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 risk factors of airflow obstruction in a Caribbean population

SETTING: The prevalence of airflow obstruction (AO) in the Caribbean population is unknown.OBJECTIVE: To measure the prevalence of and risk factors for AO (post-bronchodilator ratio of forced expiratory volume in 1 sec to forced vital capacity of <0.7) in the Trinidad and Tobago general population using the Burden of Obstructive Lung Disease methodology.DESIGN: National cross-sectional, stratified, cluster sampling of adults aged ≥40 years.RESULTS: AO prevalence was 9.5% among 1104 participants, most of whom were unaware of this. Compared to those aged 40-49 years, the adjusted odds ratio of AO by age group was 2.73 (60-69 years) and 3.30 (≥70 years). Risk factors for AO were unemployment (OR 4.31), being retired (OR 2.17), smoking ≥20 pack-years (OR 1.88) and exposure to dusty jobs for more than 1 year (OR 2.06). Related symptoms were history of wheezing, unscheduled visits to the doctor or admission to hospital for breathing problems and in subjects with at least one respiratory symptom (OR 1.90), at least one risk factor (OR 2.81), either symptoms or risk factors (OR 3.71) and both symptoms and risk factors (OR 5.78) (P < 0.05 in all cases).CONCLUSION: AO prevalence in the general population of Trinidad and Tobago aged ≥40 years was 9.5%, almost all of which was undiagnosed. AO was associated with smoking, age >59 years, lack of employment and working in a dusty job.

Risk factors for first-time acute myocardial infarction patients in Trinidad

Background

The relative importance of coronary artery disease (CAD) risk varies globally. The aim of this study was to determine CAD risk factors for acute myocardial infarction (AMI) among patients in public health care institutions in Trinidad using a case–control type study design.

Methods

The sample comprised 251 AMI patients hospitalized between March 1, 2011 and April 30, 2012 and 464 age- and sex-matched non-AMI patients with no terminal or life-threatening illness and who did not undergo treatment for CAD. SPSS version 19 was used for data analysis that included chi-square tests, unadjusted and adjusted odds ratios (OR) and conditional multiple binary logistic regression.

Results

There was no difference in age between AMI and non-AMI patients (p = 0.551). Chi-square test revealed that clinical and lifestyle variables including stressful life, diabetes, hypertension, hypercholesterolaemia, ischaemic heart disease (IHD), a family history of IHD (p ≤ 0.001), smoking (p = 0.007) and alcohol consumption (p = 0.013) were associated with AMI; sex (p = 0.441), ethnicity (p = 0.366), age group (p = 0.826) and renal failure (p = 0.487) were not.

Both unadjusted and adjusted (for age) ORs showed that the odds of hypertension, IHD and alcohol consumption were greater among AMI patients than among non-AMI patients for males; diabetes and IHD for females; and that the odds of a stressful life was greater among non-AMI patients and were the same for both groups with respect to sex, age > 45 years, hypercholesterolemia, renal insufficiency, and family history of IHD.

Conditional multiple logistic regression showed that smoking [OR: 0.274, p ≤ 0.001, 95% CI for OR (0.140, 0.537)], a stressful life [OR: 2.697, p ≤ 0.001, 95% CI for OR (1.585, 4.587)], diabetes [OR: 0.530, p = 0.020, 95% CI for OR (0.310, 0.905)], hypertension [OR: 0.48, p = 0.10. 95% CI for OR (0.275, 0.837)] and IHD [OR: 0.111, p ≤ 0.001, 95% CI for OR (0.057, 0.218)] were the only useful AMI predictors.

Conclusions

Smoking, diabetes, hypertension, IHD and decrease stress are useful AMI predictors.

Relationship of fasting total homocysteine, high sensitivity C-reactive protein and features of the metabolic syndrome in Trinidadian subjects

OBJECTIVES

To assess the relationship of homocysteine, hs-CRP, with known cardiovascular risk factors of the metabolic syndrome.

METHOD

Cross sectional study comprised 182 diabetic outpatients (70 males and 112 females), attending endocrinology clinics in Trinidad.

RESULTS

Both male and females showed significant linear relationships between high sensitive C-reactive protein (hs-CRP), blood pressure and diabetes (r = -0.2 < R or R > 0.2). In females hs-CRP showed significant linear relationship with HDL, triglyceride, blood pressure and diabetes mellitus (p < 0.0001). The inverse relationship of hs-CRP with HDL implies the strong association of hs-CRP with metabolic syndrome. The multivariate logistic regression analysis showed significant relation of hs-CRP, metabolic syndrome and diabetes mellitus. There was no significant relationship of tHCY to any of the features studied.

CONCLUSION

Serum C-reactive protein is significantly related to features of the metabolic syndrome. Total plasma homocysteine, appears to be independent of both hs-CRP and features of the metabolic syndrome.

Five-year follow-up of patients treated with imatinib mesylate for chronic myeloid leukaemia in Trinidad and Tobago

OBJECTIVE

Data on the use of Imatinib (IM) in developing countries remain limited. A retrospective study was done to assess the efficacy and toxicity of IM in treating chronic myeloid leukaemia (CML) in Trinidad and Tobago.

METHODS

Patients in all phases of CML who started IM therapy between February 2001 and February 2004 were included. All had received other previous therapy. They were assessed for haematological, cytogenetic and molecular response, overall survival (OS), event free survival (EFS) and adverse effects (AE).

RESULTS

Twenty-five patients were followed-up for a median 61 months. At initiation of IM, 18 were in the chronic phase (CP), 3 in accelerated phase (AP), 3 in blast crisis (BC) and one in myelofibrotic transformation (MF). Overall, 96% of patients achieved complete haematological remission (CHR). Among CP patients, 67% attained a major cytogenetic response (MCR) and 44% a complete cytogenetic response (CCR). Overall survival and event free survival in the CP group were 82% and 76% respectively. Overall survival for advanced phase patients was 14% at 61 months. The adverse effects of IM were the same as previously described and generally tolerable. No patient opted to discontinue IM because of side effects.

CONCLUSION

After 5 years of follow-up, IM was found to induce favourable and durable survival responses with an acceptable side effect profile in CP-CML patients who had received prior treatment with alternative agents.

A preliminary investigation of periodontal disease and diabetes in Trinidad

OBJECTIVES

To describe periodontal disease status in diabetic patients in Trinidad.

METHOD

A cross-sectional study was conducted. Patients attending a tertiary referral centre for diabetes at an out-patient clinic were invited to undergo oral examinations. The basic periodontal examination (BPE) was used to assess periodontal disease status.

RESULTS

Seventy-two patients participated in the study. Mean age was 55.7 years, 54.2% were female, with 66.7% and 22.2% being of Indo-Trinidadian and Afro-Trinidadian ethnicity respectively. There were 61.1% who had not attended for dental treatment within the last year and 56.9% only attended when in pain; 15.3% had a history of cigarette smoking and 31.9% currently wore a denture. Plaque was detectable with the use of a probe in 40.3% of the 67% that underwent a BPE assessment; 38.8% were found to have advanced periodontal disease.

CONCLUSION

The prevalence of periodontal disease in this sample of diabetic patients suggests that regular dental examinations, oral health education, and collaborative patient care between medical and dental practitioners should form part of the routine management of diabetic patients in Trinidad.

Audit of sudden deaths in the accident and emergency department of a tertiary hospital in Trinidad and Tobago

OBJECTIVE

To determine the proportion of deaths due to confirmed myocardial infarction (CMI) and the aetiology of sudden death at the Port-of-Spain General Hospital (A&E) department for January to June 2008.

METHODS

This retrospective study utilized the death register to determine the number of A&E deaths for the study period. Patients dying from MI were investigated using records to obtain ECG and postmortem reports.

RESULTS

During the study period, 150 patients were certified dead in the A&E department. Cardiovascular causes accounted for 42.7% (n = 64) of deaths. Confirmed MI accounted for 27.3% (n = 41) of deaths and 3.3% (n = 5) were certified by a private practitioner without post-mortem examination and were classed as unconfirmed MI. Trauma related deaths followed with 27.3% (n = 41). Deaths from firearm injury were the next most common, 19.3% (n = 29). The mean age of patients dying from CMI was 64.1 years with a male to female ratio of 2:1. Males died from CMI on average 6.3 years before females. Mortality peaked for females in the 80 - 89-year age group while for males it was the 60- 69-year age group. Afro-Trinidadians accounted for 58.5% (n = 24) deaths due to CMI. More CMI patients had combined DM and HTN 36.6% (n = 15) than either condition alone. Afro-Trinidadians were more likely to be hypertensive and Indo-Trinidadians, diabetic. Death on arrival was the most common presentation for MI patients, 65.9% (n = 27).

CONCLUSIONS

This study shows that the main cause of death in the A&E Department at the Port-of-Spain General Hospital was MI. Trauma related deaths followed. Men died from MI at an earlier age than women. Most MI patients were dead on arrival.

The slipping slipper sign: a marker of severe peripheral diabetic neuropathy and foot sepsis

BACKGROUND

Peripheral neuropathy is a major contributor to diabetic foot complications including ulceration, sepsis and limb loss. The aim of this study was to document the frequency of this previously undocumented clinical marker of peripheral neuropathy, the "slipping slipper sign" (SSS), characterised by unrecognised loss of slippers from one's feet while walking, and to compare it with traditional clinical tests for peripheral neuropathy.

OBJECTIVE

To evaluate the relationship between a positive SSS and diabetic peripheral neuropathy.

SUBJECTS AND METHODS

The study included 105 diabetic outpatients without active foot problems, 40 diabetic inpatients with active foot sepsis, and 69 other patients with neither diabetes nor active foot sepsis as negative controls. Demographic data, clinical neuropathy scores and the presence or absence of the SSS were obtained.

RESULTS

No control subjects had a positive SSS. In contrast, 64 of 145 diabetic patients had severe neuropathy of whom 53 had a positive SSS (83% sensitivity) and 74 of 81 without severe neuropathy had a negative SSS (91% specificity). Diabetic patients with concurrent foot sepsis had a higher frequency of severe neuropathy (70%) and positive SSS (65%) compared with those without (36% and 35%, respectively, p<0.001). Multivariate analysis showed that a positive SSS was strongly related to severity of neuropathy independent of duration of diabetes.

CONCLUSION

The SSS reflects severe peripheral neuropathy and is particularly prevalent among those with active foot disease. Patients who have experienced the SSS should be encouraged to seek attention and preventive action taken.

Obstructive lung disease in acute medical patients

OBJECTIVES

To determine the proportion of adult medical patients who have chronic obstructive pulmonary disease (COPD), using the Global initiative for Chronic Obstructive Lung Disease guidelines (GOLD), and its relation to vascular disease.

METHODS

This is a prospective cross-sectional study of adult patients admitted to acute medical wards. Interviewer administered questionnaire, anthropometric and spirometric measurements were done.

RESULTS

Spirometry was performed in 720 acute admissions [Mean (SD) age 50.0 (18.9) years, FEV1: 1.98 L (0.83), FEV1/FVC%: 75.1 (11.9)%; males 332 (46.1%), smokers 318 (44%); 43.2% had vascular disease]. Sixty-seven per cent of patients (480) had no airway disease including 35 (4.5%) with chronic cough and sputum with normal spirometry; 89 (12.4%) had asthma and 151 (20.9%) had COPD. Patients with COPD were significantly older [60.3 (16.6) years] than non-COPD patients [47.3 (18.5) years], p < 0.001 and had a greater number of pack years of smoking. A greater percentage of patients with COPD had vascular disease (52%) than the non-COPD patients (40.1%), p = 0.017). Multivariate analysis with vascular disease as outcome variable revealed relationships with older age (p < 0.001) and Indo-Trinidadian ethnicity (p = 0.015), but not with gender (p = 0.321) and smoking (p = 0.442). FEV1% as well as FEV1 showed a significant inverse relationship with vascular disease (p < 0.05).

CONCLUSIONS

The prevalence of COPD using GOLD guidelines in acute hospital admissions is 20.9%; 11.7% of admissions have chronic sputum or cough with normal spirometry. Vascular disease is more prevalent in those with COPD. Patients admitted to acute medical care with vascular disease may also have COPD.

Respiratory viruses, symptoms, and inflammatory markers in acute exacerbations and stable chronic obstructive pulmonary disease

The effects of respiratory viral infection on the time course of chronic obstructive pulmonary disease (COPD) exacerbation were examined by monitoring changes in systemic inflammatory markers in stable COPD and at exacerbation. Eighty-three patients with COPD (mean [SD] age, 66.6 [7.1] yr, FEV(1), 1.06 [0.61] L) recorded daily peak expiratory flow rate and any increases in respiratory symptoms. Nasal samples and blood were taken for respiratory virus detection by culture, polymerase chain reaction, and serology, and plasma fibrinogen and serum interleukin-6 (IL-6) were determined at stable baseline and exacerbation. Sixty-four percent of exacerbations were associated with a cold occurring up to 18 d before exacerbation. Seventy-seven viruses (39 [58.2%] rhinoviruses) were detected in 66 (39.2%) of 168 COPD exacerbations in 53 (64%) patients. Viral exacerbations were associated with frequent exacerbators, colds with increased dyspnea, a higher total symptom count at presentation, a longer median symptom recovery period of 13 d, and a tendency toward higher plasma fibrinogen and serum IL-6 levels. Non-respiratory syncytial virus (RSV) respiratory viruses were detected in 11 (16%), and RSV in 16 (23.5%), of 68 stable COPD patients, with RSV detection associated with higher inflammatory marker levels. Respiratory virus infections are associated with more severe and frequent exacerbations, and may cause chronic infection in COPD. Prevention and early treatment of viral infections may lead to a decreased exacerbation frequency and morbidity associated with COPD.

Effect of temperature on lung function and symptoms in chronic obstructive pulmonary disease

The present study investigated whether falls in environmental temperature increase morbidity from chronic obstructive pulmonary disease (COPD). Daily lung function and symptom data were collected over 12 months from 76 COPD patients living in East London and related to outdoor and bedroom temperature. Questionnaires were administered which asked primarily about the nature of night-time heating. A fall in outdoor or bedroom temperature was associated with increased frequency of exacerbation, and decline in lung function, irrespective of whether periods of exacerbation were excluded. Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) fell markedly by a median of 45 mL (95% percentile range: -113-229 mL) and 74 mL (-454-991 mL), respectively, between the warmest and coolest week of the study. The questionnaire revealed that 10% had bedrooms <13 degrees C for 25% of the year, possibly because only 21% heated their bedrooms and 48% kept their windows open in November. Temperature-related reduction in lung function, and increase in exacerbations may contribute to the high level of cold-related morbidity from chronic obstructive pulmonary disease.

Effect of temperature on lung function and symptoms in chronic obstructive pulmonary disease

The present study investigated whether falls in environmental temperature increase morbidity from chronic obstructive pulmonary disease (COPD). Daily lung function and symptom data were collected over 12 months from 76 COPD patients living in East London and related to outdoor and bedroom temperature. Questionnaires were administered which asked primarily about the nature of night-time heating. A fall in outdoor or bedroom temperature was associated with increased frequency of exacerbation, and decline in lung function, irrespective of whether periods of exacerbation were excluded. Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) fell markedly by a median of 45 mL (95% percentile range: -113-229 mL) and 74 mL (-454-991 mL), respectively, between the warmest and coolest week of the study. The questionnaire revealed that 10% had bedrooms <13 degrees C for 25% of the year, possibly because only 21% heated their bedrooms and 48% kept their windows open in November. Temperature-related reduction in lung function, and increase in exacerbations may contribute to the high level of cold-related morbidity from chronic obstructive pulmonary disease.

Renal acidosis, thyroiditis, hemolytic anemia: an autoimmune link?

Distal renal tubular acidosis (DRTA) is characterized by a urine of inappropriately high pH in the presence of a metabolic acidosis. Female patients with DRTA may have associated autoimmune disorders. We have described a patient with DRTA, followed by acute thyroiditis and autoimmune hemolytic anemia within 2 years. This combination of autoimmune diseases has not been described previously. These conditions are likely linked by an autoimmune pathogenesis. Clinicians are advised that some patients with DRTA may subsequently have features of any autoimmune disorder as the natural history of the disease.