toxic effects of cigarette smoke on endothelial cells; (2) generation of auto-antibodies directed against endothelial cells; (3) vascular inflammation; (4) increased oxidative stress levels in vessels inducing increases in lipid peroxidation and increased activation of the receptor for advanced glycation end-products (RAGE); (5) reduced activation of the anti-oxidant pathways in endothelial cells; (6) increased endothelial cell release of mediators with vasoconstrictor, pro-inflammatory, and remodeling activities (endothelin-1) and reduced endothelial cell expression of mediators that promote vasodilation and homeostasis of endothelial cells (nitric oxide synthase and prostacyclin); and (7) increased endoplasmic reticular stress and the unfolded protein response in endothelial cells. We also review the literature on studies of drugs that inhibit RAGE signaling in other diseases (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers), or vasodilators developed for idiopathic pulmonary arterial hypertension that have been tested on cell culture systems, animal models of COPD, and/or smokers and COPD patients.

Predictive value of ADAMTS-13 on concealed chronic renal failure in COPD patients

Background

Impaired renal function is often neglected in COPD patients. Considering that COPD patients usually have an ongoing prothrombotic state and systemic inflammation status, we investigated the association among them and explored the predictive value of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13), on concealed chronic renal failure (CRF) in COPD patients.

Methods

COPD patients were recruited from the First Affiliated Hospital of Sun Yat-Sen University between January 2015 and December 2016. Control was selected from contemporaneous hospitalized patients without COPD and matched by age and gender at a ratio of 1:1. Estimated glomerular filtration rate (eGFR) was calculated by using the Chronic Kidney Disease Epidemiology Collaboration formula, and all subjects were categorized as having normal renal function (eGFR ≥60 mL min^-1 1.73 m^-2) and having concealed CRF (normal serum creatinine while eGFR <60 mL min^-1 1.73 m^-2). Independent correlates of concealed CRF were investigated by logistic regression analysis, and receiver operating characteristic (ROC) curves were used to determine the predictive value of ADAMTS-13.

Results

In total, 106 COPD and 106 non-COPD patients were finally recruited, and the incidences of concealed CRF were 19.81% and 7.55%, respectively. ADAMTS-13 (odds ratio [OR] =0.858, 95% CI =0.795-0.926), D-dimer (OR =1.095, 95% CI =1.027-1.169), and C-reactive protein (OR =1.252, 95% CI =1.058-1.480) were significantly associated with concealed CRF. Sensitivity and specificity at an ADAMTS-13 cutoff of 318.72 ng/mL were 100% and 81.2%, respectively. The area under the ROC curve was 0.959.

Conclusion

Prothrombotic state and systemic inflammation status might contribute to explaining the high incidence of concealed CRF in COPD, and plasma ADAMTS-13 levels may serve as a strong predictor.

Lung Function and Incident Kidney Disease: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Reduced lung function is associated with clinical outcomes such as cardiovascular disease. However, little is known about its association with incident end-stage renal disease (ESRD) and chronic kidney disease (CKD).

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

14,946 participants aged 45 to 64 years at baseline (1987-1989) in the Atherosclerosis Risk in Communities (ARIC) Study (45.0% men and 25.2% black), with follow-up through 2012.

PREDICTORS

Race- and sex-specific quartiles of percent-predicted forced vital capacity (FVC) and the proportion of forced expiratory volume in 1 second of expiration to FVC (FEV1/FVC) at baseline determined with spirometry.

OUTCOMES

Incident ESRD (defined here as renal replacement therapy or death due to CKD) as the primary outcome and incident CKD (defined here as ESRD, ≥25% decline in estimated glomerular filtration rate to a level <60mL/min/1.73m2, or CKD-related hospitalizations/deaths) as the secondary outcome.

RESULTS

During a median follow-up of 23.6 years, 526 (3.5%) participants developed ESRD. After adjusting for potential confounders, the cause-specific HR of incident ESRD for the lowest (vs highest) quartile was 1.72 (95% CI, 1.31-2.26) for percent-predicted FVC and 1.33 (95% CI, 1.03-1.73) for FEV1/FVC. Compared to a high-normal lung function pattern, a mixed pattern (ie, percent-predicted FVC<80% and FEV1/FVC<70%; 3.4% of participants) demonstrated the highest adjusted cause-specific HR of ESRD at 2.28 (95% CI, 1.50-3.45), followed by the restrictive pattern (ie, percent-predicted FVC<80% and FEV1/FVC≥70%; 4.8% of participants) at 2.03 (95% CI, 1.47-2.81), obstructive pattern (ie, percent-predicted FVC≥80% and FEV1/FVC<70%; 18.9% of participants) at 1.47 (95% CI, 1.09-1.99), and low-normal pattern (ie, percent-predicted FVC 80%-<100% and FEV1/FVC≥70%, or percent-predicted FVC≥80% and FEV1/FVC 70%-<75%; 44.3% of participants) at 1.21 (95% CI, 0.94-1.55). Similar associations were seen with incident CKD.

LIMITATIONS

Limited number of participants with moderate/severe lung dysfunction and spirometry only at baseline.

CONCLUSIONS

Reduced lung function, particularly lower percent-predicted FVC, is independently associated with CKD progression. Our findings suggest a potential pathophysiologic contribution of reduced lung function to the development of CKD and a need for monitoring kidney function in persons with reduced lung function.

Chronic obstructive pulmonary disease and comorbidities: a large cross-sectional study in primary care

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is common, and a major cause of morbidity and mortality worldwide. Recent studies suggest that comorbidities of COPD increase the risk of hospitalisation, polypharmacy, and mortality, but their estimated prevalence varies widely in the literature.

AIM

To evaluate the prevalence of 38 physical and mental health comorbidities in people with COPD, and compare findings with those for people without COPD in a large nationally representative dataset.

DESIGN AND SETTING

A cross-sectional data analysis on 1 272 685 adults in Scotland from 314 primary care practices.

METHOD

Data on COPD, along with 31 physical and seven mental health comorbidities, were extracted. The prevalence of comorbidities was compared between people who did, and did not, have COPD, standardised by age, sex, and socioeconomic deprivation.

RESULTS

From the total sample, 51 928 patients had COPD (4.1%). Of these, 86.0% had at least one comorbidity, compared with 48.9% of people without COPD. Of those with COPD, 22.3% had ≥5 comorbid conditions compared with 4.9% of those who did not have COPD (adjusted odds ratio 2.63, 95% confidence interval = 2.56 to 2.70). In total, 29 of the 31 physical conditions and six of the seven mental health conditions were statistically significantly more prevalent in people who had COPD than those who did not.

CONCLUSION

Patients with COPD have extensive associated comorbidities. There is a real need for guidelines and health care to reflect this complexity, including how to detect those common comorbidities that relate to both physical and mental health, and how best to manage them. Primary care, which is unique in terms of offering expert generalist care, is best placed to provide this integrated approach.