Association between lung function and dyspnoea and its variation in the multinational Burden of Obstructive Lung Disease (BOLD) study

BACKGROUND

Dyspnoea is a common symptom of respiratory disease. However, data on its prevalence in general populations and its association with lung function are limited and are mainly from high-income countries. The aims of this study were to estimate the prevalence of dyspnoea across several world regions, and to investigate the association of dyspnoea with lung function.

METHODS

Dyspnoea was assessed, and lung function measured in 25,806 adult participants of the multinational Burden of Obstructive Lung Disease study. Dyspnoea was defined as ≥2 on the modified Medical Research Council (mMRC) dyspnoea scale. The prevalence of dyspnoea was estimated for each of the study sites and compared across countries and world regions. Multivariable logistic regression was used to assess the association of dyspnoea with lung function in each site. Results were then pooled using random-effects meta-analysis.

RESULTS

The prevalence of dyspnoea varied widely across sites without a clear geographical pattern. The mean prevalence of dyspnoea was 13.7 % (SD=8.2 %), ranging from 0 % in Mysore (India) to 28.8 % in Nampicuan-Talugtug (Philippines). Dyspnoea was strongly associated with both spirometry restriction (FVC

CONCLUSION

The prevalence of dyspnoea varies substantially across the world and is strongly associated with lung function impairment. Using the mMRC scale in epidemiological research should be discussed.

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Key Words

• Breathlessness
• Dyspnoea
• Lung function
• Spirometry

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Affiliation(s)

A Müller Ludwig Boltzmann Institute for Lung Health, Vienna, Austria; Care and Public Health Research Institute, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands.
E F Wouters Ludwig Boltzmann Institute for Lung Health, Vienna, Austria; Sigmund Freud University, Faculty of Medicine, Vienna, Austria; Department of Respiratory Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
P Koul Department of Pulmonary Medicine, Sheri Kashmir Institute of Medical Sciences, Srinagar, India
T Welte Department of Respiratory Medicine/Infectious Disease, Member of the German Centre for Lung Research, Hannover School of Medicine, Hannover, Germany
I Harrabi Faculté de Médecine, Sousse, Tunisia
A Rashid RCSI and UCD Malaysia Campus, Penang, Malaysia
L C Loh RUMC, Penang, Malaysia
M Al Ghobain King Abdullah International Medical Research Center, King Saud ben Abdulaziz University for Health Science, Riyadh, Saudi Arabia
A Elsony The Epidemiological Laboratory, Khartoum, Sudan
R Ahmed The Epidemiological Laboratory, Khartoum, Sudan
J Potts National Heart and Lung Institute, Imperial College London, London, UK
K Mortimer University of Cambridge, Cambridge, UK; Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
F Rodrigues Pulmonology Department, Lisbon North Hospital Centre, Lisbon, Portugal; Institute of Environmental Health, Associate Laboratory TERRA, Lisbon Medical School, Lisbon University, Lisbon, Portugal
S N Paraguas Philippine College of Chest Physicians, Manila, Philippines
S Juvekar KEM Hospital Research Centre, Pune, India
D Agarwal KEM Hospital Research Centre, Pune, India
D Obaseki Department of Medicine, Obafemi Awolowo University, Nigeria; Faculty of Medicine, University of British Columbia, Canada
T Gislason Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Department of Sleep, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland
T Seemungal Faculty of Medical Sciences, University of West Indies, St Augustine, Trinidad and Tobago
A A Nafees Aga Khan University, Karachi, Pakistan
C Jenkins Woolcock Institute of Medical Research, Sydney, Australia
H B Dias Escola Superior de Tecnologia da Saúde de Lisboa, Politecnico de Lisboa, Lisbon, Portugal
F M E Franssen Department of Respiratory Medicine, Maastricht University Medical Center, Maastricht, the Netherlands; Department of Research and Development, Ciro, Horn, the Netherlands
M Studnicka Department of Pulmonary Medicine, Paracelsus Medical University, Salzburg, Austria
C Janson Department of Medical Sciences: Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden
H H Cherkaski Faculty of Medicine, University Badji Mokhtar, Annaba, Algeria
M El Biaze Department of Respiratory Medicine, Faculty of Medicine, Mohammed Ben Abdellah University, Fes, Morocco
P A Mahesh Department of Respiratory Medicine, JSS Medical College and Hospital, Mysore, Karnataka, India
J Cardoso Pulmonology Department, Centro Hospitalar Universitário de Lisboa Central, Lisboa, Portugal; NOVA Medical School, Nova University Lisbon, Lisboa, Portugal
P Burney National Heart and Lung Institute, Imperial College London, London, UK
S Hartl Ludwig Boltzmann Institute for Lung Health, Vienna, Austria; Sigmund Freud University, Faculty of Medicine, Vienna, Austria
D J A Janssen Care and Public Health Research Institute, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; Department of Research and Development, Ciro, Horn, the Netherlands
A F S Amaral National Heart and Lung Institute, Imperial College London, London, UK; NIHR Imperial Biomedical Research Centre, London, UK

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Prevalence and determinants of chronic respiratory diseases in adults in rural Sudan

BACKGROUND: Chronic respiratory diseases (CRDs) greatly contribute to worldwide mortality. Despite new data emerging from Africa, prevalence estimates and determinants of CRDs in rural settings are limited. This study sought to extend the existing research conducted in urban Sudan by conducting a rural comparison.METHODS: Participants aged ≥18 years (n = 1,850), living in rural Gezira State completed pre-and post-bronchodilator spirometry and a questionnaire. Prevalence of respiratory symptoms and spirometric abnormalities were reported. Regression analyses were used to identify risk factors for CRDs.RESULTS: Prevalence of chronic airflow obstruction (CAO) was 4.1% overall and 5.5% in those aged ≥40 years. Reversibility was seen in 6.4%. Low forced vital capacity (FVC) was seen in 58.5%, and at least one respiratory symptom was present in 40.7% of the participants. CAO was more common among people aged 60-69 years (OR 2.07, 95% CI 1.13-3.82) and less common among highly educated participants (OR 0.50, 95% CI 0.27-0.93). Being underweight was associated with lower FVC (OR 3.07, 95% CI 2.24-4.20).CONCLUSIONS: A substantial burden of CRD exists among adults in rural Sudan. Investment in CRD prevention and management strategies is needed.

Prevalence and determinants of chronic respiratory diseases in adults in Sudan

BACKGROUND: Chronic respiratory diseases (CRDs) are considered a significant cause of morbidity and mortality worldwide, although data from Africa are limited. This study aimed to determine the prevalence and determinants of CRDs in Khartoum, Sudan.METHODS: Data were collected from 516 participants aged ≥40 years, who had completed a questionnaire and undertook pre- and post-bronchodilator spirometry testing. Trained field workers administered the questionnaires and conducted spirometry. Survey-weighted prevalence of respiratory symptoms and spirometric abnormalities were estimated. Regression analysis models were used to identify risk factors for chronic lung diseases.RESULTS: Using the Third National Health and Nutrition Examination Survey, 1988-1994 (NHANES III) reference equations, the prevalence of chronic airflow obstruction (CAO) was 10%. The main risk factor was older age, 60-69 years (OR 3.16, 95% CI 1.20-8.31). Lower education, high body mass index and a history of TB were also identified as significant risk factors. The prevalence of a low forced vital capacity (FVC) using NHANES III was 62.7% (SE 2.2) and 11.3% (SE 1.4) using locally derived values.CONCLUSION: The prevalence of spirometric abnormality, mainly low FVC, was high, suggesting that CRD is of substantial public health importance in urban Sudan. Strategies for the prevention and control of these problems are needed.

Clinical standards for the assessment, management and rehabilitation of post-TB lung disease

BACKGROUND: Increasing evidence suggests that post-TB lung disease (PTLD) causes significant morbidity and mortality. The aim of these clinical standards is to provide guidance on the assessment and management of PTLD and the implementation of pulmonary rehabilitation (PR).METHODS: A panel of global experts in the field of TB care and PR was identified; 62 participated in a Delphi process. A 5-point Likert scale was used to score the initial ideas for standards and after several rounds of revision the document was approved (with 100% agreement).RESULTS: Five clinical standards were defined: Standard 1, to assess patients at the end of TB treatment for PTLD (with adaptation for children and specific settings/situations); Standard 2, to identify patients with PTLD for PR; Standard 3, tailoring the PR programme to patient needs and the local setting; Standard 4, to evaluate the effectiveness of PR; and Standard 5, to conduct education and counselling. Standard 6 addresses public health aspects of PTLD and outcomes due to PR.CONCLUSION: This is the first consensus-based set of Clinical Standards for PTLD. Our aim is to improve patient care and quality of life by guiding clinicians, programme managers and public health officers in planning and implementing adequate measures to assess and manage PTLD.

Post-tuberculosis lung health: perspectives from the First International Symposium

ALTHOUGH CURABLE, TB frequently leaves the individual with chronic physical and psycho-social impairment, but these consequences have been largely neglected. The 1^st International Post-Tuberculosis Symposium (Stellenbosch, South Africa) was held to discuss priorities and gaps in addressing this issue. A barrier to progress has been the varied terminology and nomenclature, so the Delphi process was used to achieve consensus on definitions. Lack of sufficient evidence hampered definitive recommendations in most domains, including prevention and treatment of post-TB lung disease (PTLD), but the discussions clarified the research needed. A consensus was reached on a toolkit for future PTLD measurement and on PTLD patterns to be considered. The importance of extra-pulmonary consequences and progressive impairment throughout the life-course was identified, including TB recurrence and increased mortality. Patient advocates emphasised the need to address the psychological and social impacts post TB and called for clinical guidance. More generally, there is an urgent need for increased awareness and research into post-TB complications.

The locus C11orf30 increases susceptibility to poly-sensitization

A number of genetic variants have been associated with allergic sensitization, but whether these are allergen specific or increase susceptibility to poly-sensitization is unknown. Using data from the large multicentre population-based European Community Respiratory Health Survey, we assessed the association between 10 loci and specific IgE and skin prick tests to individual allergens and poly-sensitization. We found that the 10 loci associate with sensitization to different allergens in a nonspecific manner and that one in particular, C11orf30-rs2155219, doubles the risk of poly-sensitization (specific IgE/4 allergens: OR = 1.81, 95% CI 0.80-4.24; skin prick test/4+ allergens: OR = 2.27, 95% CI 1.34-3.95). The association of rs2155219 with higher levels of expression of C11orf30, which may be involved in transcription repression of interferon-stimulated genes, and its association with sensitization to multiple allergens suggest that this locus is highly relevant for atopy.

Prevalence of Calodium hepaticum (Syn. Capillaria hepatica) in house mice (Mus musculus) in the Azores archipelago

Calodium hepaticum (Syn. Capillaria hepatica) is a zoonotic liver nematode of mammals distributed worldwide. Rodents are believed to be the main reservoirs of this nematode. In this paper, prevalence of the parasite was analyzed in liver histological sections from 51 house mice (Mus musculus) caught in human-inhabited houses, from two localities (Furnas and Rabo de Peixe) on São Miguel island from the Azores archipelago (Portugal). Mean prevalence of infection was 19.6%, with 33.3% prevalence in Furnas and 4.1% in Rabo de Peixe (P=0.07). No significant differences were found between the prevalence of infection and the age, body weight and the sex of mice. Hepatic lesions found were either acute and/or chronic stage and consisted of moderate to severe multifocal pyogranulomatous hepatitis with encapsulated eggs with typical bipolar plugs and moderate to severe necrotizing hepatitis consistent with larva tracks. Periportal inflammatory infiltration, hepatocyte regeneration and bile duct hyperplasia were also noted. In most cases, hepatic lesions occupied more than 50% of the liver, but despite severe lesions, in some mice, no signs of hepatic failure were noticed. The high rate of infection found in the present study suggests that house mice are an important reservoir for this parasite in the Azores and could have a role in human transmission.